Dr. Jay F. Brunner, Chairman
This research was supported through a grant from the Washington State Tree Fruit Research Commission.
Chair: Jay F. Brunner
Several species of Pentatomidae (stink bugs) feed on pome and stone fruits in Washington. Feeding by Euschistus conspersus Uhler and Chlorochroa ligata (Sayii) results in sunken areas on the fruit, 1/4 to 1/8 inch in diameter that appear corky beneath the skin(injury.gif). Orchards in Chelan County with high infestations of stink bugs suffered significant loss due to cullage of damaged fruit. These orchards are surrounded by host plants that play a major role in stink bug development. Euschistus conspersus and C. ligata were regularly found on mullein, bitterbrush, and currant throughout all sites in 1996 and 1997. The development of E. conspersus was investigated at 4 constant temperatures and a lower developmental threshold was determined to be 12oC. These species are univoltine in Washington and are attacked by several species of natural enemies, especially egg parasites. Surveys of parasites determined that 60% of stink bug eggs, in native habitats, are parasitized between late June and early July; this coincides with peak stink bug oviposition. Sampling strategies were developed to evaluate pest populations levels during the season. Two traps, the Jug and Fisher designs were determined to be effective in monitoring pest populations (jug trap.gif). Suggestions are made for further research.