Friday, July 19, 2013

Moth Week and "Mothapalooza"

This coming week, from July 20-28, 2013, is the second annual “National Moth Week” across the U.S. (and also abroad in a few places). I wrote about the inaugural event last July, and in return got some props from the organizers. Their website includes the locations of all events this year. There is at least one in every state, though not all are open to the public.


Luna Moth

Meanwhile, “Mothapalooza” held at the Shawnee State Park Lodge in Scioto County, Ohio last month (June 14-16) was a resounding success. Over one hundred people attended, from as far away as Colorado (moi), Nebraska, and even Canada.


Seabrooke Leckie

It was Seabrooke Leckie, co-author of the Peterson Field Guide to Moths of Northeastern North America, who came from Ontario. It was a joy to finally meet her in person. She is personable, humble, and quietly goes about the business of nudging others into an obsession with moths and other fauna. She is also one of those rare writers who can pen both fiction and non-fiction. Look for a novel from her sometime soon.


Mary Ann Barnett

Mary Ann Barnett, the principal organizer, warmly greeted everyone upon their arrival at the lodge. I don’t think I ever saw her without a smile on her face. Her enthusiasm was contagious, and it showed in the excitement of all who went afield and attended workshops. It is no mean feat creating an event like this, especially when field outings happen around blacklights and white sheets after dark on nearly the longest day of the year. Surprisingly, no one seemed to suffer from sleep deprivation.


Common Spragueia Moth

I was surprised by the diversity of moths that came to the lights stationed near the lodge, and other places like the Eulett Center in adjacent Adams County. My expectations were low, and I had mentally prepared myself for what I assumed would be an absence of giant silkmoths, most of which emerge in late spring. Well, I was thrilled to see four Luna Moths, a Bisected Honeylocust Moth, and a male Io moth (“eye-oh,” not the number ten, like I thought when I was a kid).


Black-waved Flannel Moth

There were plenty of Waved Sphinx moths, one Abbott’s Sphinx, Walnut Sphinx, and a Pine Sphinx. Great Leopard Moths were in relative abundance as well. Painted Lichen Moths, though small, drew “oohs” and “ahs” for their snappy striped pattern. Plenty of owlet moths and geometer moths (adults of inchworm caterpillars) provided material for debates as to their proper identities.


Keynote speaker Dave Wagner

While the nights were taken up with moth-gawking, the mornings were devoted to workshops on topics like moth identification and insect photography. Guest speakers addressed attendees on Friday and Saturday evenings after dinner. Saturday afternoon we had daytime field trips, some of which yielded day-flying moths like the Delicate Cycnia, Cycnia tenera.


Delicate Cycnia Moth

Butterflies, the diurnal counterpart to most moths, were out and about, too, including the Harvester, the adult form of North America’s only carnivorous caterpillar.

Harvester Butterfly

Harvester larvae eat aphids, especially on alder trees.


Pete Whan showing a toad to captivated onlookers

You do not need to have a blacklight or mercury vapor set-up and a white sheet to enjoy moths. Simply turn on your porch light. Moths can be found in even the most urban situations. I found at least six species of underwing moths (genus Catocala) alone in downtown Cincinnati, Ohio when I lived and worked there in the 1990s.


Beautiful Wood Nymph Moth

Identifying moths might seem to be an overwhelming task, but with references like Seabrooke’s book (with David Beadle as co-author), and online resources like the Moth Photographer’s Group and Bugguide.net, you can easily put a name to most of the striking, colorful, and common species, if not also the more obscure and less common ones.


The Beggar

One word of caution, however: You are likely to become hooked on moths, and spend many nights gazing at lights, maybe even driving to rural gas stations in hopes of seeing a greater variety. Don’t be surprised if you meet others with the same inclination, flocking to lights like….well, moths to a flame.

P.S. I will be attending National Moth Week events here in Colorado and in Arizona. Watch this space for reports on both.

Monday, July 15, 2013

A "Fool" for You

One of the ways I use field guides is to look at the range maps to find out what species occur in the area I am currently living, or the place I am about to visit. This habit usually leaves me with unfulfilled objectives as it is not always possible to find species I want to see. Such was the case of the “Green Fool Grasshopper,” Acrolophitus hirtipes, until Sunday, July 14.


male

I had expected to see this odd, handsome acridid last year, especially since one of the plants it associates with is Mentzelia decapetala, the Giant Blazingstar, a common weed in a degraded shortgrass prairie just up the street and over the hill from my Colorado Springs townhouse. I did not see a single one last year despite the abundance of the flowering plant.

