Drosophila is an excellent model to study spontaneous mutation due to the availability of a large collection of spontaneous mutants, such as body pigment mutants. Previously, we found a spontaneous pigmentation mutant, bsr (black strip), which was confirmed as an allele of ebony (e) and we named it as e^bsr. Subsequent sequencing of genomic DNA revealed a deletion of 953 nucleotides at the 5′end of e^bsr including 206 nucleotides of exon 1 and flanking 747 nucleotides of intron 1. Reverse-transcriptase PCR (RT-PCR) showed that the deletion at the 5′end of e^bsr leads to defective splicing, resulting in a transcriptional product with an additional 3.2 kb upstream of initiation codon AUG. RNA secondary structure analysis indicated that the unspliced 5′UTR folds into complex structure containing several more stem-loops than that of wild-type e. Western blotting results indicated that translation of e was totally suppressed in e^bsr. This favors a model that the change of 5′UTR structure of mRNA prevents the protein translation.

Insect defense against pathogen invasion mainly rely on innate immunity system. Recent research showed that Imd pathway is involved in limiting the number of Plasmodium berghei oocysts developing in mosquito midgut, and PGRP-LC1 is one of the receptors of Imd pathway. In order to investigate PGRP-LC1 in Anopheles stephensi, we cloned the PGRP-LC1 gene through a combination of reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) approaches. Two cDNA fragments, with the open reading frame (ORF) of 1 365 bp and 1 290 bp respectively, were obtained. The 3′untranslated region (UTR) is 320 bp, and the 5′ UTR 240 bp. We named the two sequences as AsPGRP-LC1a (GenBank accession no. GU214232) and AsPGRP-LC1b (GenBank accession no. GU214233), respectively. AsPGRP-LC1a encodes a polypeptide of 454 amino acids with a predicted molecular weight of 49.07 kDa. AsPGRP-LC1b encodes a polypeptide of 429 amino acids with a predicted molecular weight of 46.3 kDa. AsPGRP-LC1b contains one exon less than AsPGRP-LC1a. The exon is 75 bp and present in some of the alternative splicing isoforms of Anopheles gambiae PGRP-LC1 too. The two PGRP-LC1 genes were over-expressed in both A. gambiae cell line L3-5 and A. stephensi cell line MSQ43. The expression profile of antimicrobial peptides was monitored by dual luciferase assay system, and the results showed that the PGRP-LC1 we cloned could activate Imd pathway in both cell lines, which provided basis for further investigations of Imd pathway in A. stephensi.

Previous studies indicated that Bemisia tabaci B biotype, an important invasive pest, had the advantage in interspecific competition with Myzus persicae on tobacco. To explore the effect of physiological adaptability of the two insects on their interspecific competition, the changes of activities of main protective enzymes and digestive enzymes in B. tabaci and M. persicae feeding on tobacco preinfested by B. tabaci were studied using biochemical analysis. The results showed that the activities of PPO and SOD in B. tabaci significantly increased after feeding on the preinfested tobacco plants for 6, 12, 24, 48 and 72 h (P<0.05), and the POD activity in B. tabaci also significantly increased after feeding on the preinfested tobacco plants for 6, 48 and 72 h, respectively (P<0.05). The maximum activities of SOD, PPO and POD in B. tabaci on the preinfested tobacco plants were 1.62, 2.71 and 2.57 times higher than those in the control, respectively. In contrast, the activities of PPO and SOD in M. persicae increased a little in most time-span after feeding on the preinfested tobacco plants, while the SOD activity was obviously suppressed after feeding on the preinfested tobacco plants for 12 h (P<0.05). POD activity in M. persicae was significantly inhibited except after feeding on the preinfested tobacco plants for 24 h (P<0.05). Activities of protease and amylase in B. tabaci significantly increased in all time-span after feeding on the preinfested tobacco plants, and the maximum activities were 1.54 and 1.33 times that in the control, respectively. Activities of protease and amylase in M. persicae did not change after feeding on the preinfested tobacco plants for 6 h (P<0.05); however, the activities were inhibited with the extending of feeding time, and the lowest activities in M. persicae feeding on the preinfested tobacco plants were 0.39 and 0.72 times that in the control, respectively. The results suggest that the increase of the activities of protective and digestive enzymes in B. tabaci feeding on the preinfested tobacco plants should be one of the causes of its higher adaptability compared with M. persicae.

