In case any of you who are subscribed to this wonder if we’ve dropped off the blogosphere, we haven’t. However, for various uninteresting reasons, we now do most of our posting at https://progressoftheseasons.wordpress.com/.
So, if you like some of these older posts, perhaps check-out our current blog.
(We may still use this site for particularly detailed and long postings.)
By Dylan
On an icy walk through a patch of forest in Canaan, NY, I noticed how calcium rich bedrock has influenced the natural world. It has helped form caves where mammals find cover during these cold and difficult months, and its breakdown into soil has created a kind of forest (commonly called “rich woods”) that is important to biodiversity conservation.
To get a good look at the underlying rock itself, Zion and I stopped at an abandoned train tunnel that has exposed the calcium rich bedrock. The whitish-gray color of the Stockbridge Marble bedrock was sparkling with ice crystals, and the giant ice formations looked like stalactites. This is probably the closest thing to spelunking that Zion and I will ever do.
Porcupine feeding sign was abundant around the den. I found this shrub that had clearly been gnawed on by the bark eating rodent, and several small Eastern Hemlock trees in the area had been killed, presumably by their feeding.
by Kendrick Fowler
(Kendrick has been a technician with the Program since June 2018 and, as this blog amply illustrates, has ‘gotten into’ wasps.)
Hawthorne Valley Farm in winter.
When I tell someone that I work in entomology, their first reaction is often to ask me something along the lines of “So, what do you do during the winter? ‘Cause there aren’t any bugs around in winter, right?” The answer, of course, is that winter gives me the opportunity to do something with all of the insect specimens that the Farmscape Ecology Program (FEP) team collects during the spring, summer, and autumn (though it is worth pointing out that some very interesting insects can be found crawling around on the snow). Specifically, I identify and count the insects that we captured during the warm months, and I use the resulting data to create content to support the FEP’s research and outreach efforts. Each member of the entomology team, including me, specializes in identifying a few groups of insects whose biology makes them particularly interesting and fruitful subjects on which to focus our studies, usually because they are pollinators, predators, or otherwise considered beneficial to farmers: Conrad works with ground beetles, Dylan has mastered the moths, hover flies, and bees, and I am teaching myself to recognize ants and wasps. I feel like I lucked out when I was assigned my specialty: I am biased, of course, but I feel that the wasps are the most exciting and interesting of our beneficial insects.
My workstation in the Farmscape Ecology Program’s “bug room.” The open boxes on the desk are filled with wasp specimens collected during the 2019 field season.
When most people think of wasps, they think of large, conspicuous, social species like hornets, yellowjackets, and paper wasps. The name “wasp,” however, is also used to encompass an enormous variety of insects that most people rarely (if ever) notice, yet which collectively may have a far larger impact in our lives than the creatures who occasionally invite themselves into our picnics and our homes. Most of these other wasps are small, solitary insects that make their living as what we call parasitoids: organisms that complete their larval development by feeding on or in a single host organism, and that kill their host as a normal part of their development. They are, in essence, real-life versions of the Alien. Fortunately for you and me, they attack only other insects and arachnids, and do not share their fictional analogue’s taste for human flesh.
Wasp cocoons hang from the body of a sphinx moth caterpillar. As larvae, these wasps slowly consumed the caterpillar from the inside. When they were ready to pupate, they worked their way out of the caterpillar’s body and immediately spun cocoons to protect themselves during their transformation into winged adults. A video by The Caterpillar Lab depicting the larvae of wasps similar to these emerging from their host caterpillar is available here (external link).
From the perspective of farmscape ecology, parasitoid wasps are interesting because many species feed on insects that damage crops or that are otherwise regarded as pests, and their activity can therefore contribute to suppressing populations of those insects. It is quite possible—perhaps likely, even—that parasitoids naturally prevent the populations of many kinds of insects from ever reaching levels where they can cause economic injury; it is, however, considerably easier to notice those insects that become pests than those that do not, so any such effect is surely underappreciated. On the other hand, considerable effort has been (and continues to be) expended toward devising ways to manipulate parasitoids into controlling the populations of those insects that do become pests. Often, such work entails introducing parasitoids into regions where they are not native, usually for the purpose of controlling a pest that is likewise an alien in the area; for example, the wasps Tiphia popilliavora and T. vernalis were brought to the eastern United States from Asia during the early 20th century in an attempt to control the Japanese Beetle (Popillia japonica). Another popular strategy involves rearing wasps in large numbers and releasing them at the site of pest infestations to supplement natural causes of mortality (including the activity of wild parasitoids): wasps in the genus Trichogramma, for example, can be purchased by the thousands from commercial insectaries for release into a variety of crops, where they destroy the eggs of caterpillars. Less frequently, attempts are made to increase local populations of wild parasitoids by altering the environment to make it more favorable for their survival and reproduction, such as by planting wildflowers around field edges to provide adult wasps with sources of food. My research into parasitoid wasps at the FEP falls under the latter umbrella: we hope to understand the ecology of our native parasitoids (and other beneficial insects) in order to develop strategies for managing habitats on and around farms to maximize the benefits that these insects provide to agricultural production.
A parasitoid wasp (Microctonus brevipetiolatus) stalks a Striped Flea Beetle (Phyllotreta striolata), a pest of crucifers. M. brevipetiolatus belongs to a group of wasps that share the unusual habit of attacking adult insects; most other species parasitize the immature stages of their hosts.
While parasitoid wasps’ usefulness to humans is easily their most popular attribute, I personally find these insects fascinating because they are wonderfully diverse. Over 80,000 species have been discovered worldwide, and they come in a dizzying variety of shapes and colors. Many are decorated in bold, contrasting patterns of black and white, red, orange, or yellow, whilst others resemble tiny jewels, their bodies glimmering with bright, iridescent colors. A few are so miniscule that they approach the physical limits constraining how small an insect can be, and a handful of others grow to impressively large sizes. Even more compellingly, much of the aforementioned diversity is represented here in the Northeast. Some of the largest, smallest, and most colorful wasps in the world are common in our area, and could show up in your backyard or along your local nature trail (assuming, of course, that those places have appropriate habitat). And in terms of numbers, the Northeast is home to many hundreds, if not thousands, of wasp species. During the 2019 field season alone, the FEP collected specimens representing more than 200 species of parasitoid wasps from within a single, 1 mi² study area. Here, I’ll introduce you to just a small selection of my favorites.
Parasitoid wasps of all shapes and sizes collected during the FEP’s 2019 field season. A disk of the same diameter as a penny and an Eastern Yellowjacket (Vespula maculifrons) are included in the image to provide a size comparison. From left to right, the wasps are: Baeus sp., Cheiloneurus sp., Torymus sp., Diadegma stenosomus, Tiphia sp., and the aforementioned yellowjacket. Baeus is so small that it appears as merely a speck! Except for the yellowjacket (which is not a parasitoid), all of these wasps are profiled below.
Bracon sp.
Braconidae: Bracon sp.
The most famous of the parasitoid wasps are those that belong to the closely-related families Braconidae and Ichneumonidae, which together contain many of our largest, most conspicuous, and most economically important parasitoids. The Braconidae take their name from the genus Bracon, some species of which are common and rather pretty. The needle-like structure at the end of the pictured specimen’s abdomen is its ovipositor, the organ that wasps use for laying their eggs. A pair of flexible sheaths cover the ovipositor when it is not in use; here, the near one is bent to reveal the ovipositor nestled inside.
Epimicta konzaensis
The outward facing mandibles of Epimicta konzaensis. (The mandibles have been digitally outlined for clarity.)
Braconidae: Epimicta konzaensis
Braconids in the subfamily Alysiinae share the unusual trait of having mandibles with teeth that curve outward, away from their mouth opening (outlined in the image above). All alysiines parasitize flies, and they use their unusual mandibles to escape from the hardened shelters (called puparia) inside which many flies pupate and to dig through detritus in search of new hosts. One of the most interesting alysiines in our collection is Epimicta konzaensis, a rare species that went undiscovered until the early 2000s, when a handful of individuals were captured in Kansas and Tennessee; our specimens might be the first collected from the Northeast.
Colpotrochia crassipes
Ichneumonidae: Colpotrochia crassipes
The bold yellow-and-black coloration of Colpotrochia crassipes, an ichneumonid, gives it a striking resemblance to a yellowjacket or a potter wasp. Conspicuous color patterns such as the one that these wasps share (often called aposematic or warning colors) are believed to function as a signal to predators that the organisms bearing them are well-equipped to defend themselves when attacked. Ichneumonids and braconids lack the potent stings of yellowjackets (and other related wasps), but they will nevertheless attempt to jab attackers with their ovipositors, and they are also speculated to produce noxious chemicals that make them unappetizing meals. It is worth noting that, despite their sometimes intimidating appearance, all parasitoid wasps are non-aggressive and harmless to humans (although a few particularly large species with short, stout ovipositors might give a painful prick if handled carelessly).
