Seasonal distribution of the flower thrips (Frankliniella tritici) (Fitch) and onion thrips (Thrips tabaci Lindeman) (Thysanoptera: Thripidae) on safflower in eastern Montana.
Thrips were sampled in 1984 and 1985 on safflower plants that had been planted in Montana on 3 dates in April-May. In 1984, Thrips tabaci accounted for 57% of the adults collected and Frankliniella tritici 42%; the corresponding percentages in 1985 were 52 and 44. Four other species were recorded. Regardless of planting date, T. tabaci was the first species detected; populations peaked on 12 and 5 July in the 2 years, respectively. Populations of F. tritici peaked on 2 and 8 August. It is suggested that T. tabaci overwinters in the area, whereas F. tritici does not.