Prophenoloxidase-activating system (proPO-AS ) is one of the most important humoral immunity systems in insects. The crude extracts of Trichogramma ostriniae, T. chilonis and T. dendrolimi were collected by grinding and centrifugation, and PO activities of three Trichogramm species induced by calcium ions, laminarin, dextran, and PMSF were compared. The results indicated that the highest PO activity was found in the crude extract from T. ostriniae, followed by T. chilonis, and then T. dendrolimi. Ca²⁺ was required for PO activation, and the maximal activation was observed at the Ca²⁺ concentration of 0.03 mol/L. Laminarin and lipopoyusaccharide could also effectively activate proPO, and 0.01 and 0.05 mg/mL laminarin caused strong activation. Cellulose and dextran were proved to be significant inhibitors to PO. A model for proPO-AS studies of small insects was established, which provides an experimental basis for studying the interaction of immune system of symbiotic bacteria-small insects.

A large number of field trials were carried out to explore the synergistic effect of plant volatile compounds derived from host plants and flowers and sex pheromones, viz. (9Z, 11E)tetradecadienyl acetate and (9Z,12E)tetradecadienyl acetate 10∶1, of the tobacco cutworm moth, Spodoptera litura (Lepidoptera, Noctuidae), and eventually to improve the attractiveness of sex pheromone lures to male moths. Nine compounds selected from the headspace volatiles of host plants and floral odors were individually added into pheromone lures and tested in the fields for their attractiveness to the male moths. The results indicated that only phenyl acetaldehyde significantly increased the attractiveness of the pheromone at certain dosage (0.4 mg per lure) to male moths. High dosage of phenyl acetaldehyde dramatically inhibited the responses of pheromone lures. Other compounds in single or mixture tested in our experiments showed no significant synergistic effect with pheromones at the dosages tested. The lures contained only phenyl acetaldehyde or its mixture with some compounds attracted the male moth weakly. However, only the complete blend of sex pheromones showed the synergistic effect with plant volatiles. Missing minor sex pheromone components resulted in no attractiveness to male moths. These results suggest that the synergism of phenyl acetaldehyde with sex pheromone can be used to upgrade the efficiency of S. litura pest control and monitoring by sex pheromone.

Locke, a Canadian entomologist, recently suggested that caterpillars have evolved lungs for hemocyte gas exchange. Based on his research, the structure and function of lungs in larvae of Leucania separata and Sylepta derogata were studied by means of electron microscope and other chemical methods. The results indicated that lungs are located at the trachea of the 8th abdominal segment. Their trachea branches are taper, short and abundant, forming tracheal tufts. Through labelling hemolymph with methylene blue, we observed that the hemolymph moves backwards laterally and ventrally to flow through the 8th abdominal segment and tokus, and finally into the heart. The tracheal tufts of the 8th abdominal segment have thinner cuticle than those of the other abdominal segments, and the cuticular intima of tracheal tufts have more tubules appropriate for them to move, which are in favour of the permeation of gas. Normally these tracheal tufts have all kinds of hemocytes, which are abundant in the tufts. A large number of hemocytes released from tissues attach to the tufts by changing their structure when anoxic stress happens, which is favorable to the exchange of gas. These characteristics are similar to lungs of other higher animals, so it is concluded that this structure has the function of lung.

Photoperiod response of diapause induction and the photo-sensitive stage in Chouioia cunea Yang were investigated. The photoperiodic response curves under 24 h light-dark cycles showed that the species is a typical long-day species, entering diapause as mature larvae. The critical photoperiod for diapause induction was estimated to be between 13L∶11D and 14L∶10D at 18℃, and between 12L∶12D and 13L∶11D at 21℃ and 24℃. The late instar larvae were most sensitive to photoperiod. However, the short day light received at all larval stages was also important for the increase of their diapause rate. The developmental duration for post-diapause development of C. cunea was determined by exposing diapause larvae to different constant temperatures (18, 21, 24 and 30℃). The results showed that the threshold temperature and effective accumulative temperature for post-diapause development of mature larvae were 14.60±0.31℃ and 209.38±8.72 day-degrees, respectively. These results may provide a theoretical basis for long-term preservation, commercial production and release time of C. cunea.

