Impact Evaluation of Insect-Resistant Transgenic Rice on the Feeding and Oviposition Behavior of Its Non-Target Insect, the Brown Planthopper, Nilaparvata lugens (Homptera: Delphacidae)

The feeding and oviposition behavior of the brown planthopper (BPH), Nilaparvata lugens on two transgenic indica rice homogenous genotypes (B1 and B6) with cry1Ab gene from Bacillus thuringiensis and transgenic restored line of hybrid rice (MSA) with SCK gene (a modified CpTI gene) were measured, compared with those on their corresponding non transgenic parental cultivars Jiazao935 and Minghui86 performed by BPH. Under the selection condition of host plants by BPH, loading percentage, oviposition preference and laying egg number of BPH both on transgenic cry1Ab rice and transgenic SCK rice were not significantly different from those on their controls, while their total number of probing wound caused by PBH expect for feeding on B1 plants was markedly more than that on the control. In contrast, under the non selection condition, total number of probing wound caused by BPH on either transgenic cry1Ab rice or transgenic SCK rice was pronouncedly more than those on their controls. Conversely, their honeydew amount excreted by BPH after feeding for 24 h was significantly less than those on the control. As a conclusion, three tested transgenic rice genotypes with insect resistance acted adverse effect on BHP feeding, and no marked effect on BPH oviposition.

Effect of Nitrogen on Water Content, Sap Flow, and Tolerance of Rice Plants to Brown Planthopper, Nilaparvata lugens

Water content (WC) and sap flow from leaf sheath of rice plants with varying nitrogen levels at different growth stages, and fluctuations in relative water content (RWC) of rice plants being damaged by brown planthoppcr (BPH), Nilaparvata lugens were determined in the laboratory, and the tolerance of rice plants to BPH at different nitrogen regimes was evaluated in the greenhouse at International Rice Research Institute (IRRI), the Philippines. The results indicated that both WC and RWC were increased significantly, as the amount of sap flow from rice plants was reduced statistically, with the increase of nitrogen content in rice plants. RWC in rice plants applied with high nitrogen fertilizer decreased drastically by the injury of BPH nymphs, while the reduced survival duration of rice plants with the increase of nitrogen content was recorded. These may be considered to be one of the important factors in increasing the susceptibility to BPH damage on rice plants applied with nitrogen fertilizer.

A large scale screen for genes （3rd chromosome） related to Wingless signaling pathway

A wing specific F 1 genetic screen was carried out using the powerful Drosophila genetic system, combined with yeast FRT/FLP and GAL4/UAS system. Form the wing phenotypes and germline clone embryonic cuticle phenotypes observed in these mutant alleles, a number of mutant alleles of known or unknown genes were isolated. Among them, fifteen mutant alleles related to Wingless signal transduction were further isolated; the arm of these mutations located were determined, and their location in the chromosome were roughly mapped.

Effects of nitrogen on the tolerance of brown planthopper,Nilaparvata Lugens, to adverse environmental factors

The effect of nitrogen content in rice plants on the tolerance of brown planthopper (BPH), Nilaparvata lugens Stal to high temperature, starvation and insecticide, was studied in the laboratory at International Rice Research Institute (IRRI), Philippines. Survival of nymphs and adults, fecundity and egg hatchability were significantly increased by the increase of nitrogen content in host plants at 38℃. Moreover, the survival of nymphs,fecundity and egg hatchability were significantly higher in BPH populations on rice plants with a high nitrogen regimen than those on rice plants with a low nitrogen regimen.Meanwhile, the tolerance of female adults to starvation and nymphs to growth regulator buprofezin on rice plants with a high nitrogen regimen were slightly increased. This indicates that the tolerances of BPH to adverse environmental stresses were positively increased by the application of nitrogenous fertilizer. The outbreak potential of BPH induced by the excessive application of fertilizer in rice fields was also discussed.

Ovicidal activity of two fungal pathogens (Hyphomycetes) against Tetranychus cinnabarinus (Acarina:Tetranichidae)

