The scarab beetleAnomala albopilosa sakishimana utilizes the same sex pheromone blend as a closely related and geographically isolated species,Anomala cuprea

Two components were identified in the sex pheromone system of the green chafter,Anomala albopilosa sakishimana Nomura: (R,Z)-5-(–)-(oct-1-enyl)oxacyclopentan-2-one (buibuilactone) and (R,Z)-5-(–)-(dec-1-enyl)oxyacyclopentan-2-one (japonilure), which have been previously identified as sex pheromone constituents ofA. cuprea andA. octiescostata. A female-specific minor component, (R,E)-5-(–)-(oct-1-enyl)oxacyclopentan-2-one, did not seem to be involved in pheromonal communication because it was not EAD active, but its role remained unclear. A synthetic blend of the two components captured significantly more beetles than any other treatments. Nevertheless, the fact that both the synthetic sex pheromone and field-captured female beetles were weak lures convinced us that the sex pheromone system may be only part of a complex communication system, probably involving plant volatiles. Although the sex pheromone was released during both the scotophase and photophase, there was an increase of 60% in the photophase.     

Decadienoates: Sex Pheromone Components of Nettle Caterpillars Darna trima and D. bradleyi

This study was undertaken to identify sex pheromone components of nettle caterpillars Darna trima and Darna bradleyi (Lepidoptera: Limacodidae) whose larvae defoliate oil palm, Elaeis guineensis, in southeast Asia. Coupled gas chromatographic–electroantennographic detection (GCEAD) analyses of pheromone gland extracts revealed two antennally active compounds produced by female D. trima and two by female D. bradleyi. Molecular structures of these candidate pheromone components were identified by electron-impact and chemical-ionization mass spectrometry; retention-index calculations on DB-5, DB-23, and DB-210 columns; microanalytical treatments, as well as syntheses of "auxilliary" compounds that facilitated identification of the compounds. The compounds from D. trima were 2-methylbutyl (E)-7,9-decadienoate (A) and (E)-2-hexenyl (E)-7,9decadienoate (B); from D. bradleyi we identified methyl (E)-7,9-decadienoate (C), and isobutyl (E)-7,9-decadienoate (D). In field experiments in Malaysia, (S)-2-methylbutyl (E)-7,9-decadienoate (SA) in combination with B proved to be essential and synergistic pheromone components for attraction of male D. trima. (R)-2-Methylbutyl (E)-7,9-decadienoate (RA) had no behavioral activity. Compound D singly attracted male D. bradleyi, but addition of C to D at a 1 : 10 ratio significantly enhanced attractiveness of the bait. Synthetic pheromone blends were more effective trap baits than unmated female moths and could be developed for monitoring populations of D. trima and D. bradleyi in Asian oil palm plantations.     

Attraction of Piezodorus hybneri to the Aggregation Pheromone Components of Riptortus clavatus

The aggregation pheromone of Riptortus clavatus (Heteroptera: Alydidae) consists of (E)-2-hexenyl (Z)-3-hexenoate (E2HZ3H), (E)-2-hexenyl (E)-2-hexenoate (E2HE2H), and myristyl isobutyrate (MI). Experiments were conducted to examine the attraction of Piezodorus hybneri (Heteroptera: Pentatomidae) to the pheromone components of R. clavatus, individually and in combination, and to determine if P. hybneri produces these compounds. Electroantennogram (EAG) responses of P. hybneri to E2HE2H were significant in a dose dependent manner, while those to E2HZ3H were not significantly different from those to hexane and air. Field trapping tests using E2HZ3H, E2HE2H, and MI, individually or in combination, showed that only E2HE2H was attractive to P. hybneri. E2HE2H was not detected in whole-body extracts or volatile collections from either sex of P. hybneri adults. We propose that the response of P. hybneri adults to the R. clavatus aggregation pheromone may be related to finding suitable host plants.     

