Bite of the Black Fly

It happened at the zoo. I was parked innocently opposite the African Elephant yard, with the window rolled down on this nice late afternoon of September 19, 2015, waiting for Heidi to get off work. I noticed a tiny fly had flown into the car, but was truly shocked to see it was a female black fly, likely a species of Simulium....and she wanted my blood.

She got it, too, because I so rarely see members of the family Simuliidae, let alone adult females. I was able to get some respectable images of the 3-4 millimeter vampire precisely because she was occupied pumping blood out of my knuckle. What was she doing here, though?

I was under the mistaken impression that black flies, also known as "buffalo gnats" and, here in Colorado at least, "turkey gnats," seldom venture far from fast-flowing streams and rivers. That is because they spend the egg, larva, and pupa stage of their lives in aquatic torrents. It occurred to me that the elephant yard does have a waterfall, and I would bet that black fly larvae live on the very edge of that artificial cataract.

Well, I have since learned that female black flies are perfectly capable of flying miles in search of a blood meal. There are some records in Canada of black flies migrating over ninety (90) miles from where they grew up as larvae.

Only the female black fly bites. Like mosquitoes, she needs the protein for the proper development of her eggs; and she can lay several hundred eggs in her two- or three-week adult lifespan. Unlike mosquitoes, black flies do not have beak-like mouthparts to extract blood from our capillaries. Black flies slice you open with knife-like mouthparts, then lap up what spills out.

Depending on the species, the black flies lay their eggs on vegetation or other objects in the water, under the water, or scatter them on the water's surface. Interestingly, freshly-laid eggs apparently produce a pheromone (scent) that attracts other adult female flies of the same species, and stimulates them to lay their eggs in the vicinity.

The larvae that hatch spin silken pads on the surface of stones or vegetation in the middle of flowing water. They then anchor themselves to the silk pads with special hooks on the rear of the abdomen. The larvae feed in a unique manner, by deploying a pair of "cephalic fans" that intercept organic particulates from the current. Larvae molt 7-11 times.

Black fly larvae in Arizona

At the end of its larval life, the creature spins a silken bag in which it will pupate. The tapered rear of the bag points upstream into the current, while the wider, open portion projects downstream. The larva molts one final time to reveal a resting stage with branching gills that may reach beyond the lip of the silken bag.

Black fly pupae in Arizona © Tony Palmer

The adult fly emerges in a few days or so, rising to the water surface in an air bubble and floating to an emergent object it can climb onto and finish expanding its wings and hard its exoskeleton. The total time from egg to adult takes roughly 3-4 weeks and is heavily influenced by water temperature. The colder the water, the longer the life cycle. There can be three or four generations per year; winter is typically spent in a dormant larva stage.

Male black fly (note huge eyes meeting at top of head)

There are about forty species of black flies in Colorado, in three genera: Simulium, Prosimulium, and Metacnephia. Different species live at different elevations, and on different sides of the Continental Divide. Surprisingly, the majority are not pests of people or livestock, preferring to feed on birds and other wildlife.

The species that do afflict horses, cattle, poultry, and people can cause severe distress, and may carry diseases. I will spare you the agonizing details of suffering incurred by victims of black fly attacks, as there is no end to the resources where you can learn such information if you are so inclined.

Suffice it to say that it pays to be prepared with an excellent insect repellent if you plan to be in black fly territory. Prevention is always the best tactic for battling *any* bloodsuckers. Take care.

Female black fly on Feb. 24, 2014

Sources: Bechinski, Edward John, and Marc J. Klowden. 2005. Black Flies - Biology and Control. Division of Entomology, University of Idaho (available online as a PDF).
Cranshaw, W.S., F.B. Pearis, and B. Kondratieff. 2013. Biting Flies. Colorado State University Extension. Fact Sheet 5.582.
Kuhn, Dwight. "Black Flies - Life Cycle," Kuhn Photo.

