Reproductive Biology Of Leptocybe Invasa Fisher & LaSalle

Leptocybe invasa Fisher & La Salle(Hymenoptera: Eulophidae),which is a new invasive species specialize in damaging eucalyptus.It was considered as a parthenogenetic species since no male was found in Israeli where the model specimen was built by female in 2004.And then the male was found in Turkey,India and C hina.Meanwhile,there is a higher proportion of male in C hina.In order to explore the sex ratio determination of Leptocybe invasa,several experiments were carried out as follow:1.The morphological characteristics and reproductive system of Leptocybe invasa were observed and compared among female,male and orange phenotype.The female and orange phenotype have the similar reproductive system(including ovary,fallopian tube and ovipositor tube),whereas their color of body and the shape of abdomen are different.Mating behavior can be observed between female and male,whereas no mating behavior between orange phenotype and male in laboratory.Female and male offspring were produced by sex reproduction.However,no orange phenotype was produced by sex reproduction in laboratory.2.The number of adults emerged from host plant,Eucalyptus exserta collected in South China Agricultural University(SCAU)weekly in Guangzhou were recorded every day from August,2013 to September,2016.The results showed that the adults of Leptocybe invasa emerged from April every year in SCAU.The number of adults emerged reached the peak of the year in June.The total number of adults and the ratio of female are decreased from July,whereas the ratios of male and orange phenotype are increased from July.The ratios of male and orange phenotype reach the peak by 23% and 27% in September and in October,respectively.The ratios of male and orange phenotype are increasing by the temperature increasing.Moreover,the orange phenotype was emerged following the male emerging.3.The ratio of male produced by an isofemale infecting in Eucalyptus exserta increase by the temperature increasing during temperature interval from 19? to 28?,whereas it decreased when the temperature over 28? in the laboratory.Meanwhile,the ratios of maleproduced by individual gall in Eucalyptus exserta among different temperature intervals are no significant difference in 19?~31? in laboratory.4.Insect symbionts were screened by special primers PCR Ars23 s Sequences with high homologous to Enterobacter,Escherichia coli and other sequences(99%)were amplified and sequenced from male and female samples of Leptocybe invasa.Sequences with 96%~98% homologous to 16 S of Enterobacter cloacae were detected in larvae,pupae,female,male and organge phenotype.Moreover,a sequence was 98% homologous to an untransformed bacterium was detected by the Eubacterical special primers.