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The dotted white geometrid moth, Naxa seriaria Motschulsky (Lepidoptera: Geometridae), is a pest of Oleaceae in Korea, Japan, and China. In this study, we identified (3Z,6Z,9Z,12Z,15Z)-heneicosapentaene (C-21 pentaene) as the only compound in extracts of the pheromone glands of female N. seriaria causing a response from receptors on the antennae of males in analyses by gas chromatography with electroantennographic detection. The synthetic sex pheromone elicited dose-dependent electrophysiological responses from antennae of male N. seriaria. In field tests, more male moths were captured in traps baited with synthetic C-21 pentaene than in unbaited traps, and increasing the loading of C-21 pentaene in the lure increased catches of male moths. Significantly more male N. seriaria moths were caught in delta traps than in bucket traps. Based on these results, C-21 pentaene is proposed to be the major, if not the only, component of the sex pheromone of N. seriaria.

In the study of the chemical communication of adults of the Melolonthidae family, bacteria have been observed in the epithelium of the genital chamber; possibly, bacteria are involved in the production of sex attractants in their hosts. Therefore, it is important to identify the volatile organic compounds from bacteria (VOCsB) released by these microorganisms and study the biological activity stimulated by VOBCs in adults of Melolonthidae. In this study, bacteria were isolated from the genital chamber of Cyclocephala lunulata and Cyclocephala barrerai , from which VOCsB were extracted using static headspace solid-phase microextraction (SHS-SPME) and dynamic headspace Super Q solid-phase extraction (DHS-SPE) and analyzed using gas chromatography-mass spectrometry. The effect of VOCsB on the hosts and conspecifics was evaluated utilizing an olfactometer and electroantennography (EAG). Two species of Enterobacteria were isolated from the genital chamber of each female species, and VOCsB derived from sulfur-containing compounds, alcohols, esters, and fatty acids were identified. An attraction response was observed in olfactometry studies, and antennal responses to VOCsB were confirmed in EAG bioassays. With these results, new perspectives on the relationship between these beetles and their bacteria emerge, in addition to establishing a basis for management programs in the future.

Long-range sex pheromones are generally considered to be a main cue for mate recognition in the order Hymenoptera. Although considerable attention has been given to the identification of semiochemicals in the superfamily Chalcidoidea, which comprises 19 families, no study has identified active components in a field bioassay. We herein report the sensitive and selective pheromone communication system of the Korean apricot wasp, Eurytoma maslovskii (Eurytomidae), whose larvae feed on Prunus mume seeds. Using gas chromatography coupled with electroantennographic detection (GC-EAD) and mass spectrometry (GC-MS), we detected 2,10-dimethyldodecyl propionate and 2,8-dimethyldecyl propionate in thoracic extracts of female E. maslovskii at a ratio of 8:2 as the active pheromone components. Field experiments showed that the attractive effect of the two compounds is highly enantioselective. Racemic 2,10-dimethyldodecyl propionate and 2,8-dimethyldecyl propionate were not attractive to E. maslovskii males. In bioassays with single enantiomers, the (2 S,10 R)-enantiomer was highly attractive to male wasps, and the (2 S,8 S)-enantiomer was also attractive, although to a lesser degree. No synergistic effect between (2 S,10 R)- and (2 S,8 S)-enantiomers was identified, and the (2 S,10 R)-enantiomer alone caught significantly more males than the natural pheromone extracts. The addition of other enantiomers to the (2 S,10 R)-isomer significantly decreased the attraction of conspecific males. In addition, a very low dose of synthetic pheromone attracted conspecific males, showing that both female signaling and male response traits may have evolved to contribute to species-specific sexual communication in this species.

The Asian eulophid wasp Tetrastichus planipennisi is being released in North America as a biocontrol agent for the emerald ash borer (Agrilus planipennis), a very destructive invasive buprestid beetle that is devastating ash trees (Fraxinus spp.). We identified, synthesized, and tested a female-produced sex pheromone for the wasp. The key component eliciting behavioral responses from male wasps in flight tunnel bioassays was identified as (6S,10S)-(2E,4E,8E)-4,6,8,10-tetramethyltrideca-2,4,8-triene. Female specificity was demonstrated by gas chromatographic (GC) comparison of male and female volatile emissions and whole body extracts. The identification was aided by coupled gas chromatography/mass spectrometry analysis, microchemical reactions, NMR, GC analyses with a chiral stationary phase column, and matching GC retention times and mass spectra with those of synthetic standards. The tetramethyl-triene hydrocarbon was synthesized as a mixture of two enantiomeric pairs of diastereomers, and as the pure insect-produced stereoisomer. In flight-tunnel bioassays, males responded to both the natural pheromone and the chiral synthetic material by upwind flight and landing on the source. In contrast, the mixture of four stereoisomers was not attractive, indicating that one or more of the "unnatural" stereoisomers antagonized attraction. Field trials, using yellow pan traps baited with natural pheromone, captured significantly more male wasps than control traps over a four week trial. The identified pheromone could increase the efficiency and specificity of the current detection methods for Tetrastichus planipennisi and aid in the determination of parasitoid establishment at release sites.

The bumblebee wax moth, Aphomia sociella, is a parasite of bumblebees. In this species, males produce sexual pheromone to attract females, while females produce an aphrodisiac pheromone that initiates male courtship. Both pheromones contain 6,10,14-trimethylpentadecan-2-one (TMPD-one) and the corresponding alcohol, 6,10,14-trimethylpentadecan-2-ol (TMPD-ol) in sex specific quantities. Male sex pheromone consists of 7 components with TMPD-one as a minor one and traces of TMPD-ol. In female aphrodisiac pheromone, TMPD-ol is the major component, while TMPD-one is present in traces. Here we report on the absolute configuration of TMPD-one in male sex pheromone and TMPD-ol in female aphrodisiac pheromone of A. sociella. The configuration was determined from GC/MS of prepared (S)-acetoxypropionyl esters of TMPD-ol. TMPD-one was first reduced to the alcohol that was then derivatized with (S)-acetoxypropionyl chloride. The GC/MS data of obtained diastereoisomers were compared with synthetic standards. The absolute configuration of TMPD-one in the male pheromone was (6R,10R). The configuration of TMPD-ol in the female pheromone was (2R,6R,10R). Electrophysiological experiments showed that TMPD-one and TMPD-ol are perceived by both sexes. The synthetic standards of naturally produced stereoisomers elicited higher responses than mixtures of all stereoisomers.

The flower bug Orius sauteri is a generalist predator that occurs throughout Japan, and is a promising indigenous natural enemy for micro-pests such as thrips, aphids, and spider mites. We aimed to manipulate the attraction, dispersal, and settlement behavior of Orius bugs using natural chemical substances emitted by the bugs themselves. To identify potential candidates, we screened components in the whole-body extract of O. sauteri based on antennal response and then determined their chemical structure. A gas chromatograph electroantennographic detector (GC/EAD) indicated that the antennae of males responded to two components in the extract of females. GC/mass spectrometry (MS) showed that these two components were octenal and octadienal. Derivatization or GC-FT-IR analysis identified these components as (E)-2-octenal and (E)-2,7-octadienal. To assess the effect of these components on O. sauteri behavior, we conducted two assays. A field bioassay demonstrated that a blend of the two components functioned as a sex pheromone, and a dispersal assay showed that (E)-2-octenal generated a dose-dependent dispersal response. Our study will provide baseline information for enhancing the retention of O. sauteri on important commercial crops to prey on pest species.

