Synthetic Female Sex Pheromone Research Articles

Diversity of Lepidoptera (Insecta) recorded in a forest nursery of Nordeste County on São Miguel Island (Azores).

The diversity of moth species (Insecta, Lepidoptera) recorded in the forest nursery of Nordeste County on São Miguel Island (Azores) is given. Adults were sampled between March and December 2019 using three methods: (i) light trap to catch Noctuidae species, (ii) open-sided delta trap baited with a synthetic female sex pheromone lure to attract Epiphyaspostvittana (Walker) males and (iii) entomological net to collect microlepidopteran moths. This contribution focuses mainly on the diversity of moths present in one forest nursery of Nordeste County of São Miguel Island (Azores), especially on the species associated with endemic and native plant species. It also contributes to better plan strategies for integrated protection and conservation measures, since nurseries host a great diversity of plants from the Laurel Forest, which may attract many lepidopteran species. A total of 10160 adults belonging to 33 lepidopteran species were recorded and listed by families, including: Argyresthiidae, one species (3%), Crambidae, four species (12%), Erebidae, one species (3%), Geometridae, five species (15%), Noctuidae, 18 species (55%), Sphingidae, one species (3%), Tineidae, one species (3%) and Tortricidae, two species (6%). The families Noctuidae, Geometridae and Crambidae were the most diverse. Those with the highest abundance of adults were the Noctuidae family, followed by the Geometridae, Crambidae, Tortricidae and Tineidae. The number of caught adults was consistently higher during spring and summer, decreasing sharply in late autumn. For 13 species caught in the light trap, the adult sex ratio was favourable to females. An analysis of the colonisation status, feeding and primary hosts of these endemic, native or exotic moth species contributes to our understanding of the factors that may lead to their establishment in Laurel Forest environments and to what extent there is a need to monitor and control them mainly with biological control agents.

Male Grapholita molesta (Busck) adults responding to various component combinations of synthetic female sex pheromone

Male <i>Grapholita molesta</i> (Busck) adults responding to various component combinations of synthetic female sex pheromone

The effect of synthetic female sex pheromone on the transmission of the fungus Metarhizium brunneum by male Agriotes obscurus click beetles

Autodissemination techniques can potentially be used to distribute insecticides, including microbial insecticides, to cryptic pests. This approach is reliant on the target insect either passing the pathogen passively to other insects or the pathogen cycling within the population after the initial host dies. Here we examine, in small scale experiments, whether male Agriotes obscurus click beetles passively transmit the spores of the fungus Metarhizium brunneum directly, or indirectly via the environment, and whether this is influenced by exposure to synthetic female pheromone. We found that the beetles did not avoid M. brunneum spores and that this behaviour was not affected by pheromone. Exposure to pheromone increased beetle movement and uptake of spores, but this did not result in an increase in infected beetles under our conditions. Beetles were able to transfer spores at high levels via environmental contamination. However, contamination of the environment declined rapidly after exposure to the spores. The results are discussed in the context of developing an autodissemination strategy for click beetles.

Response to a Synthetic Pheromone Source by OX4319L, a Self-Limiting Diamondback Moth (Lepidoptera: Plutellidae) Strain, and Field Dispersal Characteristics of its Progenitor Strain.

The diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae), is a global pest that infests vegetable and field crops within the Brassica family. A genetically engineered strain of P. xylostella, OX4319L, carrying a 'self-limiting' gene, has shown potential for managing P. xylostella populations, using sustained releases of OX4319L male moths. In order for such a strain to provide control, the transgenic individuals must exhibit attraction to female P. xylostella sex pheromone and adequate dispersal in the field. In this study, we tested these key traits. First, we compared the responses of the OX4319L male moths to a synthetic female sex pheromone source in wind tunnel trials to those of males from three other strains. We found that OX4319L males responded comparably to strains of non-engineered males, with all males flying upwind towards the pheromone source. Second, we used mark-release-recapture studies of a wildtype P. xylostella strain, from which the OX4319L strain was originally developed, to assess dispersal under field conditions. Released males were recaptured using both pheromone-baited and passive traps within a 2.83 ha circular cabbage field, with a recapture rate of 7.93%. Males were recaptured up to the boundary of the field at 95 m from the central release point. The median dispersal of males was 14 m. These results showed the progenitor strain of OX4319L retained its ability to disperse within a host field. The results of these experiments are discussed in relation to the potential for the effective use of engineered male-selecting P. xylostella strains under field conditions.

