Behavioural And Electrophysiological Responses Of Amitus Hesperidum Silvestri To Volatiles From Tea And Aleurocanthus Spiniferus Quaint

Amitus hesperidum Silvestri (Hymenoptera:Platygasteridae) is an effective parasitoid of Aleurocanthus spiniferus Quaint during its larva and pupae period which is a pest on tea and citrus. It is a gregarious parasitoid that have a big natural control functions and the application potentiality. In the past 10 years, Aleurocanthus spiniferus Quaint has resulted in big losses in tea production,and developing better management becomes high request, especially by using Amitus hesperidum Silvestri as an effective control agent. This research dealt with the following questions.Firstly, There are a investigation about parasitic bees in Yaan, The second, Behavioural and Electroantennogram (EAG) responses of Amitus hesperidum Silvestri at different developmental stages to extracts from pests and plant-host feeding complex. The experiments based on above two questions were designed for understanding and answering. The results are summarized as follows:1,There are dominant species of parasitic bees on Aleurocanthus spiniferus in Ya'an.There are total 3 kinds of parasitic bees on Aleurocanthus spiniferus Quaint which were found in the resources dominant species of parasitic bees on Aleurocanthus spiniferus Quaint in Caoba and Zhongfeng village in Ya'an City. The analysis found that Amitus hesperidum Silvestri is the dominant species of parasitic bees on Aleurocanthus spiniferus in Ya'an.2,Antennal sensilla of Amitus hesperidum Silvestri observedThe antennae of Amitus hesperidum Silvestri were observed by means of electric scanning microscope. It was found that seven types of sensilla, including Bohm's bristles, Sensilla trichodea, sensilla placodea, Sensory pore, Sensilla coeleoconica, Sensilla cylindric and Sensilla styloconicum were found on the antenna of wasp. The shape of these sensilla and their distribution were described. There were obviously sex dimorphisms, including differences in the number of Sensilla trichodea and distribution of sensilla placodea, Moreover, Sensilla styloconicum were only found on female's antenna.3,The response of Amitus hesperidum Silvestri adults to Different volatilesThe role of volatile cues from host plants and hosts in the host-selection behavior of parasitic wasps was investigated by Y-tube olfactomete. The results show that the response of parasitoid is trend to plant-host feeding complex. Attract action appear tensity as:plant-host feeding complex>Leaf feeding insects Larval parasites>intact tea shoots> me-chanically damaged shoots; the response of Amitus hesperidum Silvestri adults to Different plant-host feeding Complex, the parasitoid significantly trend to density of 100/g,while the volatiles from plants infested with 50,200,400,800 did not; The response of Amitus hesperidum Silvestri adults to Different Leaf feeding insects, There existed a Significant regressive relationship between the tendency (Y)and the weight of whitefly-damaged tea(X); The response of Amitus hesperidum Silvestri adults to Different Larval parasites,when the number of insect body is 400, the effect could be boosted up to a highest exent. However,the number of insect body contune to increased,the effect of whiteflies on Amitus hesperidum Silvestri is decrease.4,The EAG responses of the male and female parasitoid to the different volatilesEAG response of female and male adult to five different volatiles was tested by electrophsiology. The results were similar to that of behavior. The parasitoid had a strongest reaction to plant-host feeding complex, intact tea shoots.The paired T test showed that the EAG response of female and male were not significantly different, However, the response of female is stronger than males in addition to intact tea shoots.