The sloe bug, Dolycoris baccarum L. (Hemiptera: Heteroptera: Pentatomidae), is a Palearctic species and an important polyphagous pest. Previous studies have reported that male D. baccarum produce an aggregation pheromone, to which conspecific adults of both sexes respond. We used solid-phase microextraction (SPME) to collect volatiles released by sexually mature virgin males and females, and identified potential components of the male-produced aggregation pheromone. Analysis of the SPME samples by gas chromatography-mass spectrometry (GC-MS) revealed three male-specific components, α-bisabolol, trans-α-bergamotene, and β-bisabolene, at a ratio of 100:10:3. A field trapping experiment showed that (±)-α-bisabolol alone attracted D. baccarum adults, and it was synergized by trans-α-bergamotene, but not (S)-β-bisabolene. However, neither trans-α-bergamotene nor (S)-β-bisabolene was attractive individually. A binary blend of (±)-α-bisabolol and trans-α-bergamotene in a 10:1 ratio was less attractive than caged live males, suggesting that further study is necessary to determine the absolute configuration or steroisomeric composition of the natural pheromone components. This is the first report of α-bisabolol and trans-α-bergamotene as semiochemicals among Pentatomidae, and the first to identify α-bisabolol from insects.

Gregarious parasitoids usually clump their cocoons together and the adults emerge in a synchronized fashion. This makes it easy for them to find mating partners and most copulations indeed take place at the natal patch. Yet, males should leave such sites when females are no longer receptive. As yet, this decision-making process and the possible involvement of pheromones were poorly understood. Here we report on a remarkable use of attractive and repellent pheromones of the well-studied gregarious parasitoid species Cotesia glomerata (L.) (Hymenoptera: Braconidae). Virgin C. glomerata females were found to release an attractive as well as a repellent compound, which in combination arrest males on the natal patch, but after mating the females stop the production of the attractant and the males are repelled. The repellent compound was identified as heptanal, which was also released by males, probably reducing male-male competition on the natal patch. We also confirmed that the sex ratio of the emerging wasps can vary considerably among patches, depending on the relative quality of hosts and the number of females that parasitize a host. The newly revealed use of attractive and repellent pheromone compounds by C. glomerata possibly helps maximize mating success under these variable conditions.

The elytra of females of the white-spotted longhorn beetle, Anoplophora malasiaca (Coleoptera: Cerambycidae), are coated with a contact sex pheromone, which was previously shown to be composed of at least three chemical groups. Individually, the chemical groups had little pheromonal activity, but a blend of all three exhibited activity equal to that of the crude female extract. Two groups are female-specific aliphatic hydrocarbons and ketones, which were previously synthesized and confirmed to elicit mating behavior. The third group consists of three lactones, gomadalactones A, B, and C, whose chemical structures were previously identified. These have now been synthesized, and the contact sex pheromone activities of synthetic gomadalactones A, B, and C, and the diastereomer of gomadalactone C, were tested in bioassays in this study. When tested in combination with synthetic hydrocarbons and ketones at the same doses as found in female elytra extract, the individual gomadalactones and a blend showed potent pheromonal activity equivalent to that of the crude extract of the elytra of female beetles. This completes the identification of the essential components of the contact sex pheromone of A. malasiaca. Redundancy of components in the hydrocarbon and ketone groups required to elicit mating behavior was observed previously, and this was also true for the gomadalactones.

The spherical mealybug Nipaecoccus viridis is a pest of several major crops including soybeans, grapes and citrus varieties. Sessile virgin females of N. viridis release two volatiles, 2,2,3,4-tetramethyl-3-cyclopentene-1-methanol (γ-necrodol) and γ-necrodyl isobutyrate, on a circadian rhythm with peak at 17:00 (11 hr of photophase) as determined by automated, sequential solid phase micro extraction with gas chromatography-mass spectrometry analysis. The females increased the released amounts with age by about seven-fold from 5 to 6 d to 10-12 d of age. trans-3,4,5,5-Tetramethyl-2-cyclopentene-1-methanol (trans-α-necrodol) and trans-α-necrodyl acetate, found in essential oil of Spanish lavender, Lavandula luisieri, were rearranged to γ-necrodol and then used to synthesize γ-necrodyl isobutyrate. GC-MS and NMR data confirmed the identifications. In a petri dish bioassay, N. viridis males were significantly attracted to filter paper discs impregnated with γ-necrodyl isobutyrate but not to γ-necrodol or controls. A mixture of the two compounds was not more attractive than γ-necrodyl isobutyrate alone. Similar results were obtained with trapping flying adults, suggesting that the sex pheromone consists only of γ-necrodyl isobutyrate. This compound has not been reported previously in insects. Conversion of α-necrodol in lavender essential oil simplifies the synthesis of the sex pheromone and should allow its use in management of this cosmopolitan invasive pest.

Plagionotus arcuatus ssp. arcuatus (L.) is a common saproxylic cerambycid beetle in most parts of Europe, and is designated as an occasional pest of oak wood that is stored outside during the summer months. In an effort to identify attractants that can be used for monitoring this species, we collected headspace samples from adult beetles and conducted field bioassays with the resulting compounds as potential aggregation-sex pheromone components for this species. Three compounds, (R)-3-hydroxyhexan-2-one, (R)-3-hydroxyoctan-2-one, and (R)-3-hydroxydecan-2-one, were consistently present in relatively large quantities in headspace extracts from male P. arcuatus populations in both Hungary and Sweden, regardless of the adsorbent media (activated charcoal or Porapak™ Q) used to sample beetle odors, or the type of solvent (hexane, diethyl ether, or dichloromethane) used to elute trapped volatiles from the collectors. None of the hydroxyketone and related compounds were detected in corresponding extracts from females. In field bioassays in both countries, the blend of the C 6 and C 10 compounds, and the ternary blend both attracted significantly more beetles than the control, while other combinations or single compounds were not significantly attractive. Males and females showed similar patterns of responses to treatments. Our results demonstrate that (R)-3-hydroxyhexan-2-one and (R)-3-hydroxydecan-2-one constitute a male-produced aggregation-sex pheromone of P. arcuatus, whereas the role of (R)-3-hydroxyoctan-2-one remains unclear. Lures with the pheromone could be developed for monitoring of P. arcuatus populations as an indicator of fresh oak wood resources.

Three novel bile acid derivatives, petromylidenes A⁻C ( 1 ⁻ 3 ), featuring uncommon alkylidene adductive scaffolds, were isolated from water conditioned with sexually mature male sea lampreys ( Petromyzon marinus ). Their structures were elucidated by mass spectrometry and NMR spectroscopy, and by comparison to spectral data of related structures. The identification of compounds 1 ⁻ 3 , further illustrates the structural diversity of the 5α bile salt family. Compounds 1 ⁻ 3 exhibited notable biological properties as well, including high olfactory potencies in adult sea lampreys and strong behavioral attraction of ovulated female sea lampreys. Electro-olfactogram recordings indicated that the limit of detection for 1 was 10 -9 M, 2 was 10 -11 M, and 3 was less than 10 -13 M. These results suggested 1 ⁻ 3 were likely male pheromones, which guide reproductive behaviors in the sea lamprey.