Monitoring Mexican Rice Borer (Lepidoptera: Crambidae) Populations in Sugarcane and Rice With Conventional and Electronic Pheromone Traps.

The Mexican rice borer, Eoreuma loftini (Dyar), is a major pest of sugarcane, Saccharum spp., rice, Oryza sativa L., and other graminaceous crops in Texas and Louisiana. The ability of conventional and electronic pheromone traps to monitor E. loftini in sugarcane and rice habitats was evaluated in two separate 2-yr field studies. Bucket traps baited with a synthetic female sex pheromone monitored E. loftini populations in commercial sugarcane fields in Calcasieu and Jefferson Davis Parishes throughout the 2014 and 2015 growing seasons. The number of E. loftini captured differed among months, but not between years or parishes. The percentage of E. loftini-injured stalks was greater in 2015 than in 2014, peaking in September of both years. Daily trap capture was correlated with the percentage of injured stalks. Injury from E. loftini in Louisiana sugarcane remained relatively low (<3% bored internodes) in both 2014 and 2015. In a second experiment, electronic traps were compared with conventional pheromone traps for monitoring E. loftini populations in sugarcane and rice habitats in Texas in 2013 and 2015. Performance of earlier electronic trap prototypes in 2013 was inconsistent and less effective than conventional traps. Improved trap design in 2015 resulted in more than threefold greater moth capture in electronic traps than in conventional pheromone traps. Electronic traps demonstrated potential to improve monitoring strategies for this pest and should be evaluated for lepidopterous pests in a variety of cropping systems.

The Active Space of Mexican Rice Borer Pheromone Traps.

The Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Crambidae), is an invasive pest of sugarcane, Saccharum spp., rice, Oryza sativa L., and other graminaceous crops in the United States. Traps baited with the synthetic female sex pheromone of E. loftini are used for monitoring and management of this invasive pest. However, the active space, or radius of attraction, of these traps is not known. Two field experiments examined the effect of intertrap distance on trap captures with hexagonal arrays of traps deployed in rice stubble habitat in Texas (2011) and Louisiana (2013). Trap capture increased with increasing intertrap distance. Trap interference occurred at intertrap distances ≤50m in the 2011 experiment. Results from the experiment conducted in 2013 indicate that trap interference occurs at intertrap distances of 50m, but not at distances ≥100m. These results suggest that under field conditions, E. loftini pheromone traps attract males from distances of 50-100m. The active space of pheromone traps also was examined under controlled wind conditions by direct observation of male response to detection of the female sex pheromone. Eoreuma loftini males responded to the pheromone blend by becoming active, fanning their wings, and rapidly walking in circles. The mean distance from the pheromone source at which males responded was 47.6m. This work provides the first documentation of active space for traps baited with female sex pheromone for a crambid species, and these data will improve pheromone trap deployment strategies for E. loftini monitoring and management.

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.

Extrinsic and Intrinsic Factors Influencing the Emerging and Burrowing Behaviors of Reproductively Active Adults of the White Grub Beetle, Dasylepida ishigakiensis

The subtropical scarab beetle, Dasylepida ishigakiensis, has a two-year life cycle. This study showed the time of adult emergence from the soil relative to the time of dusk and the presence of the female sex pheromone. Beetles collected on Miyako Island were transported to Tsukuba where they were immediately placed under natural day lengths in February. They exhibited two emergence peaks that corresponded to the times of dusk in Tsukuba and on the island, respectively. Males emerged precociously if a lure containing synthetic female sex pheromone was placed in their container, whereas the females’ behavior was unaffected. Previous observations that mated females dig deeper in the soil than virgin females, males or mated males were confirmed. To explore the underlying mechanism controlling the behavioral change associated with mating, liquid material derived from the male accessory glands, seminal vesicles and female bursa copulatrix was injected into beetles, but without any significant influence on burrowing behavior. No significant influence was also observed in beetles injected with anisomycin, an inhibitor of protein synthesis related to memory in other animals.

