Cold Storage And Effects Of The Ovipositor Stabbing Of Aphelinus Maculatus (Hymenoptera:Aphelinidae) On Its Host Myzus Persicae (Hemiptera:Aphididae)

The aphid parasitoid,Aphelinus maculatus Yasnosh,as Aphelinus of Aphelinidae of Hymenoptera,was first described as a new record in China in 2016.It is one of the important parasitoids of Myzus persicae.At present,the study of A.maculatus is less,for effective utilization of A.maculatus,we through laboratory breeding and observation,scientific assessment with aphid in A.maculatus of M.persicae control function,studies the A.maculatus ovipositor pierce survivors of aphids and their growth and development for the host,the influence of the fertility and population life table,and through the low temperature cold storage with aphid in A.maculatus mummy and into a A.maculatus,To provide a theoretical basis for future mass reproduction and practical application,the experimental results are as follows:（1）The eclosion rate of A.maculatus mummy at different stages of cold storage at4℃and 8℃for 7,14,21,30 and 60 days were all lower than 30 at 4℃,and 0 at 60 days.After storage at 8℃,the rate of eclosion decreased with the extension of storage time.After 60 days of storage,the rate of eclosion was lower than that of the control,and the rate of eclosion was the highest at the third day of age.The feeding number,death number,parasitism number,longevity and emergence rate of offspring of A.maculatus mummy at the third day of age of mummy were decreased compared with the control after 7,14,21and 30 days of storage at 8℃,and the number of male offspring was more than that of female offspring after 30 days of storage.（2）After being refrigerated at 4℃and 8℃for 7,14,21,30 and 60 days,the survival rate of A.maculatus at different stages of storage at 4℃for 14 days were less than 30.The survival rate of female wasps was significantly higher than that of male wasps,and the survival rate of male wasps decreased to below 50 after 30 and 60 days of storage at 8℃.The number of feeding,death,parasitism and emergence rate of offspring of aphid mummy decreased with the extension of cold storage time at 8℃,while the female longevity was not related to cold storage time,and there was no difference between the two groups.The number of male offspring was more than that of female offspring after 60 days of storage.（3）The effects of the ovipositor stabbing of A.maculatus on peach aphid included lethal,survival and parasitism.The mortality of peach aphid stabbed by the ovipositor of A.maculatus decreased with the increase of peach aphid age,and that of the 1-day-old nymphs stabbed by ovipositor of A.maculatus was the highest（45%）.The longer the stabbing time,the higher the mortality of the peach aphid.The survival rate of peach aphid and parasitism rate of A.maculatus increased with the increase of the peach aphid age.The nymphal survival period and pre-reproduction duration of survival peach aphid were longer than that of the control（not being stabbed）,but the reproduction duration and post-reproduction duration were significantly shorter than that of the control.The reproduction duration of the 3-day-old nymphs stabbed by the ovipositor of A.maculates was the shortest,being shortened by 13.7±1.7 d as compared to that of the control.The adult longevity of survivors of the peach aphid stabbed by the ovipositor of A.maculatus was significantly shortened and related to the age of peach aphid when being stabbed.The adult longevity of the 2-day-old and 3-day-old nymphs stabbed by the ovipositor of A.maculates was impacted greatly,being shortened by 12.5 and 11.2 d,respectively,as compared to that of the control.The fecundity（number of offspring produced per aphid）of the stabbed survivors decreased significantly,and the younger the stabbed age,the fewer the fecundity.The stabbed survivors from the 1-day-old nymphs and adults produced 39.1±4.9 and 25.2±2.7 offspring fewer than their non-stabbed controls,respectively.（4）The net proliferation rate（R₀）,the intrinsic rate of nature increase（R_m）,the finite rate of increase（λ）,and the population doubling time（T）of aphid survivors decreased after oviposition of A.maculatus.