Odorant-binding proteins (OBPs) are responsible for physiological function via perception of volatile odors. Here we reported the successful expression and purification of a general odorant binding protein Lsti-GOBP1 from Loxostege sticticalis L. Lsti-GOBP1 was expressed using Escherichia coli Rosetta (DE3) prokaryotic expression system, and then purified using Histrap HP column, and the protein functions of Lsti-GOBP1 were tested by fluorescent probe N-phenyl-1-naphthylamine (1-NPN) binding assays and competitive binding assays with 50 kinds of chemical molecules. The results showed that Lsti-GOBP1 had the capability of binding 35 odorants. However, only 1-hexanol, 1-heptanol, cinnamaldehyde and camphene replaced 1-NPN from Lsti-GOBP1 by 50%, and their binding constants were 8.997, 7.283, 7.289 and 9.814 μmol/L, respectively. So, it can be speculated that Lsti-GOBP1 has a wide binding characteristics, but it has strong binding specificity to 1-hexanol, 1-heptanol, cinnamaldehyde and camphene, which probably all play a critical role in the process of recognizing different odorants in L. sticticalis.

The researches focusing on key developmental genes in non-holometabola insects are relatively insufficient, especially for the reports on the structure and sequences of Hox genes. In order to understand the structure of Ubx gene (a member of Hox genes) in non-holometabola insects, we selected the large milkweed bug, Oncopeltus fasciatus (Dallas, 1852), as a representative, and used RACE and RT-PCR to clone the whole ORF of Ubx gene. The results showed that the full-length ORF of Ubx gene of O. fasciatus (Of-Ubx) is 888 bp, encoding 295 aa. Southern blot analysis verified that Of-Ubx exists as a single copy and has introns within it. We found alternative splicing sites between YPWM and homeodomain motif, which lead to 3 types of transcript variants. Compared with the Ubx gene from Drosophila melanogaster (Meigen, 1830), Of-Ubx had similar splicing sites, conserved elements around splicing sites and isoform combination, suggesting that their splicing mechanism should be similar. This is the first detailed report about the multiple transcripts of Ubx genes within Insecta except for the genus Drosophila.

In order to understand the adaptability of Pleonomus canaliculatus under different environmental conditions, we detected respiratory rate of insects by using Sable Systems at different temperatures, oxygen concentrations, illumination and humidity. The results indicated that the breathing pattern of P. canaliculatus was the variable-amplitude oscillated type. The CO₂ release rate was significantly influenced by temperature and illumination, and there were significant differences between different treatments. The minimum value of the CO₂ release rate (7.22 μL/h) was detected at 5℃, while its maximum value was detected (180.74 μL/h) at 35℃, and there was extremely significant difference between the two treatments (P<0.01). Respiration intensity of P. canaliculatus under intense light source was two times as high as that under dark (P<0.05). The changes of oxygen concentration and air humidity had no significant contribution to the CO₂ release rate. The Q₁₀ model which represents the sensitivity of respiration rate of insects to temperature was successfully established by the data analysis. It is so concluded that the temperature and light play a main role in P. canaliculatus respiratory metabolism process whereas low oxygen and humidity are less involved.

It had been reported that silkworms Bombyx mori reared on cudrang (Cudrania tricuspidata) leaves are sensitive to B. mori nucleopolyhedrovirus (BmNPV). In order to explore the mechanisms of this phenomenon, we investigated the activities of different anti-BmNPV proteins in digestive juice of the silkworm reared on cudrang leaves and mulberry (Morus alba) leaves, respectively. The results showed that there was no significant change in intensity of red fluorescent protein (RFP) in the digestive juice of the silkworm reared on cudrang leaves. However, the enzymatic activities of lipase and trypsin in the silkworm reared on cudrang leaves were 1 421.71±202.60 U/L and 19.67±8.17 U/mL, respectively, much lower than those of the silkworms reared on mulberry leaves, which were 1 976.03±139.92 U/L and 199.18±181.71 U/mL, respectively (P<0.05). The results suggest that the susceptibility of silkworms to BmNPV may be related with the lower activities of lipase and trypsin in digestive juice.