Termite colonies are almost always founded by a pair of winged dispersers, in spite of the high costs and low success rates inherent in independent colony foundation. The dispersal flights of imagoes from natal colonies are followed by mate search, mediated by sex-pairing pheromones. Here, we studied the chemistry of sex-pairing pheromones and the related aspects of mate search in winged imagoes of two facultatively parthenogenetic species, Embiratermes neotenicus and Silvestritermes minutus, and an additional species from the same subfamily, Silvestritermes heyeri. All three species are widespread in the Neotropics, including the rainforests of French Guiana. After the dispersal flight and spontaneous loss of wings, females expose their hypertrophied tergal glands situated under abdominal tergites VIII - X. The females are attractive to males and, upon direct contact, the two sexes form characteristic tandems. Chemical analyses indicated that the females secrete species-specific combinations of unbranched, unsaturated C 12 primary alcohols from the tergal glands, (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol (approx. 200 pg per female) and (3Z)-dodec-3-enol (185 pg) in E. neotenicus, (3Z,6Z)-dodeca-3,6-dien-1-ol (3500 pg) in S. heyeri, and (3Z,6Z)-dodeca-3,6-dien-1-ol (300 pg) and (3Z)-dodec-3-enol (50 pg) in S. minutus. (3Z,6Z,8E)-Dodeca-3,6,8-trien-1-ol and (3Z,6Z)-dodeca-3,6-dien-1-ol act as major pheromone components in the respective species and mimic the function of female tergal gland extracts in electrophysiological and behavioral experiments. Biologically relevant amounts of the third compound, (3Z)-dodec-3-enol, elicited non-significant reactions in males of E. neotenicus and S. minutus, and slight synergistic effects in males of S. minutus when tested in combination with the major component.

The Mediterranean fruit fly (medfly) Ceratitis capitata is a polyphagous pest of fruits and crops with a worldwide distribution. Its ability to use different larval hosts may have multiple effects, including impacts on adult reproductive biology. The male sex pheromone, which plays a key role in attracting both other males to lekking arenas and females for mating, is a mixture of chemical compounds including esters, acids, alkanes and terpenes known to differ between laboratory strains and wild-type populations. The relationship between larval diet and adult pheromone composition remains unexplored. Here, we investigated the effect of larval diet, including laboratory media and fresh fruits, on the composition of the male pheromone mixture. Using Headspace Solid Phase Microextraction we collected the pheromone emitted by males reared as larvae on different substrates and found both qualitative and quantitative differences. A number of alkanes appeared to be typical of the pheromone of males reared on wheat bran-based larval medium, and these may be cuticular hydrocarbons involved in chemical communication. We also detected differences in pheromone composition related to adult male age, suggesting that variations in hormonal levels and/or adult diet could also play a role in determining the chemical profile emitted. Our findings highlight the plasticity of dietary responses of C. capitata, which may be important in determining the interactions of this pest with the environment and with conspecifics. These results also have applied relevance to increase the mating competitiveness of mass-reared C. capitata used in Sterile Insect Technique programs.

Sex pheromones play a central role in intersexual communication for reproduction in many organisms. Particularly in insects, reproductive isolation that leads to speciation is often achieved by shifts of pheromone chemistries. However, the divergence and evolution of pheromones remain largely unknown. This study reveals a unique evolutionary consequence for terpenoid pheromones in coccoid insects. Coccoids, such as mealybugs, show clear sexual dimorphism: males are dwarf and short-lived, whereas females are wingless and almost immobile. Female pheromones are therefore indispensable for males to navigate for sexual reproduction, but some females can reproduce asexually. Interestingly, a derived asexual lineage that reproduces by parthenogenesis coexists with its ancestral lineage that reproduces sexually in a population of the pineapple mealybug, Dysmicoccus brevipes Here, we isolated, characterized and synthesized a novel monoterpene, (-)-( anti -1,2-dimethyl-3-methylenecyclopentyl)acetaldehyde, as a pheromone of the sexual females of D brevipes This monoterpene aldehyde, with an irregular linkage of isoprene units, is notable, because all mealybug pheromones previously reported are carboxylic esters of terpenols. This compound was, however, never produced by the asexual females. As a consequence of acquiring parthenogenetic reproduction, the asexual females appear to have abandoned the production of the sex pheromone, which had been essential to attracting males in their ancestors., (© 2017 The Author(s).)

The male red-bellied newt (Cynops pyrrhogaster) approaches the female's cloaca prior to performing any courtship behaviour, as if he is using some released substance to gauge whether she is sexually receptive. Therefore, we investigated whether such a female sexual attractiveness pheromone exists. We found that a tripeptide with amino acid sequence Ala-Glu-Phe is secreted by the ciliary cells in the epithelium of the proximal portion of the oviduct of sexually developed newts and confirmed that this is the major active substance in water in which sexually developed female newts have been kept. This substance only attracted sexually developed male newts and acted by stimulating the vomeronasal epithelial cells. This is the first female sexual attractiveness peptide pheromone to be identified in a vertebrate.

The four-spotted coconut weevil, Diocalandra frumenti Fabricius (Coleoptera: Dryophthoridae), is a small weevil found attacking economically important palm species, such as coconut, date, oil, and Canary palms. Given the scarcity of detection and management tools for this pest, the availability of a pheromone to be included in trapping protocols would be a crucial advantage. Previous laboratory experiments showed evidence for aggregation behavior; thus, our main goal was to identify the aggregation pheromone in this species. The volatile profile of D. frumenti individuals was studied by aeration and collection of effluvia in Porapak-Q and also by solid phase microextraction (SPME) techniques. Moreover, solvent extraction of previously frozen crushed individuals was also performed. All resulting extracts and SPME fibers were analyzed by gas chromatography coupled to mass spectrometry (GC-MS). The comparison of male and female samples provided the candidate compound, 5-ethyl-2,4-dimethyl-6,8-dioxabicyclo[3.2.1]octane (multistriatin), whose biological activity was evaluated in olfactometer and field assays.

Giant silk moths (Lepidoptera: Saturniidae) typically are not well represented as larvae or adults in community level inventories of Lepidoptera, and as a result, little is known about their population dynamics. Furthermore, in recent years, many species of silk moths appear to have experienced population declines. Volatile sex pheromones are powerful sampling tools that can be used in operational conservation and monitoring programs for insects. Here, we describe the identification of the sex attractant pheromone of a giant silk moth, the luna moth Actias luna. Coupled gas chromatography-electroantennographic detection and gas chromatography-mass spectrometric analyses of extracts from pheromone glands of female luna moths supported the identification of (6E,11Z)-6,11-octadecadienal (E6,Z11-18:Ald), (6E)-6-octadecenal (E6-18:Ald), and (11Z)-11-octadecenal (Z11-18:Ald) as the compounds in extracts that elicited responses from antennae of male moths. These identifications were confirmed by synthesis, followed by testing of blends of the synthetic compounds in field trials in Ontario, Canada, and Kentucky, USA. Male moths were attracted to synthetic E6,Z11-18:Ald as a single component. Attraction appeared to be enhanced by addition of E6-18:Ald but not Z11-18:Ald, suggesting that the luna moth pheromone consists of a blend of E6,Z11-18:Ald and E6-18:Ald.

