Thursday, May 30, 2013

"Mothapalooza" and More Upcoming Events

My posts here have been more sporadic than I would like lately, and given what is on the horizon, that is not likely to change any time soon. Here is what has been happening, and what is forthcoming:

Contract work. I have recently become contracted with Splash Media of Dallas, Texas to do work from home. This entails being part of a team that is writing blog posts for a major third party client. Assignments have been lagging lately, but that is in part because Splash has been moving their offices. I am very impressed with our team leader, and look forward to continuing my relationship with Splash Media.

Contributing to another Kaufman Field Guide. I am about halfway through my contribution to another regional field guide in the Kaufman series, this one treating the Upper Midwest (Ohio, Indiana, Illinois, Michigan, Minnesota, Wisconsin, and Iowa). If you have seen the Kaufman Field Guide to Nature of New England, then you know what to expect: comprehensive, accurate yet entertaining treatment of all things flora, fauna, and geologic.

Something really big. I am not at liberty to say much about this, but a major online enterprise recently approached me concerning a new addition to their...empire(?) Suffice it to say that if this comes to pass, it will change everything for me as far as my online presence. I hope to be able to explain this soon, but the wheels of corporate America turn slowly at times. I completed the application and testing required, and remain cautiously optimistic thanks to a friendly and supportive contact at the company.

Unidentified sphinx moth from Teller County, Colorado

"Mothapalooza." When I heard about this event, I made it known to organizer Mary Ann Barnett that I would love to attend, but didn't think I could afford it financially. Well, she promptly decided that I should be one of the "experts" in a leadership role, in exchange for registration and other expenses. How could I say "no" to that? Bonus: I get to hang out with David Wagner, author of the Princeton Field Guide to Caterpillars of Eastern North America, and Seabrooke Leckie, co-author of the Peterson Field Guide to Moths of Northeastern North America, among many other fine people. Mothapalooza is occurring at the Shawnee State Park Lodge and Conference Center, with field trips to other locations in Scioto and Adams counties, Ohio. The event runs from the evening of Friday, June 14 through the morning of Sunday, June 16. I don't think anyone is going to get much sleep....

"Bug Fest." My good friends Jeff and Sandy Belth persuaded me to present at the first inaugural "Bug Fest" at the Hilltop Garden and Nature Center on the campus of Indiana University in Bloomington on Saturday, June 22, from 10 AM to 4 PM. Thanks to Janet Creamer Martin and her husband Eric, I'll be whisked straight from Ohio's Mothapalooza to the Belth house in preparation for that event. I look forward to signing books and leading field outings there. "gathering." My great friend Margarethe Brummermann has taken it upon herself to organize the 2013 Bugguide Gathering at the Santa Rita Experimental Range research station outside of Green Valley, Arizona, Thursday, July 25 through Sunday, July 28. I encourage my readers to consider attending, as it is a very unique part of the U.S., with some amazing insects, reptiles, birds, and other creatures....including me and Margarethe!

While I am pretty much spoken for as far as events go this summer, please keep me in mind for nature festivals and other events if you need a guest speaker or field trip leader. It would be my pleasure to help introduce more people to the joys of "bugwatching" as my friend and mentor Steve Prchal calls casual entomology. Safe travels, friends.

Friday, May 24, 2013


It’s “Fly Day Friday,” and while not everyone thinks of mosquitoes as flies, that is exactly what they are. Mosquitoes make up the family Culicidae. The majority are aquatic in the egg, larva, and pupa stage of their life cycle. They do not require a great deal of water, or time, to complete their development, and this makes them very difficult to control.

Female Culiseta incidens, the "Cool Weather Mosquito"

The adult female insect, in most species, needs a meal of blood in order to nourish her eggs. Human beings are not usually the host of choice, but we will do in a pinch. Mosquitoes are often cited as the most dangerous of all animals because of their efficiency in delivering disease pathogens to human populations. West Nile Virus may make headlines, but other dangerous mosquito-borne illnesses fly under the radar. Our pets and livestock are also at risk.

