Abstract:
Objective To provide insights into carrying out ecological regulation of new mixed forest, the physiological adaptation mechanism of Dendrolimus houi Lajonquiere to different host plants was analyzed based on the effects of different host plants on the growth, reproduction, detoxification enzyme and digestive enzyme activities of D. houi.
MethodsThe developmental duration of the larvae and pupae as well as the fecundity of adult of D. houi were measured through indoor rearing in hots plants of Cryptomeria fortunei Hooibrenk, Platycladus orientalis (L.) Franco, Cupressus funebris Endl., Pinus yunnanensis Franch. and Pinus massoniana Lamb. The activities of detoxification enzymes (i. e. glutathione S-transferases (GSTs), cytochrome P450 (CYP450), and carboxylesterase (CarE)) and digestive enzymes (i. e. protease, amylase (AMS), and lipase (LPS)) in the 5th instar larvae of D. houi feeding on different host plants were also assayed.
ResultsD. houi larvae feeding on C. fortunei, C. funebris, P. orientalis and P. yunnanensis had a complete life cycle, while the larvae feeding on P. massoniana only survived to the 5th instar and did not have a complete life cycle. At the same time, the larvae and pupae of D. houi feeding on C. fortunei and C. funebris had shorter developmental duration, heavier female pupae and more fecundity of adult compared with other host plants. The activities of GSTs and CYP450 in the 5th instar larvae of D. houi feeding on C. fortunei and C. funebris were significantly higher than those feeding on P. yunnanensis, P. orientalis and P. massoniana (P<0.05). Among the three digestive enzymes, the activities of protease in larvae of D. houi feeding on C. fortunei and C. funebris were relatively high.
Conclusion Dendrolimus houi has better adaptability to Cryptomeria fortunei and Cupressus funebris than the other host plants, and detoxification enzymes and proteases within D. houi may be the key factors which affect their adaptability to Cryptomeria fortunei and Cupressus funebris.
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