The influence of different heating rates on mortality of Tribolium castaneum(Herbst)(Coleoptera: Tenebrionidae)

In order to elucidate the ability of stored product insects to resist high temperature at varying temperature conditions,the influence of different heating rates on the mortality of all life stages of Tribolium castaneum(Herbst)(Coleoptera:Tenebrionidae)was investigated.After acclimation from 28 to 42,44 and 46℃ at different heating rates(0,1.25,2.50,5.00,and 10.00℃/h),eggs,larvae,pupae,and adults of T.castaneum were exposed at 50℃ for 0(as a control),10,15,20,25 and 30 min,respectively.The corrected mortality of T.castaneum was determined after 24 h.The results showed that different exposure times and heating rates had significant effects on the mortality of T.castaneum.The mortality of all life stages of T.castaneum with the same acclimation experience increased significantly with the increasing exposure time,and acclimation improved the heat tolerance of T.castaneum.The mortalities exposed at 50℃ for 30 min of T.castaneum eggs(acclimated to 46℃ at 5.00℃/h),larvae(acclimated to 44℃ at 2.50℃/h),pupae(acclimated to 46℃ at 5.00℃/h),and adults(acclimated to 46℃ at 2.50℃/h)were 62.50%,54.44%,58.89%and 53.33%,respectively,significantly lower than that of corresponding life stages of T.castaneum acclimated at 1.25 and 10.00℃/h.The present results are in favor of developing an effective heat treatment protocol for pest control.