Wasp Wednesday: A Real Surprise

I am certainly finding the Front Range region to be exceptionally diverse when it comes to wasps, but nothing could have prepared me for what I found in the field yesterday, August 7. I was looking over a White Sweet Clover (isn’t there a song about that?), when a very large wasp commanded my attention. I immediately recognized it as a paper wasp, but not a species I would have expected in Colorado Springs.

This is a male specimen of Polistes carolina or Polistes perplexus. Either way, it is most likely going to turn out to be a county record, potentially a state record, and perhaps even a range extension. Both species are recorded for Kansas, so what is a couple hundred more miles or so?

I also managed to collect the specimen, so I’ll be able to eventually examine it under a microscope for the details necessary to separate the two species. Until very recently, it was thought that the males could not be distinguished at all, but apparently there are transverse (horizontal) ridges on the propodeum (hindmost segment of the thorax) that are weak in P. carolina and much more evident in P. perplexus. Watch this space for the final determination of the species.

For now, I’m ecstatic over this discovery. I’d sure like to find the nest this fellow came from. Females are a little easier to identify, and finding the nest would verify that this is a species breeding here. Even so, this male is in immaculate condition, suggesting it did not travel a long distance.

Because these two species were once thought to be a single species (P. carolina), most documentation of their biology is somewhat suspect. Polistes carolina apparently nests in exposed situations, such as under the eaves of buildings, for example; and reports of that species nesting in hollow trees and other protected locations actually apply to Polistes perplexus. Prey is probably similar in both species, consisting mostly of caterpillars chewed up by the adult wasps and fed to the larvae in the nest. Still, wasps this large can probably tackle much larger prey, and a single record of an attack on a cicada (Tibicen auletes) could be for either species of wasp.

I find that in current literature the size of these wasps is measured by the length of the forewing, which is 15-20.5 millimeters in P. carolina, and 17-21.5 millimeters in P. perplexus. Contrast this with the measurements of the abundant and widespread Northern Paper Wasp, Polistes fuscatus. Forewing length for that species averages between about 13 and 17 millimeters.

Polistes carolina is most common in the southern U.S., but ranges from New York, Pennsylvania, and Ohio south to Florida and west to Illinois, Kansas, Arkansas, and eastern Texas. There is one record for Ontario, Canada, but the species is not established there. That could be the case here in Colorado, too: a fluke. P. perplexus ranges from Maryland to Georgia, and west to southern Illinois, Kansas, Oklahoma, and Texas. One recent record has come from Pennsylvania.

Keep your own eyes open for species that seem “misplaced.” Interstate (and international) commerce, climate change, and other factors are changing the distribution patterns and abundance of many species. We also haven’t looked that closely at insect species with little or no economic impact. You stand a good chance of adding to our collective knowledge with relatively minimal effort.

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

Summer 'hoppers Part II

A couple of weeks ago I blogged about summer grasshoppers in the immediate vicinity of Colorado Springs. Since late May I have also had opportunities to travel to other parts of Colorado and found some very interesting species in those locations, too.

Before I leave the city limits in the virtual sense, let me add two other species to the list. The Big-headed Grasshopper, Aulocara elliotti (above), is technically one of the slant-faced grasshoppers, but it has a very round face. It lives in the entire western half of the U.S. and adjacent southern Canada, ranging as far east as extreme western Iowa and Minnesota. It also slips far into the middle of Mexico. Look for it mostly in shortgrass prairies and desert grasslands with sparse vegetation. Even so, I encountered it at higher elevations in conifer woodlands. Go figure. The big head, and bright blue hind tibiae, helps identify this species, which can easily be mistaken for a band-winged grasshopper. It can occasionally reach pestiferous population levels and become damaging to crops.

The Western Spotted-wing Grasshopper, Cordillacris occipitalis, is unquestionably a slant-faced grasshopper. The long, white antennae are pretty distinctive. I noticed this species into late fall as well. This is another shortgrass prairie species with a range similar to the Big-headed Grasshopper. It is likewise prone to population booms that can make it a rangeland pest.

