Daily and temporal occurrence of Frankliniella spp. (Thysanoptera: Thripidae) on tomato

Daily occurrence and flight activity of Frankliniella spp. (Thysanoptera: Thripidae) in tomato fields was studied on five dates in 1990 and four dates in 1992. Higher number of Frankliniella occidentalis (Pergande) were observed on tomato flowers in the morning than in the afternoon on 3 of 5 and 2 of 4 sample dates in 1990 and 1992, respectively. Numbers of Frankliniella tritici (Fitch), Frankliniella fusca (Hinds) and immature thrips on flowers or foliage did not differ among sample hours. On tomato foliage, F. fusca and immature thrips were dominant, while few F. occidentalis or F. tritici were collected. Temperature was an important factor in the flight activity of F. tritici. Populations of F. tritici peaked earlier in the season and declined sooner than those of F. occidentalis. F. occidentalis and F. tritici both inhabited tomato flowers and subdivided this niche temporally, while F. fusca occupied a different niche, tomato foliage.