Analysis of sex pheromone production and field trapping of the Asian corn borer(Ostrinia furnacalis Guenée)in Xinjiang,China

Identifying the sex pheromone systems of local pest populations facilitates their management,especially for moth species that show significant geographic variation in sex pheromone communication.We investigated the pheromone production and behavioral responses of the Asian corn borer(Ostrinia furnacalis Guenée;ACB)in Xinjiang,China.The ACB produces three compounds:(Z)-12-tetradecenyl acetate(Z12-14:Ac)and(E)-12-tetradecenyl acetate(E12-14:Ac)which are two sex pheromone compounds,and n-tetradecyl acetate(14:Ac)which has variable roles in mediating behavioral responses.The ratios of these three compounds produced in female gland are geographically distinct among different populations.Quantitative analysis of pheromone production showed that the proportions of Z12-14:Ac in the E/Z isomers(i.e.,Z and E12-14:Ac)and the proportions of 14:Ac in the ternary blend respectively averaged 60.46%(SD=5.26)and 25.00%(SD=7.37),with their probabilities normally or near-normally distributed.Trapping experiments in a cornfield indicated that deploying the E/Z isomers and the three compounds in rubber septa close to their gland ratios yielded the most captured males,while other ratios that deviated from the gland ratios showed reduced field captures.The ternary blend was significantly more attractive to males than the E/Z isomers in the field,indicating a functional role of 14:Ac as the third pheromone component used by the local population.Additionally,the dose-response test demonstrated that the application of the three compounds at dosages between 200 and 350μg attracted significantly more males compared to other dosages.Therefore,the characterization of this local ACB pheromone system provides additional information about its geographic variation and serves as a basis for optimizing the pheromone-mediated control of this pest in Xinjiang.

Development of a high-efficiency sex pheromone formula to control Euproctis pseudoconspersa

The tea tussock moth(Euproctis pseudoconspersa)is one of the most destructive chewing pests in tea plantations and causes a serious allergic reaction on the skin of tea plantation workers.The sex pheromone components of its Japanese population were first identified as 10,14-dimethylpentadecyl isobutyrate(10Me14Me-15:iBu)and 14-methylpentadecyl isobutyrate(14Me-15:iBu),with a stereogenic center.Only 10Me14Me-15:iBu has been identified in the Chinese E.pseudoconspersa population.However,field tests have shown that 10Me14Me-15:iBu cannot meet the demand of effective pest control in China.To develop a high-efficiency E.pseudoconspersa sex pheromone formula,electroantennogram(EAG)recordings of(S)-and(R)-enantiomers of 10Me14Me-15:iBu and 14Me-15:iBu were obtained in the present study.The results demonstrated that the EAG responses of male antennae to(R)-enantiomers were significantly higher than responses to the(S)-enantiomers,and 14Me-15:iBu also elicited EAG activity.Field tests showed that the catch numbers of male moths by(R)-enantiomers were significantly higher(P<0.05)than those of(S)-enantiomers.Addition of 14Me-15:iBu significantly increased the catch numbers of both the(S)-and(R)-enantiomers.The efficient pheromone formula containing 0.75 mg(R)-10Me14Me-15:iBu and 0.1 mg 14Me-15:iBu showed significantly higher attractiveness than commercial pheromone products.Our study demonstrated that(R)-10Me14Me-15:iBu was the major sex pheromone component of E.pseudoconspersa,and 14Me-15:iBu might be the minor sex pheromone component.Furthermore,a high-efficiency sex pheromone formula for E.pseudoconspersa control was defined in this study.

A larval specific OBP able to bind the major female sex pheromone component in Spodoptera exigua(Hübner)

Odorant binding proteins （OBPs） in insects are postulated to solubilize and transport the hydrophobic odorants across the hydrophilic antennal lymph to the olfactory receptors （ORs） located on the dendrite membrane of the sensory neurons. OBPs in adult insects have been intensively reported, but those in larvae are rarely addressed. In our study, a full-length OBP cDNA, namely SexiOBP13, was cloned by RT-PCR and RACE strategy from the heads of Spodoptera exigua larvae. The quantitative real-time PCR （qPCR） measurement indicated that SexiOBP13 was highly expressed in larval head, but very low in other parts of larva and was not detected in any tissues of adult. The binding affinities of SexiOBP13 to plant volatiles and female sex pheromone components were measured by competitive binding assays. Interestingly, SexiOBP13 displayed a high binding affinity （Ki=3.82 IJmol L-1） to Z9,E12-14：Ac, the major sex pheromone component of S. exigua, while low affinities to the tested host plant volatiles （Ki〉27 μmol L-l）. The behavioral tests further confirmed that Z9,E12-14：Ac was indeed active to elicit the behavioral activity of the third instar larvae of S. exigua. Taken together, our results suggest that SexiOBP13 may play a role in reception of female sex pheromone in S. exigua larvae. The ecological significance of the larvae preference to the adult female sex pheromone was discussed.