Farther out on the plains in El Paso County, one finds most of the grasshoppers found in city vacant lots, but in greater numbers. You also get other species like the big Coral-winged Grasshopper, Pardalophora apiculata, shown below. It ranges from deep into western Canada and south through northeast Washington, eastern Wyoming and Colorado, and south through Oklahoma, Missouri, Tennessee, and northward into eastern Canada. It is a mostly early- to mid-summer species in the adult stage. Females are heavy-bodied and reluctant to fly, which may explain why I was able to get so close to this one, in the middle of a road. This grasshopper gets its name from the orange or red hind wings, bordered with a dark brown or black band.

A road trip between Cañon City and Pueblo that took me into more rangeland produced a trio of really spectacular grasshoppers. Just outside the Custer County Conservation District boundary, I spied a single specimen of the Three-banded Range Grasshopper, Hadrotettix trifasciatus.

Large, and strikingly marked with three black bands across the front wings, it is hard to miss. Still, once it lands, it walks into dense grasses, making it difficult to get an image. Note the long, black antennae, and bright orange hind tibiae. The hind wings are pale yellow with a noticeable black band. This is a species of the Great Plains from Canada to Mexico, west throughout most of Arizona. It prefers to eat broadleaved herbs, but will stoop to feeding on grasses occasionally.

The largest grasshopper in Colorado is the Plains Lubber, aka “The Homesteader,” Brachystola magna, and I found one of those later on the trip. While the other grasshoppers profiled here belong to the family Acrididae, the Plains Lubber belongs to the family Romaleidae, which includes the Eastern Lubber Grasshopper and the Horse Lubber. Brachystola is a wingless insect, even as an adult. It measures 40-60 millimeters, females on the higher end of that spectrum. It comes in a variety of colors, too. Some are green, some brown, some pinkish, some even bluish.

The eggs of this species, typically laid in poor soil along roadsides and marginal rangeland, apparently pass through two winters before hatching. This may account for population booms and busts. While it feeds mostly on the foliage of sunflowers and various other broadleaved plants, it is also omnivorous, feeding on dead insects encountered in its wanderings. It will even eat road-killed members of its own kind. Large numbers of dead lubbers can grease the pavement, creating a real road hazard.

By far the most amazing grasshopper I saw was a by-product of trying to follow the Plains Lubber. My jaw dropped when I spotted a red, white, and blue Rainbow Grasshopper, Dactylotum bicolor. Much smaller than the lubber at only 24-32 millimeters, this species more than makes up for its size with its color pattern. This is another grasshopper of the Great Plains, from Saskatchewan to Mexico. Like the lubber it is wingless in all life stages, and feeds mostly on low-growing broadleaved plants. The colors and pattern can vary from specimen to specimen and area to area, but it is always a stunning sight.

I can hardly imagine any other grasshoppers that would be as thrilling to see as those last three, but I’m still in search of the “Green Fool Grasshopper,” so stay tuned.

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.
Helfer, Jacques R. 1972. How to Know the Grasshoppers, Cockroaches, and Their Allies (Second Edition). Dubuque, Iowa: Wm. C. Brown Company Publishers. 359 pp.

Wasp Wednesday: The Wasp Tree Part II

Last week I wrote about a single, blooming Saltcedar tree (Tamarix sp.) that was attracting a great diversity of insects, especially wasps. Well, after spending several more days at that (introduced, invasive) tree, I can add to the list significantly.

The butterflies alone now include Checkered White, Orange Sulphur, Dainty Sulphur, Gray Hairstreak, Acmon Blue, Reakirt's Blue, Painted Lady, American Lady, Variegated Fritillary, American Snout, Common Checkered Skipper, Common Sootywing (image above), and Uncas Skipper (identification tentative). Bees include the following families: Colletidae, Apidae, Megachilidae, and Halictidae.