Laboratory evaluation of attract-and-kill formulations against the Indianmeal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae)

Pheromone-based population suppression methods for stored-product insects can reduce or eliminate application of chemical insecticides near finished food products. The responses of adult male Indianmeal moth males (IMM), Plodia interpunctella (Hübner), to the attract-and-kill formulations of a gel, a flat wax panel, and a plastic cylinder device, mixed or sprayed with the pyrethroid insecticides permethrin, cyfluthrin, or organically compliant natural pyrethrin, combined with the synthetic female sex pheromone (Z,E)-9,12 tetradecadienyl acetate, were evaluated in a laboratory wind tunnel. The wax panel and cylinder, which utilized controlled-release pheromone lures, were more attractive to IMM males over the course of an eight-week aging period than was the gel, which had the pheromone incorporated into the gel matrix. The contact time for responding males was longer on the wax panel and plastic cylinder than on the gel formulation. The percentage of mortality of males was higher with wax panels formulated with cyfluthrin at 6.0% AI, permethrin at 6.0% AI and the cylinder formulated with cyfluthrin at 2.0% AI, compared to the gel over the eight-week study. These same formulations had the greatest impact on egg-laying by females paired with treated males and on the percent of eggs that hatched. Of all the attract-and-kill formulations tested, the most promising for field applications to suppress IMM pest populations was the wax panel containing 6.0% AI of either cyfluthrin or permethrin.

Development of bisexual attractants for diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae) based on sex pheromone and host volatiles

Males and females of the diamondback moth (DBM), Plutella xylostella (L.) were investigated for electroantennogram responses to 13 volatiles from Brassicaceae in the laboratory, and showed stronger responses to benzaldehyde, phenylacetaldehyde, allyl isothiocyanate, (Z)-3-hexen-1-ol and (Z)-3-hexenyl acetate than to monoterpenic volatiles. In field trapping experiments, traps baited with the synthetic female sex pheromone of DBM+(Z)-3-hexenyl acetate or pheromone+(Z)-3-hexen-1-ol significantly enhanced male catches in three brassicaceous crops, compared with traps baited with synthetic sex pheromone alone. Traps baited with pheromone+(Z)-3-hexenyl acetate and pheromone+(Z)-3-hexenyl acetate+(Z)-3-hexen-1-ol+allyl isothiocyanate enhanced male catches by 46.4% and 75.0%, respectively, compared with synthetic sex pheromone alone, and caught an average of 15.8±2.2 and 18.6±2.7 females/trap/day, respectively, during the whole trapping period. Results indicate that traps baited with pheromone+(Z)-3-hexenyl acetate+(Z)-3-hexen-1-ol+allyl isothiocyanate have a stronger attraction to both male and female DBM and may provide more effective tools for monitoring and controlling this insect pest.

DEVELOPMENT OF TRAPPING METHODS WITH A SYNTHETIC SEX PHEROMONE OF THE PINK HIBISCUS MEALYBUG, MACONELLICOCCUS HIRSUTUS (HEMIPTERA: PSEUDOCOCCIDAE)

The pink hibiscus mealybug, Maconellicoccus hirsutus (Green), threatens numerous crops of economic importance and could spread from populations in California and Florida to 33 other states. Field experiments conducted in Florida evaluated 3 commercially available trap designs baited with synthetic female sex pheromone for efficiency in trapping adult male M. hirsutus as well as ease in processing. Delta traps and double-sided sticky cards captured more males than Jackson traps. The Delta and Jackson traps were more effective at minimizing the capture of non-target insects. The effect of lure age on males captured was also evaluated by pre-aging lures outdoors for 0 to 8 months before testing. Fewer males were caught in Delta traps as the age of the lure increased, with significantly fewer caught in traps that had been pre-aged for 2 months. Monitoring of male flight activity throughout diel cycle with baited Delta traps indicated that males were most active around dusk. The field experiments also showed that the pheromone traps often capture males in areas where no visual indication of an infestation is evident. The pheromone trap may serve as a valuable tool to detect new infestations of pink hibiscus mealybug.

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

AbstractCotton bollworm, Helicoverpa armigera (Hübner) (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 ‘Brsquo;, 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.

Female sex pheromone of brinjal fruit and shoot borer, Leucinodes orbonalis (Lepidoptera: Pyralidae): trap optimization and application in IPM trials.