The Mosquito Life Cycle

Many mosquitoes breed in treeholes

Female mosquitoes deposit eggs in “rafts,” or singly, on the surface of still water. Larvae, called “wrigglers,” emerge from the eggs and begin their aquatic lives. They breathe through a spiracle at the end of an elongated tube called a “siphon,” at the tip of the abdomen. Most species are filter-feeders that use their mouthparts to strain food particles and/or microorganisms from the water. A few species are predators of other mosquito larvae.

Larvae grow by molting, shedding their flexible yet constraining exoskeleton periodically. Eventually, they molt into the pupa stage, known as a “tumbler.” The pupa is not inert, but quite active, able to dive when danger threatens by thrashing its abdomen. Tumblers breathe through paired siphons (“trumpets”) on its “shoulders.”

Mosquito Life Cycle, © Eric R. Eaton

The adult mosquito pops out of the top of the pupa, and sits on the water surface while its new, winged body hardens and pigments become evident. Adult mosquitoes are covered in scales that may serve to attract mates, but also allow the insects to skip off spider webs, shedding scales instead of becoming entangled.

Mosquito Diversity
There are 176 species of mosquitoes currently recognized in North America. This includes species introduced from other parts of the world through commerce. A new species, Anopheles grabhamii, was described from the Florida Keys in 2002, so there is certainly potential for future additions to our mosquito fauna through several avenues. Only female mosquitoes bite, and not all species bite mammals. Many feed only on birds, a few on amphibians. Some species don’t bite at all.

Male Culex mosquito

Male Mosquitoes
Male mosquitoes are often easily identified by their plumose (feathery) antennae, which they use in part to find females of the same species. They also frequently have enlarged, brush-like palps, paired appendages that are part of their mouthparts. The palps might be mistaken for antennae themselves. Both male and female mosquitoes fuel their flight muscles with flower nectar which they sip through that needle-like proboscis.

Asian Tiger Mosquito

Asian Tiger Mosquito

One prominent example of an exotic species is the Asian Tiger Mosquito, Aedes albopictus. It was first documented in Texas in 1985. One year later it turned up in Florida, among tires imported from overseas for re-treading. This is probably how it spread, as this is one of the “container-breeding” mosquitoes that needs little water to complete its life cycle. Rainwater collects in discarded tires exposed to the elements, and mosquitoes in general are adept at finding such resources. The Asian Tiger Mosquito is now found over much of the eastern U.S. An outbreak in Los Angeles, California in 2001 was traced to a shipment of “lucky bamboo” from China. The insects were eradicated, but subsequent introductions may not have been so successfully suppressed.

Mosquito vs. Mosquito
Aedes albopictus has largely replaced the Yellow Fever Mosquito, Aedes aegypti here in the U.S. Larvae of the Asian Tiger Mosquito compete better for food, and parasites brought with the Asian Tiger Mosquito have had an adverse impact on A. aegypti. Sterility of offspring from interspecific matings has also affected the Yellow Fever mosquito disproportionally. Today, Aedes aegypti is limited to the southeast U.S., a few isolated areas in New York state, and Arizona.

Yellow Fever Mosquito

Disease Transmission
The success of the Asian Tiger Mosquito is ironically somewhat helpful to us. While A. albopictus is known to be able to transmit over thirty viruses, it is not a very efficient vector. Western and Eastern Equine Encephalitis, St. Louis Encephalitis, LaCrosse Encephalitis, and dengue fever are all serious diseases potentially vectored by the Asian Tiger Mosquito.

Malaria is, thankfully, not currently a problem in North America. This was not always the case. Anopheles quadrimaculatus was the vector of this disease in the U.S. and Canada. Malaria affected most of the United States by 1850. One century later, thanks to improvements in sanitation that reduced breeding spots for mosquitoes, and the widespread use of DDT and other potent pesticides, the disease was largely eradicated.

Female Anopheles mosquito

West Nile Virus is transmitted almost exclusively by mosquitoes in the genus Culex. Birds and horses suffer much more frequently from this disease than people; and there is a vaccination available for equines. The elderly, and those people with compromised immune systems, are most at risk.

Dog Heartworm is also a mosquito-borne disease that occasionally afflicts cats as well. The illness itself is caused by a roundworm that is transmitted by at least sixteen species of mosquito. Risk for Dog Heartworm is greatest along the southern Atlantic and Gulf coasts, and the Mississippi River Valley (Nayar & Rutledge-Connelly, 2012).