To explain the infection ability of Beauveria bassiana to cotton bollworm Helicoverpa armigera (Hübner), pathogenicity of B. bassiana HFW-05 strain to 2nd instar larvae of H. armigera was measured using feeding method and cuticle infection, and the mode of infection of HFW-05 strain to H. armigera was observed through histopathological section and scanning electron microscopy observation. The results showed that HFW-05 strain could infect H. armigera successfully through the digestive tract (feeding method) on 2nd instar larvae of cotton bollworm, with the corrected mortality 75.8% at 6 d after infection. But it did not infect the larvae through cuticle infection (dipping method), and the average body weight and food consumption of the test insects were similar to the control, with the corrected mortality only 17.3% at 6 d after infection. The results indicated that HFW05 strain could infect cotton bollworm mainly through the digestive tract under 26±1℃ condition and the pathogen occurred in intestinal tissue, fat bodies and the Malpighian tubules. After invading the host, it caused the intestinal tissue microvilli to shed seriously and to dissolve gradually with only membrane of the bottom left. The Malpighian tubules became atrophic and deformed, and their edges became swelled and the diameter became enlarged. Fat bodies were disintegrated and loose. The epidermal cells of the hosts had been damaged by hyphae. Cuticle infection by dipping method was observed through histopathological section, hyphae were not found in host body and the intestinal tissues were normal and integral at 6 d after treatment. The scanning electron microscope results showed that conidia failed to penetrate the host cuticle by cuticle infection, but affixed to the cuticle surface of host, and grew to break as blastospores under the right condition. The results suggest that digestive tract infection could compensate environmentally unfavorable effect to B. bassiana infection, and this may have important significance for B. bassiana application in bio-control.

Wolbachia is a group of intracellular inherited endosymbiontic bacteria infecting a wide range of arthropods and other animals. The infection status of Wolbachia in the migratory pest Cnaphalocrocis medinalis (Guenée) was studied to provide the basis for revealing the reproductive manipulation mechanism and transmission mechanism of Wolbachia in this pest. In this study, specific primers derived from ftsZ and 16S rDNA genes were used to amplify DNA of Wolbachia from 20 populations of C. medinalis in China by polymerase chain reaction (PCR). The results indicated that the C. medinalis populations in China were widely infected by Wolbachia, the highest infection rate was 90% in Wenzhou of Zhejiang and Yangzhou of Jiangsu, and the lowest rate was 40% in Ya’an of Sichuan, Changsha of Hunan and Ninghe of Tianjin. The ftsZ sequences and 16S rDNA sequences were exactly the same in all positive samples from different regions. Wolbachia ftsZ sequences and 16S rDNA sequences in C. medinalis showed 99%-100% and 98%-99% similarity with others belonging to Group B, respectively, suggesting that Wolbachia in C. medinalis belong to Group B. The results show that the infection type of Wolbachia in the C. medinalis is relatively single. This is the first report that Wolbachia is distributed in the populations of C. medinalis in China.

【Aim】 The western flower thrips (WFT), Frankliniella occidentalis (Pergande), is an invasive pest in China, while tomato spotted wilt virus (TSWV), which is mainly transmitted by WFT, is a very serious virus around the world. Through the study of the interactions between WFT and TSWV, the mechanism of the outbreak of both WFT and TSWV can be further understood. Furthermore, it will provide a theoretical basis for developing reasonable and sustainable control strategies of WFT and TSWV. 【Methods】 Age-stage and two-sex life tables were used to study the effects of the mature excised foliages of three treated peppers (healthy, CK; mechanically damaged, MD; mechanically inoculated by TSWV, MI) on biological characteristics of WFT. 【Results】 The results showed that the developmental periods of preadult thrips were 12.45, 11.97 and 11.18 d on CK, MD and MI foliages, respectively. There were significant differences in adult longevity and female fecundity between different treatments (P<0.05). On MI-leaves, the adult longevity was the longest (female: 13.51 d; male: 12.69 d), and the total number of 1st instar nymphae produced was the highest, up to 33.01 1st instar nymphae per female. The intrinsic rate of increase (r_m) on CK, MD and MI were -0.009, 0.153, 0.190 d^-1, and the net reproduction rate (R₀) were 0.84, 14.54, and 21.79, respectively. 【Conclusion】 The results suggest that infection of host plants with TSWV may benefit WFT through shortening developmental time, prolonging adult longevity, increasing fecundity, and accelerating the population growth of WFT.

