Male Catches Research Articles

Estimating and Simulating with a Random Utility Random Opportunity Model of Job Choice Presentation and Application to Belgium

We present the Random Utility Random Opportunity (ruro) model of job choice (Aaberge, Dagsvik and Strom, 1995, and Aaberge, Colombino and Strom, 1999) and report estimation results from an application of a version of that model on Belgian data (eusilc 2007). We discuss the effect of education level on the intensity of preference for leisure relative to consumption, on the intensity of job offers, and on the wage offer distribution. Finally, we report simulation results with respect to the impact on labour market participation by letting the male catch up the arrears in educational attainment they currently have with respect to females

Synergism of 1-Octen-3-Ol with Sex pheromone in Legume Pod Borer,Maruca VitrataFabricius (Lepidoptera: Crambidae)

Sex pheromone components of Maruca vitrata include (E, E)-10, 12-hexadecadienal (major component), (E, E)-10, 12-hexadecadienol and (E)-10-hexadecenal (minor components). As increasing field attractancy of these have not been satisfactory world over, an effective blend for field trapping, five blends of sex pheromone components and isomers through electroantennography (EAG) was attempted. Blend that had (Z, E)-10, 12-hexadecadienal (100 parts); (E, E)-10, 12-hexadecadienol (5 parts); (Z)-10hexadecenol (5 parts) and 1-Octen-3-ol (10%) elicited maximum EAG response (P < 0.05). Dose response evaluated at 10 μg, 100 μg, 500 μg and 1000 μg doses through EAG, flight behaviour (wind tunnel) and field experiments revealed that 1000 μg elicited higher electrophysiological and taxis response and male moth catches compared to remaining blends. These findings hint at a possible synergistic action of 1-Octen-3-ol with pheromone components or their isomers.

Female sex pheromones of two Japanese saturniid species, Rhodinia fugax and Loepa sakaei: identification, synthesis, and field evaluation.

While 11 species in the family Saturniidae are found in Japan, no sex pheromones of the native species had been investigated previously. We collected larvae of Rhodinia fugax in Nagano and Tottori Prefecture, and of Loepa sakaei in Okinawa Prefecture, and extracted sex pheromones of these two species from virgin female moths. In gas chromatography-electroantennogram detection (GC-EAD) analyses, male antennae of each species responded to one component in the respective pheromone extracts of conspecific females. Chemical analyses of the extracts by GC/mass spectrometry revealed that the EAD-active compounds of R. fugax and L. sakaei were a hexadecadienal and a tetradecadienyl acetate, respectively. The two species belong to the subfamily Saturniinae, and the mass spectra of both were similar to that of the 6,11-hexadecadienyl acetate identified from Antheraea polyphemus, classified in the same subfamily, suggesting the same 6,11-dienyl structure for the C16 aldehyde and a 4,9-dienyl structure for the C14 acetate. Based on this assumption, four geometrical isomers of each dienyl compound were stereoselectively synthesized via acetylene intermediates, compared to the natural products, and tested in the field. Male catches confirmed the pheromone structures of the two Japanese saturniid species as (6E,11Z)-6,11-hexadecadienal for R. fugax and (4E,9Z)-4,9-tetradecadienyl acetate for L. sakaei. The compounds have a characteristic 1,6-dienyl motif common to the pheromones of Saturniinae species.

Similar worldwide patterns in the sex pheromone signal and response in the oriental fruit moth, Grapholita molesta (Lepidoptera: Tortricidae)

