Adult Behavior Characteristics Of Jaapiella Sp.and Its Chemical Communication Relationship With Host Plant

Lycium barbarum,which is one of the medicine food homology plants announced by the former National Ministry of Health,is used frequently as a crude drug traditional Chinese medicine.Its dried fruits are used as medicinal materials.Jaapiella sp.,known as "cancer",is the most serious pest in Lycium barbarum plantation region.In general,Jaapiella sp.like to choose flower buds to oviposit,although flowers and fruits appear at the same season,resulting in bud galls.Eventually,Lycium barbarum is unable blossom and fruit normally.Few studies were reported on the pest up to date.Here,we systemically described morphology of Jaapiella sp.and adult behavioral characteristics,and elucidated host plant selection mechanism.The results are as follows:1.Morphology and adult behavior characteristicsMorphological characteristics of different stage and adult behavior characteristics of Jaapiella sp.were clearly described.Eggs were oval,colorless and smooth,about 0.3 to 0.5 mm long and 0.05 to 0.08 mm wide.Larvae were spindle shaped,body rich and wrinkled,with no head and no feet,about 2.0 to 3.0 mm long and 0.5 to 1.0 mm wide.Pupae were oval,2.0 to 3.0 mm long and 1.0 to 1.5 mm wide.The adult was small in size and the body length was about 2.0 to 3.0 mm.A large difference in morphological characteristics between male and female adults.Emergence mostly occurred during morning and evening in a day(6:00-7:00 am,18:00-19:00 pm),and emerging peaks of both sexes were same.Females extended their ovipositor to attract males in 5 minutes after emergence.The peak of mating occurred in l hour after emergence peak(7:00-8:00 am).The duration of mating was from 30 seconds to 3 minutes.The females started to lay eggs upon mating,and oviposit peaks occurred from 10:00 to 11:00 am and 12:00 to 14:00 pm.The oviposition duration was from 20 to 30 minutes.Each female could lay 3?50 eggs each time,and eggs was either distributed or aggregated.The lifespan of adults was very short and in general was about 1 day.The lifespan of females was longer than that of males.Life span of mated adults was slightly longer than non-mated individauls.2.The chemical communication relationship between Jaapiella sp.and host plantHeadspace collection and gas chromatography-mass spectrometry were used to extract and identify volatiles released from Lycium barbarum at different growth stages.Attractiveness of volatiles from different growth stages was evaluated by Y-tube olfactometer.In total,156 volatile compounds were identified from five growth stages of Lycium barbarum,including eight groups:alcohols,aldehydes,ketones,alkanes,benzenoids,esters,alkenes and phenols.Volatiles profile in different growth stages were different in qualitatively and quantitatively.Volatiles in the burgeoning stage were composed of alkanes(63.15%)and ketones(12.01%).During the flower buds stage,alkanes(38.69%),ketones(29.26%)and alkenes(13.37%)were adundant.During the early bloom period,olefins(31.26%),ketones(27.89%)and alkanes(15.76%)were adundant.During the full bloom stage,alkane(28.21%)compounds were adundant.Volatiles in the post flower period were composed of alkanes(46.45%),ketones(12.38%)and phenols(7.48%).There were 20 common volatile compounds at five growth stages:nonanal,3-ethyl-benzaldehyde,4-ethyl-benzaldehyde,decane,dodecane,pentadecane,hexadecane,heptadecane,2,6,10,14-tetramethyl-pentadecane,octadecane,nonadecane,eicosane,heneicosane,tetracosane,pentacosane,1-(4-ethy lphenyl)-ethanone,hexadecanoic acid methyl ester,1-ethenyl-4-ethyl benzene,1-pentadecene,1-nonadecene.Y-tube olfactometer behavioral bioassay showed that volatiles from flower buds period were more attractive to mated females,followed by volatiles blends from burgeoning stage and early bloom stage.Volatiles at flower buds stage contained unique volatile compounds(1-heptyl-2-methyl-cyclopropane,2,6,1 0-trimethyl-dodecane,1,2-dimethyl-cyclohexane,2-methy1-2-propenyl benzene,5-methyl-3-undecene,(Z)-2-dodecene).Volatiles at burgeoning stage and the early bloom stage contained high proportions of ketones(2-octanone,1-(4-ethylphenyl)-ethanone)and alkenes(a-Pinene,limonene,1-octene).Volatiles from full bloom and post flower had a certain repellent effect on mated females,with a high proportion of aldehydes(heptanal,benzaldehyde,nonanal)and a certain proportion of esters((Z)-3-hexen-l-ol acetate,hexadecanoic acid,methyl ester,dibutyl phthalate)and benzenoids(p-xylene,1,3-dimethyl benzene,acetophenone).This results showed the relationship between host location of oviposition site and special volatile chemical signal from certain seasonal stage.