(Z)-11-Hexadecenal and (3Z,6Z,9Z)-tricosatriene: sex pheromone components of the red banded mango caterpillar Deanolis sublimbalis

The sex pheromone of the red banded mango caterpillar, Deanolis sublimbalis (Lepidoptera: Crambidae), a serious pest of the mango Mangifera indica (Anacardiaceae) in India and Southeast Asia and a recent invader into northern Australia, has been identified. Three candidate compounds were identified from pheromone gland extracts of female moths, using gas chromatography (GC), GC-electroantennographic detection and GC-mass spectrometric analyses, in conjunction with dimethyldisulfide derivatization. Field bioassays established that both (Z)-11-hexadecenal (Z11-16:Ald) and (3Z,6Z,9Z)-tricosatriene (3Z,6Z,9Z-23:Hy) were required for attraction of male D. sublimbalis moths, and 1,000 μg of a 1:1 mix of Z11-16:Ald and 3Z,6Z,9Z-23:Hy was more attractive to male moths than caged virgin females. However, the binary blend was only attractive when the isomeric purity of the monounsaturated aldehyde was >99%, suggesting that the (E)-isomer was inhibitory. Although (Z)-11-hexadecen-1-ol (Z11-16:OH) was tentatively identified in gland extracts, the addition of this compound to the binary blend did not increase the numbers of moths captured. The pheromone can now be used in integrated pest management strategies. Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users.     

Pheromone emission and blend percentages inEoreuma loftini determined by two methods

Calling behavior and pheromone emission by virgin femaleE. loftini moths were investigated in laboratory experiments. Calling peaked during the last three hours of the night. Three-day-old moths called more than older or younger moths and began calling earlier in the night than younger moths. Female emissions were collected in flasks without airflow and cylinders with airflow. Control tests indicated that the pheromone components (Z)-11-hexadecenyl acetate (HDA) and (Z)-13-octadecenylacetate (ODA) were 69 and 54% adsorbed on moths, respectively, and the component (Z)-13-octadecenal (ODL) was 92–99% adsorbed depending on its concentration, when put into flasks with noncalling females for 4 hr. Pheromone exposed to moths for less than 4 hr was adsorbed less. After correction for adsorption, the pheromone blend from females calling in flasks was 9:42:49% of HDA/ODL/ODA with an overall emission rate of 58 ng/female/4 hr. Three-day-old females emitted more pheromone than 0- to 2- or 4- to 5-day-old moths, in flasks. Little or no pheromone put into cylinders either downwind or upwind from a male moth was adsorbed by the moth. The pheromone blends from females calling in cylinders, corrected using downwind and upwind control test results, respectively, were 15:35:50 and 13:40:48% of HDA/ODL/ODA with overall emission rates of 32 and 35 ng/female/night.Lepidoptera: Pyralidae.     

Sex pheromone of fall armyworm,Spodoptera frugiperda (J.E. Smith)

Analyses of extracts of pheromone glands and of volatiles from calling female fall armyworm moths,Spodoptera frugiperda (J.E. Smith), revealed the presence of the following compounds: dodecan-1-ol acetate, (Z)-7-dodecen-1-ol acetate, 11-dodecen-1-ol acetate, (Z)-9-tetradecenal, (Z)-9-tetradecen-1-ol acetate, (Z)-11-hexadecenal, and (Z)-11-hexadecen-1-ol acetate. The volatiles emitted by calling females differed from the gland extract in that the two aldehydes were absent. Field tests were conducted with sticky traps baited with rubber septa formulated to release blends with the same component ratios as those emitted by calling females. These tests demonstrated that both (Z)-7-dodecen-1-ol acetate and (Z)-9-tetradecen-1-ol acetate are required for optimum activity and that this blend is a significantly better lure than either virgin females or 25 mg of (Z)-9-dodecen-1-ol acetate in a polyethylene vial, the previously used standard. Addition of the other three acetates found in the volatiles did not significantly increase the effectiveness of the two-component blend as a bait for Pherocon 1C or International Pheromones moth traps.Mention of a commercial or proprietary product does not constitute an endorsement by the USDA.     

