烟粉虱的耐寒能力与自然越冬北界分析*

室内耐寒性测定结果表明，烟粉虱成虫在4 ℃和0 ℃暴露时的致死中时分别为13.86 h和12.07 h，在-2 ℃和-8 ℃分别为4.74 h和1.7 h，它们之间有明显差异。2009年2月14-22日野外调查显示，仙桃市、南昌市、金华市在露地和大棚均发现烟粉虱以伪蛹和卵在杂草上存在，九江市只在大棚发现烟粉虱；而孝感市大棚与露地均没有发现烟粉虱。根据已经调查到的越冬地点及其所在地的温度，给出了全国烟粉虱自然条件下可能的越冬北界模型图。首次探讨了烟粉虱在我国的自然越冬北界分布线为浙江省金华市，江西省南昌市，湖北省仙桃市，四川省和云南省。

The cold hardiness and northern distribution boundary of overwintering whiteflies, Bemisia tabaci, in China

The results showed that significant differences in median lethal time for whitefly, Bemisia tabaci, were observed under different temperatures by determining their interior cold resistance. LT50 of B. tabaci under 4 ℃, 0 ℃, -2 ℃ and -8 ℃ were 12.07 h, 13.86 h, 4.74 h and 1.7 h, respectively. The results of fieldwork from February 14th to 22th, 2009 showed that B. tabaci could overwinter safely in the fields and greenhouses with eggs and pupae on the weeds. But it could not be found in the fields of Jiujiang City of Jiangxi Province and Xiaogan City of Hubei Province. According to the local temperature in the cities where whiteflies can overwinter in January, the northern distribution boundary for overwintering B. tabaci under the natural conditions in China had been determined as model diagram. They were Jinhua City of Zhejiang Province, Nanchang City of Jiangxi Province, Xiantao City of Hubei Province, Sichuan Province and Yunnan Province.