The carmine spider mite, Tetranychus cinnabarinus, is an economically important pest that devastates varieties of crops worldwide and develops significant resistance to common chemical pesticides, most of which lack ovicidal activity. In the present study, two isolates of entomopathogenic fungi, Beuaveria bassiana SG8702 and Paeccilomyces fumosoroseus Pfr153, were bioassayed against T.cinnabarinus eggs at 25℃ under a photophase of 12:12(L:D). Infected eggs on Vicia faba var. minor leaves failed to hatch due to distortion and shrinkage and had fungal outgrowths when maintained under moist conditions. Sprays of B. bassiana conidia to T. cinnabarinus eggs (on leaves) at the concentrations of 58, 298 and 1306 conidia/mm^2 (3 replicates per concentration and 35-65 fresh mite eggs per replicate)resulted in corrected egg mortalities of 20.4±4.2%,36.0±7.6% and 64.6±12.5% (F=43.14, P<0.01), respectively;sprays of P. fumosoroseus at 129, 402 and 2328 conidia/mm^2 caused egg mortalities of 16.1±11.1%, 44.2±13.3%, and 63.4±11.7% (F=15.37,P=0.01), respectively. In contrast,natural egg mortalities in blank controls were 7.8% and 10.3% only. Based on probit analysis, the estimates of LC50 with 95% confidential limits were 548 (393-858) conidia/mm^2 for B. bassiana and 914 (625-1550) for P. fumosoroseus, respectively. Apparently, both fungal species were capable of infecting T. cinnabarinus eggs, but the ovicidal activity of the B. bassiana isolate was greater than that of the P. fumosoroseus isolate. This represents the first report on the ovicidal activity of the two entomopathogenic Hyphomycetes against T. cinnabarinus.

NUTRITIONAL VALUE OF THE FIELD CRICKET （GRYLLUS TESTACEUS WALKER）

The chemical composition and the nutritional quality of protein, fatty acids and chitin of adult field cricket Gryllus testaceus Walker were investigated. The adult insect contalned: crude protein 58.3 %; fat 10.3 %, chitin 8.7 % and ash 2.96 % on dry matter basis respectively. The essential amino acid profile compared well with FAO/WHO recommended pattern except for cysteine and methionine. The fatty acid analysis showed unsaturated acid of the field cricket to be present in high quantities, and the total percentage of oleic acid, linolic acid and linolenic acid was 77.51%. The chitin content of the insect was 8.7 % with a better quality than the commercial chitin that was prepared from shells of shrimp and crab. Therefore the chemical composition of the field cricket indicates the insect to be a good supplement to nutrition for food and feed, even a raw material for medicine.

Biological aspects on the cultures of the entomophthoralean fungus Pandora delphacis grown on broomcorn millets

A novel method was developed to use glutinous broomcorn millets (Panicum miliaceum L.) as solid substrate to make cultures of the entomophthoralean fungus Pandora delphacis specifically pathogenic to planthoppers, leafhop-pers and aphids. Steamed millets with water content of 45% were inoculated with a liquid culture of P. delphacis at a ratio of 20% (v/w) and then incubated at 25℃ and L:D 12:12. The millets cultured for 3—17 d exhibited high potential for co-nidial production. The 5-d-old millet culture sporulated most abundantly, discharging up to 17.12 (1.31) 104 conidia/ millet. The cultures incubated for 7—11 d also had a satis-factory sporulation capability, yielding 13.00—13.90 104 conidia/millet. Compared to 2.32 (0.34) 104 conidia dis-charged from each of Myzus persicae adults killed by P. del-phacis and a ≤60-h duration of sporulation, each of the millets cultured for 5—11 d produced 5.6—7.4 times more conidia with an over doubled duration for conidial discharge (144 h). Among 106 M. persicae adults exposed to the shower of conidia discharged from the cultured millets, a total mor-tality of 69.8% caused by P. delphacis infection was observed within 7 d after exposure, but no death was attributed to the fungal infection in the aphids unexposed. The results indi-cate that the millet cultures of P. delphacis are biologically similar to aphid cadavers killed by the same fungus. Due to the superiority of the cultured millets to the cadavers in sporulation potential and duration, the method for making cultures of P. delphacis on the broomcorn millets is highly recommended for use in study of entomophthoralean fungi for microbial control. This is the first report on the success of the solid culture of Pandora species on cereals.

TWO GENARA OF CHEILONEURINI（HYMENOPTERA：ENCYRTIDAE） NEWLY RECORDED FROM CHINA WITH DESCRIPTIONS OF TWO NEW SPECIES

The paper presents two new species of Cheiloneurini, Encyrtidae, collected from Liaoning and Jian-gsu, China. i.e. Ectroma loui Xu, sp. nov. , Platencyrtus aclerus Xu, sp. n. , which are described in detail.These two genara Ectroma Westwood and Platencyrtus Ferriere are first recorded from China, and are all parasi-toids of scale insects. All specimens are deposited in Institute of Applied Entomology, Agriculture & Biotechnology College, Zhejiang University, Hangzhou.

