OrThoptera Thursday: Lesser Angle-wing Katydid

Last week I wrote about the Greater Angle-wing Katydid, a common species over much of the U.S. While reviewing images for that post, I discovered I also had images of its cousin, the Lesser Angle-wing Katydid, Microcentrum retinerve, from the same location in south-central Ohio.

The Lesser Angle-wing, as its name suggests, is a smaller animal, adults ranging from 44-53 millimeters in length compared to the 52-63 millimeter Greater Angle-wing. Males of Microcentrum retinerve have the stridulatory area consistently brown in color, a sharp contrast to the bright green of the rest of the insect. I also find that Lesser Angle-wing Katydids have the veins of the front wing more explicitly defined than in the Greater Angle-wing, making the creature even more convincing as a leaf mimic. This rougher texture is not always a defining character, but it helps.

The key character in separating these two species of Microcentrum would naturally be the most difficult to capture from images of wild, living specimens. The front edge of the pronotum (top of thorax) is smooth and straight in M. retinerve. This front margin has a very small, central tooth in M. rhombifolium.

Both species occupy the same kind of deciduous forest habitat, but the Lesser Angle-wing Katydid has a more restricted range. It occurs from Long Island and New Jersey south to northern Florida and west to Missouri and extreme east Texas and Oklahoma.

Locating a singing male can be highly frustrating, as the interval between songs is even longer than in the Greater Angle-wing; and they don’t have a “courtship song” of repeated tics. Each call is a rapid series of 3-5 pulses, too fast to count (but revealed visually in sonagrams), repeated about once per second for a short period.

Look for the adults at the tips of branches on trees at night. It is actually easier to see them in a flashlight beam than during the day because they are more active, and stand out vertically against the otherwise horizontal plane of foliage. Moving katydids are always easier to spot than stationary ones.

The Lesser Angle-wing Katydid will also fly to lights at night, which is how I obtained these few images. I am still not absolutely certain that the female is not actually a Greater Angle-wing specimen. It was climbing high on the wall and windows of a building and I could not gauge its size accurately, let alone note whether there was a tooth on the front edge of the pronotum.

Adults are most commonly encountered between late July and mid-October, but depending on latitude they may reach maturity as early as May. Other facets of behavior and life cycle are essentially identical to those of the Greater Angle-wing Katydid.

Sources: Capinera, John L., Ralph D. Scott, and Thomas J. Walker. 2004. Field Guide to Grasshoppers, Katydids, and Crickets of the United States. Ithaca: Comstock Publishing Associates (Cornell University Press). 249 pp.
Elliott, Lang and Wil Hershberger. 2007. The Songs of Insects. Boston: Houghton Mifflin Company. 228 pp.

Moth Monday: California Oak Moth

Welcome to the first post in a semi-regular feature I call “Moth Monday.” When possible I will include images of the adult, caterpillar, and pupa stages. I will strive to update previous posts if I am able to obtain images of adults or larvae that I did not have at the time of the original posting. Note that this feature is irregular in part because my family’s “weekend” is Sunday and Monday rather than Saturday and Sunday.

Rarely am I able to complete the life cycle of any insect in images, even over months if not years, let alone in one day at one location, but this improbable event occurred on March 25, 2011 in Carpinteria, California. My wife and I (we were dating at the time) were visiting her uncle and his wife, and strolling the neighborhood we came across one tree that was full of every life stage of the California Oak Moth, Phryganidia californica.

This species is legendary for its periodic population outbreaks that can, in epidemic years, result in the complete defoliation of oak trees along the California coast. California Live Oak, Quercus agrifolia, is the preferred host, but other species are on the menu. Incidental hosts include eucalyptus, chestnut, Tan Oak (Lithocarpus densiflorus), and azalea. The California Oak Moth also occurs in southwest Oregon where it eats Giant Chinkapin (Castanopsis chrysophylla) and Canyon Live Oak, as well as Tan Oak.

Despite the visually devastating effects of its caterpillars, the moth is rarely, if ever, responsible for the outright death of trees. We tend to severely underestimate the resilience of plants in general to withstand the attacks of insects and other herbivores.

