Egg - When first laid, the 1.4 x 1.2 mm barrel-shaped eggs of the green stink bug are yellow to green, later turning pink to gray. The white kettle-shaped eggs of the brown stink bug are slightly smaller than those of the green stink bug. Leaffooted bug eggs are slightly keg shaped.
Nymph - Nymphs of all three bugs are smaller than, yet similar in shape to the adults. Green stink bug nymphs are predominantly black when small, but as they mature, they become green with orange and black markings. Nymphs of the brown species are light green. Leaffooted bug nymphs are bright red.
Host Plants - Stink bugs feed on over 52 plants, including native and ornamental trees, shrubs, vines, weeds, and many cultivated crops. The preferred hosts are nearly all wild plants. Stink bugs build up on these hosts and move to cultivated hosts as their preferred food becomes unpalatable. Among vegetable crops, stink bugs attack bean and cowpea seeds, okra pods, ripening tomato fruit, and stems of melons and asparagus. Bean, cowpea, sorghum, eggplant, potato, tomato, peach, strawberry, okra, and watermelon are only a few of the leaffooted bug's many host plants.
Damage - Nymphs and adults of both kinds of bugs pierce plants with their needle-like mouthparts and suck sap from pods, buds, blossoms, and seeds. The degree of damage depends, to some extent, on the developmental stage of the plant when it is pierced by the stink bug. Immature fruits and pods punctured by bugs become deformed as they develop. Seeds are often flattened and shriveled, and germination is reduced.
Life History - Stink bugs overwinter as adults in ditch banks, along fence rows, on roadsides, and in other similar places. They become active in spring when temperatures rise above 21 degrees C (70 F). Each female deposits up to several hundred eggs, usually in mid- to late June. These eggs are laid in clusters, primarily on leaves and stems, but also on pods. Nymphs hatch from these eggs and pass through five instars before becoming adults. Approximately 5 weeks elapse between hatching and adult emergence. Two generations per year occur in Arkansas while only one generation per year has been reported in Virginia. In any case, stink bugs usually reach high population levels in late September or early October.
The biology of leaffooted bugs is not well documented. They overwinter as adults and have been collected all months of the year. However, they are most common from May onward into the fall months.
Thorough weed control may reduce overwintering populations near fields but infestation by stink bugs emerging from nearby woods or other areas is inevitable. The use of insecticides is the most reliable method of control. For up-to-date recommendations, consult the current North Carolina Agricultural Chemicals Manual.
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