Molecular differentiation of the microgastrine species commonly found in paddy fields from Southeast Asia,with additional data on their phylogeny （Hymenoptera：Braconidae）

Partial DNA sequences of three genes, that is, mitochondrial large ribosomal subunit (16S), nuclear large ribosomal subunit (28S D2) and mitochondrial NADH1 dehydrogenase (NADH1) gene, were sequenced from different microgas trine species(Braconidae: Microgastrinae) collected fresh from paddy fields. The DNA sequences were used to determine the extent of sequence variation among species in order to evaluate the specific status of each species. Cladistic analysis was also used to infer a phylogenetic relationship among these species. The results showed that sequence divergence among species of the same genus Cotesia was much lower than those among different genera, such as Cotesia, Exoryza and Apanteles; the sequence similarity of 16S rDNA and NADH 1 genes between Cotesia sp. and C. chilonis was higher than that between C. sp. and C. ruficrus.Phylogenetic analyses suggested that four species of Cotesia were always grouped in the same clade regardless of using different analysis methods; Cotesia sp. and C. chilonis are more closely related to each other than to C. ruficrus, different from previous morphological results. Additionally, sequence analyses indicated that NADH1 gene has more parsimony informative characters than 28S rDNA D2 and 16S rDNA at the species-level analysis,indicating that NADH1 gene might be a useful marker for species-level analysis.

Influences of insecticides on toxicity and cuticular penetration of abamectin in Helicoverpa armigera

Synergistic actions for mixtures of abamectin with other insecticides in some insect pests were evaluated, and the possible synergistic mechanism was studied by the comparison in toxicity and cuticular penetration of abamectin between with and without other insecticides or synergists in Helicoverpa armigera larvae. The results of bioassay showed that horticultural mineral oil (HMO), hexaflumuron, chlorpyrifos, and some other insecticides were synergistic to abamectin with 152.0-420.0 of co-toxicity coefficient(CTC) in some agricultural insect pests. In topical application tests, HMO or piperonyl butoxide (PBO) increased the toxicity of abamectin in larvae of H. armigera, but the mortality was not affected by s,s,s-tributylphorotrithioate (DEF) and triphenylphosphate (TPP). The synergistic action of HMO was obviously higher than PBO, and when treated simultaneously with abamectin, HMO gave a more significant synergism than if treated 2 hours ahead. The highest synergistic effect (SE) was found in the mixture of ‘abamectin+HMO (1:206)'. The mortality did not increase or the toxicity drop, when a synergist or HMO was added into the mixture of ‘abamectin+HMO' or ‘abamectin+synergist', respectively. Results from the isotope tracing experiments showed that HMO significantly enhanced the penetration of ^3H-abamectin through the cuticle of H.armigera larvae, which resulted in the synergism of the mixture. The cuticular penetration of ^3H-abamectin was not accumulatively affected by chlorpyrifos, nor by hexaflumuron,though there was an inhibition within 30 seconds or 1 hour after treated by these two chemicals respectively. Results suggested that the synergism of abamectin mixed with hexaflumuron or chlorpyrifos might be related to inhibition of metabolic enzymes or target sites in the larvae.

EXPRESSION OF A BEE-VENOM PHOSPHOLIPASE A2 FROM APIS CERANA CERANA IN E,.qCHERICHIA COLI

The venomous phospholipase A2 (AcPLA2) coding reading region of the Chinese honeybee (Apis cerana cerana), which is composed of 405 bp encoding a mature glycosylated peptide with 134 amino residues was transformed into the expression vector pETblue-1. Then the recombinant vector was introduced into Escherichia coli Tuner (DE3) plac I for expression. Analysis result of SDS-PAGE showed that the expression products had a protein band of about 15 kD. Detection of western blot using ant-European honeybee (Apis mellifera) phospholipase A2 (AmPLA2) polyclonal serum as the first antibody showed that the expression products appeared a special blot same as the native AmPLA2.The result demonstrated that the AcPLA2 peptide had been expressed in E. coli and the AcPLA2 has the similar antigenicity as the AmPLA2.

CELLULAR LOCALIZATION AND EXPRESSION OF pygo DURING DROSOPHILA DEVELOPMENT

Wg/Wnt signaling is a key signaling pathway in Drosophila. Many genes involved in Wingless(wg) signal transduction pathway downstream of Wg, or it'' s vertebrate Wg homologue Wnt, have been identified.Transduction of the Wg signal downstream of Wg is mediated by nuclear TCF/LEF-1, through association with Ar-madillo (Arm)/β-catenin. Pygopus (pygo) is a new identified component in this pathway . Cellular localization experiment showed that pygo was expressed specifically in the nucleus. The expression profile of pygo in embryos was examined using in situ hybridization. Although pygo expressed ubiquitously in the embryos, it expressed at relatively high level in pre-blastoderm embryos which indicate a high degree of maternally provided message, fol-lowed by a low level of ubiquitous zygotic expression. This continues into larval tissues (including wing disc, eye disc and leg disc), where pygo appears to be expressed at low level. Comparison of pygo expression levels, in the wing disc, eye disc and leg disc, showed pygo expression level in the wing disc pouch and leg disc were rela-tive higher.