Diadegma stenosomus
Ichneumonidae: Diadegma stenosomus
In my opinion, some of our most elegant wasps are those that belong to the ichneumonid subfamily Campopleginae, like this Diadegma stenosomus. Though widespread in North America, the sole host reported for D. stenosomus in the scientific literature is Carcina quercana, a non-native moth that has only established populations in the Pacific Northwest. In our area, then, D. stenosomus must be parasitizing other moths—presumably, native species related to C. quercana—but their precise identities have yet to be documented.
Diplazon laetatorius
Ichneumonidae: Diplazon laetatorius
Diplazon laetatorius is probably the most widespread ichneumonid in the world: it has been recorded on every continent (except perhaps Antarctica) and on a number of small oceanic islands. It is sometimes regarded as a pest, as it parasitizes the larvae of aphid-eating hover flies, which are some of our most important beneficial insects.
Mesochorus sp.
Ichneumonidae: Mesochorus sp.
Remarkably, some wasps attack other parasitoids, a phenomenon called hyperparasitism. Some hyperparasitoids, including Mesochorus, seek out hosts that are still developing as larvae inside the bodies of other insects, while others, sometimes called pseudohyperparasitoids, wait until their hosts pupate—and thus, in most cases, have emerged from their victims’ bodies—to attack. The Caterpillar Lab has produced an excellent video of a hyperparasitoid wasp (but not Mesochorus) in action; you can watch it here (external link).
Cheiloneurus sp.
Encyrtidae: Cheiloneurus sp.
Some of the most colorful of our parasitoid wasps belong to a large group of closely-related families collectively referred to as the Chalcidoidea. Most of these species, however, are quite tiny, and it is difficult to appreciate their beauty without the aid of a microscope. This Cheiloneurus, for example, is slightly smaller than a mustard seed.
Torymus sp.
Torymidae: Torymus sp.
Many chalcidoids, like this Torymus, are colored in shimmering, metallic shades of green and blue. Though brilliant to our eyes, these colors might function as camouflage, hiding the wasps amongst green vegetation or making them difficult to follow when they move between sun and shade.
Blepyrus sp.
Encyrtidae: Blepyrus sp.
When viewed in the right light, the wings of most parasitoid wasps shine with patterns of bright, rainbow-like colors. Long regarded as little more than a curiosity, it has recently been discovered that each wasp species possesses its own, unique pattern of colored wing reflections, and it is now believed that these patterns function as some kind of communication signal; perhaps wasps flaunt the reflections when interacting with each other. The colors are formed by a process similar to the one that gives a soap bubble its psychedelic sheen; unlike the ever-changing pattern on a soap bubble, however, that of a wasp’s wing remains consistent regardless of the angle from which it is observed.
Paracentrobia sp.
Trichogrammatidae: Paracentrobia sp.
Many of our smallest wasps, such as these Paracentrobia, complete their entire development inside the eggs of other insects. It boggles the mind to imagine a creature small enough to rely on an insect egg as its sole source of food (three of the pictured Paracentrobia could crowd onto the head of a pin)—yet a remarkable video produced by The Caterpillar Lab, available here (external link), shows not one but several wasps sharing a single moth egg. The smaller wasps in the video are probably a relative of Paracentrobia.
Neomymar vierecki
Mymaridae: Neomymar vierecki
Many of the tiniest insects, including many parasitoid wasps, develop wings in which the membrane is largely replaced by a fringe of long bristles. This characteristic is particularly pronounced in wasps belonging to the chalcidoid family Mymaridae (commonly called “fairyflies”), such as this Neomymar vierecki. The adaptive value of bristled wings is not well-understood; however, at the minute scale of these wasps, air’s viscosity has a much greater effect on the way air flows around the wing than it does for larger insects, birds, or airplanes; as a consequence, air flows poorly through the gaps between the bristles, and a bristled wing can exert almost as much force against the air as one formed by a continuous membrane. Meanwhile, it has been suggested that drag caused by friction between the air and the wing surface might be considerably lower in a bristled wing than in a similarly-sized membranous one because the bristled wing has a much smaller surface area. It therefore appears likely that bristled wings are an aerodynamic adaptation that minimizes the effort required for flight in the smallest insects by trading a small decrease in power for a larger reduction in drag.
Pseudometagea schwarzii
Eucharitidae: Pseudometagea schwarzii
One of our strangest chalcidoids, Pseudometagea schwarzii belongs to a family of wasps (Eucharitidae) whose members are all specialized parasitoids of ants. P. schwarzii in particular parasitizes the larvae of the Cornfield Ant (Lasius neoniger). Unlike most parasitoid wasps, P. schwarzii and its relatives lay their eggs on vegetation near ant colonies rather than directly on or in their hosts, and the newly-hatched larvae are free-living. When the larva is passed by a worker ant, it clings to the ant and hitches a ride back to the colony and into the ants’ brood chamber, where it burrows into the body of an ant larva and then—in the case of P. schwarzii—becomes dormant for many months, overwintering inside its host. The wasp begins to feed as the ant larva completes its development in the spring, and it pupates inside its host’s cocoon. Upon emergence, the adult wasps leave the ant nest to mate and start the cycle again.
Inostemma sp.
Platygastridae: Inostemma sp.
The large horn on the back of this Inostemma is a structure for housing the wasp’s ovipositor. Inostemma belongs to a group of wasps (Platygastroidea) that carry the entire length of their ovipositors internally. Those species that require long ovipositors (for attacking hosts concealed in plant tissues, soil, or other hard-to-reach locations) have consequently developed remarkable shapes and structures to create space for the organ inside their tiny bodies. Dorsal humps and horns are particularly common, appearing across a number of unrelated species within the family, but only rarely do their proportions become as spectacularly bizarre as they do in Inostemma.
Baeus sp
Platygastridae: Baeus sp.
Big-headed and squat-bodied, wasps in the genus Baeus are fundamentally cute. These miniscule wasps (many are smaller than a poppy seed) are parasites of spider eggs. The females’ wings are reduced to tiny scales, an adaptation which renders them flightless but might help them to burrow through the silken walls of their hosts’ egg sacs. Most of the world’s Baeus species remain undescribed, even in well-studied regions such as the Northeast. Imagine: an insect that no human has ever documented could be crawling around in your garden!
Tiphia sp.
Tiphiidae: Tiphia sp.
Wasps in the genus Tiphia are some of our most common and conspicuous parasitoids, though their hairy bodies might cause one to mistake them for bees. Tiphia parasitize the larvae of scarab beetles, and as mentioned previously, two Asian species, T. popilliavora and T. vernalis, were introduced to the eastern U.S. during the early 20th century in an attempt to control the Japanese Beetle (Popillia japonica). Many native species also occur in our area.
Insect traps set in the Farmscape Ecology Program’s experimental pollinator meadows. Several distinct habitats appear in this image: a native wildflower meadow, a fallow field, a field planted in rye (used as a cover crop), a riparian woodland, and an upland forest. All are home to a myriad of parasitoid wasps.
Want to see parasitoid wasps for yourself? In the Northeast, any well-vegetated habitat is likely to be home to an abundance of these wasps, and in the warm months finding one can be as simple as going for a walk in the woods and keeping a sharp eye out for insects. Large species, like the spectacular American Pelecinid (Pelecinus polyturator), can be quite conspicuous during the time of year when they are active. However, most parasitoid wasps are quite small and difficult to detect, and will be much easier to find by following some kind of intentional, targeted search strategy. Like many other insects, parasitoid wasps are attracted to nectar and honeydew, and can be found visiting flowers or aggregations of aphids and other plant-sucking insects. Presumably due to their small size, parasitoid wasps seem to prefer to visit small flowers; those of plants in the carrot family, such as Queen Anne’s Lace (Daucus carota), Water Hemlock (Cicuta maculata), and Wild Parsnip (Pastinaca sativa), can be particularly rewarding places to search. Alternatively, if your interest lies in finding wasps that parasitize particular insect hosts, searching locations where those host species occur can likewise be a fruitful strategy. It is also possible to rear wasps by taking potential host insects into captivity and keeping them alive to see whether parasitoids emerge (though one must be careful to avoid collecting host species that are rare or threatened). Many of our parasitoid wasps have not been associated with their hosts, and discoveries are waiting to be made for anyone reasonably dedicated to seeking new rearing records.
The American Pelecinid (Pelecinus polyturator), one of our largest and most conspicuous parasitoid wasps, is a common sight in Northeastern woodlands during July and August. Its long, flexible abdomen allows it to probe deep into soil in search of its hosts, the larvae of June beetles (Phyllophaga spp.).
