October 10, 2014 at 6:04 am (plant-eating insects)
Tags: Melanoplus femurrubrum, red-legged grasshopper
by Carl Strang
This is the first year in which I have searched for singing grasshopper species with the same intensity as for cicadas, crickets and katydids. Since the grasshoppers seldom sing, and when they do have essentially identical songs, I have had to learn about the structure of grasshoppers so as to identify them. The most common species in the region seems to be a non-singing one, the red-legged grasshopper. It therefore is an important one to learn about.
Red-legged grasshoppers belong to the spur-throated grasshopper group. Here is a close relative, the pine tree spur-throated grasshopper. The rounded peg between the front legs is the uniting feature of the group. None of the singing grasshoppers possess it.
Here is a red-legged grasshopper female. Female grasshoppers have pointed abdomen tips, formed from the valves of the ovipositor.
Female structures are similar enough that species identification is more difficult. It is best to focus on males.
Note the rounded abdomen tip in the male red-legged grasshopper. The dark, relatively unbanded but somewhat herringbone pattern of the femurs, along with the red tibias and the wing length, are helpful in identifying this species in either gender.
In the male red-legged, the abdomen tip is swollen. The cerci (the pale pair of small structures a bit back from the tip and on top of the abdomen) are shaped like elongated triangles with rounded points.
Viewed from the end, the rounded edges and the U-shaped central depression in the subgenital plate (the structure occupying most of what you see from the end) are diagnostic for the male red-legged grasshopper).