The scarab beetleAnomala cuprea utilizes the sex pheromone ofPopillia japonica as a minor component

GC-EAD analyses revealed that the scarab beetleAnomala cuprea, the cupreous chafer, utilizes, in addition to the previously identified major sex pheromone (R,Z)-5-(–)-(oct-1-enyl)oxacyclopentan-2-one, a minor component, (R,Z)-5-(–)-(dec-1-enyl)oxacyclopentan-2-one, which has been previously identified as the sex pheromone of the Japanese beetle. Release of the sex pheromone blend did not significantly differ when collected from feeding or starving female beetles, nor did it differ from volatiles collected in the scoto- and photophase. However, after mating, the amount and the ratio of the two components changed. Field tests revealed that traps baited with the synthetic sex pheromone captured more beetles than traps containing only virgin females. Based on field experiments, 10 mg of a 9010 blend of the pheromone was suggested as appropriate for monitoring of the cupreous chafer, although the optimal ratio for attractiveness is yet to be established. The occurrence of minor components in the pheromone system of other scarab beetles is also discussed.     

Beyond 9-ODA: SEX Pheromone Communication in the European Honey Bee Apis mellifera L.

The major component of the mandibular gland secretion of queen honeybees (Apis mellifera L.), 9-ODA ((2E)-9-oxodecenoic acid), has been known for more than 40 yr to function as a long-range sex pheromone, attracting drones at congregation areas and drone flyways. Tests of other mandibular gland components failed to demonstrate attraction. It remained unclear whether these components served any function in mating behavior. We performed dual-choice experiments, using a rotating drone carousel, to test the attractiveness of 9-ODA compared to mixtures of 9-ODA with three other most abundant components in virgin queen mandibular gland secretions: (2E)-9-hydroxydecenoic acid (9-HDA), (2E)-10-hydroxydecenoic acid (10-HDA), and p-hydroxybenzoate (HOB). We found no differences in the number of drones attracted to 9-ODA or the respective mixtures over a distance. However, adding 9-HDA and 10-HDA, or 9-HDA, 10-HDA, and HOB to 9-ODA increased the number of drones making contact with the baited dummy. On the basis of these results, we suggest that at least 9-HDA and 10-HDA are additional components of the sex pheromone blend of A. mellifera.     

Sex Pheromone of <Emphasis Type="BoldItalic">Lonomia obliqua</Emphasis>: Daily Rhythm of Production,Identification, and Synthesis

The sex pheromone of Lonomia obliqua Walker (Lepidoptera: Saturniidae) was studied in the laboratory. All female calling occurred during the scotophase. Most females (70.6%) called first within 24 hr of eclosion. Calling varied with age of female, with older (5- to 6-day-old) females calling earlier in the scotophase and for longer durations than younger (0- to 1-day-old) females. The sex pheromone gland of 1- to 3-day-old virgin females was extracted during the calling peak. A Y-olfactometer bioassay showed significant attraction of males to a filter paper containing the female gland extract. Gas chromatographic-electroantennogram detection (GC-EAD) analysis of the extract indicated the presence of at least two possible pheromone components. Gas chromatographic-mass spectrometric analysis of the major GC-EAD-active peak indicated a hexadecenyl acetate; chemical derivatization indicated Δ11 unsaturation. Synthetic samples of (E)- and (Z)-11-hexadecenyl acetate were obtained by coupling 10-bromo-1-decanol and 1-hexyne, utilizing lithium chemistry. The comparison of the retention time of dimethyl disulfide derivatives of the natural compound, to those of synthetic chemicals, confirmed the natural compound as (E)-11-hexadecenyl acetate. The minor component was identified as the related alcohol, (E)-11-hexadecenol. The ratio of the two components in female extract was 100:35. Preliminary tests of males in a Y-olfactometer showed that their response to a mixture of the two compounds was not significantly different from that to gland extract.     

Sex Pheromone of Apple Blotch Leafminer, Phyllonorycter crataegella, and Its Effect on P. mespilella Pheromone Communication