The response of Grapholita molesta (Busck) males to three-component sex pheromone blends containing a 100% ratio of the major sex pheromone component, (Z)-8-dodecenyl acetate and a 10% ratio of (Z)-8-dodecenol, but with varying ratios of (E)-8-dodecenyl acetate (0.4, 5.4, 10.4, 30.4, and 100.1% E-blends) was tested with populations in eight stone and pome fruit orchards in Europe, Asia, and North and South America. Traps baited with the 5.4% E-blend caught significantly more males than traps with any other blend with all populations. Significantly more males were caught in traps baited with the 10.4% E-blend than in traps with the remaining blends, except with the 0.4% E-blend in Turkey. Significant differences in male moth catches occurred between the other blends with the 0.4>30.4% E-blend, and the 30.4>100.1% E-blend. Male moth catches with the 100.1% E-blend only differed from the hexane control in Chile. No apparent differences were noted to these blends in populations collected from pome or stone fruits. Flight tunnel assays to synthetic blends with a subset of populations were similar to the field results, but the breadth of the most attractive E-blends was wider. Flight tunnel assays also demonstrated a high level of male-female cross-attraction among field-collected populations. Female gland extracts from field-collected populations did not show any significant variation in their three-component blends. The only exceptions in these assays were that long-term laboratory populations were less responsive and attractive, and produced different blend ratios of the two minor components than recently collected field populations.

Detection and monitoring of pink bollworm moths and invasive insects using pheromone traps and encounter rate models

Summary The pink bollworm moth Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) is one of the most destructive pests in agriculture. An ongoing eradication program using a combination of sex pheromone monitoring and mating disruption, irradiated sterile moth releases, genetically modified Bt cotton and local insecticide applications have all but exterminated the pink bollworm from the south‐western USA and portions of northern Mexico. However, the continued threat of reinvasion from Mexico reinforces the need to improve pheromone‐based monitoring. Invasions from other parts of the world such as India, where resistance to single‐gene transgenic Bt cotton has evolved, further heightens the need for better monitoring strategies. The mean flight height and standard deviation (SD) of the vertical flight distribution of pink bollworm males were estimated from catches on transparent sticky cylinder traps baited with synthetic pheromone at several heights above‐ground. An effective attraction radius (EAR) of a standard pheromone lure was estimated from male moth catches on the pheromone‐baited sticky traps and many similar blank traps. The circular EARc was estimated from the spherical EAR and SD. The EAR of a pheromone lure for pink bollworm was 1·03 m, and the EARc was 2·61 m. The mean flight height of males was 0·82 m, and the vertical flight distribution SD was 0·26 m. A computer program simulated male moth movement and capture on various numbers of traps of EARc distributed over areas of 1–100 km2. The simulated catch results were comparable to predictions using the EARc with modified encounter rate equations of Royama and Rogers. The encounter rate equations were solved for initial populations of male moths in the regions, and Poisson statistics were used to calculate population confidence limits. Synthesis and applications. Encounter rate models and Poisson methods can be used to determine levels of pheromone trap densities that are likely to detect and estimate low population levels of resident or invasive pink bollworms and many other pest insect species.

Green Light Synergistally Enhances Male Sweetpotato Weevil Response to Sex Pheromone

Sweetpotato, commercially grown in over 100 countries, is one of the ten most important staple crops in the world. Sweetpotato weevil is a major pest of sweetpotato in most areas of cultivation, the feeding of which induces production in the sweetpotato root of extremely bitter tasting and toxic sesquiterpenes which can render the sweetpotato unfit for consumption. A significant step towards improved management of this weevil species was the identification of a female-produced sex pheromone [(Z)-3-dodecenyl (E)-2-butenoate] to which males are highly attracted. Reported here are results of research that documents a nearly 5-fold increase in male sweetpotato weevil catch in traps baited with this pheromone and a green light provided by a solar-powered, light-emitting diode (LED). The combination of olfactory and night-visible visual cues significantly enhanced trap effectiveness for this nighttime-active insect species. These results provide promise for improved sweetpotato weevil detection and suppression in mass trapping programs.