The following list of wasps will be the final one. I will amend it as I make more specific identifications, and/or add new species during future forays to the tree:

• Argidae: Argid sawflies
• Braconidae: Braconid wasps
• Ichneumonidae (Ichneumon wasps)
• Chalcididae (Chalcid wasps):
• Brachymeria sp. (chalcid wasp)
• Leucospidae (Leucospid wasps):
• Leucospis sp.
• Chrysididae: Cuckoo wasps
  
  
• Scoliidae (Scoliid wasps):
• Campsomeris sp.
• Trielis octomaculata
• Tiphiidae (Tiphiid wasps):
• Myzinum sp.
  
  Myzinum male
  
  Myzinum female
  
• Mutillidae (Velvet ants):
• Dasymutilla sp.
• Vespidae (social wasps, mason wasps):
• Polistes dominula (European Paper Wasp)
• Polistes aurifer (paper wasp)
• Vespula sp. (yellowjacket)
• Eumenes sp. (potter wasp)
• Euodynerus spp. (mason wasps)
• Parancistrocerus? sp. (mason wasp)
• Pompilidae (Spider Wasps):
• Hemipepsis ustulata (“tarantula hawk”)
  
  
• Cryptocheilus sp.
• Anoplius spp. (spider wasps)
• Poecilopompilus interruptus (spider wasp)
• Sphecidae (Sphecid Wasps):
• Sceliphron caementarium (Black & Yellow Mud Dauber)
• Chalybion californicum (Blue Mud Dauber)
• Sphex lucae (katydid hunter)
• Isodontia elegans (grass-carrier wasp)
• Prionyx spp. (grasshopper hunters)
• Podalonia spp. (cutworm hunters)
• Ammophila juncea (caterpillar hunter)
• Ammophila wrightii (caterpillar hunter)
• Crabronidae (Crabronid Wasps):
• Sphecius grandis (Western Cicada Killer)
• Tachytes spp. (sand-loving wasps)
• Bembix sp. (sand wasp)
• Stictiella pulchella (sand wasp)
• Steniolia elegans (sand wasp)
  
  
• Bicyrtes sp. (stinkbug hunter)
• Astata sp. (stinkbug hunter)
• Dryudella sp. (true bug hunter)
• Stizoides renicinctus(image below, blog coming soon)
  
  
• Oxybelus sp. (fly hunters)
• Clypeadon sp. (harvester ant hunter)
• Aphilanthops sp. (“ant queen kidnapper”)
• Philanthus gibbosus (“beewolf”)
• Philanthus ventilabris(“beewolf”)
• Philanthus spp. (“beewolves,” at least two other species)
• Cerceris spp. (weevil wasps)
• Eucerceris sp. (weevil wasp)

All of the above were found either on the tree or in very close proximity. Male wasps take advantage of the fact that females will seek nectar at an isolated shrub and then create territories around it which they defend from other males. I found this was especially true of Tachytes and Philanthus, but I observed other wasps (and flies, too), mating on or close to the tree.

I have put together a “set” of images on my Flickr photostream entitled “Wasp Tree” that illustratse more of these insects. It is an ever-growing set, so please visit often. Thank you.

Wasp Wednesday: Wasp City

Wasp-watching is better around some places than it is others. Yesterday, June 12, I happened upon a lone, blooming Saltcedar tree in the middle of a huge vacant plot of land here in Colorado Springs. In a few hours I saw a greater diversity of wasps than I had seen up until then in all the time I’ve spent here.

Unfortunately, Saltcedar, also known as Tamarisk (Tamarix sp.) is an invasive plant. It is native to Eurasia and Africa and was brought to North America as an ornamental tree sometime in the early 1800s. It can grow in a variety of habitats but seems to favor disturbed situations, riparian corridors, and moist pastures. It has deep taproots that can reach low water tables, interfering with natural aquatic systems. It is also tolerant of high salinity. Efforts have been made to eradicate it, but with little success. One tactic has been the introduction of a leaf beetle, Diorhabda elongate, and a mealybug (Trabutina mannipara), to eat the plant into submission.

