Determination of Supercooling and Freezing Points of Tuta absoluta at Different Development Stages
This study aimed to investigate the cold tolerance of Tuta absoluta at different developmen-tal stages,providing a basis for establishing overwintering conditions and forecasting the pest's sur-vival in differing climates.The supercooling and freezing points of larvae,pupae and adults of T.abso-luta were measureed using an insect supercooling point tester.The results showed that the average supercooling point was lowest in first-instar larvae(-21.63 ℃)and highest in third-instar larvae(-15.97 ℃),while values for other stages followed in descending order:adults(-21.40 ℃)＜fourth-instar larvae(-19.98 ℃)＜pupae(-19.37 ℃)＜second-instar larvae(-17.96 ℃).The average freezing point was lowest in adults(-19.37 ℃)and highest in third-instar larvae(-12.60 ℃),with other developmental stages ordered as follows:first-instar larvae(-18.93 ℃)＜fourth-instar larvae(-16.32 ℃)＜pupae(-16.16 ℃)＜second-instar larvae(-14.24 ℃).These findings indicate that first-instar larvae and adults of T.absoluta exhibit a high cold resistance,where-as the third-instar larvae display relatively lower tolerance.T.absoluta is unlikely to overwinter in open field conditions in Ningxia,although the greenhouse may provide protective environments for survival under adverse climates.Controlling the population density of is critical for preserving the yield and quality of early spring crops.
Tuta absolutaSupercooling pointFreezing pointHardinessOverwintering
万方数据
维普
