Parasites on Grasshoppers

Grasshopper

• The grasshopper is an insect found in various areas of the U.S., including the Northern Plains where hatching of eggs begins around late April and early May. The grasshopper life cycle takes in three broad stages, of egg, nymph and adult, North Dakota State University reports. Once a grasshopper emerges from an egg it enters the nymph phase, which resembles the adult phase although smaller, wingless and with less mobility. In agricultural communities the grasshopper is seen as a pest because of the amount of crops and other plants certain species of grasshoppers consume.

Parasites

• There are a number of parasites that survive within and on the grasshopper, including insects, nematodes and mites. The different phases of the life of the grasshopper see different types of parasites surviving on a host grasshopper, according to North Dakota State University. The egg phase of the life cycle of a grasshopper is attacked by members of the Scelionidae family of insects, which resemble wasps. Other animals survive on or inside the grasshopper in the nymph and adult stages, such as flesh flies and techinid flies, which lay their eggs on the grasshopper. Following the hatching of the eggs, the young flies feed on the grasshopper for survival. Red mites survive on the exterior of the grasshopper but do not cause major problems for the insect.

Nematodes

• The family of parasites known as nematodes are one of the main parasites that attack the grasshopper. These parasites, also known as hairworms and threadworms, survive within the adult grasshopper, often reaching sizes of three or four times larger than the host grasshopper. The nematode often completely fills the cavity of the host grasshopper, except for the head and legs, emerging from the rear of the grasshopper when ready to mate. The exact form of infection of grasshoppers by nematodes is unknown, although it is thought infection occurs through nymph grasshoppers drinking water infected by nematode larvae, according to National Geographic.

Death

• Infection of parasites can lead to the death of the grasshopper, sterility or a reduced amount of energy within the insect. The infection of nematodes can lead to the death of the grasshopper by suicide, the hairworm is thought to introduce a collection chemicals into the body of the grasshopper to control its behavior, according to National Geographic. When the hairworm is ready to mate it forces the grasshopper to dive into water, killing the grasshopper and allowing the nematode to emerge in water where it mates and lays its eggs.