When we think of singing, we usually think of people or birds. In the spring we may think of pinkletinks, but we usually think of them as chorusing rather than singing. Very few people will think of grasshoppers, crickets and katydids as singers, but they are. And in this unusual spring, when oak trees are already beginning to leaf out, these insects may start their raspy singing soon.
Perhaps we do not think of these insects as singing because they do not have vocal cords. Technically, they produce these sounds by stridulation, or rubbing parts of their bodies together.
Grasshoppers can be easily recognized because their antennae are shorter than the rest of their body. Hence, they are sometimes known as “short-horned” grasshoppers. Their dry, pitchless calls are made by rubbing their leg against the outer surface of their upper wing, although opening their hind wings rapidly can also produce a different, crackling sound.
Some species of grasshoppers can easily be seen as they use their long, strong hind legs to jump out of your way as you walk down a path. This sudden motion makes them conspicuous to us, and probably to predators as well, so most of the time they remain concealed on or near the plants that they prefer to eat.
Matt Pelikan reports that the only grasshopper he has seen so far this year is the northern green-striped grasshopper, whose nymphs (immatures) were active on warm days all winter, and the first adults were observed on April 6.
Katydids and crickets are sometimes known as “long-horned” grasshoppers because their antennae are much longer than their bodies. They are also harder to find since they tend to remain in the vegetation and they closely resemble the leaves of the trees, shrubs or grasses that they eat. If you get a close look at a katydid, you will see that they have opaque upper wings (tegmina) that wrap around their abdomen, and there are four segments (tarsi) to their foot.
There are 40 species of katydids in New England. All of them are best known for the sounds they make by rubbing together two specialized areas at the base of their upper wings. They tend to start calling in July or August, and will continue to call into the fall. In recent autumns I have been listening to the common true katydid, which lives in the crowns of both deciduous and coniferous trees. Those that are still singing in October appear to be very localized, as they can be heard near the intersection of Bigelow Road and Franklin Avenue, but not elsewhere on West Chop. Perhaps it is warmer there, so they keep singing later into the fall; it seems likely that they are more widespread during the summer. We will need to listen to find out.
Crickets live primarily on the ground, and they tend to have translucent upper wings that rest flat on their body. Their light green, brown or black coloration more resembles dead leaves and soil. Their anatomy is slightly different from the katydids, with their right upper wing overlapping a significant part of their left upper wing. And they have only three segments in their foot (tarsi). Crickets also raise their upper wings to a sharp angle with their body when they are singing.
There are 29 species of crickets in New England. Spring field crickets are usually the first insect that we hear in the spring, as they overwinter as immatures rather than eggs. Matt Pelikan has observed some immatures but no adults yet. Last year he did not hear them until the end of May, but we can expect to hear them considerably earlier this year, as everything seems to be happening up to a month early. Who will hear the first spring field cricket?
The noises these insects make — call them songs if you like — can be used to identify these insects to species. Where they are calling from (ground, grass, shrub, or top of tree) can also help their identification. There now are field guides to help you — John Himmelman’s Guide to Night-Singing Insects of the Northeast includes a CD with recordings of their songs. There are also two good Web sites: Singing Insects of North America (entnemdept.ufl.edu/walker/buzz/) and Songs of Insects (musicofnature.org/songsofinsects/index.html).
Robert Culbert leads guided birding tours and is an ecological consultant living in Vineyard Haven