Bionomics and Host Range of the Introduced Basswood Thrips (Thysanoptera: Thripidae)

The introduced basswood thrips, Thrips calcaratus Uzel, feeds on developing buds and often defoliates extensive areas of deciduous forests in the upper midwest. Little is known about the basic biology of this species. Therefore, effects of temperature and host plant on T. calcaratus development were studied. Temperature affected the duration of each life stage, except the 1st instar. Total development time and adult longevity were inversely related to temperature. Total development time ranged from 29.0 d at 15°C to 12.0 d at 30°C. The availability of pollen as a supplemental nutrient source did not enhance attraction or performance of the thrips. T. calcaratus produced the most offspring at 20°C (0.7 eggs per female per day). There is a 2-d preoviposition period before the peak of ovipositional activity. Of the 7 plant genera assayed, 2 could sustain T. calcaratus development to adulthood. Performance on linden and sugar maple was similar, except the egg stage was longer on linden. The implications of T. calcaratus development under these environmental conditions and on these alternate hosts are discussed.