Delta and wing traps baited with synthetic female sex pheromone of Leucinodes orbonalis Guenée were found to catch and retain ten times more moths than either Spodoptera or uni-trap designs. Locally-produced water and funnel traps were as effective as delta traps, although 'windows' cut in the side panels of delta traps significantly increased trap catch from 0.4 to 2.3 moths per trap per night. Trap catch was found to be proportional to the radius of sticky disc traps in the range 5-20 cm radius, discs with a 2.5 cm radius caught no moths. Wing traps placed at crop height caught significantly more moths than traps placed 0.5 m above or below the crop canopy. Replicated integrated pest management (IPM) trials (3 x 0.5 ha per treatment) were conducted in farmers fields with young and mature eggplant crops. Farmers applied insecticides at least three times a week in all check and IPM plots. In addition pheromone traps were placed out at a density of 100 per ha and infested shoots removed weekly in the 0.5 ha IPM plots. Pheromone trap catches were reduced significantly from 2.0 to 0.4 moths per trap per night respectively in check and IPM plots in a young crop and 1.1 to 0.3 moths per trap per night in check and IPM plots respectively in a mature crop. Fruit damage was significantly reduced from an average of 41.8% and 51.2% in check plots of young and mature crops respectively to 22% and 26.4 respectively in the associated IPM plots. Significant differences in pheromone trap catches and fruit damage were attained four and two weeks respectively after IPM treatments began in the mature crop whereas in the immature crop significant differences were not observed for the first eight to nine weeks respectively. The relative impact of removing infested shoots and mass trapping on L. orbonalis larval populations was not established in these trials but in both cases there was an estimated increase of approximately 50% in marketable fruit obtained by the combination of control techniques compared to insecticide treatment alone.

Can Parasitoid Sex Pheromones Help in Insect Biocontrol? A Case Study of Codling Moth (Lepidoptera: Tortricidae) and Its ParasitoidAscogaster quadridentata(Hymenoptera: Braconidae)

Abstract Synthetic female sex pheromone was used to monitor the phenology of male Ascogaster quadridentata Wesmael, an egg-larval parasitoid of codling moth, Cydia pomonella (L.), in conjunction with pheromone trapping of the moth and the banding of trees to determine larval parasitism. Catch of this parasitoid was typically ≈10 times less than the moth catch, and larval parasitism varied from 7 to 12%. The emergence of the parasitoid occurred slightly later than the female moth emergence, by both outdoor emergence cages and pheromone trapping. The seasonal activity of male parasitoids was otherwise synchronous with male codling moth flight. A survey of orchards in four regions of New Zealand showed considerable regional variation in the capture of the parasitoid in pheromone traps. The potential value of the parasitoid may be limited by the nil tolerance of the pest in export fruit, but pheromone trapping of this parasitoid could improve the understanding of biological control in non-export situations, w...

Effect of trap height and spacing in relation to crop height on catches of the millet stemborer, Coniesta ignefusalis Males

Studies were conducted using a water-based trap baited with the synthetic female sex pheromone to gain further understanding on the effect of trap height and spacing in relation to crop height on catches of males of the millet stemborer, Coniesta ignefusalis (Hampson) (Lepidoptera: Pyralidae). Regardless of crop height, catches were greatest at trap heights of 0.10 and 0.50 m when the traps were stacked vertically. When traps were sited singly at 50 m spacing there was no significant difference in catches at the different heights. When trap spacing was varied from 50,15, 5,1 to 0 m, male moth catches in traps increased at lower trap heights, regardless of crop height. Comparison of catches in light traps and pheromone-baited traps showed a significant positive correlation. These findings have implications for both monitoring and development of millet stemborer control systems through mating disruption and mass trapping.

(Z)-9-tetradecenal: a potent inhibitor of pheromone-mediated communication in the oriental tobacco budworm moth, Helicoverpa assulta

The behavioural significance of (Z)-9-tetradecenal to male H. assulta was tested by comparing the number of moths attracted to lures containing a standard synthetic female sex pheromone with lures in which (Z)-9-tetradecenal was also added. The standard pheromone mixture used contained 1000 μg (Z)-9-hexadecenal, 50 μg (Z)-11-hexadecenal, 300 μg (Z)-9-hexadecenyl acetate and 15 μg (Z)-11-hexadecenyl acetate impregnated on rubber septa. Addition of (Z)-9-tetradecenal to the standard pheromone was shown to significantly reduce the caught of male H. assulta when added in amounts greater than 10 μg or 1% of the major pheromone component in both field and net-house experiments. The reduction in catch was found to be dependent on the quantity of (Z)-9-tetradecenal added to the standard pheromone. The implications of these results on conspecific and inter-specific pheromone-mediated communication in H. assulta and related sympatric heliothine species is discussed.

