Effects Of Different Temperatures And Host Plants On Morphological And Physiological Index Of Leptocybeinvasa Fisher Et La Salle

Eucalyptus is known as one of the fast-growing tree species,which are widespread in southern provinces of China.It is faced with the damage of invasive species Leptocybe invasa Fisher et La Salle in resent years.This pest spread rapidly and pose a enormous threats to the development Eucalyptus industry in China.The eucalyptus gall wasp is a global invasive pest in Eucalyptus plantations and it attacks both the leaves and stems of new growth and can eventually weaken or cause stunted growth of the tree.The cause of rapid invasion and diffusion of L.invasa are fewer natural enemies,inducing galls for protection,abundant foods,low temperature resistance,small body and diverse modes of reproduction.According to its bioecological characteristics,we examined the effects of different temperatures and host plants on activities of morphological and physiological index in L.invasa.The main results were as follows:1.The results of the present study suggested that the body size in female adults of L.invasa varied significantly with latitude.In lower latitudes,the morphological index such as body length,head width,thorax width,gaster width,expansus and body size were lager than that at higher latitudes.The results also showed that the body sizes of female adults of L.invasa were negatively correlated with latitude.In terms of comparisons between generations of L.invasa,the morphological index were significantly different on all geographic population for generation five,compared to those of original.The morphological indexes of L.invasa were significantly different in various months and the body length,head width,thorax width,gaster width and expansus of summer population were larger than that of winner population.The morphological indexes of L.invasa were different at various temperatures and the individual size of L.invasa decreased with the temperature increasing from 20 ℃ to 35 ℃.2.The morphological indexes of L.invase were also significantly different in various host plants.The results showed that the morphological index were larger on the L.invase of DH201-2(Eucalyptus grandis ×E.tereticornis)as its host,compared to those of the L.invasa of E.exserta as its host.3.The results showed that the activities of protect enzymes in L.invasa were also significantly different in various temperatures.The activities of superoxide dismutase(SOD),peroxidase(CAT)and catalase(POD)in L.invasa decreased with the temperature decreasing from 15 ℃to 20 ℃.From 30 ℃ to 35 ℃,the activities of SOD,CAT and POD in L.invasa decreased with the temperature increasing.In 20 ℃～30 ℃,the activities of SOD,CAT and POD in L.invasa were relative stable with no significant differences,and changed fewer with the temperature.4.The activities of acetylcholinesterase(AchE),glutathione-S-transferase(GSTs),carboxylesterase(CarE)and polyphenol oxidase(PPO)in L.invasa were significantly different in various host plants.The result showed that the activities of AchE,GSTs,CarE and PPO were larger on the L.invasa of DH201-2 as its host,compared to those in L.invasa of E.exserta as its host.5.We investigated the respiratory metabolism of L.invasa under the diverse temperatures.Investigation results showed that the CO2 release rate of L.invase changed obviously in different temperatures.The release rate of CO2 at 15 ℃ or 35 ℃ had a very significantly different than the rate at the other temperatures.From 20 ℃ to 30 ℃,however,the CO2 release rate of L.invasa changed within a small range,which were not significantly.