Effects Of Volatiles From Peach And Plum On Host Location Of The Yellow Peach Moth,Conogethes Punctiferalis (Guenee)

The yellow peach moth(YPM),Conogethes punctiferalis(Guenee)is an important pests of fruits in Beijing area during recent years.In this paper,four types of commonly cultivated fruit trees in Beijing,including peach,plum,pear and apple were selected as the research material,to carry out the tests of oviposition selection,as well as effects of host plants on growth and reproduction of YPM.Upon which,headspace sampling method and GC-MS detection technology were employed to collect and identify the volatile organic compounds(VOCs)from the intact and bored peach and plum by C.punctiferalis larvae.The Y-olfactometer behavioral responses and EAG tests were conducted to clarify the effects of VOCs on host location of YPM.The main results are as follows:1.The oviposition selection tests between each host plant(peach,plum,apple and pear)and control indicated that YPM preferred lay eggs on the host plants to control.In addition,the oviposition selection between four tested fruits showed that the number of eggs-laying on peach was 152.33,significantly more than those on other three fruits.It is then inferred that the VOCs from host plants played important role on the host location of YPM.Furthermore,effects of four fruits(peach,plum,apple and pear)on the growth and reproduction of C.Punctiferais indicated that when larvae fed on peach,the development duration could be shortened,while the survival rate,the moth fecundity,and intrinsic rate of increase could be increased significantly.These results indicated that peach was the most suitable host plant of C.punctiferalis among the four tested fruits.2.The VOCs from peach and plum during their young fruit periods and mature fruit periods,as well as those damaged by larvae of C.punctiferalis,were collected and identified by dynamic headspace gas sampling and GC-MS technology.The results showed that the quantities of VOCs from peaches and plums during young fruit periods were both larger than those during their mature periods.Among which,ten compounds were collected from intact peaches during its young fruit period,with 1,3,6-Octatriene,3,7-dimethyl-and 3-Hexen-1-ol,acetate,(Z)-as the main ingredients and accounting for 44.37%and 19.62%of the total quantity respectively;whereas nine compounds were collected during its mature period,with 3-Hexen-1-ol,acetate,(Z)-,as the main compound and accounting for 30.84%of the total quantity.Comparatively,a total of 17 and 24 compounds were identified from plums during its young fruit period and mature period,respectively.Among which,3-Hexen-1-of,acetate,(Z)-was the main ingredient for young fruit period,accounting for 17.54%of the total quantity;However,6,6-1,3-Cyclopentadiene,5-(1-methylethylidene)-was the main compound during its mature period,accounting for 36.28%of the total quantity.In addition,differences were also existed both on constitutions and quantities before and after being bored by C.punctiferalis.As for peach,the differences of chemical composition between intact fruits and damaged ones were rather small,whereas the quantities of VOCs differed significantly.As for VOCs from plum,the compositions and quantites of VOCs from intact fruits and damaged ones were both different markedly.3.The Y-type olfactometer experiments and EAG tests were employed to clarify the responses of the yellow peach moth to several major compounds in peach and plum volatiles.The results indicated that 3-Hexen-l-ol,acetate,(Z)-and Acetic acid,butyl ester(at concentration of 0.01v/V),Octanoic acid,ethyl ester and Hexanoic acid,ethyl ester(at concentration of 0.001v/V)all showed rather strong attraction to the yellow peach moth.However,when the concentration of Octanoic acid,ethyl ester and Hexanoic acid,ethyl ester increases to 0.01v/V,the moth of C.punctiferalis showed avoidance behavior.Besides,the acenaphthene showed avoidance in all 4 tested concentrations,and with the concentration of 0.001 v/V was strongest.In summary,host plant volatiles played an important role in the host location of C.punctiferalis.It is necessary to develop attractants for field control of C.punctiferalis by carrying field trapping test in the future.