The "Gallinipper," Psorophora ciliata, a real giant whose larvae eat other mosquito larvae

Mosquito Control and Prevention
You can do a great deal to reduce your risk of exposure to mosquitoes and the diseases they may carry. Consider taking the following measures and precautions:

  • Eliminate standing water on your property by cleaning gutters regularly, storing toys, flowerpots, and other potential rainwater collectors indoors, and draining water wherever else it accumulates.
  • Apply insect repellents with DEET as the active ingredient, paying careful attention to the directions on the product.
  • Comply with local city and county vector control regulations.
  • Maintain swimming pools properly
  • Change the water in the birdbath frequently, remembering mosquitoes can complete their life cycle in about a week.
  • Sleep under mosquito netting when traveling overseas to locations where malaria, dengue, and yellow fever are still problematic.
  • Get your pet checked for, and immunized against, Dog Heartworm.

Mosquitoes have their own pests: this one has mites (red spots)

What good are mosquitoes?
When asked this question, I am sometimes tempted to answer “Ask a Plasmodium (the malaria parasite).” We are naturally anthropocentric in our view of other organisms, especially when we see no direct benefit to us. We do know that mosquito-borne diseases have driven our own evolution. Sickle-cell Disease was an evolutionary response to malaria, the misshapen blood cells being inhospitable to the malaria parasite. What else do we owe to mosquitoes, positive or negative? We have much yet to learn, no doubt. Meanwhile, mosquitoes are a fundamental building block in the food chain, responsible for supporting the enormous diversity of fish, birds, bats, and predatory insects found around the globe. We also don’t know what we might lose with the microbes dependent on mosquitoes for transportation from host to host. The next medical breakthrough might come from studying one of those organisms. Lastly, mosquitoes can be important pollinators of flowers. Both male and female mosquitoes visit blossoms for nectar. Still want to wipe them off the face of the Earth?

Yellow Fever Mosquito sipping nectar

Sources: “Asian Tiger Mosquitoes,” Greater Los Angeles County Vector Control District, 2012.
Rios, Leslie, and James E. Maruniak. 2004. “Asian Tiger Mosquito (EENY-319),” Featured Creatures. University of Florida.
Nayar, Jai K., and C. Roxanne Rutledge-Connelly. 2012. “Mosquito-borne Dog Heartworm Disease,” EDIS. University of Florida.
”Mosquito-borne Diseases,” American Mosquito Control Association, 2011.

Wednesday, May 22, 2013

Polistes metricus

Paper wasps tend to be quite variable in color and pattern, even within one species, so identifying them is not easy, even for experts. Case in point is differentiating the common Northern Paper Wasp, Polistes fuscatus, from the very similar Polistes metricus.

Dark specimens of the Northern Paper Wasp are nearly identical to Polistes metricus, a consistently dark species that I have found to be less abundant than P. fuscatus in areas where their geographic ranges overlap. One fairly reliable, if subtle, clue is the shape of the abdomen. Note that the abdomen of P. metricus is highly convex on the underside, creating a nearly acute angle with the underside of the petiole (stalk-like segment connecting abdomen with thorax). This is usually much less pronounced in P. fuscatus.

Another difference is in the face of the female wasps. Females of P. metricus have an almost completely red face, the black markings confined to the ocellar triangle. Ok, so what is an “ocellar triangle?” Most wasps have a trio of tiny, “simple” eyes at the top of the head, between the large compound eyes. These simple eyes are usually arranged in a triangular pattern. Females of the Northern Paper Wasp have the black marking extended from the ocelli to the base of the antennae. Males of both species have square, yellow faces.

Female P. fuscatus. Note black face; gently curved venter of abdomen

Female P. metricus. Note convex venter of abdomen.

Female P. metricus. Note all-red face.

Polistes metricus ranges from extreme southwestern Ontario and Maine south to Florida, and west to southern Ohio, Nebraska, Kansas, Oklahoma, and eastern Texas. The Northern Paper Wasp has a much larger geographic distribution.

I was fortunate enough to find three embryonic nests of P. metricus on a recent trip to Missouri. Two nests were under the exterior of a recessed door frame in Excelsior Springs. The other was under the roof of a sign and kiosk at Little Dixie Lake Conservation Area west of Kingdom City. These are typical nesting sites, though they can also be built among shrubbery and other more exposed locations.