In order to explore the negative effects of delayed mating on the population of the hawthorn spider mite, Tetranychus viennensis Zacher, a leaf disc bioassay was employed to investigate the effects of delayed mating on the female longevity, fecundity, and the intrinsic rate of increase of T. viennensis in the laboratory at the conditions of 25±1℃, RH 60%±7%, and photoperiod of 16L∶8D. Life tables were constructed in each experiment. The parameters, including the intrinsic rate of increase (rm), the finite rate of increase (λ), the net reproduction rate (R₀), mean generation time (T) and doubling time (Dt) were calculated and analyzed using Jackknife method. The results showed that delayed mating had negative effects on the longevity and fecundity of female adults, depending on the period of delay, but had no effect on the hatchability and survivorship in the offspring. These negative effects strengthened with increasing of mating age of females. Significantly reduced fecundity (26.74%) and significantly prolonged longevity (20.17%) were found in females whose mating was delayed by 7 d or more. Meanwhile, the net reproduction rate (R₀) was reduced significantly and mean generation time (T) prolonged significantly. As the result of the decreased net reproductive rate and prolonged mean generation time, the intrinsic rate of increase decreased sharply in females whose mating was delayed by 3 d or more. Unmated female mites had a significant lower fecundity (decreased by 30.08%) and a significant longer longevity (increased by 31.14%) than inseminated ones. The increased longevity of unmated females combined with a lower oviposition rate tended to increase the probability of an encounter with a male at some point in the productive life of a female. In the extreme case, the parthenogenetic producing female could shift to sexual reproduction by mating with one of her mature sons, and this was proved by backcross test. These results suggest that delayed mating has adverse impacts on the fecundity of T. viennensis.

In order to get the basic information about ground-dwelling beetle and give some suggestions for the local biodiversity conservation, we investigated the ground-dwelling beetle assemblages by pitfall trapping in natural forest, plantation forest, and dry land in lac-plantation-farmland ecosystem in Luchun County, Yunnan Province, South-western China, during 2006-2007. In total, 1 678 specimens were collected, representing 120 species in 24 families of Coleoptera. Among these beetles, Carabidae and Scarabaeidae had the highest species richness, both comprising 12.50% of the total species observed. Tenebrionidae species had the highest abundance, comprising 64.48% of all ground-dwelling beetles; and the Scarabaeidae ranked the second in abundance, comprising 17.58%. Most families did not differ in both abundance and species richness across the three habitats sampled, while Carabidae, Staphylinidae, Elateridae, Tenebrionidae, Coccinellidae and Scolytidae differed in abundance or species richness. Among the plots, natural forest had the lowest abundance and dominance, richer species, and highest diversity; plantation forest had richer species and abundance, and moderate dominance and diversity; while dry land had the highest abundance and dominance, and the lowest species richness and diversity. Hierarchical clustering of ground-dwelling beetle assemblages at the species level showed that plantation forest was nearly to dry land in species composition. While at the family level, plantation forest was close to natural forest. These results suggest that the land-use in lac-plantation-farmland ecosystem is different and diverse; the natural forest plays the most important role in maintaining the beetle diversity, while the plantation forest plays the second important role, which needs further restoration.

