螟黄赤眼蜂携带球孢白僵菌防治大豆食心虫

Control Effect of Trichogramma chilonis carrying Beauveria bassiana on Soybean Podborer

大豆食心虫作为重要害虫在我国大豆主产区造成巨大经济损失。白僵菌和赤眼蜂是大豆食心虫的两种重要生物防治手段,如何将二者相结合实现大豆食心虫的可持续防控还未见报道。本研究从大豆食心虫幼虫僵虫分离、鉴定并筛选到3株高毒力球孢白僵菌菌株,对大豆食心虫老熟幼虫致死中时间(LT50)分别为6.21 d,6.39 d和6.87 d。筛选到对螟黄赤眼蜂羽化和寄生害虫卵无明显影响的球孢白僵菌孢子高吸附性助剂0.1%(w/v)淀粉溶液,实现单头蜂带菌量3.56×10^(4)个孢子。两年田间试验表明,较单一使用螟黄赤眼蜂,螟黄赤眼蜂携带球孢白僵菌对大豆食心虫防治效果分别提高了11.80%和8.31%,分别达到了70.44%和64.75%,从而实现了在不明显增加防治成本的基础上,提高防治效率,实现协同增效。

Soybean moth is an important pest causing huge economic loss in the main soybean producing areas in China.Beauveria bassiana and Trichogramma are the two important biological control agents against soybean moth.However,how to combine the two agents to realize sustainable control of soybean moth is not addressed.Herein,three B.bassiana strains with high virulence against the pest were isolated,identified and screened from the diseased soybean moth larvae.The median lethal time(LT50)of the strains to the mature larvae of the pest were 6.21 days,6.39 days and 6.87 days,respectively.The B.bassiana conidia and their highly adsorptive adjunct,0.1%(w/v)starch solution,showed no effect on the emergence and parasitism of pest eggs of T.chilonis.With the adjunct,T.chilonis was able to carry fungal conidia of 3.56×10^(4) per wasp.The two-year field experiments showed that,compared with Trichogramma alone,the pest control effect of Trichogramma carrying B.bassiana was increased by 11.80%and 8.31%,respectively,to 70.44%and 64.75%,respectively,thereby improving the pest control efficiency and realizing synergy without increasing the control cost.