Population Dynamics of Dryinidae,Natural Predators of Rice Planthoppers in Panjin Prefecture,Liaoning Province
[Objective]Dryinidae is an important natural enemy of rice planthoppers,with both predatory and parasitic habits,plays an important role in regulating the paddy ecosystem.To understand the species composition and occurrence of Dryinidae,a four-year investigation was conducted in Panjin Prefecture,Liaoning Province,a siginicant japonica rice producing area in northern China.[Method]We used the rice planthopper with"back sac"(Hereafter referred to as"back sac"host),the cocoon and the female adult of Dryinidae as index,to research the species of Dryinidae,the population dynamics of different stages of Dryinidae in conventional paddies(CP)and crab-rice paddies(CR),and the correlation of population dynamics for Dryinidae and its host in conventional paddy fields.[Result]The results showed that there are two species of Dryinidae in Panjin Prefecture,which are Haplogonatopus oratorius(Westwood)and Haplogonatopus apicalis R.C.L.Perkins.Haplogonatopus oratorius(Westwood)is the dominant species.The peak population of Dryinidae for natural enemy of rice planthoppers appeared on August 15 in Panjin Prefecture(9.80±0.20).The number of"back sac"host,the cocoon and the female adult of Dryinidae peaked in crab-rice paddy field.The peak period is on August 15th,September 15th and July 30th in turn,and the peak value is 6.40±0.51,3.20±1.24,and 4.40±0.60,respectively.[Conclusion]There was no significant correlation of population dynamics between rice planthoppers and Dryinidae in conventional paddy fields.We believe that the population quantity of Dryinidae for natural enemy of rice planthoppers in crab-rice paddy field is larger than that in conventional paddy field in Panjin Prefecture.We speculate that this was because almost no insecticides were applied in crab-rice paddy field,which increased the population density of Dryinidae.It is beneficial to its controlling function on pests in the paddy field ecosystem.
国家科技期刊平台
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