Effect Of Temperature On B-biotype Bemisia Tabaci And Trialeurodes Vaporariorum

Bemisia tabaci(Gennadius)and Trialeurodes vaporariorum(Westwood)belong to Homoptera,Aleyrodedae.Both of them are worldwide pest ofagriculture.Insect is an animal that its body temperature changes with itsenviromental temperature. Temperatural change is one of the most importantfactors for seasonal insect population dynamics change. Bemisia tabaci ismore endurable to high temperature than Trialeurodes vaporariorum.Temperature,especially the different response to high temperature might bethe primary reason to seasonal population dynamics change. For this, studywas conducted on the effect of temperature to the development andreproductionof Bemisia tabaci. The hardiness difference to thermal stress ofBemisia tabaci and Trialeurodes vaporariorum;the relationship between coldand heat resistance.The main contents and conclusions were as follows.1) At the temperatural range of 20～29℃,the total developmentalperiods of B.tabaci from egg to adult was decreased with increasingtemperature. A common development threshold for all immature stages wasestimated at 12.41 ℃by a linear regression model, and the effectivetemperature was 278.42 day-degrees. With increasing temperature , the sexratio (♀:♂) of B.tabaci was getting lower and lower. The optimal range oftemperature for B.tabaci populationgrowth was 26～29℃. 2) Great difference also existed in heat tolerance: Upper lethal zone forthe adults of T.vaprorariorum was 39.0～42.5℃in contrast with 41.5～43.5℃for that of B.tabaci. Adult temperature of survival line was greatlydifferent, with a linear equation estimated for T.vaprorariorum and logisticregression equation for B.tabaci. These indicated that different patterns ofthermal response and regulation mechanisms which presented between thetwo species. The egg of both B.tabaci and T.vaprorariorum in the condition of hightemperature also showed different pattern. The Ltemp50 of eggT.vaprorariorum was lower than that of B.tabaci. This indicated that theegg of B.tabaci could endure great higher temperature than that ofT.vaprorariorum. and the difference.became bigger and bigger whentemperature increased. But this rule was reverse compared withthe adult. 3) Thermal Stress had significant effects on the fecundity ofT.vaprorariorum . At 25℃,the number of eggs of 20 female were 114. Afterexposured at 10℃for 4h, the number of eggs decreased to 19, which wassignificantly lower than that of controls. At 32℃eggs laid were decreasedgreatly. After exposured at 35℃for 1h the eggs laid to 4, which showedthat the high temperature absolutely restrained the egg-laid behavior ofT.vaprorariorum. 4) Thermal Stress had little effect on the offspring. It preseanted muchlittle effect on the lava survivorship, emergence and sex rate (♀:♂). All the...