Female moths lay their eggs in loose clusters on the foliage, limbs, or trunks of the host. Eggs laid on the underside of leaves late in the season are often able to overwinter there.

The caterpillars that hatch begin skeletonizing the leaves, grazing on the tissue between veins on the undersurface.

Older caterpillars are eventually able to consume all but the major leaf veins. The caterpillars undergo five molts, eventually reaching about 25 millimeters in length before they pupate.

The pupa may be mistaken for a butterfly chrysalis, as there is no silken cocoon encasing it, and it is boldly marked in black and white or yellow. Pupae are generally suspended by silken threads from the host tree or any vertical object close by.

The caterpillars and/or pupae are hosts themselves for a number of parasites. Among them are the tachinid flies Actia flavipes, Hyphantrophaga virillis, and a species of Ceranthia. An ichneumon wasp in the genus Mesochorus is also recorded from California Oak Moth caterpillars (Carmean, Miller, and Scaccia, 1989). There is also a nuclear polyhedrosis virus (NPV) and a fungus (Beauveria bassiana) that kill the caterpillars. The virus leaves the caterpillars hanging as limp, lifeless brown corpses from foliage, while the fungus may manifest itself as a white, powdery coating on the larvae, with an unpleasant odor as an accompaniment (S. Swain, et al., 2012).

The adult moths are dull brown, with a wingspan varying from 25-35 millimeters. They fly weakly, but well enough to disperse effectively. Males have pectinate (comb-like) antennae, the better to locate a female by the pheromones (scents) she releases to attract potential mates. Rarely do these moths fly to lights at night. You are much more apt to see them randomly during daylight hours in places where populations are abundant.

The California Oak Moth is also known as the California Oakworm, which is perhaps a better name since it is the caterpillars that do the damage. Formerly placed in its own family, the Dioptidae, it has recently been reclassified as one of the “prominent” moths in the family Notodontidae (subfamily Dioptinae).

Anyone living in the western half of California, from the Oregon state line to the Mexican border, is likely to encounter this species. During population booms it finds its way inland from the coast to central valleys. There are two generations each year in northern California, and three generations per year in southern California.

Sources: Carmean, David, Jeffrey C. Miller, and Brian Scaccia. 1989. “Overwintering of Phryganidia californica in the Oregon Cascades and Notes on its Parasitoids (Lepidoptera: Dioptidae),” Pan-Pac. Entomol. 65(1): 74-76
Essig, E.O. 1958. Insects and Mites of Western North America. New York: The Macmillan Company. 1050 pp.
Furniss, R.L. and V.M. Carolin. 1977. Western Forest Insects. Washington, DC: U.S. Department of Agriculture Forest Service Miscellaneous Publication No. 1339. 654 pp.
Powell, Jerry A. and Charles L. Hogue. 1979. California Insects. Berkeley: University of California Press. 388 pp.
Swain, S., S.A. Tjosvold, and S.H. Dreistadt. 2012. “Pest Notes: California Oakworm,” UC IPM Online.

OrThoptera Thursday: Greater Angle-wing Katydid

One of the joys of summer nights in North America, at least east of the Rocky Mountains, is the songs of katydids. Among the more abundant and widespread of our many native species is the Greater Angle-wing Katydid, Microcentrum rhombifolium.

This is a very large insect, adults reaching 52-63 millimeters from head to folded wingtip. Females in particular are also very heavy. Let one crawl across your hand and you will feel how weighty she is. Both genders are uniformly green throughout, somewhat mottled on the legs and face. This species is among the most “leaf-like” of our katydids and is found mostly in deciduous trees.

The Greater Angle-wing ranges from Pennsylvania and New Jersey south to Florida, west to southeast Minnesota, Iowa, southeast Nebraska, Kansas, and Texas. It also wraps around the southern tip of the Rockies and Sierras, north to San Francisco Bay and throughout Arizona and much of Utah.