In order to clarify the effects of cold acclimation on cold tolerance of adult Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), we investigated the survival rate, supercooling point (SCP), water content and reproduction capability of adults under low temperature in the laboratory condition. Adults of H. axyridis were cold acclimated at 5℃ successively for 1, 3, 5 and 10 d prior to cold stress. The results showed that the survival rate of the adults exposed to -5℃ for 3 d was improved from 46% of the control (without prior cold stress) to 60% and 67% when adults were acclimated for 3 d and 5 d, respectively, but decreased to 51% after the cold acclimation for 10 d. Returning of the adults to 25℃ caused a loss of cold acclimation within 7 d. The SCP and the water content decreased as the duration of cold acclimation prolonged. Shortterm (5, 10 d) exposure to 5℃ did not decrease the SCP even though it significantly decreased water content in the body. The pre-oviposition period of the female was delayed after acclimation. Acclimation significantly decreased the fecundity within 72 h, but did not affect the number of eggs laid in the first cluster. The effects of cold acclimation on several enzyme activities were examined, and the results showed that superoxide dismutase (SOD) and catalase (CAT) activities increased whereas lactate dehydrogenase (LDH) and Na⁺, K⁺-ATPase activities decreased after cold acclimation. These results indicate that cold acclimation is a complex physiological and biochemical process, which is very important to the survival and reproduction of H. axyridis.

To study the effects of brood pheromone esters (methyl palmitate, ethyl palmitate and ethyl oleate) on feeding and capping behavior of workers and development of the queens of Apis cerana cerana and A. mellifera ligustica, 1-day-old worker larvae were transferred to the artificial queen cells made of bee wax that were mixed with three aliphatic esters at concentrations of 1% and 0.1% (w/w), and then the acceptance of queen cells, weight of each larva, and weight of royal jelly in each queen cell were tested. Dummy larvae made of paraffin mixed with three aliphatic esters at the concentrations of 1% and 0.1 % (w/w), respectively, were introduced into the empty cells, and the worker acceptance of cells was tested. After dripping royal jelly mixed with three aliphatic esters at the concentrations of 1% and 0.1% (w/w), respectively, into the queen cells when the larvae was 1-, 2- and 3-day-old, the emergence weight and the quantity of ovarioles of queen were tested. The results showed that (1) Methyl palmitate (0.1%) significantly improved the weight of larvae in each queen cell in both A. cerana cerana and A. mellifera ligustica. (2) Methyl palmitate (1%, 0.1%) and ethyl oleate (1%, 0.1%) significantly increased the capping rate of the dummy larvae in A. mellifera ligustica. (3) Ethyl oleate (1%, 0.1%) significantly depressed weight and ovarioles of the queen in both A. cerana cerana and A. mellifera ligustica. These results indicate that different brood pheromones of honeybee have different biological effects.

The postembryonic development of optic lobes in Apis cerana cerana was comparatively studied by using immunohistochemical method (5-bromo-2-deoxyuridine, BrdU immunostaining) and in situ cell death detection. The results showed that the medulla and lamina were generated by distinct populations of neuroblasts in the outer optic anlage (OOA), and the neuroblasts divided asymmetrically to generate ganglion mother cells. Ganglion mother cells later divided symmetrically to generate immature neurons. Generation of the medulla cortex started with the onset of the final larval instar. Generation of the lamina cortex was initiated with the arrival of retinal afferents at the optic lobes. The lobula neurons were generated by neuroblasts in a second structure, the inner optic anlage (IOA). The results suggest that the optic lobe was generated from two optic anlages, the proliferation of neurons showed a peak at prepupa, and generation of the lamina cortex was initiated with the arrival of retinal afferents at the optic lobes.

The development of insect cell lines plays a significant role in research and application of virology and entomology. Two new cell lines, i.e., QB-Ha-E-1 and QB-Ha-E-5, were established from the embryonic tissue of Helicoverpa armigera (Lepidoptera: Noctuidae). The cell lines had been subcultured over 60 passages in TNM-FH medium supplemented with 10% fetal bovine serum. Each cell line has two major morphological types, round cells and spindle-shaped cells. DNA amplification fingerprinting (DAF) analysis indicated that DNA profiles of the two cell lines were similar but distinctly different from cell lines of several other insects, suggesting that both originated from the embryonic tissue of H. armigera. The cell doubling time of the 30th passages of QB-Ha-E-1 and QB-Ha-E-5 were 63.7 h and 66.9 h, respectively. Both the cell lines could be infected by H. armigera single nucleopolyhedrovirus (HaSNPV) with the infection rates of 86.6% and 56.5%, respectively, 4 d post infection (p.i.). Approximately 15% of the two cell lines were infected by Mamestra brassicae nucleopolyhedrovirus (MbNPV) 7 d p.i. The two cell lines had differential responses to Autographa californica multiple nucleopolyhedrovirus (AcMNPV) infection. The results from the fluorescent staining with DAPI and electrophoresis of genomic DNA indicated that QB-Ha-E-5 cell line had typical apoptotic response following AcMNPV infection, but QB-Ha-E-1 cell line, with the AcMNPV infection rate of 55.3%, appeared anti-apoptosis. Actinomycin D could induce apoptosis of the two cell lines at the concentration of 1.25 μg/mL. Therefore, the two cell lines can be used as ideal materials to study interactions between insect viruses and insect cells.

