The Studies On Bionomics Of Aschersonia Sp. Parasitizing In Asterodiaspis Variabile And The Pathogenetic Capacity On Trialeurodes Vaporariorum

We have studied the bionomics of the fungus Aschersonia sp. parasitizingin Asterodiaspis variabile in detailed. They included that the effects ofdifferent conditions on colonies'growth rate, the effects of different conditionson spores'germination, the effects of different conditions on size of sporesdiameters and spore-producing bionomics. And we found out that the bestconditions for colony growth, spore producing,spore growth and sporegermination. Besides, we have studied the pathogenetic capacity of the fungusAschersonia sp. to white flies Trialeurodes vaporariorum (Westwood) in thesecond or third instar and got the result of control effect on white flies and theit was estimated as well. Our mainly results are as the following.On different culture medium, at different temperature and different pHvalue and under different illumination conditions, we observed the growth anddevelopment of the fungus Aschersonia sp.. The result had turned out that atthe temperature of 25℃, pH value of 6~7, under the illumination conditions of12L:12D, on PDA culture medium and corn flour agar culture medium, thecolonies grew very well and they producing spores fast and the amount ofspores was great. Those bad conditions, such as higher or lower temperaturethan 25℃, higher or lower pH value than 6~7, without light or too much light,or on unsuitable culture media like oatmeal agar culture medium, and so on,will negatively affect the colony growth or spore producing.On different culture medium, at different temperature and different pHvalue and under different illumination conditions, we studied the growth rateof the fungus Aschersonia sp.. The result turned out that at the temperature of25℃and pH value of 6~7 of culture media, the colonies grew faster than atother temperatures or pH value of culture media. Under the illuminationconditions of 24-hour darkness, the colonies grew fastest. Under theillumination conditions of 24-hour illumination, the colonies grew slowest.Under the illumination conditions of 12L:12D, the growth rate of colonies wasin the middle. On Quercus variabilis leaves decoction agar culture media andSDYA agar culture media, the fungus grow fastest; and on PDA culture mediaand oatmeal agar culture media, the colonies growth rate was in the middle.On corn flour agar culture media, the growth rate is the lowest. At different temperature and different pH value of solutions and underdifferent illumination conditions, in different nutritional solutions, we studiedthe germination rate of spores of the fungus Aschersonia sp. The result turnedout: The best temperature for germination is 25℃and higher or lowertemperature than 25℃was not favorable for spore germination. The best pHvalue range of solution for germination was 6~7. If the pH value was too highor too low, it would be unfavorable for germination. Illumination was benefitto spores'germination and the best condition was 24-hour illumination.Saccharose solution, maltose solution, lactose solution, glucose solution and Quercusvariabilis leaves decoction solution were all benefit to spores'germination. And1% Saccharose solution and glucose solution were more favorable for spores'germination. At different temperature and different pH value of culture medium andunder different illumination conditions, on different culture medium, westudied the diameter of spores of the fungus Aschersonia sp. The result hadturned out. 25℃, pH6~7, 12L:12D and PDA culture medium and corn flouragar culture medium were favorable to spore growth and maturation, and thespores were bigger and the maturation degree was higher. Higher or lowertemperature than 25℃, Higher or lower pH than 6~7, too much light or nolight, unsuitable culture media were all unfavorable to spore growth andmaturation. Under different conditions stated as above, the results studied on thebionomics of the fungus Aschersonia sp. were that the best and suitableconditions for colonies growth, spore producing, spore growth and maturationwere 25℃, pH 6～7, 12L:12D and the suitable culture media were PDAculture medium and corn flour agar culture medium. The best and suitable...