Both the Northern Paper Wasp and P. metricus prey mostly on caterpillars, chewing up the larvae and feeding them to their own grubs back at the nest. Look for the adult wasps on flowers as they fuel themselves on nectar. They can also be seen around aphid colonies, lapping up the “honeydew” secreted by the aphids as a waste product.

Source: Buck, M., Marshall, S.A. and Cheung D.K.B. 2008. Identification Atlas of the Vespidae (Hymenoptera, Aculeata) of the northeastern Nearctic region. Canadian Journal of Arthropod Identification No. 5: 492 pp. (PDF version).

Sunday, May 19, 2013


It is often assumed that entomologists and arachnologists find no kind of arthropod to be revolting; that we never swat a mosquito, and that we vigorously advocate that the public refrain from bringing purposeful harm to any of the six- or eight-legged. Well, we have our limits. While I have a mild fascination with ticks, I don’t tolerate their presence on my body, my pets, or anyone else’s for that matter. There are good reasons to be vigilant when it comes to these parasitic mites, and Lyme Disease is only one. Bites from ticks can result in a variety of illnesses, including “heartland virus,” discovered earlier this year.

Male American Dog Tick

Tick types
North American ticks fall into two basic categories: Hard-bodied ticks, family Ixodidae, and soft-bodied ticks (Argasidae). Soft ticks are encountered infrequently, most species being associated with the burrows and nests of rodents, or with bats. A few are hosted by deer and livestock. Hard ticks are abundant, widespread, and nearly impossible to avoid.

Soft-bodied tick, Arizona

Tick biology
Ticks have a life cycle consisting of four stages: egg, larva, nymph, and adult. Larvae have only six legs, and are often referred to as “seed ticks.” The larva takes one blood meal from a host, then drops off the animal. It molts into an eight-legged nymph in about one week. The nymph locates a host and feeds, drops off, and molts into either another nymphal stage or an adult. Adult ticks are sexually mature specimens, whereas the preceding life stages are not.

"Questing" wood tick, California

Ticks find hosts by a behavior known as “questing.” The tick climbs to the tip of a grassblade, leaf, or other object and perches with front legs outstretched. Special sense organs in the legs detect carbon dioxide breathed out by vertebrate animals. Additional sensory organs hone in on odors and body heat. Ticks usually grab a passing host, but they can quickly crawl 10-15 feet to reach a source of carbon dioxide, such as a grazing deer.

Embedded tick nymph

How ticks attach
Ticks bite with mouthparts that, under high magnification, resemble a Swiss army knife of sawblades. The paired chelicerae (“jaws”) saw into the skin of the host, and later tear into tiny capillaries to get the blood flowing. The central, harpoon-like mouthpart is called the hypostome, and that is the tube the tick uses to inject saliva and anti-coagulants, as well as siphoning the blood of the host. The chelicerae anchor the tick in place, but the tick also secretes a glue-like substance that hardens around the entire apparatus. No wonder ticks are so hard to remove once they lodge themselves into a person or pet.

Engorged female American Dog Tick

Tick feeding and reproduction
The exoskeleton covering the abdomen of a female tick is deceptively thick, leathery, and wrinkled, but capable of unbelievable expansion to accommodate a gut that swells with blood. She may balloon to twenty or fifty times her normal size, and up to 200 times her original weight before feeding. She needs the nourishment to produce her eggs….

And ticks are nothing if not prolific. Mating may take place before or after feeding, and on or off of a host. Females are typically larger than males, and often marked more ornately. The two genders find each other through pheromones, chemical scents emitted into the air. Each mated female lays large masses of eggs, some containing up to 20,000 ova. The eggs may be laid on or off of a host.

Blacklegged Tick, © Karl Hillig via

Deer Ticks
The tick that most often makes the news is the Blacklegged Tick, Ixodes scapularis (formerly known as I. dammini). This is the “deer tick” that vectors Lyme disease, named for the town of Old Lyme, Connecticut where it was first discovered in 1975. The disease was actually known from Europe as early as 1910, where it went by the name erythema migrans, roughly translated to “migrating red rash.” The organism that causes the disease is a spirochaete bacterium, Borrelia burgdorferi.

