Mate Preference And Reproductive Fitness In Pine Caterpilar,dendrolimus Punctatus Walker (Lepidoptera:Lasiocampidae):Effect Of Adult Age,Body Size And Mating History

The pine caterpillar Dendrolimus punctatus Walker(Lepidoptera: Lasiocampidae)is broadly distributed across southern of China.This moth is considered to be one of the most destructive forest insect pests,which periodically outbreak to pine forests in China.In this thesis,we investigated the influence of adult age,mating history and body size on mate preference and reproductive fitness in this pine caterpillar.The results are as follows: 1.Effects of adult age on mate preference and reproductive fitness in D.punctatus.In female mate choice trial,females preferentially mated with young and middle aged males.In the single-male trial,females that mated with young and middle-aged males did not result in higher benefits of behavior and reproductive fitness.However,the relative expected reproduction was decreased 12% when female mated with old male.In male mate choice trial and single-female trial,young females had significantly greater mating success and higher fitness benefits than middle-aged and old females,although the mating latency and mating duration had no significant difference when males paired with different aged females.The relative expected reproduction was decreased 76% when male mated with old female.In the delayed mating trial,the mating success and mating duration decreased with the age of adult at first mating,and the relative expected reproduction was decreased 75% when female and male simultaneously delayed mating at 4 d after emergence.These results suggested that adult mating age significantly affected the mate preference and reproductive fitness in this caterpillar,and the young male and young female had significantly higher mating success and reproductive fitness benefits.2.Effects of adult mating history on mate preference and reproductive fitness in D.punctatus.In female mate choice trial and no-mate choice trial,73.33% and 67.86% of all females preferentially mated with experienced males respectively.When female mated with experienced male,the mating latency shorted and the relative expected reproduction increased by 11% compared with paired with virgin male.However,in male mate choice trial and no-mate choice trial,male preferentially mated with virgin female although there had no difference in mating latency and mating duration when male paired with female of different mating history.The relative expected reproduction increased by 6% when male mated with virgin female compared with experienced female.These results showed that female and male had different strateges in mate choice,that is female prefer to experienced partener and male prefer to virgin partener and they will obtain more higher reproductive fitness through this preference strategy.3.Effects of adult body size on mate preference and reproductive fitness in D.punctatus.In female mate preference trial,larger female preferentially mated with middle-sized males,while middle-sized female and smaller female preferentially mated with larger males.In male mate preference trial,all sized male preferentially mated with larger females.The mating latency decreased with female and male body size.The results of reproductive fitness measurement showed that the fecundity significantly affected by female body size and the fertility affected by male body size.When paired with smaller females and males,the relative expected reproduction decreased by 54% and 24% repectively,comparing paired with larger parteners.These results showed that larger parteners had higher mating success and reproductive fitness.