Say what you will about the negative impacts of this tree, but it certainly attracts a variety of butterflies, bees, wasps, flies, and beetles that seek nectar at its profuse pale pink blossoms. Yesterday I spotted Painted Lady, American Lady, Variegated Fritillary, Checkered White, Orange Sulphur, Dainty Sulphur, and Gray Hairstreak butterflies. There were also a variety of tachinid flies, thick-headed flies, syrphid flies, and flesh flies. Robber flies hung around to prey on the pollinators. Sweat bees, leafcutter bees, resin bees, digger bees, honeybees, bumble bees, and cuckoo bees were there, too.

The above list is just the tip of the iceberg. The wasps were even more amazing in their diversity:

• Argidae: Argid sawflies
• Braconidae: Braconid wasps
• Chrysididae: Cuckoo wasps
• Vespidae: (Vespid Wasps)
• Polistes dominula (European Paper Wasp)
• Euodynerus spp. (mason wasps)
  
  
• Stenodynerus? sp. (mason wasp)
• Pompilidae (Spider Wasps):
• Hemipepsis ustulata (tarantula hawk)
• Cryptocheilus sp.
• Sphecidae (Sphecid Wasps):
• Sceliphron caementarium (Black & Yellow Mud Dauber)
• Sphex lucae
• Podalonia spp. (cutworm hunters)
• Ammophila spp.
  
  
• Crabronidae (Crabronid Wasps):
• Sphecius grandis (Western Cicada Killer)
  
  
• Tachytes spp. (sand-loving wasps)
• Bembix sp. (sand wasp)
• Clypeadon sp. (harvester ant hunter)
• Philanthus spp. (“beewolves,” at least four species)
• Cerceris spp. (weevil wasps)

The tarantula hawk and cicada killer were somewhat surprising. I’m going back right now to see what else I can find, and try and get better images. Take a look around your own yard, garden, neighborhood, and parks, and see what flowers you can find that draw the most wasps, bees, and other pollinators. Share your findings here if you will.

Spider Sunday: Spring Spiders

It really isn’t quite spring here on the Front Range, but neither is it winter, at least not lately. The high temperature for Tuesday, March 6 was 69°F, albeit windy. Walking down the Homestead Trail in Colorado Springs at midday I was amazed by how many spiders were out and about as well.

A surprising number of spider species overwinter as adults or immature, forsaking the cozy shelter of an egg sac in which to endure the harsh, cold extremes. Among them are running crab spiders (family Philodromidae, image below), crab spiders (Thomisidae), wolf spiders (Lycosidae), and jumping spiders (Salticidae).

Most of these arachnids are ground-dwellers, so presumably they ensconce themselves in debris such as leaf litter, or tuck themselves into the base of grass tussocks. Even a blanket of snow helps insulate spiders from colder air temperatures and chilly winds.

Spider bodies also contain glycerol, a chemical compound that helps reduce the freezing point of their blood, by about one degree Centigrade (Celsius). Certain proteins in spider blood (hemolymph) apparently reduce the freezing threat even more, up to 20°C. Spiders of temperate climates that overwinter in a passive state tend to be much more cold-hardy than those that are winter-active, like some wolf spiders in the genus Pardosa.

Spiders fall into different categories depending on their reproductive cycle. “Eurychronous” species take a long time to reach maturity, and so may overwinter as adults or immatures. “Stenochronous” spiders include those that reproduce during spring and summer (overwintering as immatures); those that mate in autumn (with the spiderlings overwintering inside the egg sac); and those spiders that are active during the winter, reproducing at that time. Lastly, “diplochronous” species have two reproductive cycles, one in the spring and one in the fall. Typically, they overwinter as adults.

The most abundant adult spiders I have found recently are running crab spiders in the genus Thanatus, family Philodromidae. Numerous specimens were basking on the concrete path of the Homestead Trail. A gust of wind caught one unfortunate specimen, sending it tumbling head over heel, heel, heel, heel, heel, heel, heel, heel.