Identification of the Female-Produced Sex Pheromone of the Plant Bug Apolygus spinolae

Apolygus spinolae (Meyer-Dür) (Heteroptera: Miridae) is an important pest of fruit and tea trees in Korea and Japan. Analyses of extracts of metathoracic scent glands revealed that those of female bugs contained hexyl butyrate, (E)-2-hexenyl butyrate, and (E)-4-oxo-2-hexenal in a ratio of 20:100:7. The glands of males contained the same three compounds, but the ratio of the components was quite different, with hexyl butyrate being the most abundant. Field trapping tests with various blends of the synthetic compounds dispensed from high-density polyethylene tubes showed that (E)-2-hexenyl butyrate and (E)-4-oxo-2-hexenal were essential for attraction of male A. spinolae, and catches with a wide range of ratios of these two compounds did not differ significantly. However, adding hexyl butyrate at 50 % or more of the (E)-2-hexenyl butyrate to the binary blend strongly inhibited attraction of males. Trap catches increased with increasing amounts of a 10:1 blend of (E)-2-hexenyl butyrate and (E)-4-oxo-2-hexenal from 0.011 to 11 mg loaded into the tube. Catches of males in traps baited with lures containing 1.1 mg of the binary blend were not significantly different from catches in traps baited with live virgin females.

Identification of Conjugated Pentadecadienals as Sex Pheromone Components of the Sphingid Moth, Dolbina tancrei

Homologs of bombykal, (10E,12Z)-10,12-hexadecadienal, have been reported to be sex pheromones or sexual attractants of several species of sphingid moths. In this study, we identified novel bombykal analogs as sex pheromone components from a Japanese sphingid moth, Dolbina tancrei. Staudinger (Sphingidae: Lepidoptera). Sex pheromone gland extracts from calling female moths were subjected to gas chromatography/electroantennograhic detection (GC/EAD), gas chromatography/mass spectrometry (GC/MS), and gas chromatography (GC) analyses. GC/EAD analyses showed two active components in the crude pheromone extracts. GC/MS analysis determined these two components to be pentadecadienals. GC/MS of their MTAD derivatives showed conjugated double bonds at the 9- and 11-positions, indicating 9,11-pentadecadienals. The isomeric configurations of these candidates were determined by comparison of their Kováts retention indices with those of synthetic compounds. Field bioassays with the four isomers of 9,11-pentadecadienal and their mixtures confirmed that the two sex pheromone components of D. tancrei are (9E,11Z)-9,11-pentadecadienal and (9Z,11Z)-9,11-pentadecadienal, with the highest male catches observed for a 90:10 blend. This is the first report of 9,11-pentadecadienals as sex pheromone components in lepidopteran species.

Seasonality of the common cutworm Spodoptera litura in a soybean ecosystem

Seasonal occurrence of the common cutworm Spodoptera litura (Fab.) (Lepidoptera: Noctuidae) moths captured in synthetic sex pheromone traps and associated field population of eggs and larvae in soybean were examined in India from 2009 to 2011. Male moths of S. litura first appeared in late July or early August and continued through October. Peak male trap catches occurred during the second fortnight of September, which was within soybean reproductive stages. Similarly, the first appearance of S. litura egg masses and larval populations were observed after the first appearance of male moths in early to mid-August, and were present in the growing season up to late September to mid-October. The peak appearance of egg masses and larval populations always corresponded with the peak activity of male moths recorded during mid-September in all years. Correlation studies showed that weekly mean trap catches were linearly and positively correlated with egg masses and larval populations during the entire growing season of soybean. Seasonal means of male moth catches in pheromone traps during the 2010 and 2011 seasons were significantly lower than the catches during the 2009 season. However, seasonal means of the egg masses and larval populations were not significantly different between years. Pheromone traps may be useful indicators of the onset of numbers of S. litura eggs and larvae in soybean fields.

Communication Disruption of Guava Moth (Coscinoptycha improbana) Using a Pheromone Analog Based on Chain Length