Adult males of this species produce two kinds of songs. The first is a “calling song” that consists of a loud “lisp” repeated an average of every two to four seconds. Producing an intermittent song like this probably prevents predators from easily locating the insect. I know it has frustrated me on a number of occasions and I have better than average hearing. Once a female is attracted, the male switches to a “courtship song” that is a series of “ticks.” The female is capable of answering this call, though she does not have the well-defined sound-producing structures the male has. The male eventually moves to find the female via this “conversation.”

Contrary to popular culture, katydids do not generate their song by rubbing their legs over their wings. The front wings of the male are modified at the “shoulders” to include a file on one wing and a scraper on the other. The file is composed of a row of peg-like teeth over which the scraper is stroked rapidly. This method of sound-production is termed “stridulation,” and the part of the wing modified is called the “stridulatory area.” Both genders hear the songs through slit-like openings on the front legs.

Once male and female are together, mating may take place. This involves the transfer of a sperm packet known as a spermatophore, produced by the male. The spermatophore is a fairly substantial ball of gelatinous protein surrounding the sperm sac itself. Once the pair disengages, the female will eat the protein mass while the sperm enter her oviduct.

The first time I witnessed mating in katydids, I thought something horrible had happened to the female, that her internal organs were oozing out of her body! The edible gift provided by the male may help foster the development of her eggs, and/or encourage her to rebuff subsequent suitors, thereby insuring it is his DNA that is carried through to the next generation.

One additional, odd note. I observed a trio of Greater Angle-wing Katydids in south-central Ohio in August of 2011 that puzzled me. One of the two females appeared to be licking the back of the male’s abdomen (see image above). I am aware that male tree crickets produce glandular secretions from the thorax near the base of their wings, but I am not familiar with an analogous situation in katydids. However, I did find other references to this behavior (Fulton, 1933; Gwynne, 2001), likewise without explanation.

Mated females deposit their eggs single-file along a twig or the edge of a leaf, each ovum overlapping the last like shingles on a roof. The eggs are vulnerable to parasites, chiefly tiny wasps in the family Eupelmidae.

The nymphs that hatch feed generally on foliage, and molt four times before reaching adulthood. While it is difficult to identify most katydids in the nymphal stage, the robust body shape, relatively short hind legs, and mottled green appearance of Microcentrum nymphs helps them to be easily separated from other North American katydid genera.

Both large nymphs and adults can be preyed upon by a number of other animals, and especially by sphecid wasps like the Great Black Wasp. Adults can fly when pressed to do so, but generally creep about slowly so as not to draw attention to themselves in the first place.

Look for the Greater Angle-wing Katydid along forest edges, in gardens and yards, even in lone trees in open fields. They are also attracted to lights at night, though not in great numbers. The best way to find them is at night, with your ears and a good flashlight. Good luck.

Sources: Capinera, John L., Ralph D. Scott, and Thomas J. Walker. 2004. Field Guide to Grasshoppers, Katydids, and Crickets of the United States. Ithaca: Comstock Publishing Associates (Cornell University Press). 249 pp.
Elliott, Lang and Wil Hershberger. 2007. The Songs of Insects. Boston: Houghton Mifflin Company. 228 pp.
Fulton, B.B. 1933. “Stridulating Organs of Female Tettigoniidae (Orthoptera),” Entomol. News 44: 270-275
Gwynne, Darryl T. 2001. Katydids and Bush-Crickets: Reproductive Behavior and Evolution of the Tettigoniidae. Ithaca: Comstock Publishing Associates (Cornell University Press). 317 pp.

True Bug Tuesday: Mirid plant bug

You can’t judge a book by its cover, and you can’t identify most insects by color pattern alone. One perfect example of this is a colorful plant bug, Metriorrhynchomiris dislocatus, in the family Miridae.

I first encountered this species in South Deerfield, Massachusetts on June 7, 2009 (image above). I discovered several more in the Forest Preserve System surrounding Chicago, Illinois and its suburbs in late June, 2011. The species is common throughout the eastern U.S. and adjacent Canada, west to Alberta and Colorado, and south to Florida and Texas.