One short stretch of trail also produced two very gravid female crab spiders in the genus Xysticus. “Gravid” means full of eggs. I’ll be looking for them next in silken retreats guarding their egg sacs. Crab spiders are typically ambush hunters, lying in wait for a potential victim to come within reach. Their extra-long first and second pair of legs means that “reach” is considerable, and spines lining the inside of their legs help insure that prey does not escape the spider’s embrace.

Wolf spiders are also on the move, and a short distance from the crab spiders I spotted a plump adult female heading for cover at the edge of the trail. Fortunately, she stopped just short momentarily, posing for a couple of pictures. My friend and colleague Mandy Howe kindly identified this as a female in the genus Alopecosa. She’ll soon have an egg sac attached to her spinnerets (the spider, not Mandy!).

I also found another wolf spider, much smaller and quicker. This is probably an immature in the genus Schizocosa, judging by its color pattern. It bears a superficial resemblance to the Thanatus in that both have stripes on the cephalothorax and a dark “cardiac” mark on the top of the abdomen. This pattern is effective camouflage among grasses and seeds, rendering the animals nearly invisible unless they move. I appreciate the concrete substrate for photography, as one easily loses track of the subject on a more natural surface.

Hiking in Red Rock Canyon Open Space on March 5, a 68°F day, yielded a pair of jumping spiders along the trail. I only managed to get the image below before the tiny arachnid hopped away. I have no idea whether it is an immature or an adult, let alone what genus it might be.

I encourage you to go spider-hunting yourself on the next nice day. It need not be that terribly warm, and I have seen spiders on the surface of the snow before. Look carefully, as some of the most abundant spiders of winter and early spring are the tiniest: dwarf spiders in the subfamily Erigoninae of Linyphiidae. Some juvenile cobweb weavers (Theridiidae) and funnel weavers (Agelenidae) can also be common.

Source: Foelix, Rainer F. 2011. Biology of Spiders (Third Ed.). Oxford, UK: Oxford University Press. 419 pp.

Wasp Wednesday: Winter Wasps

Perhaps I should call this entry “early spring wasps.” We have had a very mild winter here in Colorado Springs, Colorado, and it seems that spring comes earlier and earlier now, no matter where one lives. Certainly more southerly latitudes are experiencing spring right now. Still, I am amazed by the wasps I am finding on the wing already.

While out hiking an urban trail on February 29, I found female Podalonia cutworm wasps out and about in the 58°F temperature. Perhaps they were hunting for those Army Cutworm caterpillars that have also been roaming on warm days. One of the wasps I observed was digging, but I could not discern whether she was excavating a burrow for prey she already had, or was unearthing a moth larva.

A few days previous to Leap Day, Heidi had brought me a wasp that she found flying around one of the exhibits in Primate World at the Cheyenne Mountain Zoo where she works. She had already correctly assumed it was an ichneumon wasp. Many species in the subfamily Ichneumoninae overwinter as adults, sequestering themselves under bark, deep inside rotten logs, and other protected situations. Unfortunately, I didn’t get around to imaging this specimen (below) until after it had expired, but in my defense it is very difficult to differentiate a wasp in torpor (a state of greatly reduced metabolism) from a deceased one.

Social wasps like yellowjackets and paper wasps also overwinter as adults, though it is almost exclusively females that do so. So, I was not completely surprised to find Western Paper Wasps, Mischocyttarus flavitarsis sipping water from melting snow in a narrow arroyo in Red Rock Canyon Open Space on March 5. The high temperature on that day was 68°F.

Any female paper wasp has the potential to be the “foundress” of a new colony, so most of the females survive the winter. Only yellowjacket queens are capable of reproducing, so you will find no workers until summer. I would expect to see queens of some species out by the end of March in most places, but here at higher elevations they seem to wait much longer to emerge. Can’t blame them, as blizzards in April are not uncommon along the Front Range.

