Nezara viridula (Linnaeus)
Author: David Riley, University of Georgia, 2018
Description
Immature stages: The southern green stink bug lays cluster of 30-130 eggs. Eggs are deposited in hexagonal clusters with arranged in straight rows and glued together. Eggs are about 1.3 mm long, yellowish-white to pinkish-yellow. The top of the egg is clearly indicated by a ring of tiny spines. The southern green stink bug has five nymphal instars. Nymphs are shaped similar to the adults but lack wings. Wing pads are apparent and grow longer with each instar. Color varies with instar. The head, thorax, and wing pads range from light green to very dark. The abdomen is colored similar to the thorax and marked with rose and white spots.
Adult stage: Stink bugs possess a dorsal, triangular shaped shield on their backs. The most common stink bug in vegetables in Georgia is the Southern Green Stink Bug. Adults are uniform dull light-green, though the ventral surface is paler. They are 13- 17 mm long and about 8 mm wide. Adults have a rounded spine between the last two legs. The green stink bug is similar in appearance but has a pointed spine.
Biology
Life cycle: Eggs clusters are generally laid on the underside of leaves and hatch in about 5 days. Typically, all eggs in a cluster will hatch within 1-1.5 hours of each other. The southern green stink bug develops through five instars in about 32 days. Females begin oviposition about 14-20 days after attaining the adult stage.
Seasonal distribution: Stink bugs are rarely of concern in fruiting vegetables prior to flowering. Although they can feed in leaves and stems, reproductive structures, such as corn ears, tomato and pepper fruit, seeds, and pods are preferred feeding sites.
Damage
Stink bugs have piercing-sucking mouthparts to puncture plant tissue and remove sap. The greatest damage results from feeding on fruiting structures. As it heals, the feeding site becomes hard and darkens. Seeds fed upon may be shriveled, deformed and shrunken, or may simply bear a dark spot and depression at the feeding site, depending on the stage of development when attacked. Damage early in development can lead to severe deformities and abscission while damage near harvest may result in small dark spots at the feeding site. Stink bugs can also introduce bacteria and yeast, or simply provide a site of entry for disease organisms, resulting in fruit decay.
Management
In most vegetable crops sampling is conducted with visual examination of plants and fruiting structures. Stink bugs are typically controlled with insecticides used throughout the fruit production period of susceptible crops. Identification of stink bug species involved prior to selection of insecticide is important as different species respond differently to insecticides and there are predatory species of stink bugs found in vegetables.