The guava moth, Coscinoptycha improbana, an Australian species that infests fruit crops in commercial and home orchards, was first detected in New Zealand in 1997. A four-component pheromone blend was identified but is not yet commercially available. Using single sensillum recordings from male antennae, we established that the same olfactory receptor neurons responded to two guava moth sex pheromone components, (Z)-11-octadecen-8-one and (Z)-12-nonadecen-9-one, and to a chain length analog, (Z)-13-eicosen-10-one, the sex pheromone of the related peach fruit moth, Carposina sasakii. We then field tested whether this non-specificity of the olfactory neurons might enable disruption of sexual communication by the commercially available analog, using male catch to synthetic lures in traps in single-tree, nine-tree and 2-ha plots. A disruptive pheromone analog, based on chain length, is reported for the first time. Trap catches for guava moth were disrupted by three polyethylene tubing dispensers releasing the analog in single-tree plots (86% disruption of control catches) and in a plots of nine trees (99% disruption). Where peach fruit moth pheromone dispensers were deployed at a density of 1000/ha in two 2-ha areas, pheromone traps for guava moth were completely disrupted for an extended period (up to 470 days in peri-urban gardens in Mangonui and 422 days in macadamia nut orchards in Kerikeri). In contrast, traps in untreated areas over 100 m away caught 302.8 ± 128.1 moths/trap in Mangonui and 327.5 ± 78.5 moths/ trap in Kerikeri. The longer chain length in the pheromone analog has greater longevity than the natural pheromone due to its lower volatility. Chain length analogs may warrant further investigation for mating disruption in Lepidoptera, and screening using single-sensillum recording is recommended.

Intra- and Interspecific Activities of Semiochemicals from the Sex Pheromone Gland of the Welsh Clearwing, Synanthedon Scoliaeformis

Analysis of the sex pheromone gland of virgin Synanthedon scoliaeformis females by gas chromatography/mass spectrometry revealed six compounds structurally related to sex pheromone components of other clearwing moths: (E,Z)-2,13-octadecadienyl acetate (E2,Z13-18:OAc), (E,Z)-2,13-octadecadienol, octadecanol acetate, octadecanol, (Z,Z)-3,13-octadecadienyl acetate (Z3,Z13-18:OAc), and (Z)-13-octadecenyl acetate. Trapping tests demonstrated that E2,Z13-18:OAc is the sex pheromone of S. scoliaeformis and is essential for attracting males; addition of the other compounds did not enhance catch. Synanthedon scoliaeformis and S. tipuliformis are the only Palearctic clearwing moths whose distribution range and seasonal flight periods overlap and that are known to use E2,Z13-18:OAc in sex pheromonal communication. Hourly monitoring of male catches in traps revealed that sex pheromone communication in S. scoliaeformis and S. tipuliformis species follows different diurnal patterns. Z3,Z13-18:OAc, found in S. scoliaeformis females, is a known behavioral antagonist against S. tipuliformis males, while (E,Z)-3,13-octadecadienyl acetate, a minor sex pheromone component of S. tipuliformis, is an antagonist against S. scoliaeformis males. The effect of sex pheromones and antagonists, combined with different diurnal mate searching times, contribute to the specificity of sex communication channels in these two clearwing moth species.

Combined approaches using sex pheromone and pear ester for behavioural disruption of codling moth (Lepidoptera: Tortricidae)

AbstractAttractive properties of pear ester, ethyl (E,Z)‐2,4‐decadienoate, and codlemone, (E,E)‐8,10‐dodecadien‐1‐ol, the sex pheromone of codling moth, Cydia pomonella (L.), were utilized in experiments on behavioural disruption of mating. Standard dispensers loaded with codlemone alone or in combination with pear ester (combo) were applied at 500–1000/ha. Larger (10‐fold) combo dispensers (Meso) were evaluated at a rate of 80/ha. The addition of microencapsulated pear ester, PE‐MEC, sprayed with insecticides at 30 ml/ha was also evaluated. Male moth catches in unmated female‐baited traps were lower in standard combo dispenser than in codlemone dispenser–treated plots. Female moth catch in traps baited with the combination of pear ester, codlemone and acetic acid was lower in standard combo dispenser than in codlemone dispenser–treated plots. In 12 comparative experiments spanning from 2006 to 2012, male moth catch in unmated female‐baited traps was consistently and significantly lower in combo than in codlemone dispenser–treated plots. Male catch in codlemone‐baited traps did not differ between dispenser treatments in eight studies from 2006 to 2009. These results emphasize the benefit of alternatively using traps baited with unmated females over codlemone lures for the analysis of dispenser activity. Fruit injury was significantly reduced with the addition of PE‐MEC to insecticide applications across untreated and dispenser treatments. Proportion of unmated females trapped was higher in standard combo dispenser than in codlemone dispenser–treated and untreated plots. Similarly, the proportion of unmated females caught was higher in the Meso combo dispenser than in nearby or distant codlemone dispenser–treated plots. These field studies conducted in apple over 3 years demonstrate that adding pear ester both to pheromone dispensers, either standard or Meso, and to supplementary insecticide sprays can provide a significant increase in the disruption of sexual communication, reductions in female mating and reductions in fruit injury.