Enantiomers of (Z,Z)-6,9-Heneicosadien-11-OL: Sex Pheromone Components of Orgyia detrita

(6Z,9Z,11S)-6,9-Heneicosadien-11-ol (Z6Z9-11S-ol-C21) and (6Z,9Z,11R)-6,9-heneicosadien-11-ol (Z6Z9-11R-ol-C21) were identified as major sex pheromone components of female tussock moths, Orgyia detritaGuérin-Méneville (Lepidoptera: Lymantriidae), on the basis of (1) analyses of pheromone gland extracts of female O. detrita by coupled gas chromatographic-electroantennographic detection (GC-EAD) and GC mass spectrometry, and (2) field trapping experiments with synthetic standards. Z6Z9-11S-ol-C21 and Z6Z9-11R-ol-C21 in combination, but not singly, attracted significant numbers of male moths. Racemic Z6Z9-11-ol-C21 was more attractive than the 1:3.5 (R:S) blend ratio found in pheromone gland extracts from female moths. Lower and higher homologues of Z6Z9-11-ol-C21 were also detected in GC-EAD recordings of pheromone extracts, and the racemic compounds enhanced attractiveness of Z6Z9-11-ol-C21 in field experiments. Because of trace amounts of these homologues in extracts, their enantiomeric composition could not be determined. This is the first report of secondary alcohols as pheromone components in the ditrysian (advanced) Lepidoptera.     

Behavioral responses of maleHeliothis zea moths in sustained-flight tunnel to combinations of 4 compounds identified from female sex pheromone gland

Each of the four compounds that have been identified from sex pheromone glands ofHeliothis zea female moths was examined for its ability to elicit sexual responses from male moths in a flight tunnel. Males flew upwind to (Z)-11-hexadecenal alone, but greater levels of behavioral activity were evoked with the addition of (Z)-9-hexadecenal to the treatment. Addition of hexadecanal or (Z)-7-hexadecenal to the initial two components had no effect in raising the behavioral response of the males in the flight tunnel whether added singularly at both the normal gland-emission ratio or at varying ratios or in combination at the normal ratio. Live, calling females elicited levels of sexual activity from males not significantly different from that elicited by the mixture of (Z)-11- and (Z)-9-hexadecenal on cotton wicks.Lepidoptera: Noctuidae.     

Identification of sex pheromone components of darksided cutworm,Euxoa messoria,and modification of sex attractant blend for adult males

Eleven pheromone-like compounds were identified in excised abdomen tip extracts of calling adult females of darksided cutworm,Euxoa messoria (Harris). The essential pheromone components were (Z)-7- and (Z)-11-hexadecenyl acetates in a ratio of 140, which agreed with an attractant blend developed empirically by field testing the attractancies of synthetic blends. The pheromone component, (Z)-11-hexadecenol, improved the attraction of darksided cutworm males whereas the components (Z)-9-tetradecenyl acetate and (Z)-7-dodecenyl acetate inhibited their attraction. The other pheromone-like compounds identified in the female extracts had no obvious effect on the attraction of darksided cutworm males. Three compounds that functioned as parapheromones when substituted for (Z)-7-hexadecenyl acetate in the two-component blend were (Z)-7-pentadecenyl, (Z)-7-tetradecenyl, and (Z)-7-tridecenyl acetates. (Z)-11-hexadecenal was not detected in the female extracts, but it had a synergistic effect on the attraction of darksided cutworm moths and inhibited the attraction of male moths of a nontarget species,Helotropha reniformis (Grote). As a trap bait for monitoring purposes, we recommend a four-component blend of (Z)-7-hexadecenyl acetate, (Z)-11-hexadecenyl acetate, (Z)-11-hexadecenol, and (Z)-11-hexadecenal at 12.5, 500, 1, and 10 g/red rubber septum dispenser containing 5 g of antioxidant 2,6-tert-butyl-4-methyl phenol. This blend is effective under field conditions for at least six weeks.     

Sex pheromone specificity inHeliothis

Electric grid traps baited withHeliothis subflexa (Guenée),H. virescens (F.), orH. zea (Boddie) females captured conspecific males with few exceptions.Heliothis subflexa females reduced the attraction ofH. virescens andH. zea males when used as bait simultaneously with females of either of these two species. Backcrosses were made withH. virescens males and female hybrids from a cross betweenH. subflexa females andH. virescens males. The backcross (BC) females andH. virescens females attracted approximately equal numbers ofH. virescens males in field traps. BC males released in field cages were attracted toH. virescens females and to the synthetic pheromone ofH. virescens. When laboratory-reared maleH. virescens, BC males,H. subflexa males, and F₁ hybrid males were exposed to the synthetic pheromone ofH. virescens in Plexiglas wind tunnels,H. virescens males and BC males responded to the pheromone, butH. subflexa and F₁ hybrid males did not. The peak activity of bothH. subflexa andH. zea males occurred approx. 4 hr after sunset. MaleH. zea were active throughout most of the night; maleH. virescens were most active approx. 6 hr after sunset.This paper reports the results of research only. Mention of a pesticide or of a commercial or proprietary product in this paper does not constitute a recommendation for use by the U.S. Department of Agriculture nor does it imply registration under FIFRA as amended.Lepidoptera: Noctuidae.     

Identification of sex pheromone components of redbacked cutworm,Euxoa ochrogaster,and modification of sex attractant blend for adult males

Pheromone washes from calling female moths of redbacked cutworm,Euxoa ochrogaster (Guenée), contained the following acetates that are structurally similar to those of known lepidopteran pheromones (%): decanyl (8.7), dodecanyl (8.5), (E)-5-dodecenyl (3.3), (Z)-5-dodecenyl (76.4), (Z)-7-dodecenyl (3.1), and (Z)-9-dodecenyl (trace<0.5%). This is the first time that (Z)-5-dodecenyl acetate has been identified as a pheromone component. Three types of specific receptor cells were found in the male antennae, and they responded to (Z)-5-decenyl acetate, (Z)-5- and (Z)-7-dodecenyl acetates, respectively. Strong electroantennographic detector responses were also recorded for these three acetates and for (Z)-5-undecenyl acetate. The evidence for the presence of (Z)-5-decenyl acetate in the pheromone washes was inconclusive. The presence of (Z)-7- and the absence of (Z)-8-dodecenyl acetates were confirmed by a special electroantennographic detector technique in which the detector antennae were from males of other species that were known to have strong responses to these acetates. This is a very useful technique. Field results show that low concentrations (0.1–1.3%) of (Z)-5-decenyl acetate were synergistic when tested in a previously reported blend, but 6% was inhibitory. Similarly, (Z)-7-dodecenyl acetate at 2% or less may be essential for the attraction of males, but in previous tests at 14% it also was inhibitory. Species-specific attractant blends for redbacked cutworm males are described.Lepidoptera: Noctuidae     

Kairomones and their use for management of entomophagous insects

Volatile chemicals emanating from an excretion (apparently meconium) and abdominal tips of femaleHeliothis zea (Boddie) moths mediated increased rates of parasitization ofH. zea eggs byTrichogramma pretiosum Riley. A blend of synthetic chemicals, consisting of hexadecanal, (Z)-7-hexadecenal, (Z)-9-hexadecenal, and (Z)-11-hexadecenal, which has been identified as the sex pheromone of and from the abdominal tip of femaleH. zea moths, also increased rates of parasitization ofH. zea eggs byT. pretiosum in greenhouse experiments. In addition, parasitization ofH. zea eggs by wildTrichogramma spp., in field plots of cotton,Gossypium hirsutum L., treated with a similar blend of chemicals, in Conrel fibers, was more than double that in untreated plots.Hymenoptera: Trichogrammatidae.Lepidoptera: Noctuidae.In cooperation with the University of Georgea College of Agriculture Experiment Stations, Coastal Plain Station, Tifton, Georgia 31793.Mention of a proprietary product does not constitute endorsement by the USDA.     

Effects of pheromone components and their degradation products on the response ofHeliothis spp. to traps

None of the isolated degradation products of (Z)-11-hexadecenal [(Z)-11-HDAL] affected the catches of either tobacco budworm [Heliothis virescens (F.)] or bollworm [H. zea (Boddie)] moths when dispensed with pheromone from cotton dental rolls in cone traps. Also, none of the degradation products of (Z)-9-tetradecenal [(Z)-9-TDAL] had an effect on trap catches of tobacco budworm moths. Two of the three chemicals that have previously been identified in ovipositor washes of tobacco budworms but that are absent in those of bollworms caused a reduction in capture of bollworms: (Z)-9-TDAL (1.0 g/trap) caused a 96% reduction in trap catch and (Z)-11-hexadecen-1-ol (20.0 g/trap) caused a similar reduction. Tetradencenal (40 g/trap) had no effect on trap catch.In cooperation with the Texas Agricultural Experiment Station, Texas A&M University, College Station, Texas 77843.This paper reports the results of research only. Mention of a pesticide in this paper does not constitute a recommendation for use by the USDA nor does it imply registration under FIFRA as amended. Also, mention of a commercial or proprietary product in this paper does not constitute an endorsement of this product by the USDA.     

Sex Pheromones of Thysanoplusia intermixta and T. orichalcea: Identification and Field Tests

Thysanoplusia intermixta, which inhabits the temperate zone in Japan, is a defoliator of plants in the family Compositae, Apiaceae, and others. By GC-MS analysis, (Z)-7-dodecenyl acetate, (Z)-7-dodecen-l-ol, (5E, 7Z)-5,7-dodecadienyl acetate and (5E, 7Z)-5,7-dodecadien-l-ol were identified from a pheromone gland extract of the virgin females in a ratio of 18:3:100:13. A lure baited only with the major diene acetate could attract male moths of T. intermixta in the field. Other minor components had a synergistic effect on the attraction of the diene acetate. The same four components were included in a very different ratio of 100:6:11:1 in the gland extract of Thysanoplusia orichalcea, a closely related subtropical species. The monoene and diene acetates are essential for field attraction, and a 100:11 mixture is an optimum lure for T. orichalcea males. However, this mixture, including the diene acetate as a minor component, captured very few T. intermixta males, suggesting the possibility that these two Thysanoplusia species are reproductively isolated from each other by pheromonal communication.     

Genetic Basis to Divergence of Sex Pheromones in Two Closely Related Moths, <Emphasis Type="Italic">Ostrinia scapulalis</Emphasis> and <Emphasis Type="Italic">O. zealis</Emphasis>

Crossing experiments between two closely related moths, Ostrinia scapulalis and O. zealis, were conducted to gain insight into the genetic basis of the divergence of female sex pheromones. The sex pheromone of O. scapulalis comprises (E)-11- and (Z)-11-tetradecenyl acetates (E11 and Z11), and distinct genetic variation is found in the blend of components. This variation is largely controlled by a single autosomal locus with two alleles, A^E(sca) and A^Z(sca). E-type (A^E(sca)A^E(sca)) females produce a pheromone with amean E11:Z11 ratio of 99:1, whereas Z-type (A^Z(sca)A^Z(sca)) and I-type (A^E(sca)A^Z(sca)) females produce a pheromone with a mean of 3:97 and 64:36, respectively. O. zealis is distinctive in that it has a third pheromone component, (Z)-9-tetradecenyl acetate (Z9), in addition to E11 and Z11, and the typical blend ratio is 60:35:5 (Z9:E11:Z11). Our study revealed that Z9 production in O. zealis is mainly regulated by an autosomal recessive gene phr^(zea), which is suggested to be involved in the chain-shortening of a pheromone precursor fatty acid, and linked to A^E(zea), a gene corresponding to A^E(sca) in O. scapulalis. A few mutations in a gene involved in pheromone production could explain the dramatic shift between a two-component pheromone communication system in O. scapulalis and a three-component system in O. zealis.     