Bibliography
Resources preceded by an asterisk (*) were freely available online at the time of publication, and are hyperlinked. Most of the others can be acquired at your local public library via interlibrary loan, or directly through the library at your local college or university. Readers interested in a detailed, but accessible general introduction to wasps and their relatives are encouraged to seek out Eric Grissell’s Bees, Wasps, and Ants: The Indispensable Role of Hymenoptera in Gardens, which is available from many college libraries (external link); it also is reasonably affordable should one wish to purchase a copy.
Allen, H.W. 1966. A Revision of the Tiphiinae (Hymenoptera: Tiphiidae) of Eastern North America. Transactions of the American Entomological Society 92(2): 231-356.
Austin, A.D., N.F. Johnson, and M. Dowton. 2005. Systematics, Evolution, and Biology of Scelionid and Platygastrid Wasps. Annual Review of Entomology 50: 553-582.
*Ayre, G.L. 1962. Pseudometagea schwarzii (Ashm.) (Eucharitidae: Hymenoptera), a parasite of Lasius neoniger Emery (Formicidae: Hymenoptera). Canadian Journal of Zoology 40: 157-164. (external link)
*Balaban, J., et. al. BugGuide [Internet]. Ames, IA: Iowa State University. Species Carcina quercana – Oak-skeletonizer Moth – Hodges#1069 [updated 2018 February 15, cited 2020 Jan. 22]. Available from: https://bugguide.net/node/view/166225. (external link)
Barbosa, P. 1998. Conservation Biological Control. Academic Press, San Diego, California, U.S.A.
*Bennett, A.M.R. 2003. Host location behaviour in Pelecinus polyturator (Hymenoptera: Pelecinidae). Journal of the Entomological Society of Ontario 134: 131-134. (external link)
Borror, D.J. and R.E. White. 1970. A Field Guide to the Insects of America North of Mexico. Houghton Mifflin Company, Boston, Massachusetts, U.S.A.
*Buckingham, G.R. and M.J. Sharkey. 1988. Abdominal exocrine glands in Braconidae (Hymenoptera). In V.K. Gupta (ed.) Advances in Parasitic Hymenoptera Research, E.J. Brill, Leiden, South Holland, Netherlands, pp. 199-242. (external link)
*Buffington, M.L. and R.J. Sandler. 2011. The occurrence and phylogenetic implications of wing interference patterns in Cynipoidea (Insecta: Hymenoptera). Invertebrate Systematics 25: 586-597. (external link)
Cheng, X. and M. Sun. 2018. Very small insects use novel wing flapping and drag principle to generate the weight-supporting vertical force. Journal of Fluid Mechanics 855: 646-670.
Cheng, X. and M. Sun. 2019. Revisiting the clap-and-fling mechanism in small wasp Encarsia formosa using quantitative measurements of wing motion. Physics of Fluids 31: 101903.
Crompton, J. 1955. The Hunting Wasp. Houghton Mifflin Company, Boston, Massachusetts, U.S.A.
*Doucet, S.M. and M.G. Meadows. 2009. Iridescence: a functional perspective. J. R. Soc. Interface 6: S115-S132. (external link)
Eggleton, P. and K.J. Gaston. 1990. “Parasitoid” species and assemblages: convenient definitions for misleading compromises?. Oikos 59(3): 417-421.
Gibson, G.A.P., J.T. Huber, and J.B. Woolley, eds. 1997. Annotated Keys to the Genera of Nearctic Chalcidoidea (Hymenoptera). NRC Research Press, Ottawa, Ontario, Canada.
Godfray, H.C.J. 1994. Parasitoids: Behavioral and Evolutionary Ecology. Princeton University Press, Princeton, New Jersey, U.S.A.
*Goulet, H. and J.T. Huber, eds. 1993. Hymenoptera of the world: An identification guide to families. Centre for Land and Biological Resources Research, Ottawa, Ontario, Canada. (external link)
Grissell, E. 2010. Bees, Wasps, and Ants: The Indispensable Role of Hymenoptera in Gardens. Timber Press, Portland, Oregon, U.S.A.
*Heraty, J.M. 1985. A revision of the Nearctic Eucharitinae (Hymenoptera: Chalcidoidea: Eucharitidae). Proceedings of the Entomological Society of Ontario 116: 61-103. (external link)
Hoffman, M.P. and A.C. Frodsham. 1993. Natural Enemies of Vegetable Insect Pests. Cornell Cooperative Extension, Ithaca, New York, U.S.A.
*Huber, J.T. and J.S. Noyes. 2013. A new genus and species of fairyfly, Tinkerbella nana (Hymenoptera, Mymaridae), with comments on its sister genus, Kikiki, and discussion on small size limits in arthropods. Journal of Hymenoptera Research 32: 17-44. (external link)
*Kula, R.R. and G. Zolnerowich. 2005. A new species of Epimicta Förster (Hymenoptera: Braconidae) from North America and new distribution records for Epimicta griffithsi Wharton. Proc. Entomol. Soc. Wash. 107(1): 78-83. (external link)
Marshall, S.A. 2006. Insects: Their Natural History and Diversity: With a photographic guide to insects of eastern North America. Firefly Books, Buffalo, New York, U.S.A.
Marshall, S.A. 2012. Flies: The Natural History and Diversity of Diptera. Firefly Books, Buffalo, New York, U.S.A.
Mason, C.W. 1927. Structural Colors in Insects. II. The Journal of Physical Chemistry 31(3): 321-354.
*Murray, T., B. Moisset, and B. Carlson. BugGuide [Internet]. Ames, IA: Iowa State University. Species Diplazon laetatorius – Hover fly parasite [updated 2012 June 7, cited 2020 Jan. 22]. Available from: https://bugguide.net/node/view/176654. (external link)
O’Neill, K.M. 2001. Solitary Wasps: Behavior and Natural History. Comstock Publishing Associates, Ithaca, New York, U.S.A.
Poulin, R. 2011. The Many Roads to Parasitism: A Tale of Convergence. Advances in Parasitology 74: 1-40.
Pucci, T.M. 2013. Contributions to the classification of North American Microctonus (Braconidae, Euphorinae). Zootaxa 3725(1): 1-150.
Quicke, D.L.J. 2015. The Braconid and Ichneumonid Parasitoid Wasps: Biology, Systematics, Evolution, and Ecology. John Wiley & Sons, Chichester, West Sussex, U.K.
Ruxton, G.D., T.N. Sherratt, and M.P. Speed. 2004. Avoiding Attack: The evolutionary ecology of crypsis, warning signals, and mimicry. Oxford University Press, Oxford, U.K.
Sane, S.P. 2016. Neurobiology and biomechanics of flight in miniature insects. Current Opinion in Neurobiology 41: 158-166.
*Schwarzfeld, M.D. 2014. Ichneumonidae (Hymenoptera) of the Canadian Prairies Ecozone: A Review. pp. 317-397 In D.J. Giberson and H.A. Cárcamo, (eds.) Arthropods of Canadian Grasslands (Volume 4): Biodiversity and Systematics Part 2. Biological Survey of Canada, Ottawa, Ontario, Canada. (external link)
*Shevtsova et al. 2011. Stable structural color patterns displayed on transparent insect wings. Proceedings of the National Academy of Sciences of the United States of America 108(2): 668-673. (external link)
Smith, O.J. and A. Peterson. 1950. Microctonus vittatae, a Parasite of Adult Flea Beetles, and Observations on Hosts. Journal of Economic Entomology 43(5): 581-585.
*Stevens, N.B. and A.D. Austin. 2007. Systematics, distribution, and biology of the Australian ‘micro-flea’ wasps, Baeus spp. (Hymenoptera: Scelionidae): parasitoids of spider eggs. Zootaxa 1499: 1-45. (external link)
*Tooker, J.S. and L.M. Hanks. Flowering Plant Hosts of Adult Hymenopteran Parasitoids of Central Illinois. Annals of the Entomological Society of America 93(3): 580-588. (external link)
Townes, H. 1971. The Genera of Ichneumonidae, Part 4. The American Entomological Institute, Ann Arbor, Michigan, U.S.A.
*Townes, H. and M. Townes. 1959. Ichneumon-Flies of America North of Mexico: 1. Subfamily Metopiinae. Bulletin of the United States National Museum 216: 1-318. (external link)
*Valerio, 1984. Two alternative strategies for spider egg parasitoids. Revista de Biologia Tropical 32(1): 123-128. (external link)
Wäckers, F.L., P.C.J. van Rijn, and G.E. Heimpel. 2008. Honeydew as a food source for natural enemies: Making the best of a bad meal? Biological Control 45(2): 176-184.
Wahl, D.B. 1993. Cladistics of the genera of Mesochorinae (Hymenoptera: Ichneumonidae). Systematic Entomology 18: 371-387.
Walley, G.S. 1967. Nearctic species of the Diadegma stenosomus complex (Hymenoptera: Ichneumonidae). The Canadian Entomologist 99: 925-943.
