Grain Pentatomids

insects of the family Pentatomidae that harm bread and feed grains. The insects are distributed in many countries. They include the species Eurygaster integriceps, E. austriacus, E. maurus, Aelia acuminata, and A. sibirica. The insects have developmental cycles and inflict the same type of damage.

The most harmful species, Eurygaster integriceps, often reproduces in enormous numbers. It damages winter and spring wheat and, to a lesser extent, rye, barley, and other cereals. In the USSR it is distributed in the southern European portion, the Ukrainian SSR, Uzbekistan, Tadzhikistan, and Kazakhstan. The active period lasts about three or four months, beginning in March or April, when, after wintering in forests, forest strips, and orchards, the insects attack cereal crops. After spring feeding, each female deposits 28 to 260 eggs on the leaves of the plants. With an average daily temperature of 20°C, adults appear in 50 days; at higher temperatures, the adults appear earlier. Both the imagoes and the larvae damage the plants; their saliva contains enzymes that split proteins, carbohydrates, and fats. The damaged shoots turn yellow, and the leaves dry out. The plants are retarded in growth and often die. If the embryo is affected, the grain loses its viability. If the endosperm is affected, the grain loses nutritional properties. The baking and nutritional qualities of flour milled from grain affected by E. integriceps are diminished.

Control measures include harvesting the grain during the wax phase and rapid removal of dried windrows. When the number of pests is high, it is necessary to create conditions favorable for the reproduction of egg parasites (Telenomus, Microphanurus) during the winter. Also effective is the application of insecticides to plantings.