Molt-regulating transcription factor 3 (hormone receptor 3，HR3) plays important roles in regulating expression of tissue-specific genes involved in insect molting and metamorphosis, which initiates expression of chitinase and proteases but represses expression of larval cuticular protein and eclosion hormone during molting. The cDNA encoding the molt-regulating transcription factor 3 was cloned with RT-PCR using gene specific primers from Helicoverpa armigera. A recombinant expression plasmid, HHR3-pGEX-4T-1, was constructed and the protein was expressed in BL21 strain of Escherichia coli. However, the expressed target protein fo rmed complete inclusion bodies of the molecular size 94 kD. The inclusion bodies were solubilized by being denatured with CAPS（3-［cyclohexylamino］-1-propanesulfonic acid）and refolded through dialysis against Tris-HCl buffer. After cleavage with thrombin, the target protein was separated by SDS-PAGE and confirmed with N-terminal amino acid sequencing. This recombinant HHR3 was used as an antigen for preparation of rabbit polyclonal antibody. The immunoblotting results indicated that the antibody was specific to HHR3 from H. armigera and can be used for further research on the function and regulation of HHR3 Moreover, HHR3 showed high expression in the fat bodies of 5th toward 6th inst ar molting larvae and declined at 24 h post molting. HHR3 was also detected from ovaries of the adult H. armigera, but not det ectable from midguts the 6th instar larvae of H. armigera at 72 h after molting.

The morphological characteristics and inheritance of the melanic form of the oriental armyworm, Mythimna separata (Walker) that discovered in Beijing, China, was firstly reported in this article. Male and female adults of the melanic form were almost completely darkened in comparison with those of the typical form when they were reared under the same environmental conditions (temperature of 23±1℃ and photoperiod of L14∶D10). In the immature stages, the morphology of the melanic form was not basically different from that of the typical form. Larvae and pupae in the melanic form at the mass rearing condition and near emergence, however, were blacker in color than those of the normal form under the same environmental conditions. Genetic experiments showed that the inheritance of the melanic characteristics followed a Mendalian law, with the melanic allele recessive to the normal allele. Single pair of genes from the same chromosome regulated the melanic characteristics . These results indicated that the melanic form was the mutant of the typic al form, and both the melanic and typical form of the oriental armyworm still be longed to the same species although the melanic form had already become a new genotype. The significances of this finding to understanding the evolution of the oriental armyworm were discussed.

Oviposition-repelling activity of 11 synthetic polyacetylene compounds and electroantennograms (EAGs) responses in the Asian corn borer, Ostrinia f urnacalis were assayed with the method of accepting egg on paper and EAG recording techniques. The results of bioassay indicated that the majority of tested compounds, except compound 1 and 10, could inhibit the oviposition behavior of O. furnacalis, and among these compounds compound 9 (1-phenyl-2,4-hexadiyne) was the most effective one. The inhibiting rate of compound 9 was from 61.27% to 85.71% at 20 μg/cm² in 6 days of treatment. EAGs of the moths tested indicated that there were no obvious sexual differences to some tested compounds under concentra tion of 10 mg/mL, which could stimulate the receptors of antenna of the insect to produce action potential. Among these compounds, the most stimulating compounds were compound 6 (1-phenyl-4-(3-nitro)-phenyl-1,3-butadiyne) and compound 9: both compounds were significantly stronger in average EAG amplitude than other tested compounds, and the males responded more sensitively than females to the two compounds. The relative EAGs (Sr) of female and male to compound 6 were 68.2 2% and 106.60%, and to compound 9 were 199.19% and 220.60% at 10 mg/mL respectively. The dosage-responses of compounds 6 and 9 on EAGs showed that they were dose-dependent. The regression analysis of the data of two series showed that the value of depolarization amplitude of antenna receptors induced by the tested compounds correlated in some degree with inhibiting activity in behavioral test. Finally, the action target and relationship between structure and activity of polyacetylenes to O. furnacalis are discussed.