Bactrocera oleae Gmelin, also known as olive fruit fly, is the main olive tree pest. It produces a severe effect not only on the productivity but also on the quality of the olive-related products. In fact, the oil obtained from infected olives has a lower antioxidant power. In addition, an increase of the oil acidity, peroxide index and UV-absorbance can also be observed. 1,7-dioxaspiro-[5,5]-undecane (DSU), is the main component of the sexual pheromone of this pest and may be used as marker of the pest incidence. In this context, the development of new methods able to detect the pheromones in several samples, including agri-food or environmental ones, is interesting. In this work, we synthesized a molecularly imprinted polymer (MIPS) layer over magnetic nanoparticles (Fe3O4@SiO2@MIP) for the selective recognition of DSU. They were prepared using DSU as template and 3-aminopropyltriethoxysilane (APTES) to associate the target analyte on the surface of the magnetic substrate and the later polymerization of ethylene glycol dimethacrylate (EGDMA) in presence of 2,2-azobisisobutyonnitrile (AIBN). The resulting Fe3O4@SiO2@MIP composite was characterized by different techniques. The maximum adsorption capacity of DSU on Fe3O4@SiO2@MIP in hexane was 32mg/g (5.3 times than that obtained for the non-imprinted composite). In addition, Fe3O4@SiO2@MIP showed a short equilibrium time (45min) and potential reusability. The combination of dispersive magnetic microsolid phase extraction and gas chromatography with mass spectrometric detection allows the determination of DSU in real samples at concentrations as low as 10μg/L with precision better than 7.5% (expressed as relative standard deviation). The relative recoveries are in the range between 95 and 99%, which indicates the potential of the methodology. Finally, it has been applied to real olive oil samples being the presence of the pest detected is some of them., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Anoplophora malasiaca (Coleoptera: Cerambycidae) is a serious pest that destroys various landscape and crop trees in Japan. We evaluated the precopulatory responses of three different A. malasiaca populations collected from mandarin orange, willow and blueberry trees. Most of the males accepted mates from within the same host plant population as well as females from the willow and blueberry populations. However, significant number of males from the blueberry and willow populations rejected females from the mandarin orange population immediately after touching them with their antennae. Because all three of the female populations produced contact sex pheromones on their elytra, the females of the mandarin orange population were predicted to possess extra chemicals that repelled the males of the other two populations. β-Elemene was identified as a key component that was only found in mandarin orange-fed females and induced a rejection response in willow-fed males. Our results represent the first example of a female-acquired repellent against conspecific males of different host plant populations, indicating that the host plant greatly affects the female's sexual attractiveness.

Research since 2004 has shown that the use of volatile attractants and pheromones is widespread in the large beetle family Cerambycidae, with pheromones now identified from more than 100 species, and likely pheromones for many more. The pheromones identified to date from species in the subfamilies Cerambycinae, Spondylidinae, and Lamiinae are all male-produced aggregation-sex pheromones that attract both sexes, whereas all known examples for species in the subfamilies Prioninae and Lepturinae are female-produced sex pheromones that attract only males. Here, we summarize the chemistry of the known pheromones, and the optimal methods for their collection, analysis, and synthesis. Attraction of cerambycids to host plant volatiles, interactions between their pheromones and host plant volatiles, and the implications of pheromone chemistry for invasion biology are discussed. We also describe optimized traps, lures, and operational parameters for practical applications of the pheromones in detection, sampling, and management of cerambycids.

Orius minutus (L.) (Heteroptera: Anthocoridae) is a natural enemy of agricultural pests such as thrips, aphids, and various newly hatched insect juveniles. In this study, we conducted 1) behavioral assays for evidence of contact sex pheromone activity in trails of O. minutus, and 2) chemical analysis to identify the essential chemical components of the trails. Males showed arrestment to trails of mature virgin females but not to trails from either conspecific nymphs or immature females. Females also showed arrestment to trails from conspecific males, although the response was weaker than that exhibited by males. The activity of female trails lasted for at least 46 h after deposition. Males showed a response irrespective of mating experience. Following confirmation that a contact sex pheromone was present in the trails of female O. minutus, we used a bioassay-driven approach to isolate the active chemicals. After fractionation on silica gel, the n-hexane fraction was found to be biologically active to males. A major compound in the active fraction was (Z)-9-nonacosene; this compound was found only in trail extracts of mature virgin females. Synthetic (Z)-9-nonacosene arrested O. minutus males, indicating that it is the major active component of the contact sex pheromone in the trails of female O. minutus.

The click beetle Betarmon bisbimaculatus (Fabricius, 1803) (Coleoptera: Elateridae) has a scattered distribution throughout a large area in Europe and the near East. Due to its scarcity, little is known about the ecology, biology, and development of this peculiar species. Here, we studied the composition of the female-released sex pheromone of B. bisbimaculatus. Neryl hexanoate, neryl octanoate, and neryl decanoate, in a ratio of approximately 3:1:6, were the only volatile compounds present in the extracts of pheromone glands. A synthetic mixture of all three compounds in the natural ratio was highly attractive to males in field traps. When the compounds were tested individually, only traps baited with neryl hexanoate were attractive, but they caught only a sixth of the males compared to the mixture. Based on the similarity of their sex pheromones, we propose that the tribe Pomachiliini with B. bisbimaculatus is closely related to the tribe Agriotini. This study shows the potential of sex pheromone studies for monitoring of rare and threatened insects as well as for elucidating phylogenetic relationships.

Ancistrotermes dimorphus is a common Macrotermitinae representative, facultative inquiline by its life-style, occurring in South-East China. Sex pheromone is used for couple formation and maintenance, and it is produced by and released from the female sternal gland and is highly attractive to males. Based on our combined behavioral, chemical and electrophysiological analyses, we identified (3Z,6Z)-dodeca-3,6-dien-1-ol as the female sex pheromone of A. dimorphus as it evoked the tandem behavior at short distance, and the active quantities ranged from 0.01ng to 10ng. Interestingly, GC-MS analyses of SPME extracts showed another compound specific to the female sternal gland, (3Z)-dodec-3-en-1-ol, which showed a clear GC-EAD response. However, this compound has no behavioral function in natural concentrations (0.1ng), while higher amounts (1ng) inhibit the attraction achieved by (3Z,6Z)-dodeca-3,6-dien-1-ol. The function of (3Z)-dodec-3-en-1-ol is not fully understood, but might be linked to recognition from sympatric species using the same major compound, enhancing the long-distance attraction, or informing about presence of other colonies using the compound as a trail-following pheromone. The sternal gland secretion of Ancistrotermes females contains additional candidate compounds, namely (3E,6Z)-dodeca-3,6-dien-1-ol and (6Z)-dodec-6-en-1-ol, which are not perceived by males' antennae in biologically relevant amounts., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The sex pheromone of the hibiscus flower borer Rehimena surusalis (Walker) (Lepidoptera: Crambidae) was analyzed by gas chromatography with electroantennographic detection (GC-EAD) and GC-mass spectrometry (GC/MS). Three EAD-active components were found in crude pheromone gland extracts of calling females. GC/MS and GC analyses using synthetic chemicals and derivatization of the extracts identified three components as (10E,12Z)-hexadeca-10,12-dienal (E10,Z12-16:Ald,), (10E,12E)-hexadeca-10,12-dienyl acetate (E10,Z12-16:OAc), and (3Z,6Z,9Z)-tricosa-3,6,9-triene (Z3,Z6,Z9-23:HC). In field tests, male moths were strongly attracted to a ternary blend of E10,Z12-16:Ald, E10,Z12-16:OAc, and Z3,Z6,Z9-23:HC at a ratio of 1:5:14, but single and binary blends showed only weak or no attraction.

Cuticular hydrocarbons play important roles in contact chemical communication in insects. Many of these compounds are methyl-branched hydrocarbons with one or more chiral centers, which can exist in two or more stereoisomeric forms. Although the importance of chirality for the volatile semiochemicals that insects use for long-range communication is well established, almost nothing is known about the role of chirality in insect contact chemoreception. Here, we used reverse phase high performance liquid chromatography (RP-HPLC) and digital polarimetry to isolate and determine the absolute configuration of a component of the female-produced contact sex pheromone of the cerambycid beetle, Neoclytus acuminatus acuminatus (F.). The pheromone consists of 7-methylpentacosane (7-MeC25), 7-methylheptacosane (7-MeC27), and 9-methylheptacosane (9-MeC27). The absolute configuration of the most abundant pheromone component, 7-MeC25, was found to be (R). We then utilized enantiomerically pure synthetic pheromone components to test the hypothesis that males would respond more strongly to (R)- than to (S)-enantiomers of the three pheromone components. We also tested blends of (R)-7-MeC27, the most bioactive component, with the (S)-enantiomers of the minor components and vice versa to determine if unnatural stereoisomers might decrease behavioral responses. Males responded most strongly to solvent-washed females treated with the blend of (R)-pheromone components, and to a lesser extent to (R)-7-MeC27 alone. A blend of (R)-7-MeC27 with the (S)-minor components elicited an intermediate response. Together, these findings suggest that the insects can discriminate the absolute configuration of the major and minor pheromone components, and that the configuration of all three components is likely to be (R).

The type of solvent and the volume used to load pheromone components onto rubber septa had significant effects on pheromone release ratios, the variability of those release ratios, and the recoverability of the volatile components during subsequent extraction with hexane. Volatile release ratios of synthetic Oriental fruit moth (OFM) pheromone and additional volatile compounds were determined using a gas chromatograph column as a volatile trap for rapid (≤1 hr) analysis from individual rubber septa. Volatile compound solutions were prepared in hexane, pentane, CH2Cl2, and methyl tert-butyl ether, and a 10, 33, or 100 μl aliquot of each solution was applied to rubber septa. Septa loaded with 100 μl of CH2Cl2 emitted significantly (P < 0.05) higher alcohol: acetate (OH:Ac) ratios than septa loaded with the other solvents, which were all similar. Release ratios of the alcohol and acetate components of the OFM pheromone components were assessed over a 3 week period using septa loaded with each solvent. Regardless of loading solvent, the OFM OH:Ac ratios declined logarithmically over 3 weeks; however, the decay slope from septa loaded with CH2Cl2 solutions was different from those of the other three solvents, which were nearly all the same. A high variability in OH:Ac release ratios was measured overall, regardless of the solvent used or the volume it was applied in. Four compounds of near-equal mass: 1-dodecanol, 1-dodecanal, methyl decanoate, and tridecane emitted different release ratios dependent on the solvent, hexane or CH2Cl2, with which a septum was loaded. The more polar and the greater the mass of the test compound, the slower it was emitted from a septum regardless of solvent. These combined results plus comparisons to earlier reports, suggest that researchers should empirically assess the release ratios from septa to be used in bioassays rather than just reporting the type of septum, ratios of compounds applied and solvent used to prepare them.

The baldcypress leafroller, Archips goyerana Kruse (Lepidoptera: Tortricidae), is a specialist on Taxodium distichum (L.) Richard and has caused serious defoliation in swamps of southeastern Louisiana, accelerating decline of baldcypress forests concurrently suffering from nutrient depletion, prolonged flooding, and saltwater intrusion. We investigated the composition of the sex pheromone of this species. Coupled gas chromatography-electroantennographic detection (GC-EAD) analyses indicated that male antennae were sensitive to four compounds [(Z)-11-tetradecenyl acetate (Z11-14:OAc), (E)-11-tetradecenyl acetate (E11-14:OAc), (Z)-9-tetradecenyl acetate (Z9-14:OAc), and (Z)-11-tetradecen-1-ol (Z11-14:OH)] present in female abdominal tip extracts in an approximately 100:1.5:0.6:10 ratio. In trapping trials performed in a cypress-tupelo swamp in southeastern Louisiana, moths were attracted to blends of these four components presented in approximately the female-produced ratios. Elimination of Z11-14:OH had no impact on moth response, whereas elimination of any of the three acetates strongly reduced or eliminated attraction. A blend in which the E11:Z11 ratio of 14:OAc was 5:100 was much less attractive than the same blend with the female produced ratio of 1.5:100. A. goyerana is closely related to the sympatric species Archips argyrospilus (Walker) with which it was previously synonymous. Our data revealed differences between the pheromone composition of A. goyerana and that reported for A. argyrospilus, which could account for the apparent absence of cross-attraction between these species. We conclude that a lure containing a 100:1.5:0.6 ratio of Z11-14:OAc, E11-14:OAc, and Z9-14:OAc has the potential to be used in traps to detect and measure A. goyerana populations and thereby monitor an important biotic factor contributing to the loss of coastal baldcypress forests., (Published by Oxford University Press on behalf of Entomological Society of America 2015. This work is written by US Government employees and is in the public domain in the US.)

The essential oil of the aerial parts of edible Lathyrus ochrus L. was investigated by simultaneous GC, GC/MS analyses under the same conditions. Trace amount of oil (0.01> mL) obtained by hydro distillation of 200 g fresh plants was trapped in 1 mL n-hexane. Twenty components were detected representing 91.55 ± 0.56 % of the oil. The main components were phytol 49.39 ± 0.44 %, hexadecanoic acid 20.64 ± 0.89 % and pentacosane 4.20 ± 0.09 %. Essential oil solution (1% oil: n-hexane) afforded similar DPPH scavenging activity (9.28 ± 1.30 %) when compared with positive controls α-tocopherol (9.74 ± 0.21 %) and BHT (7.79 ± 0.26 %) at the same concentrations. Antioxidant activity of the oil was determined using a new HPTLC-PRAP assay. The oil afforded two fold higher reducing activity of phosphomolybdenum complex (594.85 ± 5.14 AU) when compared with positive controls α- tocopherol (271.10 ± 2.86 AU) and BHT (210.53 ± 1.81 AU) at the same concentration.