(Z)-10,(Z)-12-Tetradecadienyl acetate (Z10,Z12–14:OAc) and (E)-10,(E)-12-tetradecadienyl acetate (E10,E12–14:OAc) are sex pheromone components of the apple blotch leafminer (ABLM), Phyllonorycter crataegella. Compounds extracted from female pheromone glands were identified by coupled gas chromatographic–electroantennographic detection (GC-EAD) analyses, retention index calculations of EAD-active compounds, and by comparative GC-EAD analyses of female ABLM-produced and authentic (synthetic) compounds. In field experiments in apple Malus domestica orchards in Connecticut, Z10,Z12–14:OAc alone attracted ABLM males. Addition of E10,E12–14:OAc to Z10,Z12–14:OAc at 0.1:10 or 1:10 ratios enhanced attractiveness of the lure. Geometrical isomers Z10,E12- or E10,Z12–14:OAc at equivalent ratios were behaviorally benign and slightly inhibitory, respectively. In field experiments in British Columbia, Z10,Z12–14:OAc plus E10,E12–14:OAc did not attract Phyllonorycter moths, supporting the contention that ABLM is not present in the fruit growing regions of British Columbia. Z10,Z12–14:OAc added to P. mespilella pheromone, (E)-4,(E)-10-dodecadienyl acetate, strongly inhibited response by P. mespilella males. Recognition of the ABLM pheromone blend by allopatric P. mespilella males suggests a phylogenetic relationship and previous sympatry of these two Phyllonorycter spp. If pheromonal attraction of ABLM males were reciprocally inhibited by P. mespilella pheromone, a generic Phyllonorycter pheromone blend could be tested for pheromone-based mating disruption of the apple leaf-mining Phyllonorycter guild in North America.     

Isolation,identification, and synthesis of sex pheromone components of female tea cluster caterpillar,Andraca bipunctata walker (Lepidoptera: Bombycidae) in Taiwan

Octadecanal (18:Ald), (E)-11-octadecenal (E11–18:Ald), (E)-14-octadecenal (E14–18:Ald) and (E,E)-11,14-octadecadienal (E11,E14–18:Ald) were isolated and identified as major components from the pheromone glands of the tea cluster caterpillar,Andraca bipunctata, in Taiwan by analyzing the mass spectra of gland components and their DMDS adducts. GC retention times and mass spectra of the components were in agreement with those of authentic synthetic compounds. The average amount of 18:Ald,E11–18:Ald,E14–18:Ald andE11,E14–18:Ald per female gland (1 to 3 days old) was 121±76, 50±20, 187±75, and 237±110 ng, respectively, in a ratio of 20:8:31:41. SyntheticE11,E14–18:Ald caught more males than each of the other three components or blank control in field trapping tests.E11,E14–18:Ald is reported as an insect sex pheromone for the first time. Male antenna responded toE11,E14–18:Ald strongly in an EAG analysis. Furthermore, 4 hr after the injection of PBAN (pheromone biosynthetic activating neuropeptide) into decapitated female moths (2 days old), the percentage of theE11,E14–C18 Ald in the gland extract increased from 0% to 75.5%, which was also significantly more than that of unligated and uninjected control at 55.1%. All these data indicated thatE11,E14–18:Ald is the sex pheromone of theAndraca bipunctata in Taiwan.     

Identification and Synthesis of Male-Produced Sex Pheromone Components of the Stink Bugs Chlorochroa ligata and Chlorochroa uhleri

The reproductive behaviors of the stink bugs Chlorochroa ligata and C. uhleri were studied in the laboratory. Adults of both species became sexually mature about 12–14 days after the final molt, and both sexes mated multiple times during their lifetimes. The mean duration of copulation was 54 ± 24 min for virgin bugs and 46 ± 33 min for experienced bugs for C. ligata and 78 ± 55 min for field-collected C. uhleri of unknown mating status. Male C. ligata were found to transfer a significant fraction of their body mass (19%) to females during mating. Sexually mature C. uhleri males produced three sex-specific compounds, methyl (R)-3-(E)-6-2,3-dihydrofarnesoate, methyl (2E,6E)-farnesoate, and methyl (E)-5-2,6,10-trimethyl-5,9-undecadienoate, in a ratio of 100:0.9:0.6. These three compounds were also produced by sexually mature male C. ligata in a ratio of 100:0.5:0.4. Identifications of the compounds were confirmed by synthesis. Production of the male-specific compounds peaked in late afternoon to early evening, coincident with the peak period of reproductive activity. Laboratory and field bioassays demonstrated that female bugs were attracted to odors from live males and to reconstructed blends of the male-specific compounds.     

