Embryonic Development Of Callosobruchus Maculatus (Fabricius) And The Parasitic Rate Of Dibrachys Xavus On Its Larvae

Callosobruchus maculatus (Fabricius) is one of the most common plant quarantine insects in China immigration quarantine. Because of its wide feeding objects and severe harm to crop, it has extremely economic significance to agricultural. Callosobruchus maculatus (Fabricius) has severe harm on all kinds of beans, such as mung beans, soybeans, red beans, lentils, adzuki beans, chickpeas and other legumes, in addition, it has certain harm to some oil plants and other crops. Nowadays, domestic and foreign experts have done a lot of researches on the prevention and control of Callosobruchus maculatus (Fabricius), however, no experts and scholars have done any detail research on the biological prevention and control on embryonic development of Callosobruchus maculatus (Fabricius).Under the condition of 28℃ and 70% relative humidity, the embryonic development process of Callosobruchus maculatus (Fabricius) had been studied. The results were as follows, The duration of eggs was 118h,0～1 lh was the cleavage stage,12h-16h was formation of blastoderm, germ band,17h-21h was formation of germ layer, germinal membrane,21h-90h was the formation of embryonic body section and appendages, 92h～118h was dorsal and mature period of embryo. Under the condition of 75% relative humidity, using red beans as food for experiment organism, the influence on the growth and reproduction of Callosobruchus maculatus (Fabricius) under different temperatureshad been studied. The results showed that under the condition of 20℃,24℃,28℃,32℃, 37℃.the developmental duration of Callosobruchus maculatus (Fabricius) from egg to adult were respectively 66.0,31.0,27.0,21.0 and 31.0 days, development threshold temperature was 13.42℃, effective accumulated temperature of 80.828 days·degrees.At room temperature, female Dibrachys xavus is inoculated on Callosobruchus maculatus (Fabricius). Morphology development of Dibrachys xavus is recorded, besides, parasitism and parasitic rate of Dibrachys xavus to Callosobruchus maculatus (Fabricius) were observed and counted. The results showed that the number of each female Dibrachys xavus which parasited Callosobruchus maculatus (Fabricius) larvae or pupae were 1 to 12.4, average was 5.8, number of birth bees were 1-143, average was 59.08. average of each female wasps spawning eggs on host was 21, maximum up to 47. Usually, about 14 eggs can spawned on the body of one host, maximum up to 36. Supply host fewer sub bee emergence is also reduced; increased host supply within a certain range, the number of sub-bee will increase proportionally. Since parasitic way of Dibrachys xavus adult not only egg parasitic, but also can parasite by feeding the host humoral, Callosobruchus maculatus (Fabricius) suffered parasitic wasps will all died, therefore, based on capability to kill Callosobruchus maculatus (Fabricius) by one Dibrachys xavus, the integrated control capability should be more than the number of parasitic eggs. In case of no chemical pesticides interference, parasitic rate of Dibrachys xavus on Callosobruchus maculatus (Fabricius) can reach 75% to 100%, and the fatality rate after parasitism was 100%. The parasitic rate reflected that the biological control by using parasitic Dibrachys xavus to Callosobruchus maculatus (Fabricius) is very effective.The embryonic development process of Callosobruchus maculatus (Fabricius) had been recorded in this study, which fills the blank of the Morphology change records of the tissue and organ of Callosobruchus maculatus (Fabricius) in embryonic stage, and provides the basis for the classification and system development of Callosobruchus maculatus (Fabricius), as well as lays a foundation for further studies in molecular biology of Callosobruchus maculatus (Fabricius), provides helpful solution to the prevention and control of Callosobruchus maculatus (Fabricius) on a gene level. This study also includes the research on the parasitic Dibrachys xavus’s biological prevention and control on Callosobruchus maculatus (Fabricius), which fills blank of domestic detial information on its hostile creatures’ biological prevention and control on Callosobruchus maculatus (Fabricius), lays the foundation and provides the basis for the future research on biological control of Callosobruchus maculatus (Fabricius).