卷蛾分索赤眼蜂和拟澳洲赤眼蜂对小菜蛾利他素各成分的嗅觉反应

卷蛾分索赤眼蜂Trichogrammatoidea bactrae Nagaraja和拟澳洲赤眼蜂Trichogramma confusum Viggiani是小菜蛾Plutella xylostella (L.)的优势寄生蜂。本研究利用“Y”型管测定了2种赤眼蜂对小菜蛾P. xylostella利他素-卵表和腹部鳞片13种饱和烷烃的嗅觉反应。结果显示: 卷蛾分索赤眼蜂交配雌蜂进入2, 6, 10, 14-四甲基十五烷、正十五烷、正十七烷处理区的百分数分别为80.65%, 68.75%和66.67%, 表明这3种烷烃对卷蛾分索赤眼蜂交配雌蜂有显著的吸引作用, 其他10种饱和烷烃对卷蛾分索赤眼蜂雌蜂无明显作用。拟澳洲赤眼蜂进入2, 6, 10, 14-四甲基十五烷、正三十五烷和正十五烷处理区的数目分别占84.38%, 70%和62.16%, 表明其对拟澳洲赤眼蜂交配雌蜂起着显著的吸引作用, 而另外10种烷烃对拟澳洲赤眼蜂雌蜂无作用。卷蛾分索赤眼蜂和拟澳洲赤眼蜂未交配雄蜂进入13种烷烃处理区和对照区的时间均无显著差异, 表明利他素各组分对2种赤眼蜂未交配雄蜂均无吸引作用。

Olfactory response of Trichogrammatoidea bactrae and Trichogramma confusum(Hymenoptera:Trichogrammatidae)to different components of kairomones of the diamondback moth,Plutella xylostella(Lepidoptera:Plutellidae)

The egg parasitoids Trichogrammatoidea bactrae Nagaraja and Trichogramma confusum Viggiani are potential biological control agents for the diamondback moth (DBM), Plutella xylostella (L.). In this study, the olfactory response of two parasitoids to saturated hydrocarbons from host egg shells and adult scales of P. xylostella were measured using a Y-tube olfactometer. The results indicated that the percentages of mated females of T. bactrae entering the treatment arms of 2,6,10,14-tetramethyl-pentadecane, pentadecane and heptadecane were 80.65%, 68.75% and 66.67%, respectively, significantly higher than those entering the control arms, suggesting that these three compounds could stimulate an intensive search behavior by T. bactrae. However, the parasitoid did not respond to other 10 hydrocarbons. The percentages of mated females of T. confusum entering the treatment arms of 2,6,10,14-tetramethyl-pentadecane, pentatriacontane and pentadecane were 84.38%, 70% and 62.16%, respectively, significantly higher than those entering the control arms, revealing that T. confusum were significantly attracted by those three compounds. While the numbers of T. confusum entering the treatment and control areas had no differences in the tests with other 10 hydrocarbons. In the case of unmated males of T. bactrae and T. confusum, there was no significant difference in entering numbers of wasps between the treatment and control arms for all 13 saturated hydrocarbons.