The 433 base pair segments of the mitochondrial cytochrome oxidaseⅠ(COⅠ) gene from 62 individuals of Frankliniella occidentalis (Pergande) and other 8 common thrips species in China were sequenced. The DNA data analysis showed that the average intra-species genetic distance was 0-0.005；there was no significant genetic divergence between the western flower thrips found in Beijing in 2003 and those reported internationally. The average interspecies genetic distance was 0.213. Thrips individuals of the same species were successfully clustered by NJ tree. The bootstrap values of the original divergence among intra-species haplotypes amounted to 100%. The results show that molecular identification based on PCR and direct sequencing is desirable for identifying thrips species.

Since Bt cotton and corn were commercially planted in 1996, remarkable economic, ecological and social benefits have been obtained. However, ecological biosafety pertinent to their introduction has become a public concern, especially the potential impact of Bt crops on non-target organisms and evolution of resistance in target insect pests. The progress of laboratory and field assessment of Bt corn and cotton on non-target arthropods and resistance management of target insects were reviewed in this article. Research has shown that field populations of some non-target herbivorous insects in Bt crops may increase due to the removal of wide-spectrum insecticides. The pollen or nectar of Bt corn and cotton as food sources of honey bees or the natural drift of pollen onto food plants of silkworms have no direct or indirect detrimental influence on these beneficial insects as well as the monarch butterfly, Danaus plexippus. Bt cotton and corn may affect natural enemies indirectly by decreasing the population of lepidopteran insects that serve as hosts of parasitoids or predators. Population densities of predators in Bt fields were significantly higher than those in non-Bt fields treated with insecticides for control of target pests. However, population size and species richness of parasitoids might decrease due to lower density or poor quality of their host insects. There were no significant negative effects of Bt cotton and corn on the abundance and diversity of foliar and soil arthropod communities. Resistance monitoring demonstrated that resistance of target insects to Bt cotton and corn has not occurred in fields after 10 years of commercial use, either in large-scale farming system  as in the U.S. and Australia or in small-scale planting of Bt cotton in as China and India where several other non-Bt host crops of the target insects can serve as natural refuge. The absence of field resistance to date is presumed to be due to the implementation of refuge strategy in the developed countries and the unique cropping pattern in the developing countries. However, caution for resistance evolution continues to be warranted because resistance to Bt crops most likely remains a question of not “if" but “when". Therefore, future work should be emphasized on the impact of long-term and large-scale planting of Bt cotton and corn on non-target organisms and resistance evolution of target pests.

We summarized progress in melittin, including the biological function, the molecular structure and characteristics, the mechanism of hemolysis and the relationship between the structure and the activity of hemolysis and antimicrobial of melittin. Meanwhile, based on the related research in our laboratory, we focused on the studies of the mechanism of melittin home and abroad in recent years. We proposed that the study on melittin should be quantified, and the calculation technology should be utilized for further illustrating the dynamical process of melittin and the relationship between structure and function, which may provide a firm theoretical basis for guiding molecular designing in future.

Cecropins are a family of antibacterial peptides synthesized in insects as a response to a bacterial infection. Two primers were designed according to cecropin B gene from Spodoptera litura and were used to PCR. As the result, two new cecropin genes, named cecD1 and cecD, were obtained, which encoded identical preprocecropin D. There was 2 amino acid residues difference between the mature peptide of preprocecropin D and that of cecropin B from S. litura. Two introns, 568 bp and 377 bp long, were found in cecD1 and cecD2, respectively, both having the same 5′and 3′splicing sites. The A+T content was 59.7% in cecD1 intron and 69.8% in cecD2 intron, conforming to the high A+T content characteristics of most eukaryotic introns.

【Objective】 To determine the contents and the existing form of cantharidin in Meloidae. 【Methods】The total cantharidin obtained with acidolysis method and the free cantharidin obtained with direct extraction method were determined in eight species of Meloidae and the control species Huechys sanguinea (De Geer) (Homoptera：Cicadidae) by gas chromatography, and the content of the bound cantharidin in each species was calculated with the content difference between the total cantharidin and the free cantharidin. The relationship between the contents of the bound cantharidin and the contents of Ca and Mg elements in Meloidae were assessed. 【Results】 The results showed that the total cantharidin contents in the samples of Meloidae were 1 to 9 times the free cantharidin contents. The total cantharidin contents were generally higher than 2.0% of dry body weight and the free cantharidin contents were all less than 1.7% of dry body weight in Meloidae. No cantharidin in any form was found in H. sanguinea. Positive relationship was found between the bound cantharidin and Ca element in Mylabris and Epicauta, and between the bound cantharidin and Mg element in Mylabris, but negative relationship was found between the bound cantharidin and Mg element in Epicauta. And the mol of Ca element in Mylabris was lower than that of the bound cantharidin. 【Conclusion】 The contents of the total cantharidin were higher than the contents of the free cantharidin in Meloidae. The bound cantharidin may exist in the forms of magnesium cantharidate and calcium cantharidate.