This year, Mentzelia has been slower to grow, as have many of the plants around here. Even yucca flowered sparingly. Surprisingly, I encountered four specimens of the grasshopper, and managed images of two: one female, then one male. I suspect I am on the front end of their life cycle, and that I will see more adults in the coming weeks. At least I hope so.


female

I admit I am a fool for grasshoppers, as their diversity is so great here in the western U.S. I have now seen twenty-seven species in Colorado Springs alone, in a little under two years. There is great variety in color and form even within a single species, as many local populations have their own camouflage pattern to match the surrounding soil and vegetation in which they dwell.

Acrolophitus hirtipes is a pretty consistent grass green color throughout, with a few white (or even pinkish) markings and long, brick-red antennae atop a pointy head. Southern populations tend to also have darker green spots and blotches. The crest on the pronotum (dorsal part of thorax) is diagnostic. The hind wings are pale, dull yellow with a contrasting dark band. Despite the banded wings, this is one of the slant-faced grasshoppers. I was surprised to learn from my images just how hairy this species is, perhaps an adaptation to help insulate it from the extreme heat of the summers here. Temperatures on the ground easily exceed 100° F on really hot days. These are pretty large insects, too, males measuring 25-42 millimeters, females 32-51 millimeters.

The Green Fool Grasshopper is a denizen of grasslands and prairies from the southern Prairie Provinces of Canada south to extreme northeast Mexico. It occupies a reasonably narrow band from the Rocky Mountains east to the western Dakotas, Nebraska, Kansas, Oklahoma, and Texas.

This grasshopper may live in shortgrass prairies, but it dines on broadleaved plants like the above-mentioned Mentzelia. Other known items on its menu include Condalia (“snakewood” in the buckthorn family of shrubs), Filago (“cudweed” or “cottonrose” in the sunflower family), Nama (plants in the Boraginaceae), and Phaecelia (“scorpionweed,” “heliotrope,” also in the Boraginaceae).

The life cycle of this species begins when eggs laid the previous year hatch in early spring, or even late winter. Nymphs mature quickly and the adult insects may be present in late spring and early summer. We had late frosts here along the Front Range this year, which has translated into many species maturing later than normal. Only recently have we had substantial rains to perk up the vegetation that grasshoppers feed on.

Surprisingly, the images I obtained yesterday will constitute a Colorado state record for Bugguide.net, the online standard for recent records of arthropods in North America. It just goes to show that you cannot assume that you cannot have an impact as an “amateur” naturalist or entomologist. Please go out there and seek. Ye shall find some amazing animals.

Sources: 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.
Ferguson, David J. 2008. “Species Acrolophitus hirtipes - Green Fool Grasshopper,” Bugguide.net.

Sunday, July 7, 2013

Shower Spiders

Just when you thought it was safe to take a bath….You throw open the shower curtain and are suddenly confronted with an eight-legged freak. Over the years I have answered many an AllExperts.com question about strange arachnids that people have found in the tub or stall, as well as finding my own specimens now and then.

Recently, I was myself taken aback upon entering the shower and spying a particularly fine specimen of a Philodromus running crab spider on the wall behind my wife. I was startled, which in turn startled her, and we spent the remainder of the time with one eye on the spider. Naturally, Ms. Phyllis Dromus dropped lower and lower, eventually settling by the place where the shower head comes out of the wall.

I know what you are thinking. How can a manly-man like me, equipped with knowledge that allows him to identify most spiders, and who knows this one is not dangerous, still be uneasy? That isn’t what you’re thinking? Why are you laughing? Please, this is a family show. Get your mind out of the gutter.

I think there are simply some places where we don’t expect to find spiders, and where we would prefer not to find them even if we normally appreciate and respect arachnids. No doubt the spiders feel the same way: “Gee, where do I have to go to get away from these monsters?! Uh-oh, it’s getting slippery!”

More recently, while attending the Mothapalooza event in Ohio, I prepared to step into the shower after a hot, sweaty field trip. Apparently, the tub had not seen much activity recently because there guarding the drain was a mature male Barn Funnel Weaver, Tegenaria domestica. I managed to snap one shot before trying to coax him into better viewing. That only drove him down the drain and though I was patient he never re-emerged.

I still wanted to wash off before dinner, so I ran a light stream of water out of the faucet. Sure enough, Mr. Barn Funnel Weaver shot out of the drain with lightning speed. He was at the other end of the tub before I blinked. A few more pictures and then I corralled him in a plastic container to show off to folks later. Now, now, no jokes about which of us is better endowed. What are you, twelve?

