Effects of host plants and temperature on the development of Thrips palmi
The effects of three temperatures (15, 26, 32 °C) and four host plants (Benincasa hispida, Capsicum annuum, Cucumis sativus, Solanum melongena) on the growth and reproduction of Thrips palmi (EPPO A1 quarantine pest) were studied in laboratory conditions, in Florida (US). Survival and egg production were the highest when thrips were reared at 26 °C on B. hispida, cucumber and aubergine compared to capsicum. However, because of shorter development time the rates of natural increase for T. palmi were highest at 32 °C on those three host plants. At 26 °C, development time is similar on the 4 host plants, but survival and reproduction are much lower for thrips reared on capsicum leaves. At 15 °C and 32 °C, these differences are even greater with only 40 and 48 % of thrips reared on capsicum which survive at these temperatures. T. palmi tolerates low temperatures better than high temperatures. 100 % adult mortality was observed at 40 °C after a 15 h treatment. Adult mortality was 55.8 % at 0 °C after 15 h and only 24.3 ± 10.8 % at -10 °C after 30 min. The authors felt that this could explain why populations are low in summer months and high in winter/spring season in aubergine, cucumber and B. hispida fields in Florida. They also expressed concerns that the insect could expand into the south-eastern states of USA where the mild winter could permit the insect to overwinter in low numbers.
Sources
Tsai, J.H.; Yue, B.; Webb, S.E.; Funderburk, J.E.; Ti Hsu, H. (1995) Effects of host plant and temperature on growth and reproduction of Thrips palmi (Thysanoptera: Thripidae).
Environmental Entomology, 24(6), 1598-1603.