Grasshoppers are sexual dimorphic, meaning that the sexes differ in size, with males being smaller. Grasshoppers also differ slightly in the shape of the abdomen depending upon their sex.
Female grasshoppers have four protrusions hanging off of the end of their abdomen. These are her ovipositors. They are darker than the rest of her body and triangular in shape. They are used to dig holes when the female is ready to lay her eggs. Normally, they are closed, but when she has recently laid eggs they may remain open for a short time.
Males have abdomens that end in a blunt edge. They also possess a hard, smooth plate that covers the underside of their abdomens. This plate can be quite prominent in some species.
The internal anatomy of male grasshoppers includes two large testis, sperm ducts, and an ejaculatory opening. Males do not have penises. They release sperm down the ejaculatory duct at the end of their abdomen with no guiding shaft.
Female grasshoppers, on the other hand, do have vaginas to receive sperm. They also have a specialized organ called a spermatheca to store sperm after mating. Eggs are not fertilized directly from mating. Instead, sperm is stored before it mixes with the eggs for fertilization.