Sunn pest

Sunn pest (Eurygaster integriceps) is a devastating insect pest belonging to the order Hemiptera and the family Scutelleridae. It is widely recognized as the most significant threat to cereal production across its distribution range.

The primary hosts of the Sunn pest are cereal crops such as wheat, barley, and rye. While it specializes in grasses, the adult bugs can occasionally feed on a wider variety of crops, including bulb onions, forage beets, winter rapeseed, cabbage, hemp, peppers, watermelons, and melons, especially when natural vegetation is depleted.

The biology of the pest involves a univoltine life cycle. Adults overwinter in leaf litter within wooded areas. In spring, as temperatures rise, they migrate to cereal fields to feed and reproduce. Eggs are laid on the leaves, and the nymphs undergo five developmental instars before molting into adults, which feed extensively on the developing grains before migrating back to overwintering sites.

The damage caused by the Sunn pest is twofold. Spring feeding on the stems causes death of the central shoot and results in "whiteheads." The most severe economic impact, however, occurs during the grain-filling stage. Nymphs and adults inject proteolytic enzymes into the grain, which degrade gluten proteins and ruin the dough-making quality of the wheat, rendering the harvest commercially useless.

Effective management requires an integrated approach. Cultural practices include planting early-maturing varieties, implementing proper crop rotation, and harvesting the crop as early as possible to minimize the feeding period. Chemical control is implemented through the application of selective insecticides when the density of the pest population exceeds the economic threshold during the early stages of crop development.