关键词: 蝗虫微孢子虫, 蝗虫, 超微结构

Abstract: The ultrastructure and development of a microspori dian,isolated from the dead body of ori ental migratory locust (Locusta migratoria manilensis) in Hebei province was observed under light-and electron-microscope.The meront was spherical or ovocylindrical containing uni-, bi-,quadri-and multinucle ate forms.The hexa-,eith-nucleate meronts measured 6.9×7.9μm were peculiar to this strain.The ultra strructure of stages in the life cycle of the mictosporidia showed that merontsdeveloped in direct contact with the host cell cytoplasm and bi-,guadrinucleates meronts were arrangment two nuclei in a diplokary on.Sporonts were differentiated from meronts with the thickened plasmalemma and observed undergoing cytokinesis.Stratified electron-dense strands were depostied in the host cell cytoplasm and sporont plas malemma surface.Studies of pathogenicity showed that the mortality increased as the dosage rised1the third-instar was more sUsceptible than that of the fourth;the mortality of locusts reard together was higher than reard sep arately;the develoment time of infected locusta were delayed 2~ 3 days;the number of eggs infected lo custs decreased;the food consumption of the infected was 35~ 75%less than controlled after 24 days’ inoc ulation.

Key words: Nosema locustae, Locust, Ultrastructure