*Weems, H.V., Jr. 1954. Natural enemies and insecticides that are detrimental to beneficial Syrphidae. The Ohio Journal of Science 54(1): 45-54. (external link)
*Wharton, R.A., P.M. Marsh, and M.J. Sharkey, eds. 1997. Manual of the New World Genera of the Family Braconidae (Hymenoptera). The International Society of Hymenopterists, Washington, D.C., U.S.A. (external link)
Wylie, H.G. and C. Loan. 1984. Five Nearctic and one introduced Euphorine species (Hymenoptera: Braconidae) that parasitize adults of crucifer-infesting flea beetles (Coleoptera: Chrysomelidae). The Canadian Entomologist 116: 235-246.
If you are like me, one of the first things you notice as the weather starts to cool off is just how quiet it is when you walk outside. The birds have stopped chirping, the frogs have stopped croaking, and the insects have stopped calling. Now that we are experiencing the long, cold, winter nights, you are probably missing those beautiful sounds of summer. However there is one good part about the darkness creeping in earlier and earlier in the evening: now you have extra time to catch up on your Farmscape Ecology reading! You may not be able to hear those summer sounds right now, but you can still learn about them!
A species of so-called ‘False Katydid’.
Insect Songs
Let’s start with some basics: can insects actually even sing? Some insects, like crickets, katydids, and grasshoppers, can make sound and communicate, but they do not vocalize like humans or birds do. The main way that these insects (Orthoptera) create sound is through stridulation. Stridulation is the rubbing together of two body parts, which are modified for sound production. In crickets and katydids, a sharp edge, often referred to as a scraper, at the base of one front wing is rubbed against a bumpy edge, often referred to as a file, at the base of the opposite wing (view image of file and scraper at songsofinsects.com).
Black-horned tree cricket with wings raised during stridulation.
Crickets and katydids lift their wings and move them back and forth to run the scraper across the file, which creates the chirping and buzzing that we associate with insect sounds. Grasshoppers also use stridulation for sound production, but most grasshoppers rub their leg against the forewing to create these sounds rather than using wing movements like crickets and katydids.
Great view of a grasshopper’s hind femur, which it rubs against the forewing in order to produce sounds.
Insects create these sounds in order to communicate with potential mates, making other individuals aware of their species, location, and even their quality as a mate. As insect songs are primarily used for mating purposes, in most species only the males produce songs. However there are a few species where the females will produce short response clicks and chirps back to the males.
Why care about insect songs?
Hearing the melodious songs of insects through the days and nights stimulate nostalgic recollections of summers past, but those songs can do so much more for us than just spark memories. They can also provide us with knowledge about the insect communities present in different areas. Every species of singing insect has its own unique song that they use to communicate with other individuals of their own species. These songs alone can allow us to identify what insect species are located throughout various landscapes.
In order to get a good understanding of what singing insects are present in an area, it is helpful to create recordings of their songs. Recordings alone can be great to listen to, but they may not always provide a clearer picture of what we are hearing. So to really break down these recordings and understand the insects, we create spectrograms. Spectrograms are graphical representations of sound frequencies over time.
This is the spectrogram of a Striped Ground Cricket song (recording from Singing Insects of North America). The calling frequency (in kHz) is represented on the y-axis, while the time (in seconds) is represented along the x-axis.
Spectrograms let us look at and read insect songs in somewhat the same way we would read a piece of music. Identifying the frequency of an insect call is just like knowing which note is being played. Identifying the number of pulses per second in an insect call is the same as knowing how many notes are played in a specific measure. So with this ability to identify the notes and count the beats, we can recognize exactly what song we are hearing.
The brighter colors on the spectrogram represent louder noises. We have outlined one insect call in red. Its calling frequency is around 5 kHz, and there are about 2 chirps per second. This call is most likely a Fall Field Cricket. The other bright green areas in the spectrogram represent songs coming from other species of singing insects, as well as ambient noises in the recording.
Identifying the song really just means identifying which species is singing, but creating a spectrogram of a recording produced in a pasture that has many different sounds may show us a whole combination of species all singing within that area. If one recording can tell us this much about a singing insect community, aren’t you curious about what else it can tell us?
Sound Maps
In order to learn even more from these recordings, we decided to start creating sound maps. Sound maps display the power of sounds over a landscape. They demonstrate where we would hear sounds coming from if we were there standing in that landscape listening for ourselves.
To create the sound maps we had in mind we had to collect a lot of recordings, 480 to be precise. So we found a shrubby Hawthorne Valley pasture that was very busy with insect songs, and then we identified the areas within that pasture that we wanted to record.
The area outlined in red is the general location of our sound mapping recordings in a shrubby Hawthorne Valley pasture.
We set up 20 recording units, spaced out 50 feet from each other in a grid.
Each yellow dot represents the location of one of our recording units.
Kenny Fowler, field technician, sets up one of the recording devices.
Each of these recording units was set to record for two minutes, on the hour, every hour, over a 24-hour period. We attached the microphone to a stake about a foot off the ground in order to limit interference with vegetation and orient all the microphones in the same direction.
This shows one of the recording units set up in the field with the microphone (circled) attached to the green stake. All twenty of these units were created by Jules Madey, and this project would not have been possible without all of his hard work.
After a full 24 hours of field recording, we created spectrograms of the recordings we collected. The spectrograms helped us identify which types of insects were calling throughout the area we monitored. Although each species of singing insect has its own unique song, it can be difficult to automatically select these songs out of the spectrogram using software programs. In the Northeast, there are about 55 species of katydids (about 20 of these are ‘traditional’ big, green, leaf-like katydids; most of the rest are Meadow Katydids, which more resemble grasshoppers with hair-like antennae) and about 40 species of crickets (including 9 tree crickets). As the air temperature changes over a 24-hour period, so does the frequency of each of these species’ songs. So our sound maps represent songs from types of singing insects (i.e. tree cricket, field and ground cricket, katydid) rather than representing songs from individual species (i.e. Black-horned Tree Cricket, Common True Katydid).
Dylan Cipkowski, biologist, and Zion, good boy, collect recording units after the 24-hour recording cycle.
Using a software program called Raven, which is also the software used to create our spectrograms, we were able to identify the relative pressure of the insect sounds in each of our 456 recordings (one unit malfunctioned). Then using ArcGIS software, we used radial basis functions interpolation techniques (available with Geostatistical Analyst extension) to map the relative pressure measurements of various sounds over the landscape. Interpolation uses the pressure data and the location data of each recording unit to approximate the sound pressure in areas between each recording device, allowing us to see where the insects are calling. Warm colors on our maps represent high pressure (i.e. louder) sounds. Cool colors represent low pressure (i.e. quieter) sounds.
This image shows the locations of calling tree crickets at 9pm.
Then we were able to use these maps to compare different aspects of the insect sounds, like what groups were calling at certain times of day.
These maps show the calling patterns of three types of singing insects at 12pm. The field and ground crickets are extremely loud at midday compared to the fairly quiet tree crickets and the moderate noise level of the katydids.
Or, how the locations and sound pressure for one type of insect change throughout the day.
These maps show the calling patterns of field and ground crickets at three different times of day. They are calling from different areas at various times of day.
Or, which habitats each type of insect is using.
These maps show the calling patterns of three types of singing insects at 12am over the different habitat types in the pasture. The areas of the map covered in gray horizontal lines represent the tree and shrub covered land, while the uncovered areas of the map represent the open grassland. At this time of day, the loudest calling from the tree crickets seems to be coming from the tree and shrub covered areas, while the loudest calling from the field and ground crickets seems to be coming from the open grasslands of the landscape.
Two recording units are clearly visible, with a third deep in the background. Both the open grassland and the tree and shrub-covered areas of our study site are visible in this photo.
Our immediate goal was to create an ‘animated soundmap’ video showing how the sound landscape evolved across 24-hours, and here it is!
Future Efforts
These maps represent our very first attempts to make 24-hour sound maps, and this is only the beginning of our sound mapping efforts. We are working to increase funding to our sound-mapping project in order to build more units and to apply this technology to other types of research.
We hope to focus on questions of (1) ecology, like ‘how does habitat use differ among the species?’, (2) farmscape management, like ‘how does the abundance of these creatures differ between organic and conventional orchards?’, (3) transmission arts, like ‘how do people’s perceptions of their sound landscape change after they see maps like these?’, and (4) phenology, like ‘how do these calling patterns change throughout the season?’.
Importance of singing insects and sound maps
At this point you might still be wondering why these maps, or even just these insects, actually matter. Singing insects are inherently valuable as part of the wondrous diversity of life on Earth. However, they also interact with lives of other organisms, including humans. Often times crickets, katydids, and grasshoppers are thought of as pest species. While this is sometimes the case, they are only able to cause significant damage to crops when there is a massive local abundance of these insects. Grasshoppers tend to be the most damaging to crops, but crickets and katydids tend to be omnivorous, meaning they feed on both plant material and other insects. We see crickets showing up at army worm egg baits we set up during field work, so they could even help control some pests. Besides occasionally eating individuals of their own species, crickets and katydids are an important food source for a lot of other organisms as well.