This is an average-size insect for the typical mired plant bug, if not a little on the large side, adults measuring 6.5 millimeters.

What is confounding about this species is its seemingly infinite variability in color pattern. No less than fifteen different color forms have been recorded, with no connection to geographic location. The entomologist Willis Stanley Blatchley (1859-1940) called such true bug species “spotted dogs,” and resisted the urge to consider each variation as a separate subspecies. This diversity in appearance is called “color polymorphism,” and it is not uncommon in the Miridae as a whole.

One is likely to encounter M. dislocatus on a fair number of different plants, but it is demonstrably associated with False Solomon’s Seal (Smilacina racemosa) and Wild Geranium (Geranium maculatum), especially in shady, moist woodland habitats. Additional plant associations that are probably not host plants include American Fly Honeysuckle (Lonicera Canadensis) in Quebec, Canada; Star-flowered Lily-of-the-Valley (Maianthemum stellatum) in Wisconsin; Kentucky Bluegrass (Poa pratensis) in Pennsylvania; Maryland Black Snakeroot (Sanicula marilandica) in Kansas; and grape (Vitis sp.) in Ontario, Canada.

This species is also a “flower visitor,” obtaining nectar from various plants. Records from Illinois show that M. dislocatus has been seen on blossoms of Canadian Horseweed (Conyza Canadensis), Philadelphia Fleabane (Erigeron philadelphicus), Smooth Oxeye, (Heliopsis helianthoides), Canada Goldenrod (Solidago canadensis), and Early Goldenrod (S. juncea) (Hilty, 2013). They have also been observed on the male flowers of Revolute Meadowrue (Thalictrum revolutum) in Pennsylvania (Wheeler, 2001). Adults are found mostly between April and July, depending on latitude.

Host plant associations are important in helping to identify most mirids, but there are many gaps to fill in as far as host records go. Furthermore, some mirids are predatory rather than phytophagous (plant-feeding), so host plant records are mostly irrelevant. Keeping track of the plants you observe mirids on is still an important exercise. Happy hunting.

Sources: Eaton, Eric R. and Kenn Kaufman. 2007. Kaufman Field Guide to Insects of North America. Boston: Houghton Mifflin Company. 392 pp.
Gregorev, Nina, et al. 2011. Plant Bug: Planetary Biodiversity Inventory.
Hilty, John. (edit.). 2013. Insect Visitors of Illinois Wildflowers. (Illinoiswildflowers.info)
Pickering, John, et al. 2013. Discover Life.
Slater, J.A. and R.M. Baranowski. 1978. How to Know the True Bugs. Dubuque, Iowa: Wm. C. Brown Company Publishers. 256 pp.
Watson, S.A. 1928. “The Miridae of Ohio,” The Ohio State University Bulletin 33(4): 44 pp. (Ohio Biological Survey Bulletin 16, vol. IV, no. 1).
Wheeler, Alfred George, Jr. 2001. Biology of the Plant Bugs (Hemiptera: Miridae): Pests, Predators, Opportunists. Ithaca: Cornell University Press. 507 pp.

Saturday Night Special: Personal News Update

Those of you who have your own blogs know that sometimes you lack inspiration to make a post, lack images to illustrate a post with, or even just don’t feel like writing. Then there are the times when you are doing other things instead of blogging. This past week I have confronted all of those obstacles. So, instead of an insect or arachnid, I’ll let you in on what I’m working on in real life, apart from the blogosphere:

• Contributing to another field guide. Once again I am collaborating with naturalist Kenn Kaufman and his wife Kimberly, furnishing text about insects and related arthropods for a regional field guide to the upper Midwest (think Chicago as the epicenter). Besides writing, I am also going through my own insect images to see if any are worthy of inclusion, too.
• Preparing a presentation. I have been invited to give a presentation to the Aiken Audubon Society of Colorado Springs at their monthly meeting on Wednesday, April 17, at 7:00 PM, at the Division of Wildlife building located at 4255 Sinton Road. The title is: “Beyond Birds: the Rewards of Bugwatching.”
• Preparing for a workshop. I have agreed to deliver another Advanced Naturalist Workshop for the Cincinnati Museum of Natural History. This one will take place August 23-25, and cover true bugs (Hemiptera: Heteroptera). I look forward to the friendly confines of the Eulett Center, the eager students, and the biodiversity there on the “edge of Appalachia.”
  