To understand the probability and direction of long-distance dispersal of the wheat midge, Sitodiplosis mosellana (Géhin), populations with air current, we analyzed the profile of S. mosellana density that was determined with a series of balloon-supported yellow traps located vertically at altitudes from 5-75 m above ground level, and the internet-based HYSPLIT-4 (HYbrid Single-Particle Lagrangian Integrated Trajectory) model was used to simulate the dispersal trajectory of S. mosellana at various altitudes in Luoning (34.35°N, 111.52°E), Henan province in 2010 and in north China in 2007. The results indicated that the aerial densities of S. mosellana (number of individuals per trap) at altitudes of 5, 45, 50 and 65 m were higher than those at other altitudes, showing stratification according to altitude above ground. The immigration populations came from Nanyang, Henan province, and the emigration populations moved with airflow to Yiyang, Henan province in 2010. The wheat midge populations dispersed step by step from southwest to northeast with southwest air current in 2007. The dispersal with air current was an important way of long-distance dispersal of S. mosellana. The results may help realize the population expansion and provide a reference value for monitoring population dynamics and optimizing integrated management of S. mosellana in China.

Studying the responses of Microplitis mediator Haliday to different instar larvae of Helicoverpa armigera Hübner and damaged cotton plants could supply the theoretical basis for effectively applying M. mediator to control cotton bollworm (CBW). In this study, responses of female M. mediator wasps to different instar larvae of CBW and damaged cotton plants were measured by using Y-shaped olfactometer in laboratory. Results showed that CBW larvae of the 3rd, 4th and 5th instars had no significant attraction to M. mediator, while CBW larvae of the 1st and 2nd instars had significant attraction. Among the behavioral responses of M. mediator to cotton plants damaged by different instar larvae of CBW, we found that both cotton plants damaged by CBW larvae and the healthy ones (the control) could strongly attract wasps. In tests with no larvae removed, M. mediator wasps had a significantly higher preference for damaged cotton plants plus CBW larvae than for the control, but there were notable differences in attraction among different instars, and the relative selective preference order was as follows: plants infested by 5th instar larvae of CBW > plants infested by 2nd and 4th instar larvae of CBW > plants infested by 1st and 3rd instar larvae of CBW. The results may provide some theoretical guidance and practical basis for application of M. mediator in biological control strategy.

Insect pollinators play an important role in agricultural production, especially for fruits and vegetables. However, there is now mounting evidence of pollinator decline in many countries all over the world and it is important to assess its potential impact on crop production. To assess the situation of insect pollinators in China, we first examined the changes in the number of honeybee colonies and the area planted with fruits and vegetables over the past half century. We then used the bio-economic approach, based upon the pollinator dependency of 44 crops used directly for human food, to assess the value of insect pollination for Chinese fruits and vegetables. The stock of honeybee colonies in China had increased by 161% between 1961 and 2009, while the area of fruits and vegetable cultivation had increased by 472%, and their production had increased by 833%. The growth in yield of insect-pollintated fruits and vegetables in China is closely related to the growth in the cultivated area (r=0.995, P<0.01), and is also related to the increase in the number of honeybee colonies (r=0.804, P<0.01). The total economic value of insect pollination of Chinese fruits and vegetables amounted to 52.2 billion US dollars in 2008, which represented 25.5% of the total production value of the 44 crops produced in China. In production value, apples, watermelons, pears, mangoes and plums are the leading crops that depend on insect pollination. Insect pollination thus represents a substantial economic factor for fruits and vegetables production in China, and Chinese fruits and vegetables have a higher economic vulnerability ratio to pollinators than the world’s average level of 15.9%. With the continuing increase in the area planted with fruits and vegetables, the need for the service provided by insect pollinators in China is likely to continue to increase.