Many insectivorous birds rely on Orthoptera (crickets, katydids, and grasshoppers) as a large portion of their diets. Some of these birds rely on them so heavily that their survival and reproductive success may be directly linked with the populations and abundance of these insects. One species of bird that depends on Orthoptera is the Eastern Meadowlark, which is facing rapid population declines. These are grassland-breeding birds, so the primary conservation concern is nest destruction from mowing and grazing, which have also been shown to cause large declines in grassland Orthoptera abundances. With this connection it is possible that understanding the abundance of Orthoptera populations in a pasture may provide some insight as to whether or not the pasture could provide a successful breeding habitat for these birds if mowing and grazing practices were carefully monitored.
Other adult birds are heavily reliant on Orthoptera as well, but not for themselves. There are multiple bird species that depend almost solely on Orthoptera for their young during the rearing phase. The fact that singing insects are relatively large and frequently abundant means they are a nutritionally valuable, easily located food item for parents to feed to their young.
Birds are not the only organisms that rely on Orthoptera for food. Some predatory insects and spiders, as well as parasitic insects, depend on crickets, katydids, and grasshoppers. Certain species of beetle larvae feed solely on grasshopper eggs, so their populations are directly reliant on grasshopper populations. There are even some flies that parasitize crickets, katydids, and grasshoppers. One interesting fact about all of this: a lot of these organisms that depend so heavily on Orthoptera actually use the sounds they produce in order to locate and predate them.
It is because so many other animals rely on Orthoptera that monitoring their populations provides some insight into the overall biodiversity of our landscapes. Organisms that depend on Orthoptera will not thrive in these areas if the Orthoptera themselves are not flourishing.
Sound maps provide a relatively non-invasive way to create Orthoptera biodiversity estimates through landscapes, and may even provide insight into relative abundances of these populations. They also provide a creative way to present and discuss scientific topics that may engage the public more than a traditional scientific study would.
If you want to learn more about the sound mapping projects we have done, including Orthopteran habitat maps from Hudson Valley orchards, visit https://hvfarmscape.org/sound-maps.
Additional Resources:
To learn insect song identifications for yourself, visit http://songsofinsects.com/.
To identify any species of cricket or katydid within North America, visit http://entomology.ifas.ufl.edu/walker/buzz/.
Helpful Singing Insect Guidebooks:
Capinera, J.L., Scott, R.D., and T.J. Walker. 2004. Field Guide to Grasshoppers, Katydids, and Crickets of the United States. Cornell University Press, Ithaca, New York.
Elliott, L. and W. Hershberger. 2006. The Songs of Insects. Houghton Mifflin Company, New York.
Himmelman, J. and M. DiGiorgio. 2009. Guide to Night-singing Insects of the Northeast. Stackpole Books, Mechanicsburg, Pennsylvania.
Works Consulted:
Capinera, J.L., Scott, R.D., and T.J. Walker. 2004. Field Guide to Grasshoppers, Katydids, and Crickets of the United States. Cornell University Press, Ithaca, New York.
Diwakar, S., Jain, M., and R. Balakrishnan. 2007. Psychoacoustic sampling as a reliable, non-invasive method to monitor orthopteran species diversity in tropical forests. Biodivers Conserv 16: 4081-4093.
Elliott, L. and W. Hershberger. 2006. The Songs of Insects. Houghton Mifflin Company, New York.
Gawałek, M., Dudek, K., Ekner-Grzyb, A., Kwieciński, Z., and J.H. Sliwowska. 2014. Ecology of the field cricket (Gryllidae: Orthoptera) in farmland: the importance of livestock grazing. North-Western Journal of Zoology 10(2): 325-332.
Humbert, J., Ghazoul, J., Richner, N. and T. Walter. 2010. Hay harvesting causes high orthopteran mortality. Agriculture, Ecosystems and Environment 139: 522-527.
Marini, L., Fontana, P., Battisti, A. and K.J. Gaston. 2009. Agricultural management, vegetation traits and landscape drive orthopteran and butterfly diversity in a grassland-forest mosaic: a multi-scale approach. Insect Conservation and Diversity 2: 213-220.
Marini, L., Bommarco, R. Fontana, P., and A. Battisti. 2010. Disentangling effects of habitat diversity and area on orthopteran species with contrasting mobility. Biological Conservation 143: 2164-2171.
There is a period in Spring, before the grass greens and other plants become gaudy with color, when one looks expectantly at the branches wondering when buds and birds will show themselves. It is also a time to look at silhouettes – some of which also have their own seasonal changes.
This series of images, initially posted on our Facebook page, are derived from photos taken on walks near Hawthorne Valley Farm, but many of the trees are widespread in our region. How many of the trees can you recognize from their outlines before looking at the captions?
Larch
Larches are our only regional native conifer which is deciduous; that is, it loses its needles each winter. During this season, it’s easy to assume they’re a dead spruce. But keep an eye on them and you’ll see that clusters of bright green needles soon appear.
Red Maple
Since the time I took this photograph (6 April) and now (11 April), these flower buds have burst, producing Red Maple’s floral fireworks. The flowers are small but look for a grey tree now hazed with red and then inspect its branches closely – these are beautiful flowers when seen up close.
Red Winged Blackbird
These birds bring a splash of visual color and plenty of auditory color. They arrived back a month or more ago. This one was calling from a snag close to a nearby wetland.
Ash
The stocky, opposite branches of ashes are easily noted in the canopy. Unfortunately, many of our regional ashes are dying because of the arrival of the Emerald Ash Borer. The trunks of such trees are often starkly obvious as woodpeckers strip the bark in apparent pursuit of the Borer or perhaps subsequent insect arrivals to the rotting wood.
Red Oak (or something close to that)
Oaks often keep their leaves in winter, providing a touch of brown tan to the grey of the forest.
Aspen
The Aspen are in flower, and their long catkins are dangling down like tiny bedraggled socks. Slightly earlier in the year, Ruffed Grouse (one of which I think I heard near here this Spring) may have browsed in these branches.
Grey Squirrel nest
Grey Squirrels sometimes make nests (aka dreys) out of twigs, leaves, moss and other materials. The nests serve both as nighttime quarters and nursery.
Shagbark Hickory
Shagbark Hickories exhibit what botanists call ‘Gothic Branching’. Just kidding, but the branches of Shagbark often seem to form thought-provoking webs against the sky. This one may be showing some ‘witch’s brooms’ (that IS an official botanical term) – those oddly spaced clusters of dense branching. Such structures occur in a variety of trees and can come about for a range of reasons.
Sumac
Sea worms? These are the now-stripped stalks that once held the sumac’s reddish seed clusters.
Red Cedar
Sun-growing Red Cedar quickly comes into old pastures, abetted by the fact that its sharp needles deter browsers. If the forest quickly grows around them, then they will often be shaded out, but Red Cedar on forest edges, such as this one, can grow long and large.
Cell Tower
Rigid is the word that comes to mind.
White Pine
One can almost hear the subtle swishing woosh that White Pine’s needles make in the wind. I haven’t yet found the audio guide to ‘tree calls’, but it could be useful.
Alder
Alders have the male flowers in supple catkins, while the female flowers are in woody cones.
Nannyberry
Purveyor of the Northwoods dates. Well, not really, but the dry, sweet fruit of this viburnum is reminiscent of true dates. It looks as if creatures or weather have already stripped this bush of its fruits.
Sugar Maple
Sugar Maple has a lighter spray than Red Maple and doesn’t show Red Maple’s tiny pompoms of flower buds.
Grey Squirrel in Elm
The squirrel may well have been feeding on this elm’s swelling flower buds.
Grape Tangle
Unlike bittersweet, grape vines aren’t stranglers. Many are native. Nonetheless, they can form a heavy, shading load. The ecology of northeastern grape vines seems to be an understudied area of forest ecology.
Willow
Willows end in wisps. Their flexible branches may help make them more resistant to damage from the floods that regularly hit their waterside haunts.
Catalpa
Catalpa’s dangling pods are distinctive (however, it’s not a legume). Originally a tree of the Deep South, it has been widely planted and can grow well north of its earlier range.
Elm
This appears to be a gangly, fast-growing elm. Although Dutch Elm disease killed many of our elms, they can still be common in various habitats, especially stream sides.
A rip, a river, a snag.
Hard to know what tree this was during life, but elm would seem to be a possibility.
Ash again.
The thick ash branches contrast with the fine whorls of seed stalks from which once hung this tree’s elongate samaras. Winter winds seem to have cleaned house.
Red Maple and spruce
We have very few native spruce trees in the County; spruce’s densely packed needles are most often seen where they were planted in backyards, parks and the like.
