Showing posts with label summer. Show all posts
Showing posts with label summer. Show all posts

Thursday, July 19, 2012

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.

Sunday, July 8, 2012

Summer 'hoppers Part I

Note: Today’s “Spider Sunday” appears on my companion blog, Sense of Misplaced, for reasons that will become clear if you visit that site.

Here on the Front Range and high plains of central Colorado, it seems that grasshoppers are ever-present and the diversity ever-changing. The continuing drought has no doubt contributed to the overall abundance of Acrididae (short-horned grasshoppers) this year. I was finding adult Speckle-winged Rangeland Grasshoppers, Arphia conspersa, on the last day of February, and it has only gotten more amazing since.

Easily the most exciting discovery I made was spotting the Crowned Grasshopper, Trachyrhachys coronata. I imaged the female shown below on June 2, just up the street in a vast vacant lot with very short grasses and herbs, and small, widely scattered elm trees. I was completely perplexed by the leopard-spotted pattern on what is really a pretty slender animal. Most leopard-spotted grasshoppers are very large and robust.

Enter David Ferguson, a grasshopper expert who lends his knowledge to Bugguide.net. I e-mailed him the image above and pleaded for help. He recognized it as a female Crowned Grasshopper, a seldom-seen species. Indeed this picture, and the one of a male taken on June 29 (below) may be the only images of live specimens in existence, at least in the digital age. No wonder I couldn’t find a match on Bugguide or elsewhere.

The most common species of Trachyrhachys is T. kiowa, shown below. Note the blue hind tibia. When it flies, the hind wings are either clear or yellow, with little or no contrasting black band. Hard to note such details when they explode from underfoot and then quickly land again. This one is on the wing right now, a very common species.

The enormous female Red-shanked Grasshopper, Xanthippus corallipes, shown below, is more typical of the leopard-spotted grasshoppers. She keeps her most vibrant colors mostly concealed. The back of her head is blue, and the inner surface of her hind femora (“thighs”), and the entirety of her hind tibiae, are bright vermilion. Her hind wings, visible only when she is flying, are bright yellow with a black band.

By the side of the road at a major intersection I found the slender little ‘hopper below, Derotmema haydeni. It was so hot that it was elevating itself on only four of its six legs, and headed for the shade of a small plant at the first opportunity. This species can have yellow or red hind wings with a black band.

In contrast to the colorful band-winged grasshoppers described above are the super-camouflaged “slant-faced” grasshoppers that mimic grasses, not the surface of the soil. Slant-faced grasshoppers are generally striped, whereas band-winged grasshoppers are speckled or spotted. The Velvet-striped Grasshopper, Eritettix simplex, is anything but simple. It has enough variation to convince you that there are several species rather than just one. The typical form is shown here (brown and white):

They also come in green and brown (and white):

Wait, there’s more. This specimen that I found on the door jamb of my apartment I had pegged as Opeia obscura, but no-o-o-o, just another Eritettix simplex.

The Velvet-striped Grasshopper is surely one of the most abundant species here in Colorado Springs. Virtually every vacant lot has them.

An even more handsome species is the Striped Slant-faced Grasshopper, Amphitornus coloradus. It favors bunchgrasses and I only found it in one little patch amid yucca and prickly pear cacti.

Stay tuned. Last Monday I went through the wilderness between Cañon City and Pueblo and turned up some incredibly stunning grasshoppers. You literally have not seen anything yet!