Wild Side: Katydids

There are at least 17 species on the Island.

A green insect with very long antennae and long hind legs gets posted on social media with a request for identification. “Katydid” is inevitably a quick reply.

It’s usually an answer that is both right and wrong. Like so many common names, “katydid” is imprecise, a generic term referring to a group of species, not a single species. And what is included in the group varies regionally. (The British, for example, refer to insects that we would call katydids as “bush crickets.”)

Eastern North American does have a so-called true katydid, an odd-looking beast whose eponymous, rasping “Kay-tee-did, Kay-tee-did” call is part of the soundtrack of a summer from Florida to Ontario. A member of a small, distinct subfamily (just four members in North America), the Eastern true katydid, Pterophylla camellifolia, occurs on the Vineyard but is scarce, and apparently recently established on our Island.

But katydid fans will rejoice to know that we have at least 17 other species here that qualify as katydids. These range from tiny creatures, barely a half-inch long, to robust two-inchers, among our largest insects. Some are common generalists, some very local specialists; some call loudly, some barely audibly; but all share the general katydid pattern of being (usually) green, having long, threadlike antennae, and having long hind legs that can propel prodigious leaps.

An 800-word column can scarcely do justice to this diversity. But to give a sense of why katydids rank among my favorite insects, here’s a look at the Vineyard’s representatives of just one genus, Scudderia — sometimes called bush katydids.

We have at least three Scudderias, and I’m hopeful that I’ve so far missed another one or two. Superficially, they all look quite similar, and that’s part of the appeal: Identifying them looks hopeless at first, but once you learn a couple of simple tricks, they become quite easy to tell apart.

The first trick doesn’t involve seeing these insects at all, but rather listening for their calls. Produced by males rubbing a wrinkled section of the base of their forewings together, these calls are all underwhelming for such large insects. But the calls have evolved to attract mates, and perhaps to warn other males of the same species to keep away. In other words, the calls are how the insects themselves recognize their own species — and we can do the same.

Fork-tailed bush katydids give a disappointing, wet-sounding call that registers to my ears as “tsi-dick.” The calls are irregularly spaced, usually several seconds apart. Male curve-tailed bush katydids give a somewhat more complex version of a similar call, with each individual call a bit crisper-sounding, and the calls are usually given in tidy groups of three. And the Northern bush katydid, the smallest species of the three, gives the most impressive call: a series of soft “tics” followed a series of soft buzzes that sound like “she, she, she.” It takes a bit of practice even to notice these sounds. But with a little work, you can use them to reliably identify invisible individuals.

Even simpler may be using anatomy to sort Scudderias out. Appendages at the very end of the abdomen — a blade-like ovipositor, used for positioning eggs, on females, and the super-anal plate, which projects from the top of the abdomen, in males — have distinct shapes in each species. These parts are often hidden by the wings, but patient photography or careful seizure and examination of a katydid can give you a good look. The Singing Insects of North America website, orthsoc.org/sina, gives details on identifying Scudderias and many other kinds of Orthoptera found on our continent.

All three of our Scudderias have similar seasonality, maturing from late July and persisting into early October. All seem to prefer deciduous woodland, though the fork-tailed bush katydid shows a marked fondness for scrub oak, and the Northern bush katydid prefers tree oaks, often with some pine mixed in.

Like almost all of our Orthoptera, our katydids, including Scudderia, have one-year life cycles. Eggs are laid in late summer or early fall, on plant stems, hatching the following spring. Tiny at first, the hatchlings, or nymphs, progress through a series of molts as the season progresses, growing larger and more like their adult forms with each molt.

Adult bush katydids are amazingly leaflike, camouflage that makes them difficult to spot. When they are disturbed is your opportunity to see them: Typically, they fly a short distance and land on vegetation a few feet off the ground. At that point, a stealthy approach will often get you within inches of them, for close-up photos or a gentle grab (hold them by the wings; those long hind legs break off easily!), if you feel the need for in-hand examination.

Despite their evident strength, these are docile insects that rarely bite, even in self-defense, and often sit calmly on your hand once they realize you aren’t going to eat them. It takes a little work to get to know them. But it’s worth it.