Effects Oftemperature On Thedevelopment And Energysourcesmetabolism Of Mythimna Separata(Walker)

Insects are poikilothermic animals. The external morphology, growth, fertility, and the physiological and biochemical reactions are obviously affected by temperature. This research aimed to study the effects of temperature on primary energy substances metabolism in the growth, reproduction and migratory processes.The M. separata were reared under four constant temperatures and an alternating temperature, respectively. At the same time, the growth and reproduction were observed and recorded. Water content, glycogen content, trehalose content, triglyceride content, and specific enzyme activity of trehalase(TRE), 3- glycerol phosphate dehydrogenase(GPD), 3-glyceraldehyde phosphate dehydrogenase(GAPDH)and 3-hydroxyacyl-coenzyme A dehydrogenase(HOAD) at four developmental stages(3rd instar larvae, 6th instar larvae, pupa and 1st-day adult in 24 hours)were measured. The main results were shown as follow:1. Developmental duration was shortened with the increment of temperature. The development duration of 15℃ was the longest with larval period up to 71 days, and the development duration of 30/20℃ was similar to 25℃. The most optimal temperature for fecundity was 25℃ with 673.40 eggsaveragely. Furthermore, the number of eggs at 15℃ and 30℃ were less than 25℃ and 30/20℃.Compared to 30/20℃, the development of ovarian tubes were delayedat 25℃.2. The results showed there was no significant difference on the water contents at five different temperatures, but the water content of the larvae was higher than pupa and adult.3. Glycogencontents, trehalosecontents, and triglyceride contents were highest in pupae stage. The three kinds of energy substance were the highestat 25℃, and that in 30/20℃ were higher than 20℃ and 30℃, suggesting that the development of ovarian tubes in altering temperatures were delayed than in constant temperatures..4. Specific activity of trehalase, HOAD, GPD at 20℃were higher than 25℃, 30/20℃ and 30℃; the highest activity of GAPDH and GPD, the twokey enzymes in glucose metabolismreached 995.97、273.72 μmol·min-1·g-1protein,separately.However, the activity of HOAD, the key enzyme in fat metabolism, were merely up to 93.33μmol·min-1·g-1protein. These results suggested that glucose metamorphism is the primary metamorphism type in distinct life stages.Above all, temperature significantly effect on the growth, reproductive, energy substances and specific metamorphism enzyme activitiesof M.separata.