Research Of Important Hymenopterous Parasitoid Scleroderma Guani Xiao Et Wu: Embryonic Development, Parasitizing Behavior And Population Rejuvenation

Scleroderma guani Xiao et Wu is the important hymenopterous parasitoids controlling many borers. In this paper, embryonic development, parasitizing behavior of the parasitical insect and population rejuvenation after successive rearing with the pupa of Tenebrio molitor were studied. The main results are as follows:The parasitizing behavior of this bathylid in the laboratory was investigated. These processes were divided into assembling, recognition, stinging, clearing, feeding, oviposition and protecting protelean bathylid. Recognition and stinging to the pupa have much difference between female individuals. The time of stinging host is 1.4~7.0d , and the ratio of the stinging host is 8.7%~91.7%. The influence factors including: mating, host freshness, temperature and tube size. The effect of stinging the host, which makes host alive and fresh, was up to be parasitized by the female bathylid. On the average, the pupa of yellow mealworm was kept 12.6d in fresh. The average of laying eggs is 30, and the biggest is 91. The distribution of eggs in the pupa body is equable. This situation makes use of host nutrition effectually beneficial to the larvae of bathylid.After mass rearing bathylid by using the pupa of the yellow mealworm, through several generations, the breeding effect is decreasing. The main cause of population decline include: using the same kind of host, inbreeding, and lower ratio of bethylid and host. According to above influence factors, finding the several measures of population rejuvenation: using natural host for one generation; by hybridizing from different populations of the bathylid; reforming means of rearing. Otherwise, using the female of stronger viability, increasing ratio of bethylid and host, and gathering generations from different rearing tube are effectively measures.The development of the embryo of egg at 24℃ and 60~70% RH is about 140h. The period of embryonic development is a continuous course, which is divided into five stages: the early development, the germ band expanding, differentiation of protocorn and protocephalon, organic formantion and the embryo maturation. The embryonic formation stage is correspondingly simple. After the enteron formation the embryo turns into cysticercus. More complete respiratory system, excretory system and circulatory system in anatomic significance cannot be found. After forming stomodaeum volume the embryo is becoming big increasingly. This indicates that embryo may absorb nutrition of the host in the course of development.