Norway Spruce
As the name suggests, Norway Spruce is not native (although Norway Pine is!). It is widely planted, and its Eeyore-like dropping branches are distinctive.
Black Cherry.
Dogged. Black Cherry is another tree of young forests. Look for its dark, scaly bark. Its branches are sometimes marked with distinctive woody swellings of Black Knot fungus.
Grey Birch
Grey Birch is the more winnowy cousin of White Birch. Grey Birches are common in our forests, especially in old field regrowth. Despite their name, their bark is quite whitish, but their stature and frequent clustering help identify them.
Sumac again.
This sumac still has some of it dried fruits, producing a cluster of dancing seed heads in contrast to the earlier sea worms of its bare branches.
The forest will soon be turning green and the woody architecture will be hidden behind lively leaves. That will bring out new personalities in many of these trees.
This past Saturday we led a walk into the southern portion of the Hand Hollow State Forest in New Lebanon. In preparation for that, we did some quick historical research and created some background documentation. This post spices those documents with a few photographs from the site.
For more information on visiting this site, please see the following DEC web site: https://www.dec.ny.gov/lands/101433.html.
The Hand Hollow State Forest and surrounding public lands are located in the northeastern corner of Columbia County, in the town of New Lebanon, NY, not far from Berkshire County, Massachusetts and in the foothills of the Taconics.
The Hand Hollow State Forest is part of a mosaic of conservation lands in this New Lebanon neighborhood (which was once called New Britain). The Columbia Land Conservancy’s Hand Hollow Conservation Area is to the west, the State Forest itself stretches both north and south of County Route 34, while to the east the Open Space Institute is holding lands earmarked for eventual inclusion in the State Forest.
For more on CLC’s Hand Hollow site, see their web site: https://clctrust.org/public-conservation-areas/hand-hollow/
On Saturday last, we walked south from the State Forest parking area north of route 34. The trail weaves its way to the pond, and follows an old public road for its southern half.
Between route 34 and Hollow Creek is a nice stand of old Hemlock. Judging by size (an admittedly risky criterion) some of these trees may well be over 200 years old. It seems unlikely that this area was ever completely opened, perhaps because it is so wet.
A bit farther along, the forest was heavily cut over in the early 2000s, but the rough topography and the presence of Yellow Birch and American Beech suggest that this part too was never completely opened for agriculture.
We soon hit the old public road, following its deeply worn, rock-bordered way.
This series of maps show our area starting about 1873 (a map from 1858 is largely similar). The red dot is the house foundation indicated in the second image of this series and located on the north side of what is now the open pond. Notice how the road and some of its connections fade to a dotted shadow and the historical wetland morphs to an open-water pond.
This and the next image are historical road pictures from the early 1890s in adjacent Berkshire County (both are from Picturesque Berkshire). They may give one an idea of what this road looked like. This picture shows a relatively well-kept, probably central road. Notice that the low rock ‘wall’ along the road is topped by a rail and cross posts fence, making it high enough to deter at least some animals.
This image may show something a bit closer to what the Hand Hollow road looked like – a somewhat rough and muddy track. The fence along this rock wall has apparently not been maintained.
This photo looks north along the ravine that drains the pond. Much of the late 19th century forest in this area was apparently along this untillable stretch.
The pond itself, with DEC’s handicap-accessible dock and a beaver excluder around the pond drain in the foreground. The pond appears to have been constructed in the 1960s from what was once an extensive wetland. This is a common fate of regional wetlands.
As background for what follows, it helps to quickly review forest history in Columbia County. As is true for much of the Northeast, opening for agriculture was widespread and peaked somewhere around 1875, when 70-80% of the County was open farmland.
Forest followed the reverse trajectory, bottoming out as farmland peaked, but then rebounding.
This aerial image from 1942, 50 years or more after maximum clearing, shows a landscape that might be about 50/50 farmland/forest. The purple lines show the approximate extent of the lands shown in the first map.
By 2017, farmland was the rare patch in a forest matrix.
According to an early map, the foundation north of the pond was the home of A. Spencer Hall. Based on census information, walls and guesswork, we have created this sketch of his farm around 1880. This would have been a wide-open landscape composed mostly of fields. The wetland was probably a meadow grazed or hayed as conditions allowed.
This map is somewhat speculative but more or less fits the census information we have. Taking the time to find and plot the original deed would probably increase its accuracy.
As one approaches the foundation from the northeast, the fact that one is walking through former fields becomes evident: flat ground surface, old-field White Pine and, although it’s somewhat hard to see here, an elevated plow terrace caused by years of plowing almost but not quite to the wall in the foreground.
Just before one arrives at the foundation, one reaches this tangle of Honeysuckle – the most evident reminder that this was once somebody’s backyard.
This is a sizable foundation with a stone-lined cellar. In the far corner, is a pile of bricks (a chimney?) while in the near corner a well hole seems to be attached to the house. Somebody familiar with the property told us that these and other bricks were made on-site. Judging by aerial imagery, the house probably disappeared in the third quarter of the 20th century.
Just beyond the house is the crossroads where the two arms of the public road’s ‘Y’ meet. This photo looks northwest along the western arm.
Below the house, a ca. 5’ high stone bank supports the road, presumably helping to prevent it from eroding into the wetland. In this picture, one’s back is to the pond, and the road runs along the ground which is even with the top of the rocks.
Spencer Hall’s farm was, according to the census records, not a particularly small or poor one. It had twice the average acreage of its neighbors, nearly ten times the number of sheep, and was valued about 40% above that of its average neighbor (at ca. $172,000 in modern currency).
In 1880, he also had 2 oxen, 3 horses, 4 milk cows and 6 pigs, and raised, together with hired help, barley, buckwheat, corn, oats, rye, and potatoes. He also had a couple of acres of orchard and cut 10 cords of wood.
This rock wall, running along the northeast edge of the modern pond, may have not only margined a field, but also indicated a property line. It may have separated hay meadow from neighboring woodlot.
Today, a walk through this landscape still reveals much evidence of the worked land that once was, although any rail and crossposts fence atop these rocks has now rotted away. We are privileged – the history of work on the land is still quite evident in the landscape, it may well be more hidden in a century or so.
Preconceptions are a challenge in historical ecology. After all, doesn’t the word ‘forest’ or ‘field’, even if written more than 150 years ago, conjure up some clear images in your mind? However, both culture and ecology can muddy this apparent clarity. The definition of a word can change with time and society. For example, medieval English references to ‘woods’ meant something other than what it does here and now. And even if there were general agreement on what was meant, changes in landscape ecology over time may mean that exact botanical equivalence is very unlikely.
The changing nature of our forests, while still only partially understood, has been widely described. Forest succession and other forms of forest change have been recognized and attempts made to document them. While not completely ignored by historical ecologists, the evolving identity of fields is less well understood and so is meat for further exploration.
This display, although far from comprehensive, asks ‘what did our 19th century fields look like botanically and zoologically?’ We will explore that question through illustrations and narratives appearing in 19th century books and will profile three organisms: Bobwhite Quail, Regal Fritillary, and Goldenrods (Goldenrods are actually several species which we won’t tease apart here).
In part, the motivation for this work is simple ‘natural historyitis’ – the affliction of some human beings for knowing what there is to know about the creatures and land around them, be that current ecologies or past lives. While not conclusively predictive, history can help us better understand an organisms’ current ecology and at least be alert to the potential outcomes of our intentional or unintentional interventions.
One final word – it is easy looking at these old books to imagine stodgy old men, bent over candle light, carefully turning their browned and brittle pages. This is, of course, far from true. These were once crisp, new, hot-off-the-press publications eagerly awaited by aspiring field naturalists. While it is true that not everybody was able to afford the more ornate works, the widespread interest from people who spent much of their lives surrounded by nature is demonstrated by the presence of economy editions meant to satisfy that market.
The Bobwhite Quail was perhaps the flagship bird of 19th century fields. De Kay, in the same 1843 book that contains Hill’s illustration, wrote, that it “occurs in every part of the State, where it breeds and is a constant resident”; Edward Forbush, harkening back to a Massachusetts childhood during the second half of the 1800s noted, “During my boyhood the cheery, heartening call of the Quail was one of the most common and welcome sounds of spring and summer. The plowman resting his team gave ear to the gladdening sound and it mingled with the ring of the whetstone on the scythe.” Others spoke of Quail feeding with chickens in the barnyard. In fact, it was such a common character that its call, now transcribed as “More Wet, More Wet“, entered the lexicon of folk weather forecasting. Even in the early 1900s, it was described as a fairly common resident breeding bird of Columbia County.