  Melanchra adjuncta
• Planning for “Mothapalooza.” I will be at the Eulett Center in June, too, participating in a moth-centered event there, from June 14-16. Many thanks to several people who are making my visit possible, and cost-effective. I actually look forward to learning a lot, as moths are not my strong suit.
• Planning for “Bug Fest” in Bloomington, Indiana. One of my good friends is organizing a weekend event at the Hilltop Garden and Nature Center on the Indiana University campus, Saturday, June 22. I will help lead field walks and provide any other assistance I can. I will spend the week between this event and Mothapalooza there in Indiana.
• Project Noah. I have been anointed the status of “Ranger” on this interactive website whereby people can post “spottings,” in the form of images uploaded from their computers, cameras, or even smartphones. The mobile accessibility is unique, as is the fact that these spottings are from all over the world. Right now I feel little more than useless since all the insect spotting are coming from the southern hemisphere and I don’t recognize any of them! I’ll be more productive at making identifications once spring has sprung north of the Equator.
• Working on *me*. My wife and I purchased a year membership to Planet Fitness and have been going to the gym regularly to improve our physical health. Some days I’m not sure whether I’m in a gym, a tattoo parlor, or a prison (seriously, one guy the other day had an ankle monitor), but I am already feeling the results after only one month. I have no illusions that I’ll miraculously get the body I had in my 30s, but I want to be as healthy as I can be, especially if I want to travel overseas (which I do).
• Birding. Well, when insects are few and far between, I tend to let my attention drift briefly to birds. This is not all bad. The Aiken Audubon Society has some very nice field trips, with delightful people, and usually great food. The promise of food alone is usually enough to get me up early, but I really enjoy the social aspect since most of my time during the week is spent home alone.
• 
  Boning up on fossil insects. Just today I spoke with people at Florissant Fossil Beds National Monument, and they would like me to teach a one-day seminar on insects of the park, both extinct and extant. The park is perhaps best known for its unique arthropod fossils. They even have a fossil wasp as their logo. We are looking at July for that possible event.

There are other projects and/or part-time jobs that are stirring, but I don’t want to jinx myself. You will hear about them when the time comes, if it ever does. Meanwhile, I’m trying to figure out how to create “Moth Monday” as a feature when Heidi has Sunday and Monday off, thus pleasantly distracting me….

True Bug Tuesday: Candystriped Leafhopper

Birds have nothing on insects when it comes to being colorful. One of the most outstanding examples of this is the Candystriped Leafhopper, Graphocephala coccinea. It also goes by the names “Red-banded Leafhopper” and “Scarlet-and-Green Leafhopper.” There are two subspecies, G. c. coccinea being found only in coastal areas along the Atlantic seaboard; and the slightly larger G. c. quadrivittata, found inland.

It might help to clarify the higher classification of this insect. When I was first learning entomology in the 1970s and 1980s, leafhoppers, spittlebugs, aphids, cicadas, treehoppers, scale insects, and related families were placed in the order Homoptera. More recent studies have resulted in a reclassification in which the “Homoptera” are now split into two suborders: Auchenorrhyncha for “hoppers” and cicadas, and Sternorrhyncha for aphids, mealybugs, scale insects, and their relatives. The traditional true bugs like assassin bugs and squash bugs comprise the third suborder, Heteroptera. All of these suborders are now under the Hemiptera.

Leafhoppers are in the family Cicadellidae, and are easily recognized by the double row of spines on the tibia (“shin” segment) of the long hind leg. Leafhoppers at rest cock their hind legs so they can leap away from danger at a moment’s notice.