I won’t go into the particulars about Lyme disease, as there are plenty of other resources available. Contrary to popular belief, only the adult ticks feed on larger mammals like deer. The larvae and nymphs are hosted by birds and rodents. Increasingly, all host reservoirs are becoming more and more adapted to urban and suburban habitats, increasing human exposure to their pathogens and parasites. The Blacklegged Tick is also a vector of babesiosis; and its bite can cause tick paralysis.

The Western Blacklegged Tick, Ixodes pacificus, is the only other known carrier of Lyme disease. Incidences of the disease in west coast states, Utah, southern Nevada, and northwest Arizona are likely attributable to this tick species.

Heartland virus was discovered earlier this year in northwest Missouri. Initially, two patients were thought to be victims of ehrlichiosis, another tick-borne disease, but the patients failed to respond to treatment. Ticks have not been identified conclusively as the vectors of Heartland virus, merely implicated thus far. Deer ticks are substantially smaller than the next two species discussed here.

Female Lone Star Tick

Male Lone Star Tick

Lone Star Tick
Lyme and Heartland may make headlines, but ticks are responsible for a surprising array of medical problems. I recently visited Missouri with my wife, and we were both plucking ticks off ourselves and each other. The first ones I found were Lone Star Ticks, Amblyomma americanum. Females are easily recognized by the bright yellow or ivory spot on their backs. Males are smaller, with a few pale spots along the margin of the abdomen. This tick is well known as a vector of ehrlichiosis, tularemia, and Southern Tick-associated Rash Illness (STARI). It has also been implicated in the transmission of tick paralysis, and suspected as a vector of Q-fever. White-tailed deer are the principal host of all life stages of the tick, though larvae and nymphs are also found on birds.

Male American Dog Tick

Wood Ticks
The other tick we found was the ubiquitous American Dog Tick, Dermacentor variabilis. We even pulled one off of our dog, who we had left with relatives in Kansas for a short time. Rocky Mountain Spotted Fever and tularemia are carried by this species. Tick paralysis is another malady caused by this species, and it is also a suspected carrier of ehrlichiosis. Larvae and nymphs of the American Dog Tick feed on small rodents, while the adults are hosted mostly by medium-sized mammals.

Ticks and pets
It is important to note that Fido can suffer from Lyme disease, too, and also anaplasmosis, another tick-borne ailment attributed to Blacklegged Ticks. Ask your veterinarian for the best ways to keep your pet from getting ticks.

Inspecting for ticks; and preventing them
Ticks have an uncanny ability to remain undetected until they find a spot to feed. Most people cannot feel a tick crawling on their body. Furthermore, ticks have a nasty habit of attaching in places you can’t readily see yourself: the small of your back, behind your knees, or behind your ears. It is recommended that you ask someone to help inspect you for ticks as soon as possible after an outdoor trek where ticks are likely to be found.

You can try to prevent ticks by wearing a longsleeve shirt, tucked into your pants, and with cuffs that fit tightly around your wrists. Long pants, the cuffs tucked into your boots, will help keep ticks at bay, too. Light-colored clothing is best because ticks are dark and more easily visible on beige or other pale colors. Insect repellants with DEET as the active ingredient have at least some efficacy in protecting you from ticks, but apply them correctly according to label instructions.

Female Lone Star Tick

Sources: Drummond, Roger. 1998. Ticks and what you can do about them (2nd edition). Berkeley: Wilderness Press. 74 pp.
Centers for Disease Control. “Ticks”

Wednesday, May 15, 2013

Priocnemis minorata

One of the more conspicuous wasps of springtime in deciduous forests of the eastern United States is the spider wasp Priocnemis minorata. Indeed, it is usually the first member of the family Pompilidae to be seen. You can find them right now, as I did in Missouri last week.

These are medium-sized insects, the length of the front wing varying from 6-12 millimeters, the entire insect a bit longer. Their long legs make them appear even larger overall. They are shiny black in color, with the wings having a smoky and/or iridescent appearance. Note the serrated top surface of the tibia (“shin” segment) on the hind leg. This character immediately sets them apart from other black spider wasps you are likely to encounter. Look for them hunting among leaf litter in places where there is dappled sunlight through the tree canopy. The wasps are active from late March to mid-June, with peak activity in April and May.