The activity of phenoloxidase in various tissues of Ostrinia furnacalis Guene fifth-instar larvae parasitized by Macrocentrus cingulum Brischke was investigated. The effects of various physiological factors on the activity of phenoloxidase and melaninization in the hemolymph of O. furnacalis larvae were examined by the injection of calyx fluid, venom, the mixture of calyx fluid plus venom of M. cingulum in vitro. The results showed that the activity of phenoloxidase in hemolymph of O. furnacalis was inhibited significantly by parasitism and the injection of calyx fluid or the mixture of calyx fluid plus venom of M. cingulum (P<0.01), and the production of melanin was also reduced. The percentage of positive FITC-labelled hemocytes of the parasitized host larvae was lower than that of unparasitized larvae (P<0.01). It was concluded that the melaninization could be inhibited by the injected the calyx fluid, venom or other components produced by the parasitic wasp along with laying eggs, in which calyx fluid was probably the main factor inhibiting the ability of immunity of host insect.

The kinetic properties of polyphenoloxidase (PPO) from Pieris rapae (L.) in different stages and instars were studied and compared. The results showed that the polyphenoloxidase activity was different at different stages and instars in this insect. The enzyme activity of the 5th instar was the highest and that of the pupa was the lowest. The order of the enzyme activity was the 5th instar > prepupa > the 4th instar > the 3rd instar > pupa. The effect of pH on the activity of polyphenoloxidase was studied, and the results showed that the optimum pH was the same value in all of the stages and instars and the best pH value for the oxidation of catechol was 7.0±0.2. The optimum temperature of the polyphenoloxidase activity was very variable in the tested stages and instars of the insect. The optimum temperature for the 3rd instar, 4th instar, 5th instar, prepupa and pupa was 36.0±0.5℃, 38.±1.0℃, 43.0±1.0℃, 45.5±1.0℃ and 50.0±1.5℃, respectively, indicating that the optimum temperature of the pupa was the highest. The activation energy of the enzyme from this insect for the oxidation of catechol was 43.10±0.28, 36.50±0.27, 5.79±0.32, 30.10±0.21 and 58.88±0.39 kJ/mol for the 3rd instar, 4th instar, 5th instar, prepupa and pupa, respectively. The kinetic parameters for the oxidation of catechol and L-DOPA by polyphenoloxidase from the different stages and instars were determined and compared.

Acid phosphatase (ACPase, EC3.1.3.2) was isolated and purified from the Italian honeybee, Apis mellifera L., and properties of the enzyme had been studied. Acid phosphatase was partially obtained from A. mellifera by homogenate, a mmunium sulfate fractionation, chromatography with DEAE-sepharose FF and gel filtration with Sephadex G-200 The purified enzyme moved as a single electrophoretic band in PAGE. The purification multiple was 77.24, and the specific activity 16.22 U/mg with pNPP as its substrate. The molecular weight of ACPase was 135 kD determined with gel filtration and its subunit weight was 63.1 kD determined with SDS-PAGE. Isoelectric focusing study showed that pI values of the enzyme were 4.46 and 4.79. NR/R single and two dimensions SDS-PAGE indicated that the enzyme contained intrachain disulfide bond. Circular dichroism spectrum was investigated, and it was found that the proportion of α-helix, β-sheet and random coil in the enzyme was 13.84%, 2.68% and 6.34% respectively. Amino acid composition analysis showed that there were about 507 amino acids in the ACPase, with plenty of Asp.

Vitellin was purified from the eggs of the bush tick, Haemaphysalis longicornis Neumann by gel filtration and ion exchange chromatography, and its property was also analyzed. PAGE and SDS-PAGE results showed that only one kind of vitellin existed in H. ongicornis. The vitellin composed of eight subunits and their molecular weights were 112, 103, 80, 78, 71, 68, 62 and 52 kD respectively. The vitellin could be stained by Sudan black B and periodic acid-Schiff (PAS), which meant that it was an hemoglycolipoprotein.

The ultra-morphology and chemical composition of waxes secreted by the scale insect Dicyphococcus bigibbus Borchsenius (Homoptera: Coccidae) was studied with the techniques of scanning electron microscope (SEM), infrared absorption spectra (IS) and gas hromatography/mass spectrometry (GC/MS). The results indicate that the wax secretions are wet at first from the glands in both nymph and adult stages. Then they coagulated into dry and glassy wax test over the body surface. The wax test with a hard and fragile quality consists of many vertical pillar-like ridges with horizontal layer upon layer. The wax tests of the young nymphs and male scale insects are small, ship-shaped, central dorsal region elevated highly and with some wax fringes around the body margin. Female wax test is larger, v-shaped at its top. The infrared spectra of the wax secretion show the characteristics for species in sharp and dense peaks. The main chemical function groups and compositions of the wax secretion are conjectured based on its infrared absorption spectra, and verified with the results of GC/MS. Through esterification and unesterification, It is found that the waxes are composed of a series of greater molecular compounds, i.e., long chain saturated and unsaturated hydrocarbons, fatty acids and esters. Their carbon atom numbers mostly are even number and range from C₁₄ to C₄₀. The proportion of ester compound is greater especially than those with carbon a toms C₃₀ to C₄₀. The wax characteristics of this scale insect were compared with that of other species in the same family, Coccidae, e.g., Eulecanium gigantea, Didesmococcus koreanus, Eriopeltis festucae and Ericerus pela. The significances of the wax secretion for the classification, systematics and control of scale insects are discussed.

Terpinen-4-ol is the main insecticidal composition in essential oil of Sabina vulgaris Ant.，an insecticidal plant. The toxicity, poisoning symptoms and biochemical effects of terpinen-4-ol on larvae of the oriental armyworm, My thimna separata (Walker) were assayed. The results showed that terpinen-4-ol was very toxic to 3-instar larvae of the armyworm with fumigating application (LC₅₀=5.3473 μL·L^-1)and the LD₅₀ of contact activity to-4-instars larvae of the armyworm was 147.8 μg/larvae. The poisoning symptom caused by the compound could be divided into4-stages, i.e., excitation, convulsion, paralysis and death; but some paralyzed insects could recover. In vivo, the activity of Na⁺,K⁺-ATPase in brain of 5th instar larvae tested was inhibited; the inhibition ratio was 21.28% in exciting stage, 25.62% in convulsing stage, 32.10% in paralysis stage, and 34.92% in recovering stage, respectively. In vitro, the I₅₀ of Na⁺,K⁺-ATPase was 133.75 μg·mL^-1(Y=2.2236+1.3058X r=0.988, χ² =1.26). It had certain influence on the activity of AChE. In the excitation stage, the activity of ester enzyme of the treated larvae was 77.0% of that of the control; in the paralysis stage, it was 1.33 times; but it was as high as that of the control in the recovery stage.

The expression of Cry1Ac or Cry1Ab toxin in transgenic Bt cotton lines (NUCOTN 33B and Gk-12) was detected; its transmission to the target pest insect, cotton bollworm Helicoverpa armigera (Hübner), the non-target pest, cotton aphis Aphis gossypii Glover, and the ladybird Propylaea japonica (Thunberg) was measured; and its effects on the ladybird were evaluated with the traditional cotton line, Simian 3 (the isogenic non-transformed line of GK-12) as the control, in cotton plots in Nanpi, Hebei, in 2002. The amounts of expressed Bt toxin in organs of transgenic Bt cotton NUCOTN 33B were higher (79.7-1390.0 ng/g fresh weight) than those in GK-12 (16.5-26.0 ng/g fresh weight). During the blooming period of NUCOTN 33B plants, the order of Bt toxin content was as follows: stigma, anther>ovary, petal> grouped tender tip; the Bt toxin concentrations were similar as well as equal to those in grouped tender tip, when the newly development tender leaf of 5－7 leaf stage, the young square of early squaring period and the young boll of blooming period of NUCOTN 33B plants were tested. And during the blooming period of GK12 plants, the order of Bt toxin concentration was as follows: anther >stigma> petal>grouped tender tip>ovary; the Bt toxin concentrations were similar and equal to those in grouped tender tip, when the newly development tender leaf of 5－7 leaf stage, the young square of early squaring period and the young boll of blooming period of GK-12 plants were detected. Moreover, the detection of trace amounts of Bt toxin in young boll, anther, stigma and ovary of the control cotton line, Simian 3, might be related to pollinators. In GK-12 and NUCOTN 33B cotton plots, Bt toxin could be transmitted to cotton aphis and cotton bollworm elder larvae. In the body of P. japonica larvae and adults, trace amounts of Bt toxin were detected only in those collected from NUCOTN 33B cotton plot. In addition, when P. japonica fed on cotton aphis collected from the transgenic Bt cotton plots, the development and survival from hatching to emerging as well as the reproductive ability of the ladybird were not significantly different with those of the control.

Interspecific competition between two parasitoids, Cotesia plutellae (Kurdjumov)(Hymenoptera: Braconidae) and Diadegma semiclausum Hellen (Hymenoptera: Ichneumonidae), was investigated at 25℃ in the laboratory, by exposing 3rd instar larvae of the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae) to both parasitoids together or either parasitoid alone, and by exposing the host larvae already parasitized by one parasitoid to the other. When host larvae were exposed to both parasitoids in one arena, initial parasitism rates of the host by each species were not reduced by the presence of the other species; and the final joint parasitism rate by the two species was not significantly higher than that by either parasitoid alone. Both parasitoids could lay eggs in to host larvae previously parasitized by the other species, leading to occurrence of multiparasitized hosts. When host larvae were parasitized first by D. semiclausum and then immediately exposed to C. plutellae, or parasitized first by C. plutellae and then immediately exposed to D. semiclausum, nearly all ensuing parasitoid adults from the multiparasitized host larvae were C. plutellae. When host larvae parasitized by C. plutellae≥2 days earlier were exposed to D. semiclausum, all ensuing parasitoids from the multiparasitized hosts were of C. plutellae. When host larvae parasitized by D. semiclausum≥2 days earlier were exposed to C. plutellae, most host larvae could not survive to prepupae and most of the ensuing parasitoid adults from the hosts that supported successful parasitism were D. semiclausum. Dissections of host larvae at various time intervals after initial parasitism by both parasitoids showed that development of both parasitoids in multiparasitized hosts were somewhat arrested, and that the first instar larvae of C. plutellae could initiate physical attack on larvae of D. semiclausum and remove the latter. These results suggest that C. plutellae have an obvious advantage over D. semiclausum in competition when both parasitoids develop in the same host.

Laboratory studies were conducted to determine the pathogenicity of the entomopathogenic fungus Metarhizium anisopliae var. acridum Driver et Milner on paddyfield spiders Pirata subpiraticus Bsenberg et Strand and Ummeliata insecticeps Bsenberg et Strand, to evaluate the effects of the fungus on the predating efficiency of the spiders on the brown planthopper, Nilaparvata lugens Stal. The results indicated that Metarhizium anisopliae var. acridum had no pathogenicity on both Pirata subpiraticus and Ummelita insecticeps. However, the activity of brown planthoppers decreased apparently after being infected with conidia of Metarhizium anisopliae var. acridum, that caused increase of the predating efficiency of the paddyfield spiders. At oncentrations of 10⁶, 10⁷, 10⁸ conidia/mL of Metarhizium anisopliae var. acridum, the mean predating efficiency of Pirata subpiraticus on brown plathoppers were 10.5 heads/d, 11.1 heads/d and 11.4 heads/d respectively; for Ummeliata insecticeps, the mean predating efficiency on plan thoppers were 3.8 heads/d, 4.3 hoppers/d and 4.7 hoppers/d respectively. Statistical analysis indicated that the differences between the treatments and control were significant. The predating efficiency of the spiders on planthopper increased slightly with the increasing of conidia concentrations of Metarhizium aniso pliae var. acridum.

The role of a high temperature of 31℃ in diapause inhibition in Pseud opidorus fasciata was investigated. All larvae developed without diapause regardless of photoperiod when they were exposed to a high temperature of 31℃. Under a diapause-inducing photoperiod of L12∶D12, nearly all individuals entered diapause when high temperature in the photophase was combined with relatively low temperatures (15－28℃) in the scotophase. However, the incidence of diapause significantly declined when the high temperature in the photophase combined with a much low temperature of 5℃ in the scotophase. Nearly all individuals developed without diapause when the high temperature in the scotophase was combined with relatively low temperatures in the photophase, indicating that the high temperature plays an important role in the period of darkness. The effect of durations （2, 4, 6, 8, 10, 12 h）of high temperature on the incidence of diapause showed that a 2 h high temperature exposure was sufficient to inhibit the incidence of diapause. When a 4 h high temperature exposure was used to interrupt the scotophase at different stages, the results showed that the first 4 h in the darkness was the most sensitive part to high temperature exposure and completely inhibited the incidence of diapause. Finally, the adaptive significance of the mechanism of high temperature regulation in life history of P. fasciata was discussed.

The red turpentine beetle (RTB), Dendroctonus valens LeConte, an invasive pest from the United States became a major forest pest in its invading areas since its first outbreak in Shanxi Province, China in 1999. As an exotic pest, effective detection and monitoring is top priority in containing its further damage. The response of RTB to its host semiochemicals was explored in Shanxi Province using Lindgren funnel trap. The results indicated that 3-carene was found to be the most attractive host monoterpene tested, and it attracted significantly more beetles than did any other single or ternary blend, which was distinctly different from the previous reports conducted in its native range, west coast of the United States. The mechanism for this regional variation of RTB response to host volatiles was discussed. Increase of (-)-β-pinene did not result in any increase of beetles trapped while adding limonene which is another main component in volatile profile of Pinus tabulaeformis, to the standard lure used in North America (a 1∶1∶1 blend of (+)-α- pinene, (-)-β-pinene, and 3-carene) significantly decreased RTB response. The effect of release rate on RTB response was tested by using the standard blend at 110 mg/day, 150 mg/day, 180 mg/day and 210 mg/day, and 150 mg/day was found to be the most optimal release rate for RTB in terms of both attractiveness and economic efficiency. Thus, this effective RTB lure can be used in RTB monitoring and control.

The species-specific mutualism between figs and pollinating fig wasps is one of the hot topics in coevolution studies. Figs host a large number of non-pollinating fig wasps besides pollinators. Philotrypesis pilosa Mayr is characterized by the extreme extension of the last two tergites of abdomen, in the form of ovipositor sheath, followed by the true ovipositor sheath. It is a cleptopar asite of Ceratosolen solmsi, the legal pollinator of Ficus hispida L. The oviposition process of P. pilosa was recorded with a digital camera. We found the following behaviors which were ignored by the previous authors: 1) When the female finds out a suitable site for ovipositing, it makes a headstand posture, freeing the hind legs to help the long ovipositor sheath to locate the site. 2) From the start of penetrating the syconium to springing the ovipositor sheath backwards, the extension part of abdomen tergites and the ovipositor sheath undergo two bouts of close-and-apart. The first bout of close-and-apart is beneficial to keep the stylets vertical so as to penetrate the wall easily. The second one is helpful to spring the ovipositor sheath backwards and make the exposed basal part of the stylets to squeeze into the wall without the clag of the sheath. 3) The stylets penetrate into the syconium along syconial diameter as the shortest way. 4) The fore and hind legs are more robust than the mid ones, which is related to their function of supporting the body during the oviposition.

The aquatic firefly Luciola substriata (Gorham) was newly found in the mainland of China. The external morphological studies showed adults were yellow in the whole except that the head and the end of elytra were black in ventral view. The light organs of adults were all cream white. Males had two luminescent organs, the first one at the 5th abdominal segment is rectangular in shape where as the second one at the 6th abdominal segment V-shaped. Females had only one luminescent organ in rectangular shape located at the fifth abdominal segment. Eggs were elliptic and yellow orange in color. There were two types of larva. The 1st－2nd instar larva had 7 pairs of branched tracheal gills located laterally on the 1st－7th abdominal segment. The 3rd-6th instar larva had no gills. Larva had a pair of spot-shaped light organs located at the 7th abdominal segment. The larval light organs regressed and were replaced by adult lantern in the pupal stage. Luciola substriata was normally found in ponds, lakes and rivers with flourish duckweeds and other aquatic vegetation. The firefly occurred one generation per year. The lastinstar larva climbed the strand and constructed earthen pupa cells, in which prepupal, pupal and preimaginal stages were spent till it matured in May next year. The prepupal stage lasted 6.17 days, and the pupal stage las td 4.43 days, in room temperature. The imaginal period lasted from May to mid September. The courtship flashing activity reached peak one hour after sunset. Eggs hatched after 12.5 days. Prey records included 2 species of aquatic snails, Lymnaea stagnalis and Gyraulus conwexiusculus. Three predators of this firef ly were recorded: red swamp crayfish (Procambarus clarkii), crab (Eriocheir sinensis) and grass carp (Ctenopharyngodon idellus). The light spectrum emitte d by Luciola substriata was measured as 425－603 nm with the peak 504 nm.

With Carposina coreana Kim as the out-group, using 44 random primers,the RAPD analysis was conducted on the host races of the peach fruit borer, Carposina sasakii Matsumura, from 6 different host plants, i.e., apple, hawthorn, peach, apricot, jujube and wild jujube, in Shaanxi Province. The results show that there exists great genetic differentiation between the host races. The genetic distances among the six host races of the peach fruit borer vary from 0.040 to 0.637, with the apricot race differs most markedly from other host races. Based on the clustering analysis, the six host races of the peach fruit borer from the various host plants can be divided into two sub-groups: the apricot race as a sub-group, and the others as another sub-group. The genetic distance is 0.465 between the two subgroups, and 0.040 to 0.369 within a sub-group. It is sugges ted that the apricot race of the peach fruit borer have been so differentiated genetically with the others that it should be considered as a good species.

