端尖食植瓢虫和柳蓝叶甲的过冷却点测定

目的]明确端尖食植瓢虫、柳蓝叶甲各虫态的过冷却点和结冰点。方法]采用数字万用电表和低温培养箱对端尖食植瓢虫和柳蓝叶甲1~3龄幼虫、蛹和雌雄成虫分别进行过冷却点和结冰点测定。结果]端尖食植瓢虫的不同发育阶段过冷却点和结冰点由高到低顺序为1龄幼虫(-12.83±0.25),(-12.14±0.14)℃]、成虫(-15.45±0.20),(-13.67±0.24)℃]、2龄幼虫(-16.26±0.21),(-14.73±0.15)℃]、蛹(-18.87±0.23),(-16.65±0.18)℃]、3龄幼虫(-22.65±0.09),(-19.67±0.09)℃]。柳蓝叶甲的不同发育阶段过冷却点和结冰点略低于端尖食植瓢虫,其由高到低顺序为1龄幼虫(-13.74±0.15),(-13.15±0.24)℃]、2龄幼虫(-16.12±0.21),(-14.28±0.16)℃]、3龄幼虫(-17.05±0.15),(-15.73±0.20)℃]、蛹(-19.57±0.13),(-17.25±0.16)℃]、成虫(-22.73±0.12),(-19.69±0.10)℃]。端尖食植瓢虫和柳蓝叶甲的雌成虫过冷却点和结冰点都低于雄成虫,端尖食植瓢虫雌成虫的过冷却点和结冰点分别为(-15.67±0.19)、(-14.81±0.22)℃,雄成虫分别为(-15.23±0.21)、(-12.53±0.26)℃,柳蓝叶甲雌成虫的过冷却点和结冰点分别为(-18.66±0.21)、(-18.11±0.22)℃,雄成虫分别为(-18.24±0.19)、(-17.23±0.26)℃。结论]端尖食植瓢虫和柳蓝叶甲不同发育阶段的过冷却点和结冰点均存在显著差异,2种昆虫各自的雌、雄成虫的过冷却点差异不显著,而结冰点呈显著差异。

Supercooling Point of Different Stages of Epilachna quadricollis and Plagiodera versicolora

Objective] Laboratory experiments were conducted to examine the supercooling point and the freezing point for the Epilachna quadricollis and Plagiodera versicolora.Method] The supercooling points and freezing points at each development stage of E.quadricollis and P.versicolora were measured by digital multimeter and low temperature incubator.Result] The sequence of supercooling point from low to high was the 1st instar larvae(-12.83±0.25),(-12.14±0.14)℃],adult(-15.45±0.20),(-13.67±0.24)℃],the 2nd instar larvae(-16.26±0.21),(-14.73±0.15)℃],pupa(-18.87±0.23),(-16.65±0.18)℃],the 3rd instar larvae(-22.65±0.09),(-19.67±0.09)℃].The supercooling point and freezing point of P.versicolora were lower than those of E.quadricollis.The sequence of supercooling point from low to high was the 1st instar larvae(-13.74±0.15),(-13.15±0.24)℃],the 2nd instar larvae(-16.12±0.21),(-14.28±0.16)℃],the 3rd instar larvae(-17.05±0.15),(-15.73±0.20)℃],pupa(-19.57±0.13),(-17.25±0.16)℃],adult(-18.45±0.20),(-17.67±0.24)℃].The supercooling point and freezing point of E.quadricollis and P.versicolora′s female adult were lower than male adult.Conclusion] There is significant difference of the supercooling point and the freezing point between E.quadricollis and P.versicolora.And the difference of adult which are in different of supercooling point is significant while the difference of freezing point is not.