While this species is most abundant in the U.S. east of the 100th meridian, it has also been recorded from the Pacific Northwest in southeast British Columbia and western Oregon. Additional Canadian records include Nova Scotia, Quebec, and Ontario.

Priocnemis minorata is a generalist predator of spiders, and probably an opportunist. Known host records include Coras juvenilis, Wadotes calcaratus, Wadotes hybridus (hacklemesh weavers, family Amaurobiidae), Hibana gracilis (ghost spiders, family Anyphaenidae), Clubiona obesa (sac spiders, family Clubionidae), Dolomedes tenebrosus (fishing spiders, family Pisauridae), Trochosa terricola, Gladicosa gulosa, Arctosa rubicunda, and Varacosa avara (wolf spiders, family Lycosidae).

Last week I found the female specimen shown here at The Inn on Crescent Lake in Excelsior Springs, Kansas, that oddly persisted in staying in one place. Eventually, I figured out that she was in the process of carting off a paralyzed, immature nursery web spider, Pisaurina mira (family Pisauridae). It turns out this is not a new host record, as this spider species was discovered as a host for Priocnemis minorata previously (Kurczewski, et al., 1987).

Dick Walton has captured some stunning video of this species in action, including what might be a new host record: a running crab spider in the genus Thanatus (family Philodromidae). He also shows another specimen dispatching a wolf spider.

The female wasp digs a burrow prior to going hunting. The entrance is usually hidden under dead, dry leaves. The tunnel itself is vertical or slightly angled, and may reach a depth of 27.5 centimeters. One cell is constructed at the bottom of the shaft, with as many as six other cells branching off progressively from the bottom up. One spider is apparently stored in each cell, on its side, with an egg laid on the spider’s abdomen. The egg hatches in two days and the larva that hatches matures in about a week. The remainder of the year is spent in the pupa stage, until the adult wasp emerges the following spring.

When I lived in Cincinnati, Ohio, I could always tell when spring had really arrived by when the spider wasps were out. I encourage you to look for this species in your own neck of the woods, among the trilliums, violets, and other wildflowers on the forest floor.

Sources: Evans, Howard E. and Carl M. Yoshimoto. 1962. “The Ecology and Nesting Behavior of the Pompilidae (Hymenoptera) of the Northeastern United States,” Misc. Publ. Entomol. Soc. Am. 3(3): 67-119.
Kurczewski, Frank E. and Edmund J. and Roy A. Norton. 1987. “New Prey Records for Species of Nearctic Pompilidae (Hymenoptera),” J. Kans. Entomol. Soc. 60(3): 467-475.
Townes, Henry. 1957. “Nearctic Wasps of the Subfamilies Pepsinae and Ceropalinae,” US Nat. Mus. Bull. No. 209. 286 pp.

Thursday, May 9, 2013

Velvet-striped Grasshopper

Another springtime grasshopper one is likely to encounter east of the Rocky Mountains is the Velvet-striped Grasshopper, Eritettix simplex. It is classified as one of the “slant-faced grasshoppers,” though its head is only slightly inclined.

This species passes the winter as a third-, fourth-, or fifth-instar nymph, with adults obvious in early spring most years. This year I have yet to see a mature individual, though I saw nymphs early on. Even the adults are rather small, females measuring 19-26 millimeters, and males 14-21 millimeters from head to the tips of the folded wings.

Individuals vary drastically in color and pattern, such that they can easily be mistaken for other grasshopper species. The one below I mistook for an Obscure Grasshopper, Opeia obscura, but David Ferguson, an expert on Colorado grasshoppers, set me straight. The pattern of stripes on the thorax of this specimen is rather unusual for E. simplex.

Some individuals even have extensive green markings, a good disguise for that time of year when new shoots are sprouting amid dry, brown dead grassblades. These insects are essentially invisible until you flush one into a hop or flight.

The male literally rocks the courtship thing. He will follow the object of his desire until he is about an inch away from her, then begin rocking from side to side. He then “sings” to her by rubbing one hind leg at a time against a raised vein on each front wing. After a chorus of this, like a fool he rushes in, mounting her. Mating takes place if she approves of her suitor.