Identification and synthesis of female sex pheromone of Oriental beetle,Anomala orientalis (Coleoptera: Scarabaeidae)

Females of the Oriental beetle,Anomala orientalis (Waterhouse), release a sex pheromone composed of a 9:1 blend of (Z)- and (E)-7-tetradecen-2-one. The double-bond position of the pheromone was determined by DMDS derivatization and interpretation of the fragmentation patterns produced by monounsaturated ketones. In a sustained-flight tunnel, males responded by flying toward female beetles and attempting to copulate with them. Both effluvium and whole-body extracts of OB females were analyzed, and the activity was found only in the airborne extracts. Flight-tunnel bioassays also showed that a synthetic 90:10Z/E blend on a rubber septum was attractive and that the responses of males to this blend were equivalent toZ isomer alone, but much better than to the singleE isomer.     

Novel type of sex pheromone structure identified fromStigmella malella (Stainton) (Lepidoptera: Nepticulidae)

Short-chain unsaturated chiral methyl carbinols are identified as a new class of lepidopteran pheromone components. The natural female-produced pheromone of the banded apple pigmyStigmella malella (=Nepticula malella) (Stainton) (Lepidoptera: Nepticulidae) was identified to be a mixture of (S)-(E)-6,8-nonadien-2-ol and (S)-(Z)-6,8-nonadien-2-ol. For monitoring traps, a 10:3E:Z blend at 100–1000 µg is recommended. It is suggested that pheromones with similar structures may be specific to Nepticulidae and other related microlepidopteran families.     

Identification, Synthesis, and Field Evaluation of the Sex Pheromone of the Citrus Fruit Borer Ecdytolopha aurantiana

The sex pheromone of the citrus fruit borer Ecdytolopha aurantiana has been identified by gas chromatography coupled to an electroantennographic detector (GC-EAD). The electron impact mass spectral (EI-MS) fragmentation of the major EAD-active peak gave identifying features for a monounsaturated acetate. Further analyses by chemical ionization mass spectrometry (CI-MS), vapor-phase infrared spectroscopy (GC-IR), along with chemical derivatization (DMDS reaction), led to full characterization of the major component as (E)-8-dodecenyl acetate (E8–12 : Ac). The second constituent was identified as the related alcohol, (E)-8-dodecenol (E8–12 : OH). The two compounds were indistinguishable from the authentic synthetic standards in chemical and EAD analyses. Samples of the two compounds were obtained by a facile synthesis utilizing lithium chemistry. Field tests showed that captures in traps baited with a mixture of E8–12 : Ac and E8–12 : OH at 100 : 1 and 10 : 1 ratios were not significantly different from the catches in traps having two virgin females. Dosage tests showed better performance of traps baited with 1 mg than those with 0.1 mg of the pheromone blend, either in 100 : 1 or 10 : 1 ratio.     

Mint root borer,Fumibotys fumalis (Guenee): Identification and field tests of female sex pheromone gland components

Compounds identified in sex pheromone gland extracts of femaleFumibotys fumalis (Guenee) consisted of (E,E)-10,12-tetradecadienyi acetate, (Z)-11-tetradecenyl acetate, (E)-11-tetradecenyl acetate, and (Z)-9-tetradecenyl acetate in a ratio of 100:18: 8:4, respectively. The compounds were identified by electroantennographic, gas Chromatographic, mass spectrometric, and chemical derivatization procedures. In mint fields synthetic components in gray elastomeric septa at ratios found in the sex pheromone gland and at doses of 3 or 10 mg of the diene produced trap catch comparable to traps baited with three females.Lepidoptera: Pyralidae     

Sensory and behavioral effects of gossyplure alcohol on sex pheromone response of male pink bollworm moths,Pectinophora gossypiella

(Z,Z)- and (Z,E)-7,11-hexadecadienol, reported to be pheromone precursors, interfere with the normal sequence of behavioral response of malePectinophora gossypiella to sex pheromone. The magnitude of the interference can be diminished with higher release rates of the sex pheromone. (Z,Z)-7,11-Hexadecadienol is more effective than itsZ,E isomer in eliciting the reduction in the behavioral response. Electroantennographic evidence suggests that each alcohol may be interfering more with receptor sites for the conformationally similar pheromone acetate than with receptor sites for the other pheromone isomer. Defining behavioral and physiological effects of pheromone analogs such as the alcohols of gossyplure may help to determine their potential for behavioral manipulations.     

Pheromones of milkweed bugs (Heteroptera: Lygaeidae) attract wayward plant bugs: Phytocoris mirid sex pheromone

The synthetic aggregation pheromone of the large milkweed bug, Oncopeltus fasciatus (Dallas) (Lygaeinae), also attracted males of the plant bug, Phytocoris difficilis Knight (Miridae). Field testing partial blends against the six-component blend comprising the Oncopeltus pheromone showed that cross-attraction of P. difficilis males was due to synergism between (E)-2-octenyl acetate and (E,E)-2,4-hexadienyl acetate. Hexyl acetate was abundant in the metathoracic scent gland (MSG) secretion of P. difficilis males, but because female P. difficilis could not initially be found in the field, further combinatorial tests were guided by prior research on the pheromones of two Phytocoris species in the western United States. The combination of hexyl, (E)-2-hexenyl, and (E)-2-octenyl acetates was as attractive to P. difficilis males as the milkweed bug pheromone, yet no milkweed bugs were drawn to this blend. Gas chromatographic (GC)-electroantennographic detection (EAD) and GC-mass spectrometric (MS) analyses of female P. difficilis MSGs determined that their secretion contained predominantly hexyl, (E)-2-hexenyl, and (E)-2-octenyl acetates (all strongly EAD-active)—the latter two compounds found only in trace amounts from males—plus five minor female-specific compounds, three of which were EAD-active. (E,E)-2,4-Hexadienyl acetate was not detected from P. difficilis females or males. The blend of the three major components, hexyl, (E)-2-hexenyl, and (E)-2-octenyl acetates (2:1.5:1 by volume), was as attractive as the blend of all six EAD-active compounds identified from females, indicating that this ternary blend constitutes the sex pheromone of P. difficilis. Hexyl acetate with (E)-2-octenyl acetate also attracted males of another species, P. breviusculus Reuter, but addition of (E)-2-hexenyl acetate and/or (E,E)-2,4-hexadienyl acetate inhibited attraction of P. breviusculus males. Attraction of P. difficilis males occurred mainly during the first half of scotophase. The possible neurophysiological basis for this asymmetrical cross-attraction is discussed.     

Sex pheromone of tomato fruit borer, Neoleucinodes elegantalis

Five candidate pheromone components were identified by analyzing pheromone gland extracts by gas chromatography (GC), coupled GC-electroantennographic detection (EAD), and coupled GC-mass spectrometry (MS): (E)-11-hexadecenol(E11–16 : OH), (Z)-11-hexadecenol (Z11–16 : OH),(E)-11-hexadecenal, (E)-11-hexadecenyl acetate, and (Z)-3,(Z)-6,(Z)-9-tricosatriene (Z3,Z6,Z9–23 : Hy). In electroantennogram (EAG) recordings, synthetic E11–16 : OH elicited stronger antennal responses at low doses than other candidate pheromone components. Field tests demonstrated that synthetic E11–16 : OH as a trap bait was effective in attracting males, whereas addition of Z11–16 : OH inhibited the males' response. Z3,Z6,Z9–23 : Hy strongly enhanced attractiveness of E11–16 : OH, but was not attractive by itself. A pheromone blend with synergistic behavioral activity of an alcohol (E11–16 : OH) and hydrocarbon (Z3,Z6,Z9–23 : Hy) component is most unusual in the Lepidoptera. The synthetic two-component pheromone is approximately 60 times more attractive than the female-produced blend and might facilitate the control of this pest.     