The wide dispersal of aphid parasitoids is most likely related to the flight of parasitized alates. This hypothesis was examined via simulated flight and post-flight colonization of green peach aphid, Myzus persicae (Sulzer) alates parasitized individually by a common obligate aphid parasitoid, Aphidius gifuensis Ashmead. Data grouped by flight time (h) and flight distance (km) were analyzed using one-way ANOVA procedure, and for all the variables, a stepwise procedure of polynomial regression analysis was used. The results showed that a total number of 378 alates flew successfully in different batches, and among them, 239 alates were mummified finally. Mummified alates flew for an average time and distance of 2.63 h and 2.16 km, respectively, survived for an average time of 6.11 d, and laid 8.5 nymphs and 162 nymphs per alate during a 6-day and 14-day post flight period, respectively. The non-mummified alates did not differ significantly in these statistics from the mummified alates. Associated parasitoids successfully developed in the mummified alates, and eventually a total of 205 mummified alates emerged as adult wasps (85.8%) with a sex ratio of 1∶5.2. We so conclude that host dispersal flight is utilized by aphid parasitoids for their own dispersal. The results highlight the significant role of aphid dispersal flight in disseminating parasitoids.

This study aims to analyze the relationship between population density of the long-horn beetle, Monochamus alternatus Hope and environmental factors. In ten standard monitoring sites in pine forest of Wuyishan Scenic Spot, six density indices and seven environmental factors were sampled and the survey results were analysed corresponding to the coordinate transformation. The results showed that altitude (Y1) had a positive effect on the six density indices, while canopy size (Y6) and ground cover area (Y7) had negative effects on them. Tree age (Y2) and height (Y3) and slope position (Y4) also had positive but not significant effects. Slope position (Y5) mostly was not closed with the index. The population densities of larvae (X1), female adults (X2) and adults at the lower layer (X5) were most susceptive to the environmental factors, followed by the population densities of male adults (X3), and adults at the canopy (X4). The adult catches in trap were the most insensitive to the environmental factors. It is so concluded that the effect of environmental factors on population densities of M. alternatus is significant but different.

An outgroup roots a network to form a tree and/or to infer hypothetical ancestral character states. Usually, multiple taxa of a closely related sister group of the ingroup are selected. To empirically evaluate the choice of outgroup, we implemented three strategies of outgroup selection: a single taxon from the sister group, multiple taxa within the sister group, and multiple taxa from successive sister groups. Subsequently, we evaluated their effects on tree topologies within the family Halictidae (Hymenoptera: Apoidea) incorporating three tree reconstruction methods: maximum likelihood, maximum parsimony and Bayesian inference. The use of multiple taxa within the sister group produced more consistent results than the other two outgroup strategies. The tree topologies were generally consistent with the putative tree topology of Halictidae. Compared with the other two tree reconstruction methods, maximum parsimony produced more consistent results with different outgroup strategies, yet often obtained less resolution.

The genetic diversity and genetic structure of six populations (totally 102 individuals) of the resource insect Schlechtendalia chinensis in China were examined using amplified fragment length polymorphism (AFLP) method in order to provide molecular evidence for proper utilization and protection of this economic insect. Four pairs of selective primers were used to amplify the total DNA of S. chinensis samples with AFLP method. The results indicated that the primers yielded a total of 126 scorable loci, of which 100% was polymorphic. The percentage of polymorphic loci in different populations changed from 23.81% to 66.67%, Nei’s gene diversity index (H) from 0.0942 to 0.1980, and Shannon's index (I) from 0.1381 to 0.3027. AMOVA analysis showed that 57.99% genetic variation came from intra-populations, 42.41% genetic variation from inter-populations, and the overall Fst was 0.4242. NJ cluster analysis showed that the six populations are grouped into two major clades (A and B), each consisting of three populations. Clade A includes three populations (Yangque, Danzhai and Hanzhong), and clade B includes the other three populations (Anxian, Zhushan and Longsheng). The results suggest that the genetic diversity of S. chinensis populations is low, but the genetic differentiation among populations is high. The genetic diversity among populations is not related to the geographic distance (P>0.05).

