Artificial Breeding And Storage Technology Of Harmonia Axyridis

Harmonia axyridis is one of the natural enemies of many agricultural and forest pests.It plays a very important role in biological control of pests.Aphid is the main feed for H.axyridis breeding at present.However breeding aphid needsmore space,time,labor and money,it restricts the breeding scale of H.axyridis and can not meet the demands of production Although artificial diet saves time and labor,supply well,it negatively affects the breeding of H.axyridis,which makes them unable to complete the whole life history or spawn normally.In order to achieve the scale breeding of H.axyridis and reduce the feeding cost,an urgent problem needs to be solved is to find a suitbale feed for H.axyridis,saveing time,labor,and adequate supply.This study used the pupae of C.cunea Yang as feed,studied H.axyridis' s growth period,growth regularity,self-infliction rate of the larvae,and the influence factors of the self-infliction rate and the natural mortality during the artificial breeding process.Next,And studied the average single female oviposition,oviposition cycle and the average daily egg production per head of H.axyridis that were fed on the pupae of the C.cunea Yang.In addition,the effects of different spawning media on the oviposition and egg number of H.axyridis were studied.Moreover,the effects of low temperature storage on the survival rate and egg hatching rate were studied.Finally,this study found the different suitable storage time and storage temperature of adults and eggs of H.axyridis.The main results were as follows:(1)Under the condition of 26 ? and RH 70%,ladybird could complete the whole life history(egg-adult)feeding with C.cunea Yang,and the development period is 16-19 d,in which: the egg stage is about 2d the first to third instar larval stage is 2-3ddays respectively;and the fourth instar larval stage is 3-4d long;the prepual stage is 1d and the pupal stage is 4d;adults spawned 20 days after eclosion.The degree of development uniformity is increased with the increasing of age.(2)The hatching rate of eggs of H.axyridis which were fed using C.cunea Yang was up to 97.37%.(3)Self-inflicted death was observed in the feeding process.The main reasons of self-infliction is the lack of feed and high breeding density.Under the condition of sufficient feed supply,the rate of self-infliction was only 11.5%,and the rate of selfinfliction under the condition of starvation reached 42.5%,respectively.Breeding density also affectted self-inflation rate,especially when there were large discrepancy in breeding space.However,when the feed was sufficient enough,there were no significant difference in self-infliction rate between mixed egg blocks and single egg blocks.(4)There were significant differences in the natural mortality of the H.axyridis in different stages of development and artificial breeding.And the overall mortality is the highest in the fourth instar larval stage which is 35.25%,and the lowest is in the egg stage,which is 3.26 %.(5)In the selected concentrated medium,the oviposition rate of H.axyridis was highest on white toilet paper,which was 68.1%.The oviposition rate was 23.40 % on the khaki toilet paper,8.49% on the white A4 paper,and the ladybug had not spawned on yellow,green and blue paper.(6)Using C.cunea Yang pupae as feed,the average oviposition number of the female H.axyridis was 200,the average oviposition period was 16 d,and the average number of oviposition was 13 per day.(7)The survival rate and the hatching rate of eggs were significantly different in different storage temperature and storage time.H.axyridis adult had the highest survival rate which was 95.56% when storage time under 8 ?was less than 20 days.When storage time was longer than 40 days,the storage temperature of 3? showed the highest survival rate of 84.44%.(8)H.axyridis could not tolerate coldness,at the storage temperature of 5 ?,10 ? and 15 ?,H.axyridis could survive 5 to 7 days,the average hatching rate under 15 ? was higher than that under 5 ? and 10 ?;however,hatch happened frequently in storage,which was not conducive to the sale and transportation.This study concluded that the storage temperature of 10 ? provided the most desirable average hatching rate and storage time of eggs of H.axyridis.