Attractiveness and competitiveness of irradiated light brown apple moths

AbstractThe sterile insect technique (SIT) potentially provides a socially acceptable approach for insect eradication of new pest incursions. The light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), was discovered in Berkeley (CA, USA) in 2006, leading to an incursion response that included this technology. In this study, we assessed factors affecting mating success from a bisex release of irradiated moths: effects of radiation dose on male multiple mating, male flight competition, female sex pheromone titre and attractiveness of irradiated females to males, and identification of successful mating in vineyards of either irradiated or wild males (identified by isotope analysis of spermatophores from sentinel females). There was a significant negative relationship between male radiation dose and mating frequency. In head‐to‐head flights of irradiated males against non‐irradiated males to a pheromone lure in a wind tunnel, irradiated males reached the lure first only 31% of the time. With increasing radiation dose, the production of the major sex pheromone component in females, (E)‐11‐tetradecenyl acetate, dropped, from 0.7 ± 0.1 ng per female in non‐irradiated females to 0.2 ± 0.07 ng per female when irradiated at 300 Gy. Male catch was reduced to 11% of control females in traps containing females irradiated at 300 Gy. Isotope analysis of spermatophores found in the bursa copulatrix of females indicated that mating success of irradiated males inside the live (entry‐only) traps containing virgin females was lower (13.1 ± 3.3%) than suggested by male catch (21.2 ± 3.8%) in pheromone traps, the current standard for assessing field competitiveness. Impacts of irradiation on male and female moth fitness should be taken into account to improve estimates of irradiated to wild male E. postvittana overflooding ratios needed for population suppression.

Mating disruption for control of the white grub beetle Dasylepida ishigakiensis (Coleoptera: Scarabaeidae) with synthetic sex pheromone in sugarcane fields

The feasibility of mating disruption with synthetic sex pheromone for the control of the white grub beetle Dasylepida ishigakiensis (Coleoptera: Scarabaeidae) was examined by permeating sugarcane fields with a racemic mixture of 2-butanol (rac-2B) released from polyethylene-tube dispensers on Miyako Island, Japan in 2011. An application of rac-2B released from 10,000 tube dispensers into 3,200 m2 sugarcane fields significantly reduced the mating rate of feral females and catches of feral males with R2B-baited traps compared with the results from untreated sugarcane fields. The larval density for the treated fields was found to be nearly zero in the following winter when the corresponding figure for untreated fields was high (1.73 and 2.33/40 × 40 cm quadrat). These results clearly show that the mating disruption technique using rac-2B could be highly promising for the control of D. ishigakiensis in sugarcane fields.

Field trials of synthetic sex pheromone lures for the large cabbage-heart caterpillar moth, Crocidolomia pavonana (Lepidoptera: Crambidae) in Indonesia

The efficacy of synthetic female sex pheromone lures for Crocidolomia pavonana (Fabricius) (Lepidoptera: Crambidae) in the cabbage fields of Java and Bali, Indonesia, was investigated by varying the composition and dosage of the components. The lure containing a synthetic pheromone blend of (Z)-11-hexadecenyl acetate (Z11–16: Ac) and (Z)-9-tetradecenyl acetate (Z9–14: Ac) at a 10:1 ratio acquired significantly more male catches than single component lures and the control lure. Meanwhile, no attraction was observed when lures with 1:1 and 1:10 blends were tested. The composition of Z11–16: Ac and Z9–14: Ac at a ratio of 5, 10 and 20:1 attracted more males than the control lures. Dosage studies showed that 0.055 and 0.55 mg of a mixture of Z11–16: Ac and Z9–14: Ac (10:1 ratio) attracted more males than the control. These results are the first demonstration of the efficacy of synthetic pheromone for C. pavonana in field conditions. The present study suggests the feasibility of pheromone-based monitoring as a simple and low-cost technique for integrated pest management of this pest.