 This paper reports one new species of the genus Chrysacris from Helan Mountain, namely Chrysacris albonemus Zheng, Zhang et Zeng sp. nov. The new species is allied to Chrysacris montanis Zhang et Zheng, 1993, but differs in: 1) with a median keel in vertex and back of head; 2) length of prozona 1.6-1.8 times that of metazona; 3) width of costal area of tegmina 1.5-2 times that of medial area. Type specimens are deposited in the Institute of Zoology, Shaanxi Normal University.

In insects, cholesterol is not only one of the main components of cell membranes, but also a precursor of ecdysone biosynthesis. However, because insects lack two key enzymes for cholesterol biosynthesis, they can not autonomously synthesize cholesterol from simple compounds and therefore have to obtain sterols from their diet. Insects must convert food sterols into cholesterol to meet the requirements of growth, development and reproduction. Sterol carrier proteins (SCPs) are main transport proteins for sterol absorption and transport in insects. It is critical to study the relationship between structure and function of SCPs for understanding the roles of SCPs in sterol transport. In this review, recent progress in the study of the structure, expression and distribution of SCP genes and proteins, post-translation modification, crystal structure, ligand-binding specificity and possible absorption and transport pathways of insect SCPs was summarized and the potential of using SCPs as a molecular target for pest insect control was also discussed. Studies indicate that transcript expression of SCP genes and post-translation modifications of SCP proteins vary depending on different species. In dipteran insects such as Aedes aegypti and Drosophila melangoster SCP-x gene encodes SCP-x and SCP-2 proteins, while there are additional SCP-2 genes and SCP-2-like genes encoding SCP-2 and SCP-2-like proteins, respectively. In lepidopteran insects such as Spodoptera littoralis, Spodoptera litura and Bombyx mori, the transcript expression and translation processes of SCP-x gene are similar to those in vertebrates, in which SCP-2 protein is produced after post-transcription and translation modifications of a unique SCP-x gene. SCP-x and SCP-2 proteins are localized in peroxisomes. SCP-2 protein consists of 5 αhelixes and 5 β-sheets and the α5-helix appears to impact the binding of the protein to substrates. SCP-2 protein can bind with different affinity to cholesterol, cholesterol derivatives, fatty acids, acyl-coenzyme A and phospholipids. Over-expression of SlSCP-x and SlSCP-2 genes can increase the uptake of cholesterol into cells and RNAi inhibits the expression of SlSCP-x and SlSCP-2 genes in S. litura larvae, resulting in a decrease in cholesterol level in the hemolymph and a delay in larval growth and pupation.

 In order to assess the effects of transgenic rice on non-target pests and their natural enemies after release, a field study was conducted over 2 years to determine the effects of transgenic Bt rice on population dynamics, hatchability and mortality of planthoppers eggs and their attack (predation and parasitism) by natural enemies at the Experimental Farm of Zhejiang University and the Experimental Farm of China National Rice Research Institute in 2008 and 2009. The results showed that the trends of population dynamics and hatchability of planthopper eggs and their predation and parasitism rate were almost the same on the three different rice lines (Kemingdao1, Kemingdao2 and Xiushui11) at two experimental farms in 2 years. Moreover, the peak of number of planthopper eggs on all the three rice lines lasted about two weeks in paddy fields. However, no uniform trend of the mortality of planthopper eggs was found on the three rice lines at two experimental farms in 2 years. Furthermore, no significant difference was found on population dynamics, hatchability and mortality of planthoppers eggs and attacks (predation and parasitism) by natural enemies among the three rice lines in general (P>0.05). We so conclude that Bt rice does not significantly affect the eggs of planthoppers in paddy fields.