Most leafhoppers are alert, and react quickly to the approach of a person by jumping and flying, or simply dodging around the other side of a leaf or stem. Getting a picture of one is often a frustrating and often futile exercise, but worth pursuing just the same. The diversity of cicadellids is mind-boggling.

Most leafhoppers are pretty small, and the Candystriped Leafhopper is actually one of the larger ones, varying from 5.7-8.4 millimeters from “nose” to wingtip. Females are slightly larger than males.

This is a widespread insect found from the Rockies eastward in the U.S. and Canada; and south to Panama.

Adults and nymphs feed on plant sap by tapping into foliage and stems with piercing-sucking mouthparts. This diet requires the extraction of great quantities of xylem fluids and the secretion of copious amounts of waste, often expelled from the anus of the insect with great force. One specimen was observed excreting one droplet per second for two minutes (Berenbaum, 1989). Shooting your excretions as far away from you as possible helps eliminate clues that predators and parasites use to track you down.

Feeding activity can also result in the transmission of diseases to plants. Pierce’s Disease, a bacterial infection, is thought to be passed to plants by the Candystriped Leafhopper. The disease can kill grapevines and other woody plants. For this reason, the leafhopper is sometimes considered an agricultural pest.

There is usually only one generation of Graphocephala coccinea each year in the northern part of its range, but potentially two in southern climates. The winter is spent in the egg stage. Eggs are inserted in between layers of leaf tissue by the adult females, with the aid of her blade-like ovipositor. Oviposition results in mechanical injury to the leaf, but may also introduce diseases into the host plant. The nymphs that hatch from the eggs molt five times before reaching adulthood.

The Candystriped Leafhopper is a generalist feeder, likely to turn up on almost any plant in your yard, garden, or in “the wild.” One reference to the species in Ohio suggests it is frequently associated with ferns (Osborn, 1928), but it is known from cranberries, rhododendron, azalea, laurel, and forsythia, to name but a few other host plants.

Several other members of the genus Graphocephala resemble the Candystriped Leafhopper, and there is great variation between individuals of each species. It pays to consult sources like Bugguide.net to learn the differences. I’ll also share information about some of these lookalikes in future “True Bug Tuesday” posts.

Sources: Berenbaum, May R. 1989. Ninety-nine Gnats, Nits, and Nibblers. Urbana: University of Illinois Presss. 263 pp.
Cranshaw, Whitney. 2004. Garden Insects of North America. Princeton, NJ: Princeton University Press. 656 pp.
Osborn, Herbert. 1928. “The Leafhoppers of Ohio,” Ohio State Univ. Bull. 32(27): 199-374 (Ohio Biological Survey)
Wilson, M.R., J.A. Turner, and S.H. McKamey. 2009. Sharpshooter Leafhoppers of the World (Hemiptera: Cicadellidae subfamily Cicadellinae). Amgueddfa Cymru – National Museum of Wales.
President and Fellows of Harvard College. 2009. “Bug of the Month,” Boston Harbor Islands@Harvard Entomology.

Spider Sunday: Striped Lynx Spider

Do you want to see a lynx? You don’t even have to go to the zoo. Chances are, in your own backyard, you can find one. Ok, maybe not the cat, but its namesake arachnid, the lynx spider (family Oxyopidae). I remember a book from my childhood called The Tall Grass Zoo, by Winifred Lubell. The lynx spider would have fit in perfectly. The Striped Lynx Spider, Oxyopes salticus, is a particularly handsome species.

Lynx spiders do in fact get their name from their cat-like styles of hunting. They either wait patiently in ambush, or actively stalk and pounce. Most are diminutive in size. Mature females of the Striped Lynx Spider are only 5.7-6.7 millimeters in body length, males 4-4.5 millimeters. The legspan is roughly 20 millimeters.

They might be mistaken for wolf spiders or jumping spiders at first glance, but note that their lanky, slender legs are all armed with long spines. The high “forehead” and eye arrangement of lynx spiders also set them apart from similar spiders.

