Studies On The Behavior Characteristic Of Dominant Parasitic Wasps Of Ericerus Pela (Chavannes)

In the white wax production systems, pest insects of wax worms and their host plants belong to 28 species of 13 families of 4 orders. Predators of white-wax insect were one of the main factors to affect the breeding of insect species and wax production. The basic research on identification, occurrence rule and damage survey of parasitic wasps, belonging to 14 species of 5 families, have been done in this study and pest control gains some efficiency by using sets cage stocking of Ericerus pela (Chavannes). Not only on wax worms, the wasps but also are parasitic on other pests. It is surveyed that there is no occurrence of major pests in traditional areas of white wax production in China. By this phenomenon, it is indicated that the production of white wax scale also could breed natural enemies to control pests in agriculture and forest. By cultivating wax insect to breed parasitic wasps and using the abundant resources parasitic of natural enemies in broad scope host, the information transmission mechanism between the wasps and the host, the host ability to capture were studied to explore the basic rules of transfer mechanism in wasps finding hosts, which is expected to provide the necessary scientific guidance on control and utilization of parasitoids of white-wax insect. On the one hand, the wax production and quality were increased by controlling insect parasitoids. On the other hand, the theoretical basis of new models for biological control in agro-forestry was built through the cultivation and utilization of parasitic wasps to control pests. The study of information transfer mechanisms between parasitoids and it host white-wax insect not only is significance in theoretical science, but also benefits the practice of production.In this paper, Studies on the behavior characteristic of dominant parasitic wasps of Ericerus pela (Chavannes), by the theory of chemical ecology, Using the Capture method of dynamic head-space collection from living plant in airtight and circulatory bagging, Techniques of TCT-GC/MS and Computer library search, the chemical compositions and changes of volatile in white wax production system were revealed objectively and scientifically, which will afford the new scientific evidence and application base for further rational development and utilization of white wax resources. Using the color trend of parasitoids, the temporal-spatial niches of E. pela (Chavannes) and its dominant parasitoids were constructed and the follow function and parasitic effectiveness of three dominant parasitoids were also discussed in order to accumulate the scientific evidence for comprehensive evaluation on the parasitic wasps of E. pela (Chavannes).The stage of parasitic damage occurring in white-wax insects and dynamics rules of population are determined by morphological structure of parasitoid ovipositor of parasitic wasps. The symparasitism in E. pela (Chavannes) was found apparently in this study. The sex ratio (female: male) of Metaphycus ericeri is 10.47:1. Its ovipositing includes the process of host searching, holing, laying eggs and carding. Usually, the females lay only one egg or very few two eggs in a host. Different concentrations of honey water may both extend the longevity of parasitoids with nutritional supplements. Metaphycus ericeri express positive trends to female adults of E. pela (Chavannes) and host branches with female adults while shows the repellent nature to wax flower. Microterys sinicus shows strong positive trends to wax cover, wax flower and host branches with female adults.One-dimensional niche breadth, niche overlap and percentage similarity of E. pela and its dominant parasitoid wasps (Microterys ericeri Ishii, M. sinicus Jiang, and Metaphycus ericeri Xu et Jiang), were analysed. Temporal niche breadths of E. pela and its three dominant parasitoids were E. pela > Metaphycus ericeri > M. ericeri > M. sinicus and spatial niche breadths were E. pela > M. ericeri > Metaphycus ericeri > M. sinicus. The niche overlap of the three dominant parasitoids were M. ericeri > M. sinicus > Metaphycus ericeri; the percentage similarities were M. ericeri > Metaphycus ericeri > M. sinicus. This suggests that M. ericeri and E. pela possesses the most similarity in the resources series, strong synchronism and sympatry, and the maximum resource utilization. M. ericeri and Metaphycus ericeri had a large overlap in temporal-spatial niches and proportion similarity. Interspecific competition for resource utilization between these species was obvious. E. pela (Chavannes)is an abundant and stable food of many parasitoids because of its large population and for longer periods.In the studies of color trend, daily activities rules, migration capacity and range of parasitic wasps, the results showed that parasitic wasps of E. pela (Chavannes) obvious owned the trend of yellow color and the sequence of color selectivity were yellow> blue> blue-green> green> white> brown> red> black. The parasitic wasps mainly occurred in the middle and under layer of host plant garden, which closely related to the white wax worms distributing in host plants. In different times of the day, an activity peak of parasitic wasps appeared in 6:00 ~ 9:00 am with a second peak in the 15:00 ~ 18:00 pm. And parasitic wasps of E. pela (Chavannes) were more active in the sunny day than in the cloudy and rainy days. Vertical flight ability of dominant parasitoids of E. pela (Chavannes) was weaker than other parasitic wasps, generally no more than 2 meters beyond the treetop, which closely related to the small, light body of parasitic wasps and wind speed, direction and sunlight. The parasitic wasps have a certain ability of horizontal flight with migration distance limited within 60 meters.Through volatile collecting, testing in wax production systems and analysis material of information transfer the between E. pela (Chavannes) and parasitic wasps, 14 compounds were detected in volatiles from host t branches, accounting for 88.29 percent of the total content. The main components include alkanes, alkenes, carboxylic acids and ketones. In the period of sugar hanging attached, 15 compounds were detected in volatiles from female adults and host branches. The volatiles were mainly composed of alkanes, alkenes, terpenes and ketones, taking 88.81% of total content and nearly as volatiles from privet branches. While only 8 compounds were detected from mature female adult of E. pela (Chavannes). The types of compound in the volatiles were significantly lower than those in volatile from host branches or from female adults and host branches in the period of sugar hanging attached, But the content of volatile accounted for 99.29% of total, significantly higher than the content of host branches or from female adults and host branches in the period of sugar hanging attached, which showed the volatiles from matured female adults are more simplex and stable, mainly composed of esters and hydrocarbons. The test results of luring parasitic wasps by using different volatile compounds in the field show that alkanes, alcohols, carboxylic acids, esters and terpene volatiles can allure three dominant parasitoids and other mixed populations of parasitic wasps in varying levels. The growth period of E. pela (Chavannes) and its relationship to the occurrence of parasitic wasps should be given priority think to luring. There is some axis to volatile component between host plant and parasitic wasps of E. pela (Chavannes), depending on taste to look for their hosts.