湖北地区豚草卷蛾发生规律与抗寒性研究

【背景】豚草卷蛾是豚草的一种重要天敌,1993年在湖南临湘野外释放后,迅速扩散至湖北、江西、福建等省,对豚草种群的蔓延与扩张起到了一定的抑制作用。【方法】为明确豚草卷蛾在湖北的发生规律与抗寒性,2009年在湖北各豚草发生区进行野外调查,并将豚草卷蛾越冬态老熟幼虫置于不同低温下观测其存活率。【结果】豚草卷蛾主要分布于鄂东地区。其越冬代成虫于5月下旬至6月上旬发生,第1代幼虫发生高峰在6月下旬至7月上旬,10月中下旬老熟幼虫进入滞育。12月份的调查结果显示,豚草有虫株率为90%,虫口密度为313头.百株-1,存活率为93.3%。越冬老熟幼虫过冷却点为-26.4℃,存活率和存活时间随温度的降低而下降。【结论与意义】豚草卷蛾已广泛分布于湖北地区,且能成功越冬,对豚草可起到持续控制作用。

Occurrence regularity and cold resistance of Epiblema strenuana in Hubei Province

Background]Epiblema strenuana is an important natural enemy of Ambrosia artemisiifolia,it has rapidly spread to several adjacent Provinces such as Hubei,Jiangxi and Fujian since it was released into Linxiang in Hunan Province in 1993,and it to some extent has suppressed the spread and expansion of A.artemisiifolia population.Method]To clarify occurrence and cold hardiness of E.strenuana in Hubei province,the field survey was conducted in the areas invaded by A.artemisiifolia Hubei Province in 2009,and the survival rate of overwintering old larvae was determined at different low temperatures.Result]E.strenuana distributed mainly in the eastern region of Hubei Province.Overwintering adults occurred in late May to early June,the peak of 1st generation larvae were observed in late June to early July,and old larvae entered into diapause in late October.The results of survey in December showed that the insect-infected rate of A.artemisiifolia plants was 90%,the density was 313 larvae per 100 plants,and survival rate of larvae was 93.3%.The supercooling point of overwintering old larvae was-26.4 ℃,and both survival rate of overwintering old larvae and survival time decreased significantly with the decreasing temperature.Conclusion and significance]E.strenuana has widely distributed in Hubei Province,it can overwinter successfully in the areas invaded by A.artemisiifolia,thus it performs a sustainable control effect of A.artemisiifolia in Hubei Province.