It is always a little easier for me to address someone else’s spider-in-the-shower experience than it is to chronicle my own, and I’m sure there will be plenty more such episodes crossing my e-mail or AllExperts.com account. I hope I am successful in calming people’s anxiety, allaying their fears, and otherwise turning fright into fascination. I always offer to accompany my female correspondents into the shower the next time, just in case….Funny, no one has ever taken me up on that.

Wednesday, July 3, 2013

Spider wasp, Dipogon calipterus

Forest edges are a great place to look for wasps. Male wasps may perch on leaves to defend territories and look for passing females. Female wasps often hunt for prey among foliage, flowers, and stems. Both genders may pause to groom and rest on sunlit leaves. I was lucky enough to catch a rarely-seen spider wasp, Dipogon calipterus, grooming herself on a leaf at the edge of a wooded area near Bloomington, Indiana on June 20 of this year.

Dipogon spider wasps are mostly forest-dwellers that hunt for spider prey on tree trunks. Most species have dark bands on the wings, which have the effect of making them look a lot like ants. Considering that many predators dislike ants, it is an effective disguise. Add to that the fact that there is frequently a good deal of ant traffic going up and down any given tree bole, and it is no wonder these wasps are rarely observed.

These are not very large wasps, either. Townes (1957) measured wasps by length of the forewing rather than body length, and male D. calipterus have a forewing length of only five millimeters, females a forewing length of 5.7-7.4 millimeters. The wooded habitat and banded wings help to identify these wasps to genus. The reddish front legs help identify the species.

The distribution of Dipogon calipterus is scattered according to the three recognized subspecies. The one depicted here is D. calipterus calipterus, and it ranges from Massachusetts to North Carolina, Indiana, and Illinois, though it is important to note that our knowledge of the geographic distribution of most insect species is incomplete. D. calipterus duplicatus occurs in Georgia and Florida, and D. calipterus nubifer ranges from southern California to Panama. Slight differences in color and pattern seem to be the factors used in segregating the subspecies.

Females of Dipogon rarely, if ever, visit flowers for nectar, but are among the few wasps that will sometimes kill prey specifically to feed themselves rather than their offspring (or they feed on the spider before using it to provision a nest). Dipogon are probably opportunists, attacking whatever spiders they encounter while searching tree trunks, but the collective prey records for the genus are rich in crab spiders (family Thomisidae, especially the genus Xysticus). Other spiders known to be prey include jumping spiders (Salticidae) and ground spiders (Gnaphosidae). There is at least one record of a hacklemesh weaver, genus Amaurobius, as prey for D. calipterus calipterus.

Prey is stung into deep paralysis, or perhaps killed outright, by the female wasp. She carries her victim by grabbing the spinnerets at the tip of the abdomen and walking sideways or backwards, dragging the limp spider in the process.

It is suspected that the female wasp finds a suitable nesting site before she begins hunting. Nests are in typically in pre-existing, tubular cavities such as the abandoned tunnels of wood-boring beetles, or the soft pith in dead or broken plant stems such as sumac. Pre-drilled wood nest blocks put out for solitary bees may be used by these wasps. The linear cavity is divided into cells. After a spider is stored in the first, bottom-most cell, the wasp lays an egg on it and then builds a curtain of mud and/or other material that serves as the ceiling of that cell and the floor of the next cell.

The conglomerate nature of the cell partitions and closing plug is rather unique and helpful in identifying the nests of these wasps. Besides mud, particles of leaves, insect body parts, and even caterpillar frass (poop) may be incorporated into the nest partitions and closures. The female wasp uses the “beard” of hairs on her maxillary palps to carry such material back to the nest. The hairy palps are the only sure way to identify the genus Dipogon, but they are seldom visible on live specimens in the field.

Keep an eye out for these ant-mimicking wasps, even in your own backyard. Yes, it may take looking at a lot of tree trunks, or foliage, but you will eventually be rewarded with at least a glimpse of these unique pompilids.

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.
Krombein, Karl V., Paul D. Hurd, Jr., David R. Smith, and B.D. Burks (eds). 1979. Catalog of Hymenoptera in America North of Mexico vol. 2, Apocrita (Aculeata). Washington, DC: Smithsonian Institution Press. Pp. 1199-2209.
Townes, Henry. 1957. “Nearctic Wasps of the Subfamilies Pepsinae and Ceropalinae,” Bull. U.S. Natl. Mus. 209: 1-286.