Sex Pheromone of the Saturniid Moth, <Emphasis Type="Italic">Hemileuca burnsi</Emphasis>, from the Western Mojave Desert of California

The sex pheromone blend of Hemileuca burnsi (Lepidoptera: Saturniidae) from the western Mojave Desert was determined to be a combination of (10E,12Z)-hexadecadien-1-yl acetate (E10,Z12-16:Ac), (10E,12Z)-hexadecadien-1-ol (E10,Z12-16:OH), (10E,12E)-hexadecadien-1-yl acetate (E10,E12-16:Ac), and hexadecyl acetate (16:Ac). (10E,12Z)-Hexadecadienal (E10,Z12-16:Ald) was tentatively identified in pheromone gland extracts based on electroantennographic responses and, when added to the above blend, it enhanced trap captures at low doses. The mean ratio of the compounds in extracts of pheromone glands was 100:23:232:14:0.4 (E10,Z12-16:Ac: E10,E12-16:Ac: 16:Ac: E10,Z12-16:OH: E10,Z12-16:Ald). Field trials indicated that although E10,Z12-16:Ac and E10,Z12-16:OH were essential for attraction, the two-component blend was not attractive by itself. Addition of the three other compounds was necessary for maximum attraction, rendering this the most complicated pheromone blend described for a Hemileuca species to date. Similarities between the sex pheromone of H. burnsi and that of the allopatric Hemileuca electra electra and differences between the blends of H. burnsi and that of the sympatric H. electra mojavensis support a case for reproductive character displacement in the pheromone communication channel of H. electra.     

Identification of sex pheromone produced by female sweetpotato weevil,Cylas formicarius elegantulus (Summers)

A sex pheromone of the sweetpotato weevil,Cylas formicarius elegantulus (Summers), was obtained from collections of volatiles from virgin females, and pheromone was isolated by means of liquid and gas chromatography. The purification procedure was monitored by quantitative laboratory and field bioassays and the compound was identified as (Z)-3-dodecen-1-ol (E)-2-butenoate by means of spectroscopic and microchemical methods. Synthesis, followed by laboratory and field bioassays, showed that the biological activity of the synthetic material was qualitatively and quantitatively indistinguishable from that of the purified natural product.Mention of a commercial or proprietary product does not constitute an endorsement by the USDA.     

Characterization of Pheromone Blend for Grapevine Moth, Lobesia botrana by Using Flight Track Recording

The behavioral responses of Lobesia botrana males to calling females, pheromone gland extracts, and synthetic sex pheromones were recorded in a wind tunnel. Gland extracts and synthetic pheromones were released from a pheromone evaporator. The numbers of males reaching the source and their flight tracks in response to calling females and pheromone gland extracts were compared to those of synthetic blends. Upwind flights to natural sex pheromone were straighter and faster than to a three-component blend of (E)-7,(Z)-9-dodecadienyl acetate (E7,Z9–12:Ac), (E)-7,(Z)-9-dodecadien-1-ol (E7,Z9–12:OH), and (Z)-9-docecenyl acetate (Z9–12:Ac) (100:20:5). The optimum ratio of E7,Z9–12:OH and Z9–12:Ac to E7,Z9–12:Ac was found to be 5% and 1%, respectively. An additional seven compounds identified in the sex pheromone gland were investigated for their biological activity. Two unsaturated acetates, i.e., (E)-9-dodecenyl acetate (E9–12:Ac) and 11-dodecenyl acetate (11–12:Ac), increased the number of males reaching the source as well as straightness, linear velocity, and decreased the track angle of upwind flight. Optimum response was obtained by releasing 10 pg/min E7,Z9–12:Ac in a mixture with 0.5 pg/min E7,Z9–12:OH, 0.1 pg/min Z9–12:Ac, 0.1 pg/min E9– 12:Ac and 1 pg/min 11-12–Ac. The saturated acetates previously identified in the female glands were biologically inactive.     

Volatile male-specific natural products of a coreid bug (Hemiptera: Heteroptera)

The large coreid bug,Pachylis laticornis (Hemiptera: Coreidae), feeds on several mimosaceous trees in Guanacaste, Costa Rica. In addition to the presumably defensive metathoracic exocrine glands that occur in both sexes of this species, the adult males also possess a ventral abdominal gland, opening midventrally in the 7–8th abdominal intersegmental membrane, that releases volatile compounds. Two esters, (E)-2-hexenyl tiglate and (E)-2-hexenyl (E)-2-hexenoate, account for over 90% of the total volatiles in the ventral abdominal gland secretion of males. (E)-2-Octenyl tiglate and (E)-2-hexenyl benzoate are present at low concentrations, as are at least three other unidentified compounds. The biological role for this fragrant male-specific exudate is unknown.