A Facile Synthetic Method for (3Z,6Z,9S,10R)-9,10-Epoxy-3,6-heneicosadiene,Sex Pheromone Component of Hyphantria Cunea (Drug)

Total synthesis of (3Z, 6Z, 9S, 10R)-9, 10-epoxy-3, 6-heneicosadiene, sex pheromone component of Hyphantria cunea (Drug), was achieved using Sharpless AE kinetic resolution and alkylative epoxide rearrangement as key steps.

Optimization of the sex pheromone-based method for trapping field populations of Phthorimaea operculella(Zeller)in South China

Despite the identification of the potato tuber moth Phthorimaea operculella(Zeller)sex pheromone,no effective application based on this pheromone has yet been developed and evaluated.This study investigated the effect of pheromone lures,trap densities,heights of trap deployment,and pheromone doses in Yunnan,China,for the purpose of increasing the control efficiency of P.operculella and improving the application of pheromone technology in the field.The results showed that lures made of corn oil and red PVC pipes attracted the highest number of moths(11.73±1.90 per trap per day).Sex pheromone loading of 100μg was optimal for trapping moths,but higher doses of pheromone inhibited attraction.The density of traps did not affect capture rates;therefore,the optimum trap density was 30–40 traps ha^(–1).The optimum height of trap deployment was not above the height of the plant canopy.This study provides technical details necessary for the monitoring and control of potato tuber moth using sex pheromones.

Suppression of Rice Stem Borer, Chilo suppressalis by Mass Trapping Using Synthetic Sex Pheromone in Paddy Field

Suppressing effects of mass trapping using synthetic sex pheromone with main active ingredients of Z-11-hexadecenal, Z-13-octadecenal and Z-9-hexadecenal on the rice stem borer, Chilo suppressalis were investigated during the flight periods of the overwintering and 1st generation in the paddy area of 60 ha in 1999. Population density of C. suppressalis in the pheromone-treated fields was lower than that in control. The egg masses decreased by 74.39% and population size of adult males of the 1st generation decreased by 61.64% in the treated fields as compared to control. Meanwhile, the damage by C. suppressalis larvae was significantly lower in the treated fields than control (t-test, P=0.05). Percentages of brownish leaf sheath, dead heart, and white head in the treated fields were decreased by 70.90%, 57.01% and 44.30%, respectively in contrast to control. The present study demonstrated that mass trapping to C. suppressalis using synthetic sex pheromone shows great potential as an alternative measure in an environment-friendly pest management and at the same challenging the insecticide use that has some environment impacts.

Control Effect and Cost Evaluation of Different Sex Pheromones and Trapping Lamps against Spodoptern litura,Helicoverpa assulta and Helicoverpa armigera in Tobacco

[ Objective] The aim was to study the control effect of different sex pheromones and trapping lamps against main pests in tobacco. [ Method] Control effect of sex pheromone of different matrix lures and Jiaduo trapping lamp against Spodoptern litura, Helicoverpa assulta and Helicoverpa armigera in tobacco in Teng- chong of Yunnan were determined and compared, and the control cast was evaluated. [Result] The use of insect sex pheromones and insecticidal light traps had certain effect against S. litura and H. armiger. The trapping effect of sex pheromone traps was better than that of Jiaduo trapping lamp, and the PVC matrix lure had better performance than rubber matrix lure, which had strongest capturing capacity, continuous control effect and significant effort against S. litura. The traps with different settled densities and hanging heights also had different trapping effect against S. litura and H. armiger, and the hanging height of 100 - 150 cm from ground was the best; as the cost was considered, the cast of the area with low density of traps was the lowest, which was reduced by over 44% than conventional chemical control area. [ Conclusion] It is safe and effective to use sex pheromone and insecticidal light traps to control S. litura and H. armigera, and it is a green environmental protection biological physical control technology, having extended application prospect in large area.

