Pear thripsTaeniothrips inconsequens(Thysanoptera: Thripidae) life history and population dynamics in sugar maple in Pennsylvania

Abstract

AbstractThe pear thripsTaeniothrips inconsequens(Uzel) was sampled for four years in a small sugar mapleAcer saccharumplantation in Centre County, Pennsylvania, USA. The life cycle ofT. inconsequenswas univoltine with the main period of emergence and flight from late March to mid May. Adults, eggs, and first and second instar larvae were associated with sugar maple budburst and early leaf development from late April to late May. Larval drop occurred from mid to late May. Mature second instar larvae, propupae, pupae and adults spent from June to March in the ground; development from larva to adult occurred between September and November. From March to May most (usually >90%) thrips adults and larvae sampled wereT. inconsequens.NoT. inconsequensmales were found. In soil samples taken in spring, summer and autumnT. inconsequenswere found to a depth of 50 cm but over 87% were in the top 20 cm. Almost noT. inconsequenswere found in the litter layer. Large variations inT. inconsequensadult emergence and larval drop were recorded. The most important contributing factors in fluctuations ofT. inconsequenspopulations were the length of sugar maple budburst, the degree of synchrony between thrips emergence and sugar maple budburst, and the occurence of sugar maple flowering.