Oxyopes salticus occurs throughout the United States and south to South America. It seems to favor fields dominated by brome grasses, rather than shortgrass prairies (Fitch, 1963). I found it to be common in moist, tall grass meadows in the forest preserves of the greater Chicago area of Illinois. Apparently, the species is scarce or absent in the Rocky Mountain states and Great Basin.

Each female fastens her egg sac to stems of grasses with a minimal web of threads, then guards the brood until the spiderlings hatch. Immature spiders apparently overwinter, reaching adulthood in late spring or early summer. Males resemble the female shown here, but the abdomen of males is covered in reflective scales that give the animal an iridescent appearance.

The sheer abundance of the Striped Lynx Spider in grassy habitats has made the species the focus of natural biocontrol of pest insects in agricultural systems, too. Known prey includes such pests as the Tarnished Plant Bug (Lygus lineolaris), Rapid Plant Bug (Adelphocoris rapidus), Cotton Fleahopper (Pseudatomoscilis seriatus), Tobacco Budworm (Heliothis virescens), and Cotton Bollworm (Helicoverpa armigera), so the potential impact on cotton plantations alone would seem promising. One study (Lockley and Young, 1987) conducted in cotton fields in Mississippi revealed that the Tarnished Plant Bug was a favorite prey item. Mosquitoes (Aedes sp.) were also killed, along with plenty of other prey species from several insect orders. Interestingly, there were no observed instances of cannibalism, or even predation on any other kind of spider. That is remarkable, since most spiders won’t pass up opportunities for eight-legged meals.

Special thanks to John Balaban for taking me into the Miami Woods Forest Preserve in Morton Grove, Illinois on June 22, 2011, where I found the specimen shown in these images. The forest preserve system around Chicago is a real urban wilderness treasure.

Sources: Brady, Alan R. 1975. “The Lynx Spider Genus Oxyopes in Mexico and Central America (Araneae, Oxyopidae),” Psyche 82: 189-243
Fitch, Henry S. 1963. Spiders of the University of Kansas Natural History Reservation and Rockefeller Experimental Tract. Lawrence: University of Kansas Museum of Natural History Miscellaneous Publication No. 33. 202 pp.
Lockley, Timothy C. and Orrey P. Young. 1987. “Prey of the Striped Lynx Spider Oxyopes salticus (Araneae, Oxyopidae) on Cotton in the Delta Area of Mississippi,” J. Arach. 14: 395-397.
Weber, Larry. 2003. Spiders of the North Woods. Duluth, Minnesota: Kollath+Stensaas Publishing. 205 pp.

Announcing "OrThoptera Thursday"

Today I am introducing what will be yet another semi-regular feature of this blog: everything cricket, katydid, grasshopper, and related insect will be the focus of “OrThoptera Thursday.” Here in the west, short-horned grasshoppers (Acrididae) are a fixture of plains, prairies, deserts, and even mountain peaks. My visits to the eastern U.S. have been fruitful for the night shift of tree crickets, conehead katydids, and other “long-horned” grasshoppers.

To whet your appetite, I offer this teaser of links to past posts that referenced orthopterans as subjects:

• Summer ‘hoppers Part I
• Summer ‘hoppers Part II
• It’s Hopper Time!
• Tucson Grasshopper Story on TV
• Pygmy Mole Crickets

As always, I welcome suggestions for topics; and I will be searching for specific species of grasshoppers, crickets, and katydids this spring, summer, and fall. I have trips planned for Kansas/Missouri, plus Ohio, and various locations here in eastern Colorado if all the pieces fall into place.

Lastly, a big thank you to all of you who follow this blog. I hope to get the chance to meet all of you in person eventually. Keep up your own great work and let me know if I can help.

Wasp Wednesday: Orussid Wasps

I do not select stories for this blog based on maximum weirdness, they just turn out that way. Take for example the strange case of wasps in the family Orussidae. For starters, they are not often seen in the forests they inhabit; and they are easily mistaken for carpenter ants at first glance.

There are only 75 species known, in sixteen genera, for the entire world. Nine species, in four genera, occur in North America north of Mexico.

