Adult phenology, abundance, and reproductive status of the locust twig borer,Ecdytolopha insiticianaZeller, were investigated during 1983 and 1984 in southeastern Kentucky using blacklight traps. First adults were captured in the second week of May and a second generation began to emerge in early July. No adults were captured after late August. Multiple matings by females were common, and egg-bearing females were present throughout most of the season. Adult females emerge with a large proportion of oocytes yolked; they oviposit primarily during the first few days following eclosion when fed a 10% honey/water solution. Males constituted 77.4% of the blacklight collection, but laboratory emergence data indicated a 1:1 sex ratio.