Grasshoppers

Several years of botched IDs.

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A Boll's Grasshopper specimen showing the diagnostic pattern on the hind tibia. This nondescript grasshopper becomes very distinctive indeed when you can see the right body parts. — Matt Pelikan

When I began studying the Vineyard’s grasshoppers about six years ago, I knew almost nothing about them. There was only one species I could put a name to. I didn’t have any sense of the taxonomy of the Orthoptera — that is, how biologists group them based on evolutionary relationships. And I knew virtually nothing about what species would be expected on the Vineyard (much less what habitats I’d be most likely to find them in). Afflicted by a sudden, deep curiosity, I simply dove right in.

It was recipe for, if not disaster, at least frustration and inefficiency. Time and again, I’ve botched identifications or made assumptions that proved false, forcing myself to backtrack and relearn things I thought I had figured out.

A particularly grisly minefield for me has been the subfamily Oedipondinae — this is the grasshopper group known, commonly and fittingly, as “band-winged grasshoppers.” On the one hand, these insects are relatively easy to find; they’re fairly large for the most part, roughly an inch or two long, and true to their name, they possess wings that show distinct bands of color.

But while some band-winged grasshoppers are easy to recognize, the group as a whole poses major ID challenges. Many species, and not necessarily ones that are closely related, simply look very much alike: brownish insects with vague, dark banding on their hind legs and, in many cases, some sort of ridge or keel down the centerline of their thorax (that’s the middle body segment, the one that legs and wings attach to).

Their banded wings, which theoretically have distinctive patterns, are invisible when the insects are at rest, and when they’re in flight, the pattern is nearly impossible to see. The differences matter if you have a pinned and spread specimen to work with — but under field conditions, these bugs give you very little to work with.

I learned a few of these species early on, and finding them to be quite common, I assumed that they were common to the exclusion of other members of this group. I’ve surely misidentified hundreds of grasshoppers because of this error, which I’m only now starting to dig out from.

Through experience and study of books and web resources, I’ve developed a sense for some of the ways insects in this group differ. When you flush them, they can fly a short distance or a long one. That keel on the thorax I mentioned can be deep or shallow, cut by zero, one, two, or more fine grooves. Wings on a resting grasshopper can be broader or narrower, the wingtips blunter or finer.

In late July, a grasshopper that I would surely have ignored in years past struck me as a bit odd. Probably one of the common species I already knew of, I thought, but let’s take a closer look. I crawled into photo range, snapped a bunch of frames, then nudged the insect into flight to see what I could of its wings. Something was definitely wrong.

I made two more visits to the same area, relocating the mystery grasshopper and gradually developing a sense of how it differed from the three familiar band-winged species it shared territory with. I took more pictures, comparing the results with website photos and emailing them to more experienced entomologists. Finally, one of the insects cooperated: As I watched, it shifted its position and rubbed a leg against a wing as if scratching an itch.

I caught a fleeting glimpse of the inside of a femur, or “thigh,” that was boldly banded in black and white, and a tibia (the next section of the leg, analogous to our shins) that showed a flash of pink. Both features, invisible most of the time since grasshoppers rest with their femurs pressed against their sides and their tibias tucked neatly out of sight under the much more substantial femurs, were dead wrong for any species I was familiar with. The next day I returned with an insect net, nabbed one of the culprits, held it by its folded wings, and took a good look (plus some one-handed photographs) at its hind legs in all their glory.

The tibias showed a distinctive pattern: a white band, a black band, and then a pink one as you move outward along the tibia. These critters were Boll’s Grasshopper, Spharagemon bolli, not just a new species for my checklist but an entirely new genus.

Mr. Boll’s grasshopper brings to 17 the number of grasshopper species I’ve documented here. This number may grow, though the biology of grasshoppers and the geologic history of the Vineyard probably cap our diversity of this group at a modest level. If there are species that have escaped me so far, discoveries like Spharagemon bolli (six years into my survey!) give me hope that I may have learned enough so that I can actually find them.