Orthoptera

Grasshoppers, Crickets, and Katydids: Orthoptera

There are more than 20,000 species of Orthoptera worldwide (Murnane). About 1,000 of these occur in North America (Murnane), and approximately 100 species are known to New England (Gurney 2017). Martha’s Vineyard exhibits respectable diversity of Orthoptera for a smallish island, with 67 species in this order included here. Some of these are known only from historical records, though given the limited attention this group has received, it’s possible that relict populations still exist somewhere on the island. Some of the extant species can be incredibly abundant: the Red-legged Grasshopper )Melanoplus femurrubrum), for example, can be found in nearly any open habitat and is sometimes present at a density exceeding a dozen individuals per square meter. Other extant species are more scarce or more specialized: the band-winged grasshopper Encoptolophus sordidus is currently known from just one population in Edgartown, for instance, while the pygmy grasshopper Tettigidea lateralis is included here on the basis of just one “Research Grade” record in iNaturalist from Aquinnah (though the actual Vineyard distribution of this small, cryptic species may be much broader).

While it is of course difficult to distinguish newly arrived species from species that went undetected for a long time before being noticed, there is compelling evidence that new Orthoptera species can and do colonize the Vineyard at least temporarily. In some cases, circumstantial evidence points to human-assisted arrival. For instance, records for the spur-throated grasshopper Melanoplus differentialis, the Differential Grasshopper, have all been associated with agriculture or horticulture: row crops at Mermaid Farm in Chilmark, ornamental plantings in Oak Bluffs, nurseries (many individuals were found in 2018 on potted chrysanthemums at Vineyard Gardens in West Tisbury and Jardin Mahoney in Oak Bluffs), and Thimble Farm, where a robust population appears to have become established. The species has never, to my knowledge, been observed in a truly natural setting on the Vineyard, and it seems likely that the species colonized the Vineyard (or perhaps re-colonized it) through importation on plants or, possibly, as eggs in soil or mulch. Schistocerca nitens, Tetrix ornata, Neoconcephalus triops, and Microcentrum retinerve, all known on the Vineyard from just one or a few sightings, are species for which the only records occurred in circumstances that suggest accidental import; with the exception of T. ornata, all of these have distributions that make a naturally-occurring population on the Vineyard highly unlikely. The same can be said for Schistocerca americana: in January 2024, one individual of this species was found, still alive, by Kim Hilliard in a package of broccoli she had recently purchased at a grocery market in Oak Bluffs.

For at least one other species, circumstantial evidence suggests recent arrival by natural means. The katydid Microcentrum rhombifolium has an easily detected and recognized call and is broadly established in eastern Massachusetts, including on Cape Cod. I know from experience on the mainland that I can readily detect this species through the open window of a car while driving as fast as 30 miles per hour. So the fact that I had never heard this species here in nearly ten years of studying Orthoptera suggests actual absence rather than just a failure to detect it. But in the wake of a powerful tropical storm in September 2017, which featured 50-knot winds from the north for more than two days, this species abruptly turned up singing in two locations near the northern apex of the Vineyard (in Post Office Square, Oak Bluffs, and near the public tennis courts in downtown Vineyard Haven). While the hypothesis can’t be proven, the arrival of these individuals on strong winds from a population on Cape Cod seems like a logical explanation. Both locations produced additional records in subsequent years, with the Oak Bluffs population expanding beyond the town center at least as far as my yard on Franklin Avenue, where I heard it in 2020, 2022, and 2023. The species seems to be well established in Oak Bluffs at present, and an individual was photographed in Edgartown in October 2022 (the photograph is in iNaturalist).