Ectoparasitic gamasid mites associated with small mammals have long been suspected to be the vectors of some zoonoses such as hemorrhagic fever with renal syndrome (HFRS) and rickettsialpox. In this paper, the results of wild investigations of the gamasid mites associated with small mammals in 28 counties of Yunnan, China is reported. The characteristics of community and describe the spatial distribution of gamasid mites along an environmental gradient are analyzed by using species richness, Shannon diversity index. In addition, the similarity of 18 mite infracommunities was compared by using hierarchical clustering analysis (SPSS 16.0). A total of 14 544 individuals of small mammals belonging to five orders (Rodentia, Insectivora, Scandentia, Lagomorpha and Carnivora), 10 families, 35 genera and 67 species were trapped, from which 80 791 individuals of gamasid mites representing 10 families, 33 genera and 112 species were collected. The results indicated that the dominant host species were Rattus tanezumi, Apodemus chevrieri, and Eothenomys miletus, while dominant gamasid mite species were Laelaps nuttalli, L. echidninus and L. guizhouensis. The mite infracommunities associated with A. chevrieri, N. confucianus and R. tanezumi exhibited the highest species richness, while mite infracommunities on Suncus murinus, Apodemus chevrieri and Crocidura attenuata presented the highest diversity. The results of cluster analysis showed that the similarity of most mite communities in accordance with the taxonomic relationship and the habitat of their corresponding small mammal hosts. The mite communities are clustered into the same group when their hosts are similar in zoological taxonomy and habitat selection. The horizontal patterns of gamasid mite species richness along a latitudinal gradient showed two peaks, the highest richness was recorded at the latitude 25°N to 26°N, while the vertical patterns presented a single-peak curve along the elevation gradient, peaking at the elevation of 2 000 m to 2 500 m. The diversity spatial distribution patterns of gamasid mites and their small mammal hosts showed the similar trends of single-peak curves which gradually increased and then decreased with increasing of latitude and elevation, peaking at the latitude 26°N to 27°N and the elevation of 2 000 m to 2 500 m. The results suggest that the community structure of gamasid mites in Yunnan Province has high species richness and diversity. The spatial distribution patterns of gamasid mites in Yunnan Province may be the results of the edge effect between the Oriental and Palaearctic realms.

Polymerase chain reaction and PCR products directly sequencing method (a few samples sequenced by cloning) were used to analyze the genetic diversity of the wild mulberry silkworm, Bombyx mandarina in China and the phylogeny of the domesticated silkworm, B. mori. A total of 715 bp nucleotides of partial amylase gene amy were sequenced in thirty-four samples from three groups of B. mandarina and four types of B. mori. Fifty-six polymorphic sites, including 28 singleton variable sites and 28 parsimony informative sites, defined 28 haplotypes. The nucleotides diversity (π) was 0.01390±0.00103 and the haplotype diversity (Hd) was 0.988±0.011. Mismatch analysis and Fu’s Fs test revealed the population expansion of B. mori in the past. Analysis of molecular variance (AMOVA) suggested that genetic variance mostly existed within populations and accounted for 82.63% of total variation. Variance between population and population-groups was not significant. The phylogenetic analysis indicated that three clusters were formed by the thirty-four samples analyzed. Cluster A consisted of B. mandarina from different regions and B. mori from different types, which was further divided into three sub-clusters. Cluster B consisted of three B. mori and one B. mandarina, while cluster C consisted of B. mandarina from different regions only. There is no ancestor haplotype and dominant haplotype in the median-joining network. The results suggest that: (1) the amy gene is a molecular marker with rich diversity in silkworms; (2) there is great genetic diversity within B. mandarina population in China; and (3) the domesticated silkworm may be domesticated from multi-typed B. mandarina, which supports the theory of multiple origins from a variety of B. mandarina.