Sex Pheromone Responses of the Oriental Beetle (Coleoptera: Scarabaeidae)

The synthetic female sex pheromone of the oriental beetle, Anomala orientalis Waterhouse, was evaluated in the field and in a sustained-flight tunnel. In a 2-wk period, > 150,000 beetles were captured on three golf course fairways in Connecticut. Contrary to earlier reports that these beetles are most active during the warm, sunny portions of the day, we observed that peak activity occurs around sunset. Ten micrograms of either (Z)-7-tetradecen-2-one or an 89/11 (Z/E) blend on a rubber septum was found to be the minimum concentration with which no significant decrease in catch was observed in the field. There was no discrimination between Z and the blend at 1 μg and higher concentrations, but the E-isomer alone trapped significantly fewer beetles than either Z alone or the blend. These results are consistent with the flight tunnel data. The effects of temperature and light intensity on the mating behavior of A. orientalis also are discussed.

Attraction of pea mothCydia nigricana F. (Lepidoptera: Tortricidae) to female sex pheromone (E,E)-8,10-dodecadien-1-YL acetate, is inhibited by geometric isomersE,Z, Z,E, andZ,Z

Field attraction ofCydia nigricana males to synthetic female sex pheromone (E,E)-8,10-dodecadien-1-yl acetate, formulated on red rubber septa, declined continuously during two weeks. This was due to isomerization of (E,E)-8,10-dodecadien-1-yl acetate: eight days after application of purifiedE,E isomer, the proportion ofE,Z;Z,E; andZ,Z isomers in rubber septa aged in the laboratory was 4%; a 5% addition of any one of these isomers to fresh lures of (E,E)-8,10-dodecadien-1-yl acetate significantly reduced male attraction. Stereospecific syntheses of (E,Z)-, (Z,E)-, and (Z,Z)-8,10-dodecadien-1-yl acetate are described. The pheromone gland ofCydia nigricana contains 0.8 ng/female of (E,E)-8,10-dodecadien-1-yl acetate, accompanied by three monounsaturated acetates, (E)-9-dodecen-1-yl acetate, (Z)-5-tetradecen-1-yl acetate, and (Z)-7-tetradecen-1-yl acetate (0.1 ng/female each). These compounds did not augment male trap catch when added to (E,E)-8,10-dodecadien-1-yl acetate.

Improved two‐component blend of the synthetic female sex pheromone of Cryptophlebia leucotreta, and identification of an attractant for C. peltastica

AbstractA series of field evaluations using the Pherocon‐1C trap examined various doses and blends of the following synthetic pheromone compounds: (E)‐7‐dodecenyl acetate (E7–12:Ac), (E)‐8‐dodecenyl acetate (E8‐12:Ac), (Z)‐8‐dodecenyl acetate (Z8‐12:Ac), decyl acetate (10:Ac), dodecyl acetate (12:Ac), tetradecyl acetate (14:Ac), hexadecyl acetate (16:Ac), and octadecyl acetate (18:Ac). It was concluded that E7–12:Ac is not a true sex pheromone in Cryptophlebia leucotreta (Meyrick) because it only led to significant male catches at doses greater than 1 mg per lure and did not perform as well as mixtures of E8–12:Ac and Z8–12:Ac. The latter mixtures led to significantly higher catches of C. leucotreta when the ratio of E8–12:Ac to Z8–12:Ac was 9:1 rather than 1:1 as in commercial lures. Increases in dosages of this blend from 1 mg to 50 mg per lure did not lead to increases in male moth catches. An additional 10% 12:Ac had no consistent significant effect on numbers of captured males. 10:Ac, 12:Ac, 14:Ac, 16:Ac, and 18:Ac, individually or in various combinations with 9:1 E8–12:Ac and Z8‐12:Ac corresponding to their average proportions in female pheromone glands, did not lead to significant increases in C. leucotreta catches. Blends of E8–12:Ac and Z8–12:Ac at 1 mg per lure also resulted in catches of males of the litchi moth, Cryptophlebia peltastica (Meyrick), when containing 70% or more Z8–12:Ac. Maximum catches of C. peltastica occurred in traps baited with 100% Z8–12:Ac.

Codling Moth (Lepidoptera: Tortricidae) Control by Dissemination of Synthetic Female Sex Pheromone

Permeation of a synthetic pheromone mixture through an isolated Asian pear orchard provided excellent control of the codling moth in the Sacramento Valley of California during a 2-yr period. The synthetic pheromone mixture was applied in 1,050 plastic twist-tie dispensers and at the rate of 100 g codlemone, 50 g dodecanol, and 10 g of tetradecanol per hectare. Female codling moth antennae give electroantennogram responses to these compounds.