The true katydid Pterophylla camellifolia likewise may be a recent arrival, though the mechanism that brought it here is less clear. Again, this is a species with a loud and distinctive call, and the absence of any records before 2018 suggests that the species was at least very scarce here, if not wholly absent. But in 2018, three populations, one in Oak Bluffs and two in Vineyard Haven, came to my attention. The largest of these, near the lower end of Lambert’s Cove Road, extended along the road for about a half-mile in 2021, and its chorus was thunderous on warm nights in August. Like many other Orthoptera, Pterophylla appears to be extending its range northward, presumably as a result of lengthening growing seasons as a result of climate change. (Being relatively large, complex insects that as a rule complete one generation per year, Orthoptera probably tend to range northward to the limit of where the growing season is long enough to allow them to routinely complete their full life cycle in one season. Winter hardiness of overwintering forms may also be a limiting factor.)

It seems likely that further additions to the Vineyard checklist will follow. Handsome Trig, Phyllopalpus pulchellus, now abundant on the southern New England mainland but never to my knowledge observed on Martha’s Vineyard, would be my bet for the next addition. Say’s Trig, Anaxipha exigua, is likewise common on the Massachusetts mainland and may be poised to turn up on the Vineyard. Species known only from historical records may also still be out there, awaiting rediscovery. (Inspiration may be drawn from the fact that 30 years passed with no records for the “toothpick grasshoppper” Pseudopomala brachyptera before this species was photographed in 2021 at Katama Air Park, Edgartown.) In the case of the problematic genus Amblycorypha, I’m confident we have (at least) two species resident on the Vineyard, since long-winged and short-winged individuals have been photographed on multiple occasions. The short-winged individuals are no doubt referable to A. rotundifolia, for which there are now a handful of “research grade” Vineyard observations in iNaturalist. Which species the long-winged individuals belong to, though, still remains to be clarified. The possibility of finding new species, new locations for species currently considered rare, or individuals of species with no recent records might serve as an incentive for others to study this interesting group: discoveries are out there to be made.

The species on the following checklist have been documented by a variety of means. The largest single source of data for this list is my own field observations and photographs, which I began compiling in 2010. Many species are visually distinctive enough so that even a mediocre photo supports a firm identification. In other cases, I was able to photograph anatomical details (e.g., the cerci on male Melanoplus grasshoppers or the supra-anal plate on male Scudderia katydids) that allow a definitive identification. Broad-winged Tree Cricket (Oecanthus latipennis) is included here based on a single “Research Grade” record in iNaturalist. In a few cases, I’ve included species in this list on the basis of calls alone. Pterophylla camellifolia, for example, is easy to identify based on its very distinctive stridulation and is represented by two “Research Grade” sound recordings in iNaturalist. But I have never actually seen one on Martha’s Vineyard and am unaware of any photographs taken here. And ground crickets in the genus Allonemobius are, in my view, given the current state of knowledge, more readily identified by song than by photograph. One distinctive species, Northern Mole Cricket, is included on the basis of older sight and sound reports from an observer I consider highly reliable; confirmation that this interesting insect still persists on Martha’s Vineyard would be most welcome. A few species are included based on historical records in Albert Morse’s magisterial Handbook of the Orthoptera of New England (Morse 1920).

It is important to acknowledge that this checklist is not supported by the sort of synoptic specimen collection that would be considered necessary for formal scientific documentation. But I’ve taken great care to ensure that information included in this section is solid and up to the standards of serious naturalists.

Useful resources for the study of Orthoptera on the Vineyard include Capinera et al. 2004 and Himmelman 2009. The former struggles a bit with the challenges of capturing the continental diversity of this group, and with the extreme variation of color and pattern that many grasshopper species exhibit. But it was a groundbreaking work at the time of its appearance and remains a very helpful guide. The latter book omits a few species from its area of coverage but provides excellent descriptions of appearance and song for ID. It also includes a CD with recordings of calls. Otte 1981 and Otte 1984, despite their age, remain indispensable for serious study of grasshoppers anywhere in North America; a long-awaited third volume, covering spur-throated grasshoppers (including the difficult genus Melanoplus), is said to be approaching publication. On the web, the Singing Insects of North America site is a valuable compendium of sound recordings, physical and habitat descriptions, and probably the most reliable range maps for calling Orthoptera species.

Matt Pelikan and Andrea Brown; edited by Matt Pelikan, January 16, 2024