【Objective】 Through comparing partial sequences of mitochondrial Cytb and COⅠ genes, to analyze the genetic differentiation among the geographic populations of the cowpea weevil,  Callosobruchus maculatus Fabricius,  and to determine the relationships between the genetic structure of populations and biological invasion and provide an understanding of the evolutionary mechanisms underlying the invasion process.【Methods】 The mtDNA-Cytb and COⅠ regions of 4 populations of C. maculatus from Hainan of China,  Cameroom,  Korea and Thailand,  respectively, were sequenced by direct sequencing method. The mtDNA Cytb and COⅠ sequences among populations of C. maculatus were analyzed using MEGA3.1 and the phylogenetic trees of all haplotypes were constructed using C. chinensis as the out-group. 【Results】 As for the 420 bp mtDNA-Cytb gene of 34 individuals,  14 polymorphic sites and 5 haplotypes were found,  while as for the 822 bp mtDNA-Cytb gene of 33 individuals,  28 polymorphic sites and 9 haplotypes were found. Four haplotypes were rare haplotypes,  typically present in only one or two individuals and representative of a specific population, while other haplotypes were shared by all or partial populations. Molecular variance analysis (AMOVA) demonstrated that the genetic variation was not obvious and mainly occurred within geographic populations. The Fst value and the Nm value showed that not only the gene flow occurred among the four populations, but also the genetic differences did. 【Conclusion】 Given the observed distribution pattern of haplotypes,  China was not the origin of C. maculatus,  while Cameroon was likely to be one of the origins of C. maculatus. Gene flow between Haplotype Cameroon and Haplotype Thailand was relatively abundant, and genetic differentiation among Haplotype China and other haplotypes were relatively large.

【Objective】 Through studying the numerical taxonomy of the species of Phlebotominae from China to explore the phylogenetic position of these species in Phlebotominae.【Methods】 Cluster analysis was carried out with 40 species of Phlebotominae from China as taxa and 68 morphological characters as index.【Results】 The result of cluster analysis is consistent with classic taxonomy in the genus classifications of Phlebotominae and subgenus classifications of genus Phlebotomus, while there are some differences in the subgenus classifications of genus Sergentomyia which is divided into 8 groups by cluster analysis. Two of them are respectively identical with subgenus Sergentomyia and nicnic group in classic taxonomy. S. quanzhouensis and S. tangi unite with subgenus Parrotomyia. S. yini is separated into subgenus Neophlebotomus. S. iyengari, S. malayensis, S. lanzhouensis, S. nankingensis and S. turfanensis aggregate as a group. S. koloshanensis, S. fanglianensis, S. yunnanensis and nicnic group unite as a group which has a far phylogenetic relationship with that composed of other species of genus Sergentomyia. 【Conclusion】 The result of cluster analysis of Chinese Phlebotominae is consistent with classic taxonomy on the whole. It confirms the reliability of classic taxonomy and also reveals the uncertain classification of some species in genus Sergentomyia in classic taxonomy. The difference between the two classifications of genus Sergentomyia suggests that refining the taxonomic position of some species and founding a new multispecies genus or subgenus or group at the subgenus level are essential.

Peritrophic membrane (PM), a semi-permeable mucous layer, serves as a lubricative and protective barrier in the midgut of the major types of insects. PM can be divided into peritrophic membrane type Ⅰ and Ⅱ according to its different ways of formation. PM is mainly composed of chitin and protein, and the latter is very important in maintaining PM dense structure. Damages to PM proteins may cause serious interference to insect growth, and even lead to the death of low-instar larva. This article introduced the composition and structure of PM, reviewed the new discovery of the insect peritrophic membrane proteins, the classification according to their structural characteristics and possible methods of peritrophic membrane proteins as the targets for pest control, and discussed the limitations of current research and the future prospects of PM proteins.