To clarify the levels of genetic diversity and search population rapid identification method of the cabbage beetle Colaphellus bowringi Baly, seven restriction endonucleases were used to analyze the amplified products of mtDNA COⅠ gene in four populations of Colaphellus bowringi, i.e., Longnan population of Jiangxi, Xiushui population of Jiangxi, Tai'an population of Shandong and Harbin population of Heilongjiang in China. The results showed that AseⅠ, MboⅠ, NlaⅢ and RsaⅠdid not produce restriction fragment-length polymorphism among C. bowringi populations. The polymorphism was detected among the four populations with AluⅠ and DraⅠ. However, the restriction fragment-length polymorphism was found either among four populations or within Tai’an population of Shandong with HaeⅢ. Four haplotypes were found in all individuals. Obviously, the populations could be distinguished with unique haplotypes. According to the proportion of restriction fragments shared, the genetic distances among the four populations were calculated with POPGEN3.2, and a cladogram was produced with MEGA3.1. The results indicated that the genetic distance of C. bowringi among four geographic populations did not match with their geographic distance, neither their genetic variance with their diapause variance. We so conclude that PCR-RFLP analysis of mtDNA COⅠ gene can be used to identify different geographic populations of C. bowringi.

Glutathione S-transferases (GSTs) play an important role in detoxification and antioxidation. In order to study the molecular mechanisms of insecticide resistance in the wild mulberry silkworm, Bombyx mandarina, we detected the transcription levels of GST genes in different tissues of the fifth instar larvae and those treated with dichlorovos and deltamethrin using real-time quantitative RT-PCR method, and took Actin3 gene as reference to dispose the results. The results showed that the expression levels of GST genes induced by dichlorovos and deltamethrin were different in various tissues, the highest expression level was found in fat body, and the second was in the midgut, and this might be due to that both tissues are major organs involved in detoxication of the pesticides. Furthermore, the GSTe2 and GSTe5 genes were highly expressed, so it is inferred that these genes may be mainly responsible for detoxification of xenobiotics.

In order to explore the role of androgen receptor-like (AR-like) during spermatogenesis of termites, immunocytochemistry method was employed to locate AR-like of reproductives and workers of Reticulitermes aculabialis during the spermatogenesis. The results showed that the AR-ike existed in the cytoplasm and the nucleus of primary spermatocyte in spermatogenesis in reproductives and workers, with a lower expression level in workers than that in reproductives. The results suggest that the expression of AR-ike is associated with the meiosis of primary spermatocytes during spermatogenesis, and androgen and AR-ike affected spermatogenesis by regulating the first meiosis of spermatocytes. Although the testes development of workers is restrained, workers have the same mechanism of hormonal regulation as the reproductives during spermatogenesis, so they are able to form sperms in their testes. These results provide new histological evidence that workers can differentiate into notenic reproductives according to the demand of the colony, even though the gonads of workers have degenerated.

The invasive red palm weevil (RPW), Rhynchophorus ferrugineus (Olivier), native to Southern Asia, is becoming a serious invasive pest of palms in China. In order to understand how well the RPW survives under cold temperature, with materials from fields in Shanghai we determined the supercooling points (SCPs) with supercooling point determinator and the degree of cold hardiness in environmental chamber at low temperatures, simulated field overwintering test in Shanghai, and analyzed the north limit for overwintering of RPW. The results indicated that SCPs of the RPW were significantly decreased as the developmental stages increased. Adults had the lowest SCPs, followed by 9th, 5th and 1st instar larvae and eggs in an increasing order. The viability of various developmental stages in the RPW was measured in 6, 24, 48 and 72 h, and the relationship between the survival rate and low temperature could be fitted with logistic model significantly or extremely significantly. Ltemp₅₀ (the temperature that results in 50% mortality of the experimental population) was increased as time prolonged at all stages of the RPW. At 72 h after treatment, Ltemp₅₀ values of eggs, 1st instar larvae, 5th instar larvae, 9th instar larvae and adults were 1.61, -1.67, -2.39, -2.40 and -0.40℃, respectively. This result showed that the larvae had the highest cold hardiness, followed by adults and eggs in order. The above data indicated that the correlation between the cold hardiness and SCPs was not uniformly positive. Thus, we speculated that either adult or larva could be possible stage of overwintering for the RPW. The field overwintering test also showed that survival rates of both larvae and adults were above 60% in continuous two years (2007 and 2008), suggesting that the RPW could overwinter in the field in Shanghai. Based on the results obtained and distribution of the hosts of the RPW, we tentatively inferred that the northern limit for overwintering of the RPW is proximate to 35°N or where the average low temperature in January is around 0℃.

The gall midge Obolodiplosis robiniae (Haldeman) (Diptera: Cecidomyiidae) was just recently found in China, it caused severe damage to black locust, Robinia pseudoacacia L. The pest is native to North America. Because the pest threats the health of R. pseudoacacia, it has been listed in the quarantine list in China now. For biocontrol purpose we investigated its insect natural enemy. In Qinghuangdao city of Hebei province, O. robiniae populations are affected by a parasitoid, Platygaster robiniae Buhl and Duso in the family Platygastridae, which is a new record in China. Primary field investigation indicated that the highest parasitism rate of P. robiniae could reach 84.8%, and this wasp has high application value for biocontrol. The external morphology observed with scanning electron microscopy (SEM) and the tentatively observed biology of P. robiniae are described in the present paper