The Velvet-striped Grasshopper ranges from extreme southern Saskatchewan to Arizona and northern Mexico, east through southern Minnesota, Iowa, Missouri, and northern Arkansas, reaching an eastern bottleneck through Tennessee, and expanding again into northern Georgia, eastern West Virginia, Connecticut, and the southeast corner of New York. It occurs in the Atlantic states, but is absent from the coastal plains. It apparently prefers shorter grasses in the tallgrass prairie biome, but I find it commonly in shortgrass prairie habitats, or mid-height grasses in open areas with patches of barren soil. In desert habitats it prefers moist swales.


There are two other species of Eritettix in North America, but both species have abbreviated wings that do not reach the tip of the abdomen in adults. E. abortivus occurs throughout much of Texas and into southeast New Mexico and southern Oklahoma, while E. obscurus is restricted to Florida.

The Velvet-striped Grasshopper and its relatives are considered to be of no economic consequence, their populations seldom rising to even potentially destructive levels. They feed almost exclusively on grasses and sedges.

Sources: Branson, David, et al. 1994. “Brownspotted Grasshopper, Psoloessa delicatula (Scudder),” Wyoming Agricultural Experiment Station Bulletin 912
Capinera, John L., Ralph D. Scott, and Thomas J. Walker. 2004. Field Guide to Grasshoppers, Katydids, and Crickets of the United States. Ithaca, NY: Comstock Publishing Associates (Cornell University Press). 249 pp.
Eaton, Eric R., Tom Bentley, and David Ferguson. 2010. “Species Eritettix simplex - Velvet-striped Grasshopper,”

Thursday, May 2, 2013

Brown-spotted Range Grasshopper

The Brown-spotted Range Grasshopper, Psoloessa delicatula, is one of the smaller of the springtime grasshoppers here on the Front Range in eastern Colorado. I have only seen one so far this year, but considering it snowed yesterday, May 1 (yes, that is not a typographical error, it really snowed on May Day), I can’t be too surprised by their lack of abundance.

Mature females of this species are only 16-27 millimeters from head to wingtip, males 18-20 millimeters. As if size alone doesn’t make them hard enough to spot, their ornate crisscross markings render them nearly invisible among the tangles of short grasses they like to dwell in. One way I recognize them most easily is by the large brown triangle on the top of each hind femur (“thigh”), that is clearly visible when looking down on the insect. Even nymphs have this marking.


Psoloessa delicatula is nearly identical in appearance to the Texas Spotted Range Grasshopper, P. texana. There is almost no reliable way to separate the two in the field without capturing a specimen and examining it very closely. Still, David Ferguson, an expert on Colorado grasshoppers, tells me that the Brown-spotted Range Grasshopper is decidedly more robust, or “stockier” as he puts it, than its Texas counterpart. That is perhaps no help if you have not seen both species, and/or you are looking at a female of one and a male of the other. Female grasshoppers are definitely the more robust gender.

The Brown-spotted Range Grasshopper is common from south-central Canada to northern Mexico, and eastern Washington, Oregon, and California to the Dakotas, Nebraska, western Kansas, the panhandle of Oklahoma, and western Texas. The Texas Spotted Range Grasshopper is more southerly in its distribution, from southern California east to central Texas and north to South Dakota.

Adults of the Brown-spotted Range Grasshopper are most abundant in May and June over most of its range. Eggs are laid in barren soil in mid-summer, and the nymphs overwinter. They emerge again in April to finish maturing, having only one or two molts left before reaching adulthood. In central Saskatchewan, this species has a two-year life cycle.

Populations of this species vary with winter survivorship of the nymphs, but seldom if ever become problematic to ranchers and farmers. The insects feed exclusively on grasses and sedges, but do not eat enough to deprive livestock of forage.

You may have to flush one of these grasshoppers numerous times before you can find where it landed after its short flight. They are incredibly cryptic. Good luck!

Sources: Branson, David, et al. 1994. “Brownspotted Grasshopper, Psoloessa delicatula (Scudder),” Wyoming Agricultural Experiment Station Bulletin 912
Capinera, John L., Ralph D. Scott, and Thomas J. Walker. 2004. Field Guide to Grasshoppers, Katydids, and Crickets of the United States. Ithaca, NY: Comstock Publishing Associates (Cornell University Press). 249 pp.