拟澳洲赤眼蜂对小菜蛾腹部鳞片和卵表十三种饱和烷烃的接触反应

为了解小菜蛾利他素对拟澳洲赤眼蜂搜索行为及寄生率的影响,在室内条件下测定了拟澳洲赤眼蜂对小菜蛾卵表和腹部鳞片13种饱和烷烃单一成分的接触反应。结果表明,在正十六烷处理卵卡上,拟澳洲赤眼蜂的活动指数(PAI)最大,为79.67;其次为正三十六烷,PAI为67.50;正二十二烷PAI最低,仅为3.00。拟澳洲赤眼蜂对正三十六烷处理卵卡的寄生总数最高,为183.17;其次为正十六烷,寄生总数为153.00;正二十二烷处理卵卡的寄生总数最低,仅为0.67。拟澳洲赤眼蜂最大寄生率在20%以上的有正十六烷、正十七烷、正二十五烷、正二十七烷、正二十八烷和正三十六烷处理;最大寄生率在5%以下的为正二十二烷处理。

Contact response of Trichogramma confusum to 13 saturated hydrocarbons from host egg shells and abdominal scales of Plutella xylostella

In order to understand the influence of kairomones from diamondback moth (DBM), Plutella xylostella, on searching behavior and parasitism for egg parasitoid, Trichogramma confusum Viggiani, the contact response of parasitoid to individual compounds of 13 saturated hydrocarbons from its host egg shells and abdominal scales of P.xylostella were bioassayed in laboratory condition. The results revealed that the highest parasitoid activity index (PAI) of 79.67 was observed in the egg cards treated with hexadecane than the others. Irrespective of concentration, this was followed by hexatriacontane with the PAI of 67.50, while docosane showed the weakest attraction to T.confusum with the lowest PAI of 3.00. Hexatriacontane caused the highest parasitism of 183.17 followed by hexadecane with the PAI of 53.00, while docosane exhibited the minimum parasitism of 0.67. The highest parasitism of T.confusum over 20% was found in the egg cards treated with hexadecane, heptadecane, pentacosane, heptacosane, octacosane and hexatriacontane, whereas the highest parasitism under 5% was found in the egg cards treated with docosane.