两种赤眼蜂对芥兰和菜心挥发物的嗅觉反应

Olfactory response of two parasitoids to volatiles release from Brassica alboglabra and Brassica campestris ssp. chinensis var. parachinensis

为探明植物挥发性化合物在卷蛾分索赤眼蜂Trichogrammatoidea bactrae和拟澳洲赤眼蜂Trichogramma con-fusum寄主定向过程中的作用,本研究采用"Y"型嗅觉仪测定了这两种赤眼蜂对五种不同处理芥兰和菜心挥发物的嗅觉反应,结果表明:来自芥兰的完整植株、机械损伤植株、虫害损伤植株、虫菜复合体植株以及菜卵复合体植株的挥发物对卷蛾分索赤眼蜂有显著的吸引用,进入这些处理区的赤眼蜂数量分别占总试验蜂数的70.37%、75.0%、67.74%、68.42%和67.65%,显著高于对照;而其选择上述五种处理的菜心的数量分别占总试验蜂数的70.37%、72.73%、73.91%、70.37%和71.43%,显著高于对照,表明来自菜心各处理的挥发物对卷蛾分索赤眼蜂也具有显著的吸引作用。来自芥兰完整植株、机械损伤植株、虫害损伤植株、虫菜复合体植株及相应处理菜心的挥发物对拟澳洲赤眼蜂无显著吸引作用,进入芥兰和菜心处理区的赤眼蜂数量分别占总试验蜂数的62.5%、50.0%、50.0%、54.55%和60.0%、50.0%、54.84%、54.55%,与对照相比均差异不显著;而其选择芥兰和菜心的菜卵复合体植株的数量分别为72.97%和76.47%,均显著高于对照,表明带小菜蛾卵块的芥兰和菜心植株对拟澳洲赤眼蜂有显著吸引作用。

In order to test the effect of crucifer volatiles on host location of egg parasitoids,Trichogrammatoidea bactrae and Trichogramma confusum,five treatments,viz.,healthy pant,mechanicallydamaged plant,plant damaged by feeding activity of diamondback moth （DBM）,Plutella xylostella （L.） larvae,plant with feeding activity of DBM larvae and plant with feeding and oviposition activity of DBM were provided in Y-tube olfactometer bioassays. The results showed that volatiles from above five treatments of B. alboglabra were attractive to T.bactrae,the percentage of the parasitoid entering treated arms of B. alboglabra were 70.37%,75%,67.74%,68.42% and 67.65%,respectively,statistically higher than those entering the control arms. While the percentage of T.bactrae entering above corresponding five treated arms of B. campestris ssp. chinensis var. parachinensis were 70.37%,72.73%,73.91%,70.37% and 71.43%,respectively,significantly higher than those entering the control arms,indicating that volatiles released from B. campestris ssp. chinensis var. parachinensis could significantly attract T.bactrae.However,the volatiles whether from healthy plant,mechanically-damaged plant,plant damaged by feeding activity of DBM larvae and plant with feeding activity of DBM larvae of B. alboglabra or corresponding treatments of B.campestris ssp. chinensis var. parachinensis were no remarkable differences in attractiveness compare to their controls,respectively,and the percentage of T. confusum entering the above four treated arms of B. alboglabra and B.campestris ssp. chinensis var. parachinensis were 62.5%,50%,50%,54.55% and 60%,50%,54.84%,54.55%,respectively. In contrast,volatiles from plant （B. alboglabra and B. campestris ssp. chinensis var. parachinensis） with feeding and oviposition activity of DBM were attractive to T.confusum,the percentage of the parasitoid entering the treated arms were 72.97% and 76.47%,respectively,which was statistically higher than those entering the control arms revealing that crucifers with feeding and oviposition activity of DBM show significantly attractive to T.confusum.