One wasp that really did surprise me was another specimen I encountered in that narrow dry arroyo. My initial observation led me to think it was a spider wasp (family Pompilidae), but I was able to get fairly close to it and get some respectable images. Turns out it was a wasp in the family Crabronidae, tribe Larrini. Members of this tribe prey mostly on crickets or grasshoppers. Considering that there are indeed grasshoppers out already, too, I guess I shouldn’t be surprised.

I’m still awaiting help to identify this wasp more specifically, but my guess is that it is probably in the genus Liris. Watch this space for updates in the comments, but don’t put your life on hold. These things take time.

Oh, I almost forgot! Just yesterday, a warm and windy 69°F day, I encountered yet another wasp on the Rock Island Trail near the intersection of Constitution Avenue and Academy Boulevard. Yes, this is pretty urban territory, paralleling an old railroad bed. What should come scurrying across the concrete path but a velvet ant (family Mutillidae). Female velvet ants are wingless wasps that, as larvae, are parasitic on other insects. They are often found digging open the burrows of other solitary wasps.

My friend Justin Schmidt thinks the assumption that velvet ants don't survive the winter may be incorrect. He is currently conducting catch-and-release experiments to see if he can find the same females in autumn and the following spring. The specimen I found is clearly encrusted with soil, suggesting she recently emerged from underground. Whether she emerged from a pupa or a hibernaculum is open to speculation.

The weather here is supposed to take a turn for the colder over the next few days, but bounce right back up into the low 60s early next week. I’ll be interested to see if the insect and spider populations skip a beat, but I doubt they will. One has to appreciate the endurance and resilience of insects, if nothing else about “bugs” is admirable.

It's 'Hopper Time!

Among the last insects to be seen or heard before the hard frosts of late autumn are grasshoppers. Diversity of the short-horned grasshoppers in the family Acrididae is especially great in the desert southwest and the Great Plains. Here in central Colorado, we have plenty of representatives from both of those areas, convening here on the Front Range.

I have only been here since October third, and I’ve already tallied 25 species, thanks to help from David J. Ferguson via Bugguide.net. Here is the list:

White-whiskered Grasshopper, Ageneotettix deorum

Western Spotted-wing Grasshopper, Cordillacris occipitalis

Velvet-striped Grasshopper, Eritettix simplex

Two-striped Mermiria, Mermiria bivittata

Wyoming Toothpick Grasshopper, Paropomala wyomingensis

Brown-spotted Range Grasshopper, Psoloessa delicatula

Speckle-winged Rangeland Grasshopper, Arphia conspersa

Northwestern Red-winged Grasshopper, Arphia pseudonietana

Clear-winged Grasshopper, Camnula pellucida

Northern Green-striped Grasshopper, Chortophaga viridifasciata

Wrangler Grasshopper, Circotettix rabula

Hayden’s Grasshopper, Derotmema haydeni

Carolina Grasshopper, Dissosteira carolina

Dusky Grasshopper, Encoptolophus costalis

Platt Range Grasshopper, Mestobregma plattei

Mottled Sand Grasshopper, Spharagemon collare

Finned Grasshopper, Trachyrhachys aspera

Kiowa Rangeland Grasshopper, Trachyrhachys kiowa

Pallid-winged Grasshopper, Trimerotropis pallidipennis

Red-shanked Grasshopper, Xanthippus corallipes

Two-striped Grasshopper, Melanoplus bivittatus (top of post)

Differential Grasshopper, Melanoplus differentialis

Gladston’s Spurthroated Grasshopper, Melanoplus gladstoni (above)

Lakin’s Grasshopper, Melanoplus lakinus

Migratory Grasshopper, Melanoplus sanguinipes

Most of the above were found as adults, sometimes with tattered wings or an absent leg or two. Some are nymphs at this time of year that will overwinter and become adults next spring. These includes the Velvet-striped Grasshopper, Brown-spotted Range Grasshopper, Speckle-winged Rangeland Grasshopper, Northern Green-striped Grasshopper (below), and Red-shanked Grasshopper.

