Effect of heat shock on life parameters of Frankliniella occidentalis (Thysanoptera: Thripidae) offspring

The western flower thrips (WFT), Frankliniella occidentalis (Pergande), is an invasive insect pest in China, and is known to cause great economic losses worldwid.  To understand the effect of high temperature on WFT population dynamics, we constructed life tables to demonstrate the effects of heat shock on the growth rate, survival rate, and fecundity of WFT offspring.  All insects were reared on leaves of Brassica oleracea L.  WFT adults and second instar larvae were heat-shocked at 45°C for 2 h.  The same treatment was repeated following a 24-h recovery period.  The development and various life-table parameters of their F1 offspring were evaluated.  The duration of the immature period (11,74 d) of the offspring of heat-schoked adults was shorter than that of the control group (11,86 d), whereas the duration of the immature period of the offspring of the heat-schocked larvae was 12.36 d, indicateing that heat-shock slowed the development of the offspring.  The adult preoviposition and total oviposition periods of the offspring of the heat-shocked adults were significantly longer (3.70 and 15.67 d, respectively) than those of the control group (2.47 and 14.37 d, respectively).  The fecundity of the offspring of the heat-shocked larvae and adults was 81.76 and 70.59, respectively.  Both of these values were significantly less than that of the control group (149.14).  The use of heated tents might be an effective treatment for the prevention and control of WFT infestations in greenhouses.  Our life-table analysis of the effects of heat shock on F1 survival and reproduction provides a strong theoretical basis for future studies of thermal treatments for the control of WFT.