Persistence of the Gypsy Moth Pheromone, Disparlure, in the Environment in Various Climates

Mating disruption techniques are used in pest control for many species of insects, yet little is known regarding the environmental persistence of these pheromones following their application and if persistence is affected by climatic conditions. We first studied the persistent effect of ground applications of Luretape® GM in Lymantria dispar (L) mating disruption in VA, USA in 2006. The removal of Luretape® GM indicated that the strong persistent effect of disparlure in the environment reported by previous studies is produced by residual pheromone in the dispensers as opposed to environmental contamination. In 2010 and 2011, we evaluated the efficacy of two formulations, Disrupt® II and SPLAT GMTM, in VA and WI, USA, which presented different climatic conditions. In plots treated in WI and VA, male moth catches in pheromone-baited traps were reduced in the year of treatment and one year after the pheromone applications relative to untreated controls. However, similar first- and second-year effects of pheromone treatments in VA and WI suggest that the release rate over one and two years was the same across markedly different climates. Future applications that use liquid or biodegradable formulations of synthetic pheromones could reduce the amount of persistence in the environment.

수원지역 과수원에 발생하는 유리나방류 4종의 성충 발생소장

유리나방류는 사과, 복숭아, 포도와 같은 과수의 주요 해충으로서, 유충이 기주식물의 줄기 속에서 형성층을 섭식한다. 수원지역에서 3년에 걸쳐, 성페로몬 트랩을 이용하여 사과유리나방, 복숭아유리나방, 포도유리나방, 큰유리나방의 연중 발생소장을 조사하였다. 사과원에서 사과유리나방 성충은 트랩에 5월부터 10월까지 유인되었으며, 6월 상중순과 8월 하순~9월 상순에 각각 발생최성기를 보였다. 비슷하게, 복숭아원에서 복숭아유리나방은 5월부터 10월까지 유인되었으며, 발생최성기는 5월 하순과 8월 하순~9월 중순이었다. 포도원에서 포도유리나방은 5월 하순부터 6월 중순까지 유인되었으며, 5월 하순~6월 상순에 발생최성기를 보였다. 한편, 포도원에서 큰유리나방은 6월 상순부터 7월 하순까지 유인되었으며, 발생최성기는 6월 하순~7월 상순이었다. Clearwing moths (Lepidoptera: Sesiidae) are economically important pests of fruit trees, such as apple, peach, and grape in Korea. Larvae feed on the phloem and cambium within tree branches of host plants. In this study, the seasonal fluctuation in male catches of four clearwing moths, Synanthedon haitangvora, S. bicingulata, Nokona regalis, and Glossosphecia romanovi, were monitored with the respective sex pheromone traps in Suwon for three years. In apple orchards, S. haitangvora males were captured from May to October, with two peaks in early June to middle June and late August to early September. Similarly, S. bicingulata males were trapped from May to October, with two peaks in late May and late August to middle September in peach orchards. In vineyards, N. regalis males were captured from late May to middle June with one peak in late May to early June, while G. romanovi males were trapped from early June to late July with one peak in late June to early July.

Electroantennogram and field responses of Korean population of the rice leaf folder, Cnaphalocrocis medinalis (Lepidoptera: Crambidae), to sex attractant candidates