The objective of this study was to identify the aggregation pheromone of the melon thrips Thrips palmi, a major pest of vegetable and ornamental plants around the world. The species causes damage both through feeding activities and as a vector of tospoviruses, and is a threat to world trade and European horticulture. Improved methods of detecting and controlling this species are needed and the identification of an aggregation pheromone will contribute to this requirement. Bioassays with a Y-tube olfactometer showed that virgin female T. palmi were attracted to the odour of live males, but not to that of live females, and that mixed-age adults of both sexes were attracted to the odour of live males, indicating the presence of a male-produced aggregation pheromone. Examination of the headspace volatiles of adult male T. palmi revealed only one compound that was not found in adult females. It was identified by comparison of its mass spectrum and chromatographic details with those of similar compounds. This compound had a structure like that of the previously identified male-produced aggregation pheromone of the western flower thrips Frankliniella occidentalis. The compound was synthesised and tested in eggplant crops infested with T. palmi in Japan. Significantly greater numbers of both males and females were attracted to traps baited with the putative aggregation pheromone compared to unbaited traps. The aggregation pheromone of T. palmi is thus identified as (R)-lavandulyl 3-methyl-3-butenoate by spectroscopic, chromatographic and behavioural analysis.

The greater wax moth, Galleria mellonella (L.), is a serious and widespread pest of the honeybee, Apis mellifera L. In contrast to most moths, for which long-range mate finding is mediated by female-produced sex pheromones, G. mellonella males attract conspecific females over long distances by emitting large amounts of a characteristic scent in combination with bursts of ultrasonic calls. The male scent for this species was previously identified as a blend of nonanal and undecanal. When these compounds were bioassayed, characteristic short-range sexual behavior, including wing fanning, was triggered in conspecific females, but the aldehyde blend failed to elicit attraction over longer distances. We identified, via analysis and synthesis, a third male-specific compound, 5,11-dimethylpentacosane. We show that it acts as a behavioral synergist to the aldehydes. In wind tunnel experiments, very few female moths responded to the aldehyde blend or to 5,11-dimethylpentacosane tested separately, but consistently showed orientation and source contact when a combination of all three compounds was applied. The level of attraction to the three-component mixture was still lower than that to male extract, indicating that the composition of compounds in the synthetic blend is suboptimal, or that additional pheromone components of G. mellonella are yet to be identified. The identification of 5,11-dimethylpentacosane is an important step for the development of an efficient long-range attractant that will be integrated with other environmentally safe strategies to reduce damage to beehives caused by wax moths.

Pheromone signals regulate conspecific behavior and physiology [1]. Releaser pheromones induce specific behavior by exerting acute effects on the neuronal response, whereas primer pheromones induce physiological changes with long-lasting effects by changing the neuroendocrine status of the recipients. In mammals, although several types of releaser pheromones have been identified [2-5], the identities of primer pheromones, as well as their mechanisms of action, remain largely unknown [6]. In sheep and goats, the seasonally anestrous endocrine state of females is changed to the estrous state upon exposure to male scents [7, 8]. This so-called "male effect" is one of the most conspicuous primer pheromone effects in mammals [9, 10]. In this study, we have identified an olfactory signal molecule that activates the central regulator of reproduction, the gonadotropin-releasing hormone (GnRH) pulse generator, in goats. Using gas chromatography-mass spectrometry to analyze male goat headspace volatiles, we identified several ethyl-branched aldehydes and ketones. We electrophysiologically demonstrated that one of these compounds, 4-ethyloctanal, activates the GnRH pulse generator in female goats. This is the first report of an olfactory molecule that has been shown to activate the central reproductive axis, and this discovery will provide a new direction for primer pheromone research., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The greater date moth (GDM), Aphomia sabella Hampson (Lepidoptera: Pyralidae: Galleriinae), is a serious pest of date palms, Phoenix dactylifera. The release of volatiles from both males and females was investigated using sequential SPME/GC/MS analysis. Males release a complex mixture of compounds in a circadian rhythm during the night between 03:00 and 05:00 hr. Six compounds were identified: benzaldehyde, sulcatol (6-methyl-5-hepten-2-ol), geranyl acetone [(E)-6,10-dimethyl-5,9-undecadien-2-one], phenylacetaldehyde, 2-phenylpropenal, and (R)-fuscumol [(R)-(E)-6, 10-dimethyl-5, 9-undecadien-2-ol]. Benzaldehyde, sulcatol, and geranyl acetone were found only in trace amounts. These compounds were in glands located in the forewing of males only. Small amounts of acetoin and 2,3-butanediol were found sporadically in the SPME/GC/MS analyses of volatiles from females, and these compounds probably originate from microorganisms. This is the first finding of a circadian release of male-specific compounds in moths. GC/EAD analyses with synthetic standards of compounds released by males showed that the female antenna is stimulated by all six compounds, while the male antenna responded only to phenylacetaldehyde. A possible pheromonal role for the male-specific compounds is suggested by the circadian rhythm of their release and the EAD response of females to them. However, trapping tests with the main male-specific compounds in screen cages in the laboratory or in the field did not reveal any significant behavioral responses from females or males. Copulation in the laboratory was observed only in the presence of date palm tissue, thus suggesting that sexual communication and mating of GDM moths probably occurs in the crown of date palms.

Anoplophora glabripennis (Motsch.) is a polyphagous member of the Cerambycidae, and is considered, worldwide, to be one of the most serious quarantine pests of deciduous trees. We isolated four chemicals from the trail of A. glabripennis virgin and mated females that were not present in trails of mature males. These compounds were identified as 2-methyldocosane and (Z)-9-tricosene (major components), as well as (Z)-9-pentacosene and (Z)-7-pentacosene (minor components); every trail wash sample contained all four chemical components, although the amounts and ratios changed with age of the female. Males responded to the full pheromone blend, regardless of mating status, but virgin females chose the control over the pheromone, suggesting that they may use it as a spacing pheromone to avoid intraspecific competition and maximize resources. Virgin, but not mated, males also chose the major pheromone components in the absence of the minor components, over the control. Taken together, these results indicate that all four chemicals are components of the trail pheromone. The timing of production of the ratios of the pheromone blend components that produced positive responses from males coincided with the timing of sexual maturation of the female.