Partial mitochondrial cytochrome oxidaseⅠ (COⅠ) region was sequenced from 27 individuals of 5 geographic populations of Bactrocera dorsalis (Hendel) from Ruili, Jinghong, Yuanjiang, Huanian and Hekou of Yunnan Province, respectively. Transition was higher than transversion, without insertion and deletion. In total, 23 haplotypes were identified within the sequences, with 27 sites howing polymorphism and 2 haplotypes shared. The Fst values among 5 populations were 0.0364－0.1364 (P>0.05) and Nm 3.88－3.25. Phylogenetic trees of haplotypes were constructed by N-J method. Haplotypes did not accord with their geography. All results showed that genetic differences existed among 5 populations, but the degree was lower. The main reason of the genetic differentiation among 5 populations should be related to genetic isolation, development history and ecology adaptation of Bactrocera dorsalis.

Juvenile hormone (JH) metabolism enzymes, including JH esterase, JH epoxide hydrolase and JH diol kinase, catalyze JH to metabolize. By the action of these enzymes, JH is metabolized to JH acid, JH diol, JH acid diol, and JH diol phosphate. We have summarized the methods used to study JH metabolism. On the clues of laboratories and insect species, the investigation process of each enzyme is introduced and generalized. Meanwhile, amino acid sequence alignments of JH esterase and JH epoxide hydrolase are analyzed. At the end, the study of JH metabolism is prospected.

Theoretical basis and application of stable isotope analysis in insect ecology as well as its principle and method are reviewed, and its further application prospects are suggested. The isotopic differences among host plants constitute the basis of this technique, in which D,¹³C, ¹⁵N and ¹⁸O are mainly involved. Stable isotope analysis is widely used in dietary reconstruction, host-shifting and migration, flows of mass and energy through ecosystems, and construction of food web. The longterm preserved specimens and fossil insects, when used for stable isotope analysis, can expand the temporal scale of these studies greatly. The applications of mass balance equation and mixing model along with the verification of diet turnover time are important steps to validate related ecological process; and more experiments are needed to test the effects of ecological, physiological and biochemical process on isotope fractionation.

Bemisia tabaci （Gennadius） biotype B is an important pest that have outbreaked and caused severe damage worldwide through the last 20 years. Recent progress in studying mechanisms of its invasion indicates the greater ability of competitive displacement which involves the competition of ecological niche, reproductive interference, the interactions of whitefly and virus with indigenous B. tabaci and other competing herbivores, is the most important factor. The successful invasion and rapid spread is affected by the pesticide resistance. In the meantime,　the ecological environment (such as host, climatic factor, overwintering sites) also affected the invasion of B. tabaci biotype B. Finally the importance of the invasive mechanism of B. tabaci biotype B and potential directions for future research are discussed.

In order to clone the cecropin gene from the silkworm Bombyx mori (Xinjiang race) into a T-vector, designed primer was used to amplify 350 bp cecropin cDNA fragment with RT-PCR. Cecropin sequence analysis indicates that the special cecropin fragment of the silkworm Xinjiang race contains entire coding region with 98% identity compared with other reported Bombyx mori cecropin B. The cecropin gene was cloned into expression plasmid pGEX-4T-1 and expressed as fusion protein in Escherichia coli BL21. The results showed that the growth of E.coli contained pGEX-4T-1/cecropin was restrained 30 minutes after adding IPTG and the amount of E.coli began to recover 210 minutes after IPTG induction. This result reveals that the fusion protein has antibacterial activity.

Some aminopeptidase N (APNs) serve as Bacillus thuringiensis (Bt) Cry1Ac toxin receptor in the midguts of several lepidopteran insects. Two fragments of two different APN genes in BTI-TN-5B1-4 (a cloned cell line from Trichoplusia ni ovary) were amplified with two pairs of degenerate pri mers by RT-PCR, and the lengths of them were 188 bp and 564 bp，and named as 188（GenBank Accession: CD809324）and AS564 （GenBank Accession: CD809326）respectively. Deduced protein sequences were highly similar to that of several recept or APNs in insects, with sequence identities of 45%－47% for the shorter one and 61%－63% for the other.