DISTRIBUTION OF BIOLOGICAL-CONTROL AGENTS OF LEAFY SPURGE (EUPHORBIA-ESULA L.) IN THE UNITED-STATES - 1988-1996

Leafy spurge, Euphorbia esula (Euphorbiaceae), is a perennial plant na tive to Eurasia that has become a widespread weed in North America. Si nce 1988, the United States Department of Agriculture, Plant Protectio n and Quarantine, Animal and Plant Health Inspection Service (USDA-APH IS-PPQ) has coordinated a classical biological control implementation program against leafy spurge in the United States. Through this progra m, nine Eurasian insect species have been imported and released in the United States, including six species of flea beetles, Aphthona spp. ( Coleoptera: Chrysomelidae), a root-boring moth, Chamaesphecia hungaric a (Lepidoptera: Sesiidae), a root-boring beetle, Oberea erythrocephala (Coleoptera: Cerambycidae), and a gall midge, Spurgia esulae (Diptera : Cecidomyiidae). These species have been released in 188 counties in 19 states. Established populations of at least one agent are present i n 148 counties in 18 states, while populations of at least one agent i n 62 counties in 16 states are large enough to permit collection and d istribution to other leafy spurge-infested areas. Biological control a gents have been released throughout areas of the United States infeste d by leafy spurge, and the initial phase of the USDA-APHIS-PPQ impleme ntation program is nearly complete. (C) 1997 Academic Press.