Eclosion hormone (EH), one of the neuropeptides, serves as a critical factor in the control of ecdysis behavior and development in insects. The Asian corn borer, Ostrinia furnacalis (Osf) is one of the major agricultural pests in Asia. In this study, the molecular characterizations and tissue expression of the eclosion hormone gene in O. furnacalis were elucidated. Using degenerate primers and RT-PCR method, the middle part of the cDNA of EH gene from O. furnacalis was cloned and sequenced. The full-length cDNA of EH gene was then obtained with rapid amplification of cDNA ends (RACE) method. The full Osf-EH cDNA is 986 bp (GenBank accession no. DQ668369), containing a 267 bp open reading frame encoding an 88-amino acid preprohormone. After translation,  the preprohormone was cleavaged to a　hydrophobic 26-amino acids signal peptide and a 62-amino acids mature peptide. The Osf-EH shows high identity with those from Manduca sexta (79.5%), Helicoverpa armigera (77.3%) and Bombyx mori (67.0%), but low identity with that of Drosophila melanogaster (45.5%). RT-PCR analysis showed that the EH mRNA only expressed in the brain, and was not be detected in other neural tissues, such as suboesophageal ganglion, thoracic ganglion, abdominal ganglion, and non-neural tissues, such as midgut, fat body and epidermis.

The legume pod borer, Maruca vitrata (Fabricius), is a serious pantropical insect pest of grain legumes. Adult behavior and circadian rhythm of sex pheromone production and release of  the legume pod borer were investigated at (29±1)℃ and 75%-80% RH under 14L∶10D. The results showed that the emergence activity of M. vitrata occurred throughout the day, and 86% of females and 73% of males emerged during the scotophase. The differences of emergence behavior between both sexes were statistically significant during the 4th, 5th and 8th hour of the scotophase (t>4; P<0.05). The mating behavior took place from 19: 00 to 05: 00.The mating duration varied from 20 to 90 min. The highest mating frequency occurred during the 5th hour of the scotophase for 3-day-old moths. Single mating peaks were observed for 1-, 6-and 7-day-old moths, while double mating peaks were observed for 2-to 5-day-old moths. Adults of the same age spent longer time in mating during the first half of the scotophase than during the second half of the scotophase. The mating behaviour of the moth was age-dependent. Young and old pairs spent more time in mating than mature pairs of the middle age. Advanced onset of time and peak for mating were observed directly by older moths. The EAG response of male moths was highest to the crude extract of pheromonal glands and air collection from 3-day-old virgin female moths and during the 5th and 9th hour of the scotophase. In the field tests, the highest percentage of the male moths was trapped during 23: 00-01: 00, and more male moths were trapped by 3-day-old virgin female moths than by female moths of other age. The emergence activity, mating activity and the female sex pheromone release were synchronized at different ages and time of the scotophase. The sex pheromone release was almost constant throughout the scotophase, but mating behavior concentrated between the two mating peaks.

 

In order to solve the difficulty of the identification of necrophagous flies faced by forensic pathologists and technicians, the feasibility of species identification based on a 348 bp region of the mitochondrial COⅠ (cytochrome oxidase subunit Ⅰ)  gene using RFLP and analysis of DNA was evaluated. Samples were collected in Zhongshan, Guangzhou and Xi'an. The 348 bp region of the COⅠ gene was amplified and sequenced using forward and reverse primers. Cleavage sites for several restriction endonucleases were searched using the DNASTAR. PCR products were digested with restriction endonuclease DdeⅠ, DraⅠ and HinfⅠ, and then separated on native polyacrylamide gels. Evolutionary tree and evolutionary divergence analysis were performed using MEGA 3.0. The analysis indicated that the methods could be used to identify common necrophagous flies. The results provided basis for further research, especially for the setup of mtDNA database of insects of forensic importance.

We selected 11 representative species of Mylabris Fabricius from China, analyzed and compared their hindwings, and described their morphological characteristics by taking M. calida Pallas, 1782 as the mode. As a result, the venations of Mylabris Fabricius were tentatively classified into three types as follows: Southern type, represented by Oriental species, wing dark brown with a lot of folds, veins stout and highly sclerotic; Plateau type, represented by Qingzang Plateau endemic species, wing ivorywhite and semitransparent, only the large cell enclosed by costal margin and MP₁₊₂ obvious; and Northern type, as the transition between the former two types, represented by Palearctic species, wing brown, veins clear and moderately sclerotic. At last, the vein morphological evolution of the genus was discussed.