Response ofHeliothis virescens to pheromonal components and an inhibitor in olfactometers

Summary Laboratory-reared males ofHeliothis virescens (F.) that were released in olfactometers in the laboratory were attracted to theH. virescens synthetic pheromone, but not to (Z)-9-tetradecen-1-ol formate (Z-9-TDF), or to either pheromonal component, (Z)-11-hexadecenal (Z-11-HDAL) or (Z)-9-tetradecenal (Z-9-TDAL). Also, they did not respond to the pheromone when it was dispersed simultaneously with Z-9-TDF. The proximity of the test chemicals in the olfactometer made little, if any, difference in the response ofH. virescens males to the pheromone source. Preexposure to the synthetic pheromone, Z-9-TDF, Z-11-HDAL, or Z-9-TDAL greatly reduced the number ofH. virescens males responding to the pheromone. This reduction was probably caused by habituation of the moths to these chemicals.The authors wish to thank A. H. Baumhover, E. Hart and other personnel of the Tobacco Research Laboratory, Oxford, N. C., for supplying many of the insects used in these studies.     

Enhanced production of aggregation pheromones in four stored-product coleopterans feeding on methoprene-treated oats

Summary Production of aggregation pheromones by maleOryzaephilus surinamensis, O. mercator, Cryptolestes ferrugineus, andTribolium castaneum was enhanced by feeding on methoprene-treated oats, implicating juvenile hormone in control of pheromone production. Methoprene application to control insects in stored food products may cause enhanced pheromone production by these insects, thus drawing additional beetles into the treated product.Acknowledgments. We thank Dr. G. B. Staal of Zoëcon Corp. for a generous gift of methoprene. Particular thanks are due to J. Dodic for technical assistance. Research funded by the Natural Sciences and Engineering Research Council of Canada and the Science Council of British Columbia.     

The legs ofMusca domestica andGlossina morsitans females as the site of sex pheromone release

Summary The site of sex pheromone release inMusca domestica andGlossina morsitans is the legs. Unicellular glands restricted to the tarsi and to the tibia are proposed as the source of the pheromone. The structure of the glands is described.Acknowledgments. TheMusca domestica stock, obtained from Dr H. Penner at the Department of Health, Jerusalem, was the insecticide-susceptible strain of the WHO Centre, The Zoological Institute, University of Pavia, Italy. Dr A.M. Jordan of the Tsetse Research Laboratory at Bristol suppliedGlossina morsitans pupae.     

Mating attempts between the Scarlet Tiger Moth,Callimorpha dominula L., and the Cinnabar Moth,Tyria jacobaeae L. (Lepidoptera: Arctiidae), involve a common sex pheromone composition

It has been suggested that a common sex pheromone composition may account for interspecific sexual interactions observed with certain moths in the Arctiidae. In this study, it is demonstrated that the sex pheromones released by females of the Scarlet Tiger Moth,Callimorpha dominula L., and the Cinnabar Moth,Tyria jacobaeae L., have similar activities and elute at the same retention time on analysis by coupled gas chromatography (GC)-electrophysiology with males from each species. Peak enhancement on GC, chiral GC and coupled GC-mass spectrometry using authentic compounds show that the sex pheromone for bothC. dominula andT. jacobaeae is (3Z,6Z,9S,10R)-9,10-epoxyheneicosa-3,6-diene.     

Dissection of the pheromone-modulated flight of moths using single-pulse response as a template

The upwind flight of male moths to conspecific females is mediated by the chemical and structural characteristics of a pheromone plume. We describe the reaction of maleCadra cautella, the almond moth, to the interception of single pulses of sex pheromone, the smallest structural units of odour plumes. Following loss of a pheromone plume, males cast, that is fly a crosswind course without progressing upwind. The response of casting males to interception of a pulse of 0.25 s duration was, after a delay of 0.21±0.07 s, to turn and briefly fly straighter upwind, resulting in average net upwind displacements of 18 cm in a 50 cm s^–1 wind. Upwind progress in the single-pulse response was the result of steering more upwind and an increase in airspeed, although average ground speed remained unchanged. During the last third of the surge, males turned crosswind, returning to casting flight. These behavioural reactions to pheromone contact and loss support the phasic-tonic model of odour-modulated flight, in which an underlying tonic counterturning rhythm, expressed upon pheromone loss, is briefly overridden by phasic upwind surges, expressed upon interception of the pheromone filament. The surge portion of the cast-surge-cast response was diminished and more crosswind if individual pulses were shorter (0.02 s), probably due to sub-optimal contact with pheromone. The cast-surge-cast response to interception of a single 0.25 s pulse was used as a template to interpret the form of flight tracks in plumes of known structure. The template matched portions of flight tracks of males flying in plumes of low pheromone pulse frequency, thus reflecting the male's pattern of pulse encounter. In plumes ensuring a high frequency of pulse interception, only the upwind surge portion of the template was expressed, resulting in nearly straight upwind flight tracks. Similar nearly straight upwind flight tracks occurred in flights along plumes of low pulse frequency with large volume. Thus flight tracks of maleC. cautella to point sources of pheromone depend on both the frequency and the size of filaments encountered.     

Avoidance of competition by spruce bark beetles,Ips typographus andPityogenes chalcographus

Bark beetles,Ips typographus andPityogenes chalcographus, attracted by synthetic or natural pheromone to Norway spruce logs,Picea abies, preferred to colonize uninfested logs rather than logs occupied by these beetles, probably as a means of avoiding intra-and interspecific competition. The aggregation pheromone components ofP. chalcographus, chalcogran and methyl (E, Z)-2,4-decadienoate, inhibited the attraction response ofI. typographus to its pheromone components (methyl butenol andcis-verbenol), while the converse was not true. However, verbenone released from colonized bark inhibited pheromonal response ofP. chalcographus.     

2-Phenylethanol,a presumed sexual stimulant produced by the male cabbage looper moth,Trichoplusia ni

Summary A sex pheromone produced by male cabbage looper moths,Trichoplusia ni (Hübner), has been isolated from the genital scent brushes and identified as 2-phenylethanol. It is shown conclusively to elicit specific behavioural responses in the female (such as wing vibration and abdominal elevation), as determined by a novel behