紫薇绒蚧的不同虫态过冷却点测定

目的]明确紫薇绒蚧不同发育阶段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测定紫薇绒蚧1龄若虫、2龄若虫、蛹和雌成虫的过冷却点和结冰点。结果]紫薇绒蚧不同发育阶段按过冷却点值由低到高依次为2龄若虫、蛹、雌成虫、1龄若虫,分别为(-22.62±0.16)、(-20.85±0.23)、(-17.53±0.22)、(-10.31±0.14)℃。体液结冰点也以2龄若虫最低,为(-22.12±0.21)℃;蛹次之,为(-19.43±0.22)℃;雌成虫、1龄若虫结冰点较高,分别为(-16.21±0.16)、(-9.93±0.15)℃。结论]紫薇绒蚧的不同发育阶段过冷却点和结冰点均存在显著差异。

Supercooling Point of Different Stages of Eriococcus legerstroemiae

Objective] Laboratory experiments were conducted to examine the super-cooling point and the freezing point for Eriococcus legerstroemiae.Method] The supercooling points and freezing points at different stages of E.legerstroemiae were measured by digital multimeter and low temperature incubator.Result] The supercooling point value of different stage of E.legerstroemiae from low to high were the second instar nymph,pupa,female adult and the first instar nymph in turn,with (-22.62 + 0.16),(-20.85 ± 0.23),(-17.53 ± 0.22),(-10.31 ± 0.14) ℃,respectively.Freezing points determined revealed that of the second instar nymph was the least,as (-22.12 ±0.21) ℃;the secondary,(-19.43 ± 0.22) ℃,was the pupa.The female adult and the first instar nymph were last,as (-16.21 ±0.16) and (-9.93 + 0.15)℃ respectively.Conclusion] There is significant difference of the super-cooling point and the freezing point for E.legerstroemiae.