Effects Of Mating Behavior And Symbiotic Bacteria On The Pre-Embryonic Development Of Phenacoccus Solenopsis

Phenacoccus solenopsis Tinsley is an invasive exotic pest which has been found in China recently. It is supposed to be a potential threat to agricultural and horticultural production of China. Numerous researches were published associated with its biological characteristics, morphology and taxonomy, including controversy about its reproduction mode.The premise of scientific prevention and control strategy is made clear the reproductive mode of insect pests, preliminary studies in our laboratories show that reproductive modes of P. solenopsis is sexual reproduction form biologically, but there is still a lack of evidence on reproductive physiology. In this thesis, effects of mating behavior on ovary and eggs development of the P. solenopsis is studied for the first time, which could be a reproductive physiology evidence to prove P. solenopsis should be gamogenesis. The endosymbiont play an important role in the regulation of the reproductive mode of many insects. Whether the endosymbiont has effects on reproductive mode of P. solenopsis or not, the problem has not been the answered. In this paper, preliminary study was made on the relationship between bacteria and individual development of P. solenopsis. It provides bases for the further research on effects that endosymbiont has on reproductive mode of P. solenopsis. Results are as follows:1. There was a complete reproductive system of females p. solenopsis. Reproductive system of P. solenopsis contains a pair of ovaries, fallopian tube, spermatheca and a pair of accessory glands. The whole ovary is grape-like, and there are a lot of different developmental eggs on ovarioles. Ovarioles of P. solenopsis are telotrophic. Trophoblast cells concentrated at one end of eggs charmber. Unmated spermatheca was round and translucence under a microscope, and there is nothing else except the cytoplasm in the Cyst cavity by electron microscopy. The Cyst cavity of mated spermatheca is filled with opaque material under a microscope, and it is filled with agglomerate sperm bundle by electron microscopy.2. The ovari development and total protein changes of P. solenopsis females was influenced by mating behavior. After mating, mature eggs could be observed in the ovarioles. unmated ovary can not develop normally, and no mature eggs could be observed in the ovarioles. In the late stage of the body development, with egg resorption, ovarioles is full of empty egg charmber with trophoblast cells. Total ovarian protein is affected by mating behavior. Total ovarian protein in ovarian first rised then declined after mating. And total ovarian protein in ovarian has no obvious deposition before mating.3.The mating behavior of P. solenopsis affected the eggs development and apoptosis. Mated eggs can normally develop into embryos. Peripheral shells can be observed clearly, embryos begin to differentiated and somites is clear while eggs develop to late stage. Mating behavior have an impact on the activity of Caspase 3 enzymes which regulate apoptosis. Annexin-V staining on mated and unmated eggs shows that unmated eggs can not develop normally and become cellular necrosis.4. Endosymbionts Tremblaya princeps of P.solenopsis were related to individual development and sexual differentiation of P. solenopsis. P. solenopsis Endosymbion is Tremblaya princeps. We determined the body of P. solenopsis contains symbiotic bacteria T. princeps, and T.princeps located in different tissues between in females and in males. Bacteriome collapsed when the males entered into pupal stage. The content of symbiotic bacteria increased dramatically in the pupa stage, and then decreased. In females, Tremblaya princeps only located in bacteriome rather than any other tissue or organ. Size of bacteriome was significantly linear-related to the host body size, and its expanding rate accelerated as the adults developed.5. Individual development and morphology of P. solenopsis males. P. solenopsis males is belong to hyperpaurometamorphosis. Life history of P. solenopsis include 1st instar larvae,2nd instar larvae,pupa(prepupa and pupa)and male adult. It also has a shorter Life period then famale. It also provides the basis for the classification of the insect by numbers of the 10 antennal segment, abdomen with quinquelocular pores and don’t have multilocular disc-pores.