日本平腹小蜂滞育解除条件及其在广州市田间的越冬情况

Diapause termination of parasitoid wasp Anastatus japonicus Ashmead and its overwintering in the field in Guangzhou

为明确日本平腹小蜂Anastatus japonicus Ashmead滞育解除的环境影响因子,于室内对不同光周期(10 L∶14 D和16 L∶8 D)、不同温度(17、24和27℃)及10℃低温刺激下日本平腹小蜂滞育解除率和滞育解除历期进行对比,并在广州市田间对越冬代日本平腹小蜂自然羽化情况进行调查。结果显示,高温长光照和低温短光照均可以解除日本平腹小蜂滞育,但是相对于低温短光照,高温长光照的滞育解除率更高,滞育解除历期更短,其中温度27℃、光周期16 L∶8 D条件下日本平腹小蜂的滞育解除率最高,滞育解除历期最短,分别为98.09%和22.95 d。低温刺激不是日本平腹小蜂滞育解除的必需条件,10℃下储存时间越长,滞育解除历期越短。日本平腹小蜂在田间以老熟幼虫越冬,当月平均气温达到20℃以上时开始缓慢羽化,在广州市的越冬时间长达4.5~7.0个月。表明日本平腹小蜂滞育解除最适宜的条件为温度27℃和光周期16 L∶8 D。

To clarify the environmental factors affecting the termination of diapause in parasitoid wasp Anastatus japonicus,this study explored the effects of photoperiods(10 L∶14 D and 16 L∶8 D),temperatures(17,24 and 27℃)and low-temperature stimulation(10℃)on the diapause termination of A.japonicus under laboratory conditions.The eclosion of the overwintering A.japonicus in the field of Guangzhou was also investigated.The results showed that both high temperature with long photoperiod and low temperature with short photoperiod could terminate the diapause of A.japonicus.However,the rate of diapause termination was higher and the duration of diapause termination was shorter under high temperature with long photoperiod when compared with low temperature with short photoperiod.At a temperature of 27℃and a photoperiod of 16 L∶8 D,the diapause termination rate and period was the highest and shortest(98.09%and 22.95 d respectively).Low-temperature stimulation was not a necessary condition for diapause termination of A.japonicus.The longer the storage time at 10℃,the shorter the diapause termination duration.Anastatus japonicus overwintered as mature larvae inside host eggs.When the monthly average temperature reached above 20℃,the overwintering A.japonicus began to emerge,with an overwintering period of 4.5 to 7.0 months in the field of Guangzhou.These results indicated that the optimal temperature and photoperiod for diapause termination of A.japonicus was 27℃and 16 L∶8 D,respectively.