Evaluation Of Spalangia Endius(Walker) For Control Of Bactrocera Cucurbitae(Coquillett)

The melon fly, Bactrocera cucurbitae(Coquillett)(Diptera: Tephritidae) is a worldwide quarantine insect of great harm. The larva does harm directly. It consumes pulp inside fruit causing rot and lost the edible value. Melon fly spends its pupal period in the soil, it has wide ranges of host, fast growing population, strong flight capacity and resistance. Current melon fly control methods rely heavily on the use of chemical pesticide and require significant production expense and ecological cost to melon and vegetable producers. Thus, we need to expand new control method which is healtier and more progressive. Spalangia endius(Walker)(Hymenoptera: Pteromalidae) is considered an important pupa parasitoid which can capture many species of filth flies. Inundative releases of S. endius can effectively control field poputions of the house fly in livestock farms for long. Of late years, some scholars design the functional response of S. endius to the pupae of Bactrocera dorsalis(Hendel). Melon fly is closerelative to oriental fruit fly, they both belong to Tephritidae, Bactrocera. In this trial, we expect to evaluate S. endius' parasite potential when it face the melon fly. The main results were summarized as follows:1. The functional response was oberved at 27 ± 1 ?, RH 70 ± 5 % and 14 L : 10 D. Results showed that attack responses of S. endius on melon fly were the best described by a Michaelis-Menten type II model Na=AN/(F+N), and the pupal instar of melon fly affected parasitism of S. endius significantly, but the age of female wasp adult did not affected much. Parasitic wasp prefer to the 2 d pupae.2. Laboratory studies were carried out to determine the effects of temperature on parasite potential of female S. endius on the pupae along a temperature gradient(21, 24, 27, 31, 34?). The result showed that the two parameters, parasite potential(A) and half saturated host density(F) were influenced by the temperature. The maximum parasite potential was at 27?, whereas half saturated host density decreased with increasing temperature.3. Different host pupal depths showed influence on parasitic capacity of the parasitoid. However, S. endius is able to find the pupae in the soil. The result showed that the parameter, parasite potential(A) decreased with increasing depths. We consider the limiting depth for parasitic wasp is 3 cm.4. Michaelis-Menten functional response model described S. endius to B. cucurbitae pupae at spatial scale: A=18.9080+2481.8093/S(R=0.9835, P<0.01). Along with the spatial scale increase, parasite potential of the adult female wasp tends to 18.9080. It is an asymptote.5. When the SWC is 17.0034%(Garden Soil, Outdoor), pupal depths of the melon fly were between 4 cm-7 cm in the majority. When the SWC is 16.8509%(Sands, indoor), pupal depths of the melon fly were between 2 cm-3 cm in the majority.6. There was stronger intraspecific interference in the parasitic functional response of S. endius i.e. the number of parasitized larvae decreases with increasing S. endius density. The relationship between searching efficiency of S. endius and its density could be well fitted as Hassell model E=0.1774P-0.6192(R=-0.9905, P<0.001).