Study On The Factors Affecting The Selection Of Plant Height By Locusta Migratoria Manilensis And The Change Of Body Temperature After Metarhizium Anisopliae Infection

Locusta migratoria manilensis is one of the important agriculture pest in China.It has the characteristics of aggregation and can be integrated into disasters,causing serious losses to the production of agriculture.In the coastal areas of Shandong Province,a large number of plants such reeds,alfalfa,and sedge are produced,which provide food resources for the breeding of locusts.In order to make better use of biological pesticides for prevention and control,the preference of the L.m.manilensis for height selection in natural habitats was observed.In order to improve the control effect of Metarhizium anisopliae in the field,the body temperature of M.anisopliae was measured under indoor conditions.The main contents of this study are as follows:(1)Summer locust prefers to inhabit in 0-20 cm,while autumn locust more than 80 cm.There was no significant difference between the selection of summer locust and autumn locust at0-20 cm(P>0.05),and the selection proportion of summer locust above 80 cm was significantly lower than that of autumn locust(P<0.05).When the population density of the L.m.manilensis was 5,10 and 20 heads /m2,the selection ratio of the L.m.manilensis at 3 heights above 40 cm was significantly higher than that at 0-20 cm and 20-40 cm(P<0.05).When the population density was 40 heads /m2,the opportunity of the L.m.manilensis at all heights was equal.At 4:00,L.m.manilensis with different population densities occupied the highest percentage at the height above 80 cm.At 7:00,12:00 and 16:00,the chance of roosting at all heights was equal.At 19:00,the population density was 5 and 10 heads /m2,and no locust was found in the range of 0-20 cm.At 22:00,L.m.manilensis with different population densities was found above 40 cm.Different population densities of L.m.manilensis were positively correlated with environmental humidity at heights of 20-40 cm and 40-60 cm.At 60-80 cm,there is a positive correlation with the environmental temperature and a negative correlation with the environmental humidity.It can be seen that both the environmental temperature and humidity can affect the selection of plant height by the L.m.manilensis,and the selection of plant height by the locust reflects its habitat adaptation.(2)The body temperature of nymphs in all body parts was lower than that of adults.The body temperature of the treated L.m.manilensis was lower than that of the control locust,and there was a significant difference between the two(P<0.01).Compared with adult adults,the body temperatures of treated 3rd instar nymph were more susceptible to Metarhizium anisopliae.Under the light condition,all body parts of the 3rd instar nymph had the strongest thermoregulation ability at 48 h after inoculation,and all body parts of the adults had the strongest thermoregulation ability at 72 h after inoculation.Under the condition of no light,before and after infection,the thermoregulation ability of hoppers head,thorax,frontfoot and middle foot were similar in all time periods,and the thermoregulation ability of abdomen and foot of adult locust was the strongest at 24 h.The thermoregulation ability of the 3rd instar and adult females of the control L.m.manilensis was stronger than that of the 3rd instar and adult males of the control.The thermoregulation ability of male adult of L.m.manilensis is stronger than that of female adult.