| A dominant parasitoid, Campoletis chlorideae Uchida (Hymenoptera: Ichneumonidae). which attacked two important lepidoptera pests cotton bollworm, Helicoverpa armigera (H Ubner). and tobacco cutworm. H. assitlta Guenee, plays important control role on pests in fields. It is important that mechanism of the wasps for control pests was studied extensively by chemical ecology and behavior ecology. By choosing five host plants cotton, tobacco, tomato, peanut and capsicum, the role of phytochemicals in host-finding of C. chlorideae was studied. The main results are summarized as follows.Development periods and cocoon weight of wasp in five host larvae were compared in lab, and development periods, cocoon weight, cocoon collected rate, emerging rate, and longevity of wasps in body of different day-olds larvae of S. litura were compared. The results indicated that 3~5 day-olds larvae of S. litura could act as fit host for mass-rearing C. chlorideae. Sex ratio lost balance when female mate male from offspring of unmated female.Scanning electron microscopy study was conducted on the antennal sensory sensilla of the parasitoid. Six distinct types of sense receptor were found. Sensilla trichodae I , sensilla chaetica and Bohm's bristles are considered to be a mechaosensilla, and sensilla placodea and sensilla basiconica was considered to be of olfactory function.The role of volatile cues from host plants and hosts in the host-selection behavior of parasitic wasps was investigated by Y-tube olfactometer. The result indicated parasitic wasps were attracted by host plants and can distinguish fit plants from unfit plants, and show preferences to different nutritional organic of the same plant. When the plants were treated with different ways, the strongest attractive was host plants damaged by 2-3-instar cotton bollworm, followed by plants damaged by hand and healthy plants. There was not significantly ditferent in attractiveness cues from cotton leaves damaged by hand and damaged by 2-3-instar of S. litura. Host larvae and their frass can arise oriental behaviors. Female adult wasps do not show preference to larvae of H. armigera vs. S. litura. Compared with the frass of 5-6-instar cotton bollworm, Female wasps show preference to frass of 2-3-instar bollworm. Experience affected the adult behavior. Female adult show preference to volatiles from the host plants that was experience in the last parasitilizing process. Female wasps were attracted by cis-3-Hexenol-l-ol. (Z)-3-Hexenl-yl-acetate.Benzaldehyde. Acetophone at concentration of 10?(volume ratio). 1-Hexenal. 1-Hexanol. Propan-1-o! at concentration of 10"4.Volatiles were collected from the headspace of five plants by super Q, and were analyzed and identified by GC-MS. The results indicated the component and quantity of volatiles from host plants damaged by host larvae significantly increased, compared with host plants damaged by hand and healthy host plans. Component and peak area of volatile from cotton plants damaged by 2-instar cotton bolhvorm increased 10 species and 141%. compared with that of cotton plants damaged S. litura. Main component of volatiles from cotton leaves damaged cotton bollworm were a-Pinene, p-Myrcene, trans-Caryophyllene. and (Z)-3-Hexen-l-ol acetate. Dominant chemicals in tomato were p-Thujene oc-Terpinene trans-Caryophyllene. Main volatiles emancipated from peanut damaged were (Z)-3-Hexen-l-ol acetate, 3,6-dimethyl-l,5-Heptadiene, 8-3-Carene and Linalool. Dominant compounds from capsicum fruit damaged were 3,7-dimethyl-l,3,6-Octatriene Main compounds were alkyl hydrocarbon from tobacco damaged by hand, (-)-p-Elemene and 3,7-dimethyl-l,3,7-octatriene in capsicum damaged.EAG response of female adult to different host plants was tested by electrophsiology. The results were similar to that of behavior. EAG responses of C. chlorideae to 33 compounds of four chemicals classes, aliphatic chemicals, aroma compounds and terpenoid were tested. The results showed that with 0.25 ul of stimulus load, EAG response of adult wasps to aliphati...
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