Sex pheromone of femaleMyelois cribrella Hübner (Lepidoptera: Pyralidae)

Females ofMyelois cribrella contain about 20 ng/gland of the primary sex pheromone components (Z)-9-tetradecenyl acetate, (9Z,12E)-9,12-tetradecadienyl acetate, and (Z)-11-hexadecenyl acetate in proportions of 4115, respectively. These physiologically active components are accompanied by a number of related compounds such as (Z)-9-tetradecen-1-ol, hexadecyl acetate, (9Z,12E)-9,12-tetradecadien-1-ol, (Z)-11-hexadecen-1-ol, octadecyl acetate, octadecan-1-ol, and eicosyl and docosyl acetates. Octadecyl acetate, the most abundant component, represents about 42 ng/female moth; however, no physiological activity could be attributed to it. In field tests, a trap baited with a 1-mg mixture of (Z)-9-tetradecenyl acetate, (9Z,12E)-9,12-tetradecadienyl acetate, and (Z)-11-hexadecenyl acetate in a ratio of 121 caught more male moths than three live female moths.Pheromones, 58. Pheromones, 57: Bestmann et al. (1987).     

Identification of male cabbage looper sex pheromone attractive to females

A multicomponent pheromone produced by male cabbage looper moths that is attractive to female moths in a flight tunnel bioassay was isolated and identified. Based on analyses of hairpencil extracts of male cabbage loopers and volatiles emitted by males, the pheromone has been identified as a blend consisting of (S)-(+)-linalool,p-cresol, andm-cresol. The chirality of the major component, (S)-(+)-linalool, is important for behavioral response of females. These pheromonal compounds were also identified as volatiles released by males when males were exposed to the principal pheromone component of female cabbage loopers, (Z)-7-dodecen-1-ol acetate. The amount of male pheromone released was increased significantly when males were exposed to a combination of (Z)-7-dodecen-1-ol acetate and the odor from cabbage. Neither linalool nor the cresols were detected in volatiles from cabbage or from males exposed to cabbage odor.     

Intrapopulational changes in sex pheromone composition during scotophase in oriental tobacco budworm,Helicoverpa assulta (Guenée) (Lepidoptera: Noctuidae)

Solvent extracts of individual pheromone glands were prepared from femaleHelicoverpa assulta (Guenée) at 2-hr intervals throughout the scotophase. The amounts of female sex pheromone components, (Z)-9-hexadecenal, (Z)-11-hexadecenal, (Z)-9-hexadecenyl acetate, and (Z)-11-hexadecenyl acetate, in the extracts were determined by gas chromatographic analysis. Although females called from early scotophase (2 hr) until late scotophase (6 hr) the quantity of extracted pheromone remained high at 8 hr, the end of the scotophase. More than 70% of the pheromone gland extracts contained sex pheromone components regardless of whether the donor females had been called or resting. Pheromone components were absent from gland extracts prepared at the onset of the scotophase. The quantity of (Z)-9-hexadecenal and (Z)-11-hexadecenal increased rapidly to reach a maximum of approximately 260 and 30 ng/female, respectively, that was maintained for up to 8 hr, the duration of the scotophase. The quantity of (Z)-9-hexadecenyl acetate and (Z)-11-hexadecenyl acetate increased continuously during the scotophase to peak at 600 and 30 ng/female, respectively, 8 hr into the scotophase. At the end of scotophase the quantity of all pheromone components decreased significantly.     

Differences in oxidase and esterase activities involved in pheromone biosynthesis in two species ofChoristoneura

The released pheromone and the glandular lipids, labeled with [¹⁴C]acetate, were analyzed fromChoristoneura orae andChoristoneura fumiferana budworm moths by thin-layer chromatography and autoradiography. Radiolabeled lipids in the gland appeared to be identical in the two moths with both insects containing high amounts of 11-tetradecenyl acetates. In contrast, theC. orae moths released primarily labeled acetate ester and alcohol, and the spruce budworm moths (C. fumiferana) labeled aldehyde consistent with the known composition of their respective pheromones. The levels of the enzymes responsible for converting the acetate ester into aldehyde were found to be significantly lower in gland extracts fromC. orae moths than fromC. fumiferana moths. These results implicate an acetate esterase and an alcohol oxidase in controlling the composition of the pheromone blend released from closely related budworm species.     