Synergic effect of sex pheromone(7R,8S)-cis-7,8-epoxy-2-methyloctadec-17-ene on(+)-disparlure of the Asian gypsy moth,Lymantria dispar, in Korea

field attraction test of (7R,8S)-cis-7,8-epoxy-2- methyloctadec-17-ene (= 7R,8S-epo-2me-17ene-18Hy), a trace component of the sex pheromone gland of the Asian gypsy moth,(Lymantria dispar), traps that were baited with the trace component attracted more L. dispar than traps baited with (7S,8R)-cis-7,8-epoxy-2-methyloctadec-17-ene (= 7S,8R-epo-2me-17ene-18Hy) and unbaited traps. However, traps baited with 7R,8S-epo-2me-17ene-18Hy were less attractive than traps baited with (+)-disparlure [=(7R,8S)-cis-7,8-epoxy-2-methyloctadecane], the sex pheromone of L. dispar. Combination tests with (?)-disparlure, 7R,8S-epo-2me-17ene-18Hy, and 7S,8R-epo-2me- 17ene-18Hy revealed that 7R,8S-epo-2me-17ene-18Hy acted synergistically with (?)-disparlure.

A Facile Approach for Synthesis of Sex Pheromone of California Red Scale

Introduction The isolation and structure of (3S, 6R)-3-methyl-6-isopropenyl-9-decen-1-yl acetate (1), one of the sex pheromones of the female California red scale, Aouidiella aurantii (Maskell), were reported by Roelofs. Because the California red scale is the main pest

Effects of Several Factors on Trapping Quantity of Grapholitha molesta Busck by Sex Pheromone

The key application technology for sex pheromone of Grapholitha molesta was studied from the aspects of different hanging heights and orientations, dif- ferent doses and types of traps through the tests on trapping quantity of G. molesta in fields. The results showed that the trapping effect was enhanced when the hanging height was increased, and the trapping effect was the best in west direction. The trapping effect was enhanced when the dosage was increased. When it was up to 6 lures, the trapping effect was the best with 38.75 head/trap; the next was 2 lures with 31.00 head/trap. All types of traps had trapping ability to G. mo- lesta, among which triangle trapper was the best, followed by self-made bottle trap. Their trapping effects were 138.75 and 100.25 head/trap, respectively.

LOCATION OF DOUBLE BOND POSITION OF INSECT SEX PHEROMONE BY GC/MS ANALYSIS WITH CHEMICAL IONIZATION

Ozonolysis products of four lepidopteral pheromone were identified by methane CI-MS.The spectra obtained were notably simpler than those of EI-MS,the peak of molecular ion was normally close to the base peak,and the characteristic fragment ions were high in m/z,thereby the interpretation was facilitated.

Characterization of the pheromone receptors in Mythimna loreyi reveals the differentiation of sex pheromone recognition in Mythimna species

Pheromone receptors(PRs)are key proteins in the molecular mechanism of pheromone recognition,and exploring the functional differentiation of PRs between closely related species helps to understand the evolution of moth mating systems.Pheromone components of the agricultural pest Mythimna loreyi have turned into(Z)-9-tetradecen-1-yl acetate(Z9-14:OAc),(Z)-7-dodecen-1-yl acetate(Z7-12:OAc),and(Z)-11-hexadecen-1-yl acetate,while the composition differs from that of M.separata in the genus Mythimna.To understand the molecular mechanism of pheromone recognition,we sequenced and analyzed antennal transcriptomes to identify 62 odorant receptor(OR)genes.The expression levels of all putative ORs were analyzed using differentially expressed gene analysis.Six candidate PRs were quantified and functionally characterized in the Xenopus oocytes system.MlorPR6 and MlorPR3 were determined to be the receptors of major and minor components Z9-14:OAc and Z7-12:OAc.MlorPR1 and female antennae(FA)-biased MlorPR5 both possessed the ability to detect pheromones of sympatric species,including(Z,E)-9,12-tetradecadien-1-ol,(Z)-9-tetradecen-1-ol,and(Z)-9-tetradecenal.Based on the comparison of PR functions between M.loreyi and M.separata,we analyzed the differentiation of pheromone recognition mechanisms during the evolution of the mating systems of 2 Mythimna species.

Identification of an odorant receptor responding to sex pheromones in Spodoptera frugiperda extends the novel type-I PR lineage in moths

moths,pheromone receptors(PRs)are crucial for intraspecific sexual communication between males and females.Moth PRs are considered as an ideal model for studying the evolution of insect PRs,and a large number of PRs have been identified and functionally characterized in different moth species.Moth PRs were initially thought to fall into a single monophyletic clade in the odorant receptor(OR)family,but recent studies have shown that ORs in another lineage also bind type-I sex pheromones,which indicates that type-I PRs have multiple independent origins in the Lepidoptera.In this study,we investigated whether ORs of the pest moth Spodoptera frugiperda belonging to clades closely related to this novel PR lineage may also have the capacity to bind type-I pheromones and serve as male PRs.Among the 7 ORs tested,only 1(SfruOR23)exhibited a male-biased expression pattern.Importantly,in vitro functional characterization showed that SfruOR23 could bind several type-I sex pheromone compounds with Z-9-tetradecenal(Z9-14:Ald),a minor component found in female sex pheromone glands,as the optimal ligand.In addition,SfruOR23 also showed weak responses to plant volatile organic compounds.Altogether,we characterized an S.frugiperda PR positioned in a lineage closely related to the novel PR clade,indicating that the type-I PR lineage can be extended in moths.