A series of studies was conducted to determine the optimum sex attractant for monitoring the rice leaf folder, Cnaphalocrocis medinalis, in Korea, based on the previously reported pheromone composition in this species. (Z)-13-Octadecenal (Z13-18:Al) was most active in electroantennogram (EAG) and field tests. (Z)-11-Hexadecenal (Z11-16:Al), (Z)-11-octadecenal (Z11-18:Al), (Z)-11-hexadecenyl acetate (Z11-16:Ac), (Z)-13-octadecenyl acetate (Z13-18:Ac) and (Z)-13-octadecenol (Z13-18:OH) individually elicited significant EAG responses, but were not individually attractive in field trials. (Z)-11-Octadecenol (Z11-18:OH) alone was inactive in both EAG and field tests. The addition of Z11-18:OH and Z13-18:OH to the binary mixture of Z11-18:Al and Z13-18:Al, as the previously reported composition of the Japanese blend, significantly increased the trap catches of males in field trials. In contrast, the Philippine and Indian blends were not attractive to this species. Interestingly, when Z13-18:Ac alone was added to the binary mixture of Z11-18:Al and Z13-18:Al, the trap catch number was the same as that of the Japanese blend. The present study indicates that the four-component blend (Z11-18:Al/Z13-18:Al/Z11-18:OH/Z13-18:OH=11/100/24/36) and the three-component blend (Z11-18:Al/Z13-18:Al/Z13-18:Ac=11/100/11) can be used as sex attractants for monitoring the Korean populations of C. medinalis.

Identification of the Female-Produced Sex Pheromone of Tischeria ekebladella, an Oak Leafmining Moth

The native leafmining moth Tischeria ekebladella (Lepidoptera: Tischeriidae) feeds on oaks and recently has become a pest of silviculture and urban green areas in central Europe. The behavioral responses of male moths to hexane extracts of whole bodies of calling females or males were tested under laboratory conditions. Only extracts of females elicited responses from males. Analysis of extracts by coupled gas chromatography/electroantennographic detection revealed the presence of two electroantennogram-active peaks. Structure elucidation of these compounds, by gas-chromatography/mass spectrometry and independent synthesis revealed them to be (3Z,6Z,9Z)-tricosa-3,6,9-triene and (3Z,6Z,9Z,19Z)-tricosa-3,6,9,19-tetraene. While the triene was present in both sexes, the tetraene was female-specific. The latter is a new structure for a pheromone component of Lepidoptera and a novel natural product. Field trapping tests, carried out in a mixed oak forest near Budapest (Hungary), using synthetic compounds applied to rubber dispensers, showed that the tetraene per se elicited catches of males in large numbers. When the triene was added to the tetraene in a ratio of 1:1, there was no increase in trap catch; the triene alone did not elicit catches of males. For monitoring this insect, the tetraene, applied to rubber dispensers at a dose of 300 μg, is a potent sex attractant.

Small‐plot studies comparing pheromone and juice baits for mass‐trapping invasive Synanthedon myopaeformis in Canada

AbstractRecent introduction of Synanthedon myopaeformis (Borkhausen) (Lepidoptera: Sesiidae) into organic apple‐growing areas of Canada has stimulated research on semiochemical‐based management of this European pest. Replicated, small‐plot (0.16 ha) experiments were conducted to compare sex pheromone, 3Z,13Z‐octadecadienyl acetate (10 mg), Concord grape juice (300 ml), or their combination, as mass‐trapping lures at trap densities equivalent to 12.5, 25, 50, and 100 traps ha−1. Total numbers of male and female moths removed from test plots increased significantly with trap density in all juice‐based mass‐trapping experiments. In pheromone mass‐trapping experiments, however, total catches of males did not increase significantly as trap densities were increased and catches appeared to plateau with 25–50 traps ha−1. With pheromone‐based mass‐trapping, significantly fewer males were caught in pheromone‐baited assessment traps at the centre of each mass‐trapping plot than in identical traps in untreated plots. This reduction is indicative of significant trap interference or trap ‘shut‐down’. Increasing the density of juice‐based mass‐trapping had no effect on catches of male or female moths in juice‐baited assessment traps, indicating a short range of attraction and lack of interference between juice traps. Pheromone‐ and juice‐based mass trapping removed similar numbers of males at each trap density tested, respectively, but summed catches of males and females were greatest with juice baits. Combining pheromone and juice into a single mass‐trapping treatment (50 traps ha−1) did not significantly increase catches of males or females relative to either treatment alone. If a practical bisexual mass‐trapping system is going to be developed for S. myopaeformis, then identification of volatile kairomones in Concord grape juice may be useful.