Interpopulational variation in emitted pheromone blend of cabbage looper moth,Trichoplusia ni

Female cabbage looper moths,Trichoplusia ni, from laboratory colonies initiated from three locations across the United States emitted similar quantities and blend ratios of the six known pheromone components. In contrast, females from a long-established laboratory colony emitted a greater proportion of four of the five minor components relative to the major component, (Z)-7-dodecenyl acetate; only the relative proportion of 11-dodecenyl acetate was similar in all of the populations sampled. Females from this population emitted (Z)-7-dodecenyl acetate at a rate similar to that from females from field-collected colonies. Within each population there were highly significant correlations among the quantities of pheromone components of similar molecular weights. Correlations between components of different molecular weights were not as great, but often were significant. Similarities of blend ratios among field populations may indicate that the chemical signal in this species is conservative. The difference of the blend ratios in our laboratory population from the other populations may indicate a decrease in the intensity of selection pressure that usually would maintain these values.     

Chemistry and field evaluation of the sex pheromone of western spruce budworm,Choristoneura occidentalis,Freeman

Chemical analyses and field bioassays showed a mixture of 92% (E)- and 8% (Z)-11-tetradecenal to be the sex attractant pheromone of the western spruce budworm,Choristoneura occidentalis Freeman. Females were also found to emit small amounts of the corresponding acetates and alcohols, but these components were not active in the bioassay. In contrast, in whole female tip extracts, (E)-11-tetradecenyl acetate predominates, and aldehyde pheromone components are present in lesser quantities, suggesting that final biosynthesis of pheromone takes place just prior to or during emission. At release rates approximating that of the female (2–4 ng/hr), a 928EZ blend of the synthetic aldehydes was at least as attractive as live females. Addition of the corresponding acetates or alcohols up to 50% of the aldehyde content did not significantly enhance or inhibit attraction. No major differences were apparent in pheromone production of females from a laboratory stock or from field collections from diverse geographic locations ranging from Colorado to British Columbia.     

Sex pheromone of a conifer-feeding budworm,Choristoneura retiniana,Walsingham

Sex pheromone components collected from femaleChristoneura retiniana included 11-tetradecenyl acetates and alcohols. The major component wasE-11-tetradecenyl acetate (E11–14Ac) with a lesser amount ofZ isomer necessary to induce male response. A 928 ratio ofE,Z11–14 Ac appeared optimal. The alcohol component was present at about 10% of the total pheromone mixture, and traps baited with acetates plus alcohol surpassed unmated females in their degree of attractiveness. Chemical analysis indicated a 9:1 ratio of theE — Z isomers of 11-tetradecenyl alcohol (11–14ol) pheromone components, although bait formulations containing a predominance of either theE orZ isomers were equally successful in field bioassays. Based on male response to traps,E- andZ11–14Ac (928E — Z) are essential pheromone components for long-range sex attraction. The 11–14 ol enhanced attraction when added at 10% of the total pheromone blend.This paper reports the results of research only. Mention of a commercial product does not constitute a recommendation by the U.S. Department of Agriculture.     

Identification of volatile sex pheromone components released by the southern armyworm,Spodoptera eridania (Cramer)

Analysis of sex pheromone gland extracts and volatile pheromone components collected from the calling female southern armyworm,Spodoptera eridania (Cramer), by high-resolution capillary gas chromatography and mass spectroscopy indicated that a number of 14-carbon mono- and diunsaturated acetates and a monounsaturated 16-carbon acetate were produced. Gland extracts also indicated the presence of (Z)-9-tetradecen-1-ol. However, this compound was not found in collections of volatiles. Field trapping studies indicated that the volatile blend composed of (Z)-9-tetradecen-1-ol acetate (60%), (Z)-9-(E)-12-tetradecadien-1-ol acetate (17%), (Z)-9-(Z)-12-tetradecadien-1-ol acetate (15%), (Z)-9-(E)-11-tetradecadien-1-ol acetate (5%), and (Z)-11-hexadecen-1-ol acetate (3 %) was an effective trap bait for males of this species. The addition of (Z)-9-tetradecen-1-ol to the acetate blends tested resulted in the capture of beet armyworm,S. exigua (Hubner), males which provides further evidence that the alcohol is a pheromone component of this species.