Moth sex pheromones affect interspecific competition among sympatric species and possibly population distribution by modulating pre-mating behavior

Premating behaviors mediated by pheromones play pivotal roles in animal mating choices.In natural populations of the striped stem borer Chilo suppressalis and the rice leaf roller Cnaphalocrocis medinalis in the rice field habitat,we discovered that Z11-16:Ald,a major component of the C.suppressalis pheromone,modulated the premating behavior of C.medinalis.Z11-16:Ald evoked a strong olfactory response in male antennae and strongly inhibited the sex pheromone trapping of male C.medinalis in the field.The functions of three C.medinalis sex pheromone receptor genes(CmedPR1–3)were verified through heterologous expression in Xenopus oocytes.CmedPR1 responded to Z11-18:OH and Z11-18:Ald,as well as the interspecific pheromone compound Z11-16:Ac of sympatric species;CmedPR2 responded to Z13-18:OH and Z13-18:Ald,as well as the sex pheromone compounds Z11-16:Ald and Z9-16:Ald of sympatric species;and CmedPR3 responded to Z11-18:OH and Z13-18:OH,as well as the interspecific pheromones Z11-16:OH,Z9-16:Ald,Z11-16:Ac,and Z11-16:Ald of sympatric species.Thus,CmedPR2 and CmedPR3 share the ligand Z11-16:Ald,which is not a component of the C.medinalis sex pheromone.Therefore,the sex pheromones of interspecific species affected the input of neural signals by stimulating the sex pheromone receptors on the antennae of male C.medinalis moths,thereby inhibiting the olfactory responses of the male moths to the sex pheromones.Our results demonstrate chemical communication among sympatric species in the rice field habitat,the recognition of intra-and interspecific sex pheromones by olfactory receptors,and how insect premating behaviors are modulated to possibly affect resource partitioning.

Revisiting the sex pheromone of the fall armyworm Spodoptera frugiperda,a new invasive pest in South China

The fall armyworm Spodoptera frugiperda is a worldwide serious agricultural pest,and recently invaded South China.Sex pheromone can be employed to monitor its population dynamics accurately in the field.However,the pheromone components previously reported by testing different geographic populations and strains are not consistent.On the basis of confirming that the S.frugiperda population from Yunnan Province belonged to the com strain,we analyzed the potential sex pheromone components in the pheromone gland extracts of females using gas chromatography coupled with electroan-tennographic detection(GC-EAD),gas chromatography coupled with mass spectrometry(GC-MS)and electroantennography(EAG).The results show that(Z)-9-tetradecenal acetate(Z9-14:Ac),(Z)-11-hexadecenyl acetate(Z11-16:Ac),(Z)-7-dodecenyl acetate(Z7-12:Ac)or(E)-7-dodecenyl acetate(E7-12:Ac)with a ratio of 100:15.8:3.9 induced EAD responses to varying degrees:Z9-14:Ac elicited a strong EAD response,Z7-12:Ac or E7-12:Ac elicited a small but clear EAD response,while Z11-16:Ac elicited a weak EAD response.Further single sensillum recording(SSR)showed that Z9-14:Ac and Z7-12:Ac induced dose-dependent activities in two types(A and B)of sensilla in male antennae,respectively,while the sensilla in response to E7-12:Ac and Z11-16:Ac was not recorded.Finally,wind tunnel tests reveal that Z9-14:Ac and Z7-12:Ac are two principal sex pheromone components of the tested population.

Female moths of cotton bollworm （Lepidoptera： Noctuidae） captured by waterbasin traps baited with synthetic female sex pheromone