To study the difference in sensitivity of acetylcholinesterase (AChE) from individual adult female and its relationship with insecticide resistance in different populations of Bemisia tabaci, the response of AChE to inhibition by dichlorvos and the frequency distribution of residual activity in presence of inhibitor in the susceptible SUD-S strain and six field resistant populations of B. tabaci were measured by microtiter plate kinetic assay. The results showed that dichlorvos at 300 μmol/L completely inhibited AChE activity of the SUD-S strain, and clearly distinguished the SUD-S from the six resistant populations. Significant differences were observed in frequency distribution of the residual AChE activity in adult female individuals in the six field populations of B. tabaci in presence of 2 000 μmol/L dichlorvos. The frequency distribution patterns of the residual AChE activity in ZZ-R and ZZ-R populations were similar, and most of the residual activity in adult female individuals ranged from 1.00 to 1.80 mOD/min. SM-R and ND-R populations also had similar frequency distribution patterns of the residual AChE activity, and most of their residual activity in adult female individuals ranged from 0.40 to 1.00 mOD/min; whereas in LY-R and NP-R populations, most of the residual AChE activity in adult female individuals ranged from 1.00 to 1.80 mOD/min and 0.80 to 1.20 mOD/min, respectively. The correlation coefficient between the high residual AChE activity (higher than 1.00 mOD/min) and the resistant level to dichlorvos was 0.86 (P<0.05). Since the insensitivity of AChE to inhibitor is one of the mechanisms of resistance to organophosphorus and carbamate insecticides in some insects, we suggest that the sensitivity of AChE to dichlorvos be used as a reference index for the biochemical detection of insecticide resistance in B. tabaci.

In order to screen attractive chemicals for trapping males and females Proagopertha lucidula (Faldermann), 11 plant volatiles that can trap male and female adults of other scarabs were used to test the electroantennogram (EAG) value and the taxis behavior of P. lucidula adults. The results showed that among the 11 test chemicals at the dosage of 10 μg, only (Z)-3-hexen-1-ol, geraniol, anethol and eugenol induced clear EAG response, while the other 7 chemicals elicited weak EAG response. The four compounds that induced clear EAG responses at the dose of 10 μg/μL elicited the dose-dependent EAG response. The taxis behavior of the beetle to the volatiles that induced clear EAG responses was also assayed at the doses of 1, 10 and 100 μg with Y-tube olfactometer. Corrected response percentages of both males and females to (Z)-3-hexen-1-ol, geraniol anethol and eugenol were significantly different from that of the hexane control. The study will provide the foundation for developing attractive chemicals for P. lucidula in fields.

To research the influence of temperature on development and reproduction of experimental populations of Araecerus fasciculatus, and explore the relationship between the ecological factor and life character and then provide some basic data for the control of pest, the development and reproduction of A. fasciculatus were studied at 17, 20, 23, 26, 29 and 32℃ under controlled conditions in the laboratory. The mathematical equations describing the relationship between development and temperature were fitted with line regression, Logistic model and “Wang-Lan-Ding” model, respectively. The threshold temperature and effective accumulated temperature were calculated using the least-squares method. The results showed that the developmental rate of larva increased with increasing of temperature between 17 to 29℃, and then decreased somewhat at 32℃. The highest developmental rate (0.493 d^-1) appeared at the temperature of 27.43℃. For egg, larva, pupa and egg-pupa, the threshold temperatures were 9.60, 11.48, 7.60 and 10.55℃, respectively, and the effective accumulated temperatures were 135.51, 523.57, 157.09 and 828.63 day-degrees, respectively. The influence of temperature on the development and reproduction of experimental populations of A. fasciculatus is remarkable. It is inferred that the lower threshold temperatures and lower effective accumulated temperatures are among the main reasons that the pest may cause great harm. The mathematical equations describing the relationship between development and temperature can be used to predict the occurrence of the pest and provide a theoretical basis for its integrated management.

Bemisia tabaci (Gennadius) biotypes B and Q are the two most invasive and widely distributed biotypes within the B. tabaci complex and occur mixedly in many regions at present. The rapid differentiation of the two biotypes is significant to the research of their population dynamics and invasion ecology. In order to verify the validity of microsatellite loci BEM06 and BEM23 to differentiate B. tabaci biotypes B and Q, the alleles of the two loci in the 17 B-biotype populations, 4 Q-biotype populations and 3 non-B/Q biotype populations were analyzed. The results showed that although the two loci used in combination could differentiate B. tabaci biotypes B and Q, they could not differentiate B/Q-biotype individuals from some non-B/Q biotype individuals effectively. The results suggest that the method to differentiate the biotypes B and Q with the two microsatellite loci has its limitations, especially when used for field populations in which other biotypes exist.