The promethea moth Callosamia promethea is one of three species of silkmoths from the genus Callosamia that occur in North America. Cross attraction of males to heterospecific calling females has been observed in the field, and hybrid progeny have been produced by pairing heterospecifics in captivity. These observations suggest that all three species share or have considerable overlap in the sex attractant pheromones produced by females, so that other prezygotic isolating mechanisms, such as diel differences in reproductive activity, limit hybridization in the field. Coupled gas chromatography-electroantennogram detection and gas chromatography- mass-spectrometry analyses of extracts of volatiles collected from female promethea moths supported the identification of (4E,6E,11Z,13Z)-hexadeca-4,6,11,13-tetraenal [(4E,6E,11Z,13Z)-16:Ald] as the compound in extracts that elicited the largest responses from antennae of males. The identification was confirmed by non-selective synthesis of several isomers as analytical standards, and stereoselective synthesis of (4E,6E,11Z,13Z)-16:Ald for testing in field trials. Male moths were strongly attracted to synthetic (4E,6E,11Z,13Z)-16:Ald, suggesting that this compound is the major and possibly the only component of the sex pheromone of these large saturniid moths. Based on the cross-attraction of heterospecifics, it is likely that this is also a major pheromone component of the other two North American Callosamia species as well.

trans-11,12-Epoxy-(6Z,9Z)-6,9-henicosadiene (posticlure) has been identified from a pheromone gland of the lymantriid species, Orgyia postica. Since the diversity of Lepidoptera suggests that some species utilize the structure-related epoxy compound as a sex pheromone component, epoxydienes and epoxytrienes derived from (6Z,9Z,11E)-6,9,11-trienes and (3Z,6Z,9Z,11E)-3,6,9,11-tetraenes with a C19-C21 chain were systematically synthesized and the chemical data were accumulated in order to contribute to a new pheromone research. Peracid oxidation of each triene and each tetraene produced, respectively, a mixture of three epoxydienes (cis-6,7-epoxy-9,11-diene; cis-9,10-epoxy-6,11-diene; and trans-11,12-epoxy-6,9-diene) and four epoxytrienes (cis-3,4-epoxy-6,9,11-triene; cis-6,7-epoxy-3,9,11-triene; cis-9,10-epoxy-3,6,11-triene; and trans-11,12-epoxy-3,6,9-triene). While the 9,10-epoxy compounds were unstable and, interestingly, converted into 9-ketone derivatives after chromatography over SiO2, each positional isomer was isolated by HPLC equipped with an ODS column, and the chemical structure was determined by NMR analysis. On the GC-MS analysis with a DB-23 column, the positional isomers were also eluted separately and characteristic mass spectra were proposed. By comparing the spectral data of the epoxy compounds with a different carbon chain, diagnostic fragment ions reflecting the chemical structure were determined as follows: m/z 79, 109, 113, and M-114 for the 6,7-epoxydienes; m/z 69, 97, 111, 139, and M-111 for the 9,10-epoxydienes; m/z 57, 79, 109, 136, M-151, and M-111 for the 11,12-epoxydienes; m/z 79, 91, 105, and 119 for the 3,4-epoxytrienes; m/z 79, 124, M-124, M-96, and M-69 for the 6,7-epoxytrienes; m/z 79, 95, 109, 137, and M-108 for the 9,10-epoxytrienes; and m/z 79, 134, M-149, M-109, and M-95 for the 11,12-epoxytrienes.

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.

Carrion beetles are part of the great diversity of insects collected on cadavers. In Brazil, beetles of the genus Oxelytrum have great forensic importance in post mortem interval (PMI) estimation. We investigated the system of chemical communication in the attraction of these necrophagous beetles. Gas chromatographic analysis (GC) of female and male aeration extracts revealed the presence of two male-specific compounds, produced in a ratio of 94:6. Bioassays showed that the combination of male produced volatiles and the odor of a food source (carcass volatiles) were attractive to females. Mass and infrared spectral analyses of the male-specific compounds suggested that they were both unsaturated hydrocarbons. Several micro-derivatizations were carried out with the natural products, and the target structures were identified as (Z)-1,8-heptadecadiene (major) and 1-heptadecene (minor). The structure of the minor component was assigned by co-injection with a commercial standard. A seven-step synthesis was developed to synthesize (Z)-1,8-heptadiene, which co-eluted with the major natural product on three different GC stationary phases. Y-tube olfactometer assays showed that the mixture of synthetic standards in the naturally occurring proportion was slightly attractive to females. The results contribute both to the understanding of the chemical ecology of O. discicolle and to its potential to improve the accuracy of PMI estimation.

Preparation and assignment of absolute configurations to both enantiomers of the sex pheromone of the longtailed mealybug, an irregular monoterpenoid with extraordinary biological activity, has been completed. Comparison of the biological activities of both enantiomers and the racemate in field trials showed that the (S)-(+)-enantiomer was highly attractive to male mealybugs, strongly suggesting that female longtailed mealybugs produce this enantiomer. The (R)-(-)-enantiomer was benign, being neither attractive nor inhibitory.

Archips atrolucens, Adoxophyes privatana, and Homona sp. are serious defoliators of citrus trees in the Mekong Delta of Vietnam. In order to establish a sustainable pest-management program for the three species, their female-produced sex pheromones were investigated by GC-EAD and GC-MS analyses, and the following multi-component pheromones were identified: (Z)-11-tetradecenyl acetate (Z11-14:OAc), (E)-11-tetradecenyl acetate (E11-14:OAc), and tetradecyl acetate (14:OAc) in a ratio of 64:32:4 for A. atrolucens; Z11-14:OAc and (Z)-9-tetradecenyl acetate (Z9-14:OAc) in a ratio of 92:8 for A. privatana; and Z11-14:OAc and (Z)-9-dodecenyl acetate (Z9-12:OAc) in a ratio of 96:4 for Homona sp. Each lure baited with synthetic components as a mimic of the natural pheromone attracted males of the target species specifically, indicating that each monounsaturated minor component plays a significant role for mating communication and reproductive isolation of the three species inhabiting the same citrus orchards. In an extract of the pheromone glands of A. atrolucens females, the content of 14:OAc was very low, but a synergistic effect was observed clearly when the saturated compound was mixed at the same level as the E11-14:OAc. The synthetic lures will provide useful tools for monitoring flights of adults of the three species.

This work describes the structural elucidation of the sex pheromone of the soybean stink bug, Pallantia macunaima. The biological activity of the synthetic pheromone was demonstrated by behavioral and EAD experiments. Furthermore, the absolute configuration of the natural pheromone was determined as (6R,10S)-6,10,13-trimethyltetradecan-2-one. This is the first ketone identified as a male-produced sex pheromone in Pentatomidae, and the trivial name, pallantione, was assigned to this novel pheromone molecule.

An investigation to identify a sex or aggregation pheromone of Sitona discoideus Gyllenhål (Coleoptera: Curculionidae) is presented. Antenna flicking and attraction behaviors evoked by conspecifics of both sexes were recorded in arena bioassays, where attraction of females to males was observed. Air entrainment of both males and females was conducted in separate chambers. Gas chromatographic-mass spectrometric analysis of headspace volatiles revealed that two male-specific compounds, 4-methyl-3,5-heptanedione (major) and (4S,5S)-5-hydroxy-4-methyl-3-heptanone (minor), were emitted during the autumnal post-aestivatory flight period. The stereoisomers of the minor component were separated by enantioselective gas chromatography and their absolute configurations assigned by NMR (diastereomers) and the known preference of enantioselective transesterification reactions catalyzed by Candida antarctica lipase B. Electroantennogram and single sensillum recording studies indicate that 4-methyl-3,5-heptanedione as well as all individual stereoisomers of 5-hydroxy-4-methyl-3-heptanone are detected by the antennae of male and female S. discoideus. Further, single sensillum recordings suggest that both sexes of S. discoideus have specialized olfactory receptor neurons (ORNs) for detecting 4-methyl-3,5-heptanedione and different populations of stereoselective ORNs for detecting the stereoisomers of 5-hydroxy-4-methyl-3-heptanone. Some of these stereoselective ORNs appear to be sex-specific in S. discoideus.