To study the effects of oviposition secretion on microenvironment of ovipositing incisions in Apriona germari, the influence of oviposition secretion on water content, pH level and microbial quantity was analyzed by artificial inoculation of paper mulberry (Broussonetia papyrifera) trunk caged in the field and imitated incisions. The results showed that the daily water content of the imitated incisions within 4 d after eggs being laid was significantly lower than that of CK (P<0.05), while the water content of the imitated incisions beyond 4 d after eggs being laid was higher than that of CK. The diurnal variation of water content in the ovipositing incisions was similar to that of CK. Within 5 d after eggs being laid, the diurnal variation of pH values of the barks with an ovipositing incision and the barks with an imitated incision was similar to that of common barks. Beyond 5 d after eggs being laid, the pH values of the barks with an ovipositing incision and that of the barks with an imitated incision were higher than those of common barks. But there was no obvious difference in pH value between the barks with an ovipositing incision and with an imitated incision at the same day after eggs being laid (P>0.05). The bacterial quantity of the barks was compared among imitated incisions, ovipositing incisions and CK. The results showed that at 2 d after eggs being laid, the bacterial quantity of the barks with an imitated incision was significantly (P<0.05) higher than that of the barks with an ovipositing incision or that of the common barks. At the day of eggs being laid and at 1, 6, 7, and 8 d after eggs being laid, the bacterial quantity of the barks with an imitated incision was extremely significantly (P<0.01) higher than that of the barks with an ovipositing incision or that of the common barks respectively. At 3 d after eggs being laid the bacterial quantity of the common barks (1 320.0±189.0) was extremely significantly (P<0.01) higher than that of either the barks with an ovipositing incision or the barks with an imitated incision. At 4 d after eggs being laid, the bacterial quantity of the barks with an imitated incision was higher than that of the barks with an ovipositing incision (P<0.05). There was no significant difference in bacterial quantity between the every two of the three kinds of barks at 5 d after eggs being laid (P>0.05). These results suggest that at the prophase of embryonic development, the secretion has the ability of keeping water content of the ovipositing incisions to a certain extent, and does not influence the pH values of the barks containing an ovipositing incision, but the bacterial quantity in the ovipositing incision is inhibited by the secretion.

The prevention and control of the citrus leafminers Phyllocnistis citrella (Lepidoptera: Gracillariidae) currently relies on chemical pesticides, and shows a lack of effective forecasting techniques. Sex pheromone components Z7,Z11,E13hexadecatrienal (Z7,Z11,E13-16Ald), Z7,Z11-Hexadecadienal (Z7,Z11-16Ald) and Z7-hexadecenal (Z7-16Ald) from P. citrella were synthesized and tested for their attractiveness to male moths in citrus orchards in Ningbo, Zhejiang, China during the period of June 30 to October 6, 2009. The results showed that Z7,Z11,E13-16Ald attracted male moths strongly, but neither Z7,Z11-16Ald nor Z7-16Ald trapped a significant number of male moths. The optimal ratio of binary blends of Z7,Z11,E13-16Ald and Z7,Z11-16Ald was between 30∶1 and 3∶1, and the binary blends at the ratio of 30∶1 trapped the highest number of males. The highest dosage for catching males was 1 mg pheromone blend formulated with the mixture of Z7,Z11,E13-16Ald and Z7,Z11-16Ald at the ratio of 3∶1. The trinary blends (Z7,Z11,E13-16Ald∶Z7,Z1116Ald∶Z7-16Ald=100∶10∶3) showed significant synergistic effects. The height of pheromone trap between 0.8 and 1.5 m had no significant effect on trapping efficiency. These results indicate that the synthetic pheromone lures can be used as the trap strategy of citrus leafminers and applied in pest control and forecasting in the field.

 The evaluation and optimization of synthetic pheromone blends of the rice leaf folder, Cnaphalocrocis medinalis were carried out in the rice fields in Haining City, Zhejiang Province between August 15 and September 20, 2009 to explore its application for forecasting population. Three methods including sex pheromone traps, light traps as well as disturbing and counting method (DCM) for monitoring adult populations were compared. The results showed that the chemical blend of Z11-octadecenal (60 μg), Z13-octadecenal (500 μg), Z11-octadece-1-ol (60 μg) and Z13-octadecen-1-ol (120 μg) formulated in the PVC capillary tubing had the strongest attractiveness to male moths in Zhejiang, China. The preliminary data obtained from the comparison of pheromone traps, light traps and the DCM indicated the potential application of pheromone traps in monitoring population of the rice leaf folder.