Today it is rarely seen (or heard) and may effectively be extinct in New York State, with scattered sightings probably representing game farm escapees or releases. What happened? There may be no single answer. Instead, as is often the case, a maelstrom of factors may have caused its demise, these likely included the following:
From the Bobwhite’s perspective 19th century fields, at least during the first half of the century, seemed to have been a place of bounty. Relatively loose field management ensured both food and shelter, while abundant barnyards probably served as emergency food lots. Today, our incessant drive for efficiency and our relatively new-found mechanical prowess means what few fields are left tend to be much neater than their predecessors. Because of this (not to mention the booming house cat population), even were they to be re-introduced, Bobwhite would probably be hard-pressed to survive in our modern landscape.
At about the same time that Bobwhite were winking out in New York State, Regal Fritillary was also waning. It is difficult to know how common this butterfly ever was in our region. Many more youth ventured Bobwhite hunting or trapping than took the time to note the abundance of particular butterflies, as a result, our glimpse into the butterfly past gets foggier faster. Historical records of this species exist from throughout southeastern NYS, including Columbia County. Scudder, a great 19th century lepidopterist based in Boston, described it as ‘tolerably common’ in adjacent Berkshire County, MA.
The past of the Regal Fritillary is almost as mysterious as its present: it was reported to favor wet meadows and yet apparently relied on dry field plants; it was widespread and yet rarely common; and its abundance apparently fluctuated dramatically meaning that its presence was sporadic at best. Today, its range has retracted dramatically for reasons still unclear. Once found throughout much of the East Coast, it is now gone from all but one site in the region – a Pennsylvania National Guard training area. One of the last confirmed NY sightings was in 1975. Another subspecies is still moderately common in parts of the Midwest.
Such uncertainty might be more understandable (although not necessarily excusable) were the Regal Fritillary a small, inconspicuous creature, but, at least by butterfly standards, it is not. Indeed, it is one of our physically most impressive butterflies with its relatively large size and dramatic, contrasting markings. “Fine” is how several 19th century lepidopterists appreciatively described it.
Its apparently conflicting ties to both wet and dry habitats can perhaps be reconciled if one supposes that, at least late in the season, the adults sought nectar sources that can be especially abundant in wetter meadows while nonetheless requiring drier land plants for caterpillar food. As a species of tall-grass prairies and their eastern analogies, Regal Fritillary caterpillars consume violets and some of their favored species are those of dry fields. There also seems to be a connection to native bunch grasses such as Little Bluestem, perhaps because they provide important shelter for overwintering caterpillars.
The East Coast demise of this species may yet be shown to relate to some species-specific disease, parasite or pesticide sensitivity, but more likely it was the result of a more straightforward, yet equally challenging force – habitat loss. The sporadic occurrence mentioned earlier hints at a life history based upon wide mobility and taking advantage of conditions that are patchy in time and space. This worked, so long as a sufficient number of patches appeared often enough. However, as agriculture declined and industrialization gathered momentum in the East, the species eventually fell over a demographic cliff – those populations that winked out were not subsequently repopulated and that, in turn, further reduced the repopulation pool.
Native warm-season bunch grasses are typical of dry, low-productivity pastures and hayfields. These were among the first fields to be abandoned as agriculture shrank in the East Coast. Wet meadows have probably also declined, first due to beaver extirpation and then due to draining for agriculture or excavation for ponds. As a result, except in perhaps a few special circumstances, it seems unlikely that the Regal Fritillary will again return to our landscape.
(For more on the 19th century world of North American lepidopterists, we would recommend Butterfly People, by William Leach, a spirited tale of that era’s ecology and society.)
Picture an ‘old field’. Likely as not your image includes a rough display of Blackberries and other brambles, Grey Dogwood, Multiflora Rose, Goldenrod and late-season asters. Yours is a rough and scruffy place that nonetheless produces ample wild flowers in the right seasons. It is probably an abandoned agricultural field of some sort – crop field, hay field or pasture – that has been left to its own devices for several years, perhaps even a decade or two. It is heading, faster or slower, towards forest.
Nineteenth century botanists did use the term ‘old field’, and it’s tempting to assume that they had the same conceptualization of it, but they apparently did not. To them, ‘old field’ seems to have meant something more akin to what we would call a fallow field. That is, a crop field that intentionally or not has laid fallow for a year or two, and sports an exuberance of crop field weeds. The long-abandoned farm field that we associate with ‘old fields’ was probably not a common component of the 19th century landscape, at least for its first 75 years or so. During that time, farmers were more likely to be opening new land rather forgetting old acres.
This does not mean that Goldenrod and its companions were not present in the landscape, but they were apparently largely elsewhere – lining roadsides and enveloping walls and wood fences (helping to provide, one might add, ample Bobwhite cover). The technology to mow (or spray) road edges or weed-whack fence lines was yet to come. Thus, ‘rough and scruff’ was more a habitat of edges than of whole fields. That said, hand-cut hay fields and lightly grazed pastures were no doubt more patchy than modern ones, and accounts do mention Goldenrod in some of those as well.
Solidago (Goldenrod’s scientific name) derived from Elizabeth Colden’s botanic manuscript in the British Museum, unpublished,1740s and 50s. Elizabeth Colden was the daughter Cadwallader Colden, a prominent colonial administrator and a some-time botanist. She began assembling (but never finished) a Flora of New York. She described and created uncolored pen & ink drawings of each species, sometimes including notes on use or habitat. She profiles several Goldenrod species. Many of her specimens probably came from around her family estate in Orange County.
Pictures of Roads from Picturesque Berkshire, 1893. Most 19th century photographs are of people or single buildings rather than landscapes. While this book contains its fair share of those, it also includes many photos of roadsides and fields. The landscape is late-19th century with wire beginning to replace rock walls and split rail fences, but the landscape still contains many earlier traces, and the photographs of roadsides on this page, although they do not clearly show Goldenrods, likely show where you could have found them. Note that both hayfield and pasture are rougher lands than their current incarnations and probably left more space for diversity.Taken together, Bobwhite, Regal Fritillary and Goldenrod hint at a landscape that is both familiar and foreign. Bobwhites sheltered in thickets that no doubt look somewhat like those along certain of today’s back roads, only such tangles were more common. Regal Fritillaries glided above fields perhaps similar to those one can still find on a few drier hillsides, only such fields were more numerous. Goldenrods, perhaps as common today as in the 19th century, have become flags of modern “old fields”, and are perhaps now less common – although certainly not unseen – along our roadsides and farm field edges. We are, I believe, moving from a landscape of messy gradations towards one of either/or, from one of either forest or tidy farm field, lawn and development. Certain forest creatures have benefited from the wood’s return, and that is worth celebrating. Less encouraging is the neat control of our open areas. I wonder if, in another 50-100 years, field Goldenrods (there are also a few woodland species) won’t be rarer organisms, not, perhaps, gone the way of the Bobwhite and Regal Fritillary, but nonetheless fading into memory.
[The content of this blog is almost identical to a posting on the Farmscape Ecology Program Facebook page by Conrad earlier today, which we hereby make available to readers who don’t use Facebook].
We are on the tail of Winter or the cusp of Spring. The time of year for ice and mud, snow and rain. It is the season when the Woodcocks peet bravely on a rimey mornings and evenings, when male Red-winged Blackbirds look cold and lonely around frosty ponds, and when… the salamanders and frogs move across wet roads.
To understand why creatures like Spotted Salamanders try to cross roads, one has to understand that they have their own routes to follow – the paths that lead them from the upland forest where they spent most of the year to the vernal pool or other wetland where they will mate. These are paths they may have followed year after year (Spotted Salamanders can live a couple of decades), generation after generation; and yet, more and more, they are intersecting with our own asphalt causeways.
During the first wet and warmer nights of Spring, these creatures undertake their migrations. They appear as if by some mysterious flowering from the earth for one rarely sees them at other times of year. The salamanders are slow and determined and we are fast and determined – many die beneath our car tires. Frogs are quicker but more erratic, they too are often hit. This photo collection profiles some of what we have seen so far this year.
The DEC’s Hudson River Estuary Program has a valuable project to identify road crossings and encourage volunteers to help guide salamanders and frogs safely across the road, please check out their web site: http://www.dec.ny.gov/lands/51925.html for tips and information on this citizen science network.
This year, the majority of crossings to breeding ponds has probably already happened in many areas, but the next warm, rainy evening may bring further movement, including some breeders returning to the woods. It’s not too late to take a flashlight, a reflective vest and, while mindful of your own safety, walk to a nearby stretch of wetland-bordered road and see who you can help across.
At the least, please think twice before driving out on such warm, wet evenings.
And the avian ‘road crew’ seems take advantage of this.
Sorry to lead with a family snapshot, but there’s a story behind it. That’s me, around 1970, walking through the Red Pine plantation behind our house.
Land Classification Map from the 1941 “Columbia County Agricultural Survey”. The classification was apparently based on a tour of the County. Regions in “Land Class III and higher” were still in active, profitable farming; Land Class IIR was apparently borderline in terms of its farms; most farms in Land Class IR were abandoned or obviously declining. The green dot indicates the location of the Red Pine plantation mentioned in the text.