Here in Colorado Springs, I’ve encountered 20 species. Different habitats, elevations, and micro-climates have their own unique fauna. The Two-striped Mermiria (below), for example, was found along the Arkansas River in Cañon City. These large slant-faced grasshoppers are more fond of riparian corridors with tall, thick grass.

Hayden’s Grasshopper and the Wyoming Toothpick Grasshopper were both seen in very short grass at Fountain Creek Regional Park, in a field just in front of the nature center.

At higher elevations, one can find the Wrangler Grasshopper, Circotettix rabula. These insects can sustain their noisy flights for many seconds, in contrast to most other grasshoppers. They frequent steep slopes with scree (broken rock fragments), however, so it is a dangerous challenge to get images of them. The image below came from Emerald Valley back in July, when I could shoot from a trail above the insect.

The cooler temperatures of autumn mean that grasshoppers struggle to keep warm. Many of them adopt "basking" postures like the Carolina grasshopper pictured below. The insect literally leans back to expose one side of its body fully to the sun. It even lowers its hind leg so as not to block heat from reaching its abdomen.

You can find images of most of the above species in my “grasshoppers” set on Flickr.com. I’m already looking forward to next spring, when some of the nymphs will be large, colorful adult insects. I’ll bring you the results then, too.

Wasp Wednesday: Prairie Yellowjacket

Arriving in Colorado Springs in early October, I was not optimistic that I would find many, if any, wasps still active in the chilling air. Much to my surprise there are still some on the wing, even at high altitudes. Monday, October 10, Heidi and I traveled up into the Front Range to Cripple Creek and the surrounding area. There, walking around on the snow, I found a male Prairie Yellowjacket, Vespula atropilosa.

Heidi remarked that she thought the Western Yellowjacket, Vespula pensylvanica was the only species of that genus living in the area. Actually, there are six species total known from Colorado. Yellowjackets could be considered mostly boreal in their distribution patterns, ranging south at higher elevations where the climate resembles that of higher latitudes.

This particular specimen could have been blown up to its 9,000 foot or so location, too. The colonies of V. atropilosa tend to be smaller than those of more “urban” species, and usually decline earlier in the season, too, so I was somewhat surprised to see this one.

This male exemplifies the yellow or “xanthic” phase of this species. They also come in a black or “melanic” phase that is more black than yellow, as shown in the diagram below from Roger D. Akre’s The Yellowjackets of America North of Mexico (USDA Agriculture Handbook No. 552, 1981), and another specimen I imaged on October 13 in Colorado Springs.

The Prairie Yellowjacket nests preferentially in abandoned rodent burrows. Nests have also been discovered in tree hollows, under steps, and between the walls of houses. One truly aerial nest was found in Pullman, Washington, but this is decidedly an anomaly. The paper combs are surrounded by layers of “envelope,” typically rather coarse as is the case in most subterranean yellowjacket species. V. atropilosa nests are dirtier than most, with the bodies of deceased wasps and other debris incorporated into the paper envelope.

The greatest number of workers in any of the nests studied by Dr. Akre and his colleagues was 504. These are not your picnic-harassing, garbage-gathering yellowjackets, either. They have retained their predatory nature and hunt mostly spiders, harvestmen, flies, insect larvae, and true bugs as food for the larvae back in the nest. Adults feed on aphid honeydew and flower nectar to fuel their flight.

The Prairie Yellowjacket is restricted to western North America, ranging from central British Columbia south and east through southern Alberta, Washington, Oregon, California, Idaho, western Montana, Wyoming, Utah, most of Colorado, and northern New Mexico and Arizona. It avoids nesting in truly urban locations in my experience, though nests in yards are apparently not uncommon.

I look forward to finding more interesting yellowjacket species here in the Rocky Mountains, and I reserve the right to revisit this particular species in future blog posts.