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SPECIES ACCOUNT NORTHERN GREEN-STRIPED GRASSHOPPER (Chortophaga viridifasciata) Vineyard Overview: This is one of the most common grasshoppers on the Vineyard, locally abundant in dry, open areas. It is also an insect that flourishes in human–altered habitats, including yards, roadsides, and pastures. The odds are good that this insect already occurs in or near your yard. But it can be abundant in natural habitats as well, such as along the fire lanes in Correllus State Forest. Identification: The Northern Green-striped Grasshopper is a member of the band-winged grasshopper family, though in contrast to some of its relatives, this species has nearly colorless wings with no strong coloration on them. The wings are evident, though, when a disturbed adult leaps into the air and takes flight: producing a distinct rattling noise while in use, the wings can propel this insect many yards from its launching point. The Northern Green-striped Grasshopper overwinters as an immature nymph, like this one. These are sometimes active on warm winter days. Photo: Matt Pelikan A little more than an inch long, the Northern Greenstriped Grasshopper has a misleading common name. It actually comes in two distinct color morphs: one is all brown, and the other is mostly green but with brown wing-covers. Neither morph looks conspicuously striped! While it isn’t a totally diagnostic feature, this grasshopper has an obvious, keel-like ridge running down the center of its thorax, and this characteristic is helpful for identification. found in mid- to late summer. But the Northern Green-striped Grasshopper overwinters as a nymph – an immature form that resembles a very small adult with undeveloped wings. Nymphs can sometimes be found during the winter, on warm days in sunny, sheltered spots, when they rouse themselves and feed. How much the nymphs mature during the winter depends on how mild the season is, and this in turn determines when the first adults (with fully developed wings) can be found. In exceptional years, adults appear as early as late April. But in any case, if you see a mature grasshopper on the Vineyard any time before the middle of June, it is almost certainly this species. But perhaps the most useful clue for identifying this grasshopper is seasonality. Most grasshoppers on the Vineyard overwinter in egg form, hatching in the spring and gradually maturing into adults that are Ecological functions: The Northern Green-striped Grasshopper appears to be a generalist in terms of diet. So even when it is abundant, it probably has relatively little impact on any single plant species. But The Nature Conservancy Massachusetts Islands Office 18 Helen Avenue, Vineyard Haven, MA 02568 Brian Lawlor, Program Manager | [email protected] | (508) 693-6287 Ext. 10 like other plant-eating insects, this grasshopper probably exerts some influence on the growth rate and abundance of particular plants. And it certainly plays a role, through its digestive process, in breaking down plant tissue into basic compounds that are then available for use by other plants. Such “nutrient cycling” is an essential component of a healthy ecosystem. can accomplish this by leaving parts of your yard unmowed or leaving spent plants in flower beds through the winter. For example, two places where we routinely find this species overwintering are a patch of bearberry on the south side of a picket fence, and in clumps of big bluestem grass along the southfacing side of a concrete house foundation. This grasshopper is also an important prey species for larger insects and for many species of birds. In particular, maturing nymphs in the spring are increasing their activity around the same time the first migratory songbirds are arriving. If you notice a grackle or robin rummaging through the leaf litter on the edge of your yard, it is likely that grasshopper nymphs are among the prey items the bird is taking. Since relatively few insect species are active at that point in the season, the role of this grasshopper in sustaining early bird migrants may be significant. Strategies: 1. Provide food and shelter. Like other grasshoppers, this species seems to fare best in settings that offer a fairly high diversity of plants. Such diversity increases the odds that plants suitable for the grasshopper’s diet are available, and young, rapidly growing vegetation (which tends to be more nutritious and easier to eat and digest) is more likely to be present throughout the season in a diverse area. Northern Green-striped Grasshoppers, because of their unusual life cycle, may be more reliant on leaf litter and dead vegetation in sheltered spots during the winter. Such spots keep the overwintering nymphs out of sight of potential predators, and also help them warm up on mild winter days so that they can eat and advance their development. Of course structurally complex vegetation is also important to give this species shelter during the summer: a closely cut lawn or an area with only sparse vegetation doesn’t offer effective hiding places for an insect the size of an adult grasshopper. For both of these reasons, then, the best way to encourage this species is to provide unmanaged or lightly managed vegetation in dry, open areas. You This adult Northern Green-striped Grasshopper, a brown morph, shows the distinctive “keel” along the top of the thorax – a good ID mark for this highly variable species. Photo: Matt Pelikan