BIOLOGY, ECOLOGY, AND HOST-SPECIFICITY OF EUROPEAN APHTHONA SPP (COLEOPTERA, CHRYSOMELIDAE) USED AS BIOCONTROL AGENTS FOR LEAFY SPURGE, EUPHORBIA-ESULA (EUPHORBIACEAE), IN NORTH-AMERICA

Leafy spurge (Euphorbia esula) is an herbaceous perennial of European origin that was accidentally introduced into North America where it ha s become a serious weed in pastures and rangelands. Five species of ro ot-feeding chrysomelid beetles in the genus Aphthona have been release d in North America for the biological control of leafy spurge. They or iginate from central and eastern Europe and occur in different habitat s. The brown species, Aphthona cyparissiae, Aphthona flava, and Aphtho na nigriscutis, occur predominantly in open dry habitats, and the blac k species, Aphthona czwalinai and Aphthona lacertosa, prefer moister h abitats. All five species are univoltine and overwinter as larvae. The host range of these five Aphthona species is restricted to species in the subgenus Esula. (C) 1996 Academic Press,Inc.