What makes these wasps truly unique is their history of defying proper classification within the order Hymenoptera. Let us start with the fact that evidence points to a parasitic lifestyle in the larval stage. Ok, so they must be related to Braconidae and Ichneumonidae. Nope. Anatomical features of adult orussids are much more similar to horntails and sawflies. No way! Way! At one point, two scientists tried to solve the dilemma by erecting an entirely new suborder, the Idiogastra, just for the Orussidae. Until recently, many entomologists lumped the Orussidae as an aberrant family within the suborder Symphyta, making them the most advanced of that group, and the most primitive of parasitic wasps.

Today, the family is placed in its own superfamily, Orussoidea, in the suborder Apocrita, the umbrella group for all parasitic and parasitoid Hymenoptera (Vilhelmsen, 2003).

Adult orussids are most often found on logs and dead, standing trees in those sections where the bark has been stripped off. Solid, but sun-bleached wood seems to be favored, and the female wasps crawl and dart across the surface in search of the tunnels of wood-boring insects. Each female detects a larval host through “vibrational sounding,” much like a bat hunts moths at night. She taps her antennae on the surface of the wood, and apparently receives the reverberating “echoes” through a subgenual organ inside each front tibia (the “shin” joint of the leg) (Broad & Quicke, 2000). Indeed, the tips of her antennae are thickened and club-like; and the tips of the front tibiae have thin cuticle concealing the vibrational receptors.

It is assumed that orussids are general parasitoids on various wood-boring insects including horntails, longhorned beetles, and jewel beetles. Most confirmed records in North America have been for jewel beetles (family Buprestidae). The female wasp usually accesses the host grub by backing into an exit hole from which another host beetle had already emerged. She may reach a grub with her ovipositor, which while coiled within her thoracic and abdominal cavities, can be more than twice the length of her body (Vilhemsen, et al., 2001).

The larva that hatches from the extremely long, slender egg is probably not entirely immobile, being equipped with a row of backward-curving spines on all dorsal thoracid and abdominal segments. The spines probably help it inch its way down tunnels to reach a host. Once it finds a host grub, the orussid larva attaches itself as an external parasite.

© Scott Justis via Bugguide.net

Look for adult orussids in both coniferous and deciduous forests, especially along the edges of meadows or where there are other sunny openings in the canopy. The wasps not only pace rapidly back and forth over a log, changing direction abruptly, but they can also jump.

Our four species in the genus Orussus are the ones you are most likely to see, if you don’t assume they are ants. Dark bands on the otherwise clear wings help disguise them as carpenter ants when the wings are folded over their back. Note the very globular head, with antennae inserted just above the mouth. There are teeth or tubercles on the top of the head.

© M J Hatfield via Bugguide.net

Our understanding of these insects, their geographic distribution, and behavior, are still sparse, so your observations can be key. Take a look at these images by Stephen Hart and these by Rollin Coville for inspiration.

Sources: Broad, Gavin R. and Donald L.J. Quicke. 2000. “The adaptive significance of host location by vibrational sounding in parasitoid wasps,” Proc. R. Soc. London B 267(1460): 2403-2409.
Goulet, Henri and John T. Huber, eds. 1993. Hymenoptera of the World: An identification guide to families. Ottawa: Agriculture Canada. 668 pp.
Powell, J.A. and W.J. Turner. 1975. “Observations on Oviposition Behavior and Host Selection in Orussus occidentalis (Hymenoptera: Siricoidea),” J. Kans. Ent. Soc. 48(3): 299-307.
Vilhelmsen, Lars. 2003. “Phylogeny and classification of the Orussidae (Insecta, Hymenoptera), a basal parasitic wasp taxon,” Zool. J. Linnean Soc. 139: 337-418.
Vilhelmsen, Lars, Nunzio Isidoro, Roberto Romani, Hasan H. Basibuyuk, and Donald L.J. Quicke. 2001. “Host location and oviposition in a basal group of parasitic wasps: the subgenual organ, ovipositor apparatus and associated structures in the Orussidae (Hymenoptera, Insecta),” Zoomorphology 121(2): 63-84.