2种茶翅蝽卵期寄生蜂的竞争关系及种群动态研究

Population Dynamics and Interspecific Competition between Trissolcus halyomorphae Yang and Anastatus sp. in ParasitizingHalyomorpha halys(Stl) Eggs

在室内(26±1)℃下,研究了茶翅蝽沟卵蜂和平腹小蜂对寄主卵的竞争行为。结果表明:2种蜂均能寄生已被另一种蜂寄生的卵;寄主卵先被沟卵蜂寄生,发育0～4天后再供平腹小蜂寄生时,出蜂绝大多数为平腹小蜂;发育6天后再供平腹小蜂寄生时,沟卵蜂羽化率可达92.31%。寄主卵先被平腹小蜂寄生,并发育0～1天内再供沟卵蜂寄生时,出蜂以沟卵蜂为主;发育2天以上再供沟卵蜂寄生,出蜂多为平腹小蜂。新鲜的卵利于蜂的寄生和羽化,寄生已发育4天以上的寄主卵,出蜂率很低。茶翅蝽沟卵蜂成虫在田间有两个发生高峰期,分别为6月下旬和8月上旬。在6月上旬～8月中旬可见平腹小蜂成虫活动。从9月上旬开始,2种寄生蜂及寄主卵数量减少。

Trissolcus halyomorphae Yang and Anastatus sp.are the important natural enemy to parasitize eggs of Halyomorpha halys（St？l）. Interspecific competition between two parasitoids were investigated at 26℃ in the laboratory.Both parasitoids could lay eggs into host eggs previously parasitized by the other species,leading to occurrence of multiparasitized eggs.When host parasitized by T. halyomorphae ≤4 days were exposed to Anastatus sp.,nearly all ensuing parasitoid adults from the multiparasitized host eggs were Anastatus sp.,and host parasitized by T. halyomorphae ≥6 days,T. halyomorphae emerging almost. When host parasitized by Anastatus sp.≤one day were exposed to T. halyomorphae,most of the ensuing parasitoid adults from the hosts were T. halyomorphae. When eggs parasitized by Anastatus sp≥2 days were exposed to T. halyomorphae,nearly all Anastatus sp adults from the multiparasitized host eggs.The two egg parasites prefers ovipositing in fresh eggs to old ones,and percentage of adult emergence highly. When egg age ≥4 days,a few adult could emerge.The last ten-days of June and the first ten-days of August were the peak periods of T. halyomorphae.There were Anastatus sp adults from the first ten-days of June to the middle ten-days of August.They decreased on the first ten-days of Sept..