Cotton bollworm, Helicoverpa armigera （Hüibner） （Lepidoptera： Noctuidae）, is one of the most important pest insects in cotton fields in China. Female moths were captured by waterbasin traps with a synthetic female sex pheromone blend in cotton fields over three years. The blend contained （Z）-11-hexadecenal and （Z）-9-hexadecenal with a ratio of 97：3. Each pheromone dispenser was impregnated with 2.0 mg of pheromone blend and 0.2 mg of antioxidant dissolved with 0.1 mL of hexane, and there was a control dispenser with a similar amount of antioxidant and solvent only. Waterbasin traps were deployed in three configurations in the fields. ‘A＇ was pheromone traps only, ‘B＇ was both pheromone and control traps, ‘C＇ was control traps only. （i） In four plots of ‘A＇, the average weekly female catch was 1.5, and more females were captured by centrally located pheromone traps. （ii） In three plots of‘B＇, control traps also captured female as well as male moths, but average weekly female catches of control traps was significantly lower than that in pheromone-baited traps. （iii） There were significant linear relationships between the average weekly female catch and the corresponding layer in pheromone-baited traps in both ‘A＇ and ‘B＇ plots, and in quadratic equations in control in ‘B＇ plots. （iv） With the increase of the interval of traps, average weekly female catches per trap increased but average weekly female catches per hectare decreased. （v） Among the female moths captured by pheromone traps, 88.3% were mated female moths which each containing 1.46 spermatophores, while in control traps 86.9% of the mated female moths had 0.90 spermatophores. There was a significant difference between the average numbers of spermatophores of mated females in pheromone traps and in controls.

Transcriptional analysis of sex pheromone biosynthesis signal genes in Bombyx mori

Six sex pheromone synthesis signal genes, including aeyl coenzyme A （acyl- CoA） desaturase （desatl）, fatty acyl reduetase （FAR）, pheromone biosynthesis activating neuropeptide receptor （PBANR）, fatty acid transport protein （FATP）, acyl-CoA binding protein （ACBP） and store-operated channel protein （OrailA）, were studied for their tran- scriptional regulations. The expression profiles of these transcripts at different develop- mental stages （from -96 to 48 h） revealed that the genes are expressed in an age-dependent manner. The transcripts of these genes continued to increase despite decapitation, and compared with normally developmental females, decapitation significantly inhibited their expression. Further experiments with a methoprene, a juvenile hormone （JH） analogue, challenge showed that JH was not a key inhibiting factor in the expression of these genes, and mating was found to significantly inhibit the expression of these marker genes. Alto- gether, the results provide a reference for understanding the mechanism of sex pheromone synthesis.

Molecular identification of a pancreatic lipase-like gene involved in sex pheromone biosynthesis of Bombyx mori

Cytoplasmic lipid droplet （LD） lipolysis is regulated by pheromone biosynthe- sis activating neuropeptide （PBAN） in Bombyx mori. To elucidate the molecular mechanism of cytoplasm LD lipolysis, the pancreatic lipase-like gene in B. mori pheromone glands （PGs）, designated as B. mori pancreatic lipase-like gene （BmPLLG）, was identified in this study. Spatial expression analysis revealed that BmPLLG is a ubiquitous gene present in all studied tissues, such as PGs, brain, epidermis, egg, midgut, flight muscle and fat body. Temporal expression analysis showed that the BmPLLG transcript begins to express 96 h before eclosion （-96 h）, continues to increase, peaks in newly emerged females and steadily decreases after eclosion. Translational expression analysis of BmPLLG using a prepared antiserum demonstrated that BmPLLG was expressed in an age-dependent pat- tern at different development stages in B. mori. This finding was similar to the transcript expression pattern. Further RNA interference-mediated knockdown of BmPLLG signifi- cantly inhibited bombykol production. Overall, these results demonstrated that BmPLLG is involved in PBAN-induced sex pheromone biosynthesis and release.

Synthesis and bioassay of all four stereoisomers of (2E,4E)-4,6,10,12-tetramethyl-2,4-tridecadien-7-one, the assignment of the absolute configuration of the sex pheromone of Matsucoccus matsumurae Japanese pine bast scale

A facile enantioselective synthesis of all four stereoisomers of (2E,4E)-4,6,10,12-tetramethyl-2,4-tridecadien-7-one (1) is described. The stereochemistry at 6-C and 10-C of 1 was constructed by using optically active citronellal as starting material and by the asymmetric crotylic metal reaction. In the bioassay and field tests, only la, i.e. (6R,10R)-1 was active. The other three isomers 1b (6S,10R), 1c (6R,10S) and 1d (6S,10S) were inactive. Therefore, the naturally occurring pheromone was assigned as (6K,10R)-1.

Structural elucidation of sex pheromone components of the Geometridae Semiothisa cinerearia(Bremer et Grey)in China

An extract from the female sex gland of Semiothisa cinerearia attracted conspecific males in field tests.A major active component was isolated from the extract and identified by GC-MS,GC-IR and microchemical reactions as cis-3,4-cpoxy-(Z,Z)-6,9-heptadecadiene,which showed strong EAG response.Another minor yet important component was identified as (Z,Z,Z)-3,6,9-heptadecatriene.