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.

Four trienyl hydrocarbons, (Z3, Z6, Z9)-tricosatriene (Z3, Z6, Z9-23:HC), (Z3, Z6, Z9)-pentacosatriene (Z3, Z6, Z9-25:HC), (Z3, Z6, Z9)-heptacosatriene (Z3, Z6, Z9-27:HC), and (Z3, Z6, Z9)-nonacosatriene (Z3, Z6, Z9-29:HC) were identified in a non-polar fraction of the body wax of male and female yellow peach moth, Conogethes punctiferalis. The relative amounts and ratios of these hydrocarbons differed between sexes. In females, the ratios in body wax and pheromone gland extracts were similar, with lesser amounts found in gland extracts. Synergistic effects of these hydrocarbons when added to the known aldehyde pheromone components were assessed in wind tunnel tests. A blend of (E)-10-hexadecenal (E10-16: Ald) and (Z)-10-hexadecenal (Z10-16: Ald) elicited upwind flight and orientation of males to the pheromone source, but arriving males did not remain close to source for very long. Among the hydrocarbons identified, only Z3, Z6, Z9-23:HC enhanced the activity of the aldehyde blend by increasing the time spent close to the source and the number of source contacts. Z3, Z6, Z9-23:HC and (Z9)-heptacosene (Z9-27:HC) also increased close-range responses to the aldehyde blend. The activity of the aldehyde blend plus these two hydrocarbons was similar to that of crude pheromone extract. Positive dose-response relationships between the aldehyde blend and two hydrocarbon mixtures were found. The lowest doses that elicited synergism were 10(-1) female equivalents (of body wax extracts) for the two hydrocarbons, and 10(-2) female equivalents for the total unsaturated hydrocarbon mixture.

The olive fruit fly, Bactrocera oleae (Diptera: Tephritidae), uses 1,7-dioxaspiro[5.5]undecane ("olean"), produced primarily by females, as a sex pheromone. We used sequential solid phase microextraction-gas chromatography mass spectrometry (SPME-GCMS) analysis to show that female olive flies release about 1000 ng of pheromone at the onset of scotophase for several weeks, while males release about 1/100 as much during the first week after eclosion. The present research demonstrates details of employing SPME-GCMS with the partially known pheromone system of the olive fruit fly as a model for pheromone identification and diurnal release patterns in insects, especially fruit flies. The sequential SPME-GCMS method will readily allow detection and semi-quantification of semiochemicals released by insects in minute amounts throughout the diurnal cycle.

Mealybugs, which include several agricultural pests, are small sap feeders covered with a powdery wax. They exhibit clear sexual dimorphism; males are winged but fragile and short lived, whereas females are windless and less mobile. Thus, sex pheromones emitted by females facilitate copulation and reproduction by serving as a key navigation tool for males. Although the structures of the hitherto known mealybug pheromones vary among species, they have a common structural motif; they are carboxylic esters of monoterpene alcohols with irregular non-head-to-tail linkages. However, in the present study, we isolated from the Matsumoto mealybug, Crisicoccus matsumotoi (Siraiwa), a pheromone with a completely different structure. Using gas chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy, we identified the pheromone as 3-methyl-3-butenyl 5-methylhexanoate. Its attractiveness to males was confirmed in a series of field trapping experiments involving comparison between the isolated natural product and a synthetic sample. This is the first report of a hemiterpene mealybug pheromone. In addition, the acid moiety (5-methylhexanoate) appears to be rare in insect pheromones.

This review covers the subject of pheromones, attractants and other chemical cues of aquatic invertebrates, fishes and amphibians (including salamanders and anurans). Major topics include the sex pheromones of gastropods, salamanders and a giant tree frog, and the conspecific attraction of sperm to ova of some of the organisms and animals described in this review.

Petromyzestrosterol (1), a novel polyhydroxylated steroid, was identified from water conditioned with sexually mature male sea lamprey (Petromyzon marinus), a jawless vertebrate animal. Along with this novel steroid, two known steroids, 7α,12α,24-trihydroxy-5α-cholan-3-one-24-sulfate (3k PZS) and 7α,12α,24-trihydroxy-5α-cholan-24-sulfate (PZS), were isolated. Structures of these compounds were unequivocally established by spectroscopic analyses and by comparison with spectra of known compounds. Electro-olfactogram recordings (EOG) showed that 1 at nanomolar concentrations was stimulatory for the olfactory epithelium of adult females. 3k PZS, known to function as a male sex pheromone, was more stimulatory than 1 for the female olfactory epithelia. The concentration-response curve of 3k PZS was exponential in shape with steep slopes between 10(-10) and 10(-6) mol L(-1). The concentration-response curve for 1 was shallower than that for 3k PZS., (Copyright © 2012 Elsevier Inc. All rights reserved.)

The life history traits and behavior of the butterfly Pieris napi are well-known, as the species is often used as a model organism for evolutionary and ecological studies. The species has two or more generations per year in the major part of its temperate distribution, and as different selection pressures affect the different generations, both behavioral and physiological seasonal polyphenisms have been shown previously. Here, we explored the dynamics of male sex pheromone production. The two generations are shown to have significantly different scent compositions early in life; the direct developers--who have shorter time for pupal development--need the first 24 hr of adult life after eclosion to synthesize the sex pheromone citral (geranial and neral 1:1)--whereas the diapausing individuals who have spent several months in the pupal stage eclose with adult scent composition. Resource allocation and biosynthesis also were studied in greater detail by feeding butterflies (13)C labeled glucose either in the larval or adult stage, and recording incorporation into geranial, neral, and other volatiles produced. Results demonstrate that the pheromone synthesized by newly eclosed adult males is based on materials ingested in the larval stage, and that adult butterflies are able to synthesize the pheromone components geranial and neral and the related alcohols also from adult intake of glucose. In summary, our study shows that time-stress changes the timing in biosynthesis of the complete pheromone between generations, and underpins the importance of understanding resource allocation and the physiological basis of life history traits.

The sex-pairing pheromone of the black winged subterranean termite, Odontotermes formosanus (Shiraki) (Isoptera, Termitidae), was investigated using headspace-SPME, GC-MS, GC-EAD, and attraction bioassays. Females secrete the pheromone from their sternal gland to attract males. The sex-pairing pheromone is composed of (Z,Z)-dodeca-3,6-dien-1-ol and (Z)-dodec-3-en-1-ol, estimated at 9 to 16.64 ng and 0.2 to 0.54 ng, respectively. Both short- and long-distance sex attraction bioassays were employed to show that these compounds act in synergy at long distance, but only (Z,Z)-dodeca-3,6-dien-1-ol is active at short distance. The pheromone may be useful in efforts to control this pest, which is considered one of the most harmful termite species in Southeast Asia.