This map of the extent of agricultural decline across New York comes from Vaughan’s 1928, “Abandoned Farm Areas in New York”, Bulletin 490 of the Cornell Ag. Experiment Station. In most areas, the peak of farmland was around 1880.
Abandoned farmland reverts spontaneously to forest on a Gallatin (Columbia County) hillside in this 1935 image by Rogers McVaugh. Most of the County’s former farmland has returned to forest on its own.
The distribution of seedlings as part of NYS reforestation efforts from the Atlas of Forestry of New York (1958?) by Neil Stout. A larger circle indicates a larger proportion of seedlings distributed.
European Larch is one conifer sometimes found in plantations. Unlike our other conifers, larch are completely deciduous and drop all of their needles every winter making them resemble dead snags.
Norway Spruce, a relatively common plantation tree, are distinguished by the characteristic drooping of the branches evident in this photo of an open-grown individual.
The White Pines lining this horizon could be those of a plantation, however, closer inspection would reveal that, in this case, they are probably old-field White Pine which spontaneously grew up in a former farm field. Both spontaneous and planted stands of White Pine are common in Columbia County.
Red Pine plantations can be identified by the red-barked trees evident in the first photo of this posting and the long needles grouped in clusters of two. Scotch Pine, another conifer sometimes found in our plantations, also has paired needles and red bark, but its needles are shorter and twisted.
Although pine plantations can be relatively low in diversity, some wildlife do like to use them for shelter, as evidenced by this string of deer beds.
A 1942 aerial photograph, showing the future Red Pine plantation (circled) still as field.
By the time of this 1952 aerial, the plantation had been planted.
A landscape shot, probably from the early ’50s, with the young Red Pine plantation outlined.
A 1971 aerial of the stand at about the same time that the first photo of this posting was taken from within the stand.
In 1981, the plantation appears to have been generally intact, although a few holes are evident in the pine canopy.
A false-color image from 1995; the loss of mature trees from the core of the plantation is evident.
This 2017 image, taken during leaf-off, clearly shows that much of the former plantation is now composed of deciduous trees.
A photo taken in the Red Pine plantation in early 2018. The main ingredient is no longer Red Pine, although a few of the edge trees are visible in the distance.
A grove of mature trees is evident just to the east of the future location of the pine plantation in this 1942 image. That area remains in forest up to the present day.
A LiDAR image of the topography of the plantation and the adjacent forest. Note how the rocky stream bed ’emerges suddenly’ from the ploughed field north of it. Perhaps such a stream bed once wove all the way down the hillside but was erased by farming.
Looking up the rocky creek just east of the plantation; the ploughed field is visible in the background.
The greater landscape of the Red Pine plantation in 1942. Note the patches of mature forest (together with some evidently young forest).
The same landscape in 2015 – finding ancient forest fragments in such an extensively reforested landscape can be a challenge.
How can it be possible for such exquisitely beautiful jewelled crystals to fashion themselves in the vast spaces of the heavens, among the clouds!
Jean M. Thompson, Water Wonders Every Child Should Know (1907).
(photo by Wilson Bentley)
The most important and profoundly human act of exploration is not its execution, but its conception; it is the dream of knowing.
The turn of the 19th century brought landmark advancements in the science of technology – the study of electricity, of flight, of automobiles. One could be pardoned for thinking that natural history, that grand pursuit of the 1800s, had become passé. However, even if eclipsed in scientific headlines, the exploration of nature still occupied many and, in fact, had flourished, if not in the ‘lab’, then in the backyard and farmyard.
Water Wonders Every Child Should Know by Jean Thompson was part of the canon of the Nature Study Movement. A popular educational movement pioneered in the 1890s, it focused on insuring that, in the age of industrialization, children did not lose sight of the nature around them. The Every Child Should Know series, for example, included books on birds, trees, wild flowers, and earth & sky. The book’s subtitle, Little Studies of Dew, Frost, Snow, Ice and Rain, illustrates the movement’s emphasis on getting out and looking (i.e., exploring). Like Jean Thompson, many figures in this movement were women at a time when professional scientists were mainly men. The Movement would dwindle as the century progressed, but it helped make the popularization of science a respected calling.
What brings this book to the fore at this time of year is that it is illustrated with photographs by Wilson A. Bentley, a Vermont farmer also known as the Snowflake Man. Much of Water Wonders is devoted to the ‘games’ that water can play as it freezes in snowflakes, hoar frost and other ice formations, and Bentley’s black and white photographs provide clear, sometimes dazzling, examples of those patterns. Jean Thompson visited him several times in Jericho VT and his ideas apparently permeate much of the book.
He was a country bachelor, she was an affluent NYC divorcee, and the visits were something of a local scandal. She explicitly juxtaposes their two worlds as she invites the reader into the snowy landscape,
Most of us have given little time or very serious thought to the study of the snow, and the marvelous detail which goes to fashion the individual snow crystal. In fact, if we live in crowded city, we are inclined to look upon a heavy snowfall as something of a nuisance…impeding pedestrianism and traffic, and thoroughly undesirable until cleared away.
But once outside in the open country we are inclined to gaze forth upon the pure expanse of snow-covered hill and plain, resplendent and dazzling as it stretches afar under the pale winter sunshine, with a more kindly, tolerant mood…
The book is a call to scientific reverie, to the devotion of time and thought to snow, for she continues, “when you have … studied for yourself the marvellous phenomena and detail of snow-crystal formation, you will doubtless ever after.. in watching the fluttering, swirling flakes as they descend, exclaim: Oh, the wonder and mystery of it all!”
While Thompson does an inspiring job of invoking the mystery, Bentley spent much of his life actively wondering about snowflakes. He not only pioneered snowflake photography but, by keeping careful notes on climatic conditions, began to associate particular atmospheric conditions with the formation of certain types of snowflakes (see, for instance, his 1902 paper). Each of the snowflakes pictured in the book comes with a mini-biography. For example, one photo captio
n reads, “These snow crystals are the product of a very great storm, and they travelled a long distance before reaching the earth. They were generated in a very high frigid altitude. When these singular snow crystals descended they fell in parachute fashion, the larger section downward.” How Bentley and Thompson knew the details of this biography is unclear, but whether or not they were 100% correct, Bentley’s observations and the ‘thought experiments’ that attempted to make sense of them opened up a new world, and Thompson realized and expressed its poetry.
Both Bentley and Thompson were “non-scientists” who, in some ways, bypassed the profession to bring nature directly to their followers. This was not always well-received by full-time scientists and the tension is exemplified by early critics of Bentley’s photographs. Bentley took care to select flakes and even to manipulate photographs so as to highlight the most beautiful and intricate patterns. When others tried to replicate his efforts, they found that the vast majority of flakes were not fine symmetrical “jewels” but rather broken or misshapen bodies, and they called foul. In some ways, both sides were right: rather than being a random selection of flakes, the images in Water Wonders are indeed a careful, aesthetically-shaped collection of rarities, as Thompson herself noted. However, while explorers like Bentley and Thompson did have a responsibility to make accurate observations, they also had a responsibility to ‘sing the praises’ of what they saw. If it weren’t for the selection process, the images would not have been as awe-inspiring and, it is likely, many fewer people would have ventured down that first, dreamy step of snowflake exploration.
Ideas on snowflake classification and formation have evolved since 1907, but, for the most part, they are extensions rather than refutations of the book’s ideas. Current understanding holds that a snowflake begins life as a nubbin of ice on a tiny airborne particle such as a bacteria. Because of temperature differences, the air in the ‘vast spaces’ of a cold cloud can hold more water than that in the immediate vicinity of a growing snow crystal. The result is that water vapor in the cloud begins to accumulate as ice on the starting nubbins. The structure of 
the water molecule itself determines the shape of the initial base (a hexagonal plate), but the pattern of any individual crystal’s growth is the product of temperature, humidity and history. If the air is very dry and/or cold, for instance, the snowflake will likely fall to earth as a hexagonal plate or tube. If, on the other hand, the air is humid and only moderately cold, each of the six corners will begins to sprout a feather-like arm. As a flake travels through the clouds, it may well enter different temperature and humidity zones, each of which will cause the crystal to grow in new ways. Thawing and re-freezing may occur, and ‘rough seas’ may break flakes or glue them together. The huge diversity of snowflakes occurs because it is very unlikely that any two flakes will share exactly the same biographies during their trip to the ground.
When Jean Thompson and Wilson Bentley looked up at a snow-filled sky, they may not have seen all of this, but they saw much of it. However, exactly what they knew is, in some ways, less important than what they dared to imagine. That combination of observation and imagination, of rock and dream, is at the heart of exploration by young and old. It is as an embodiment of that, as a book eloquently beckoning children to walk into the mind of a true explorer, that Water Wonders is our nomination for Book of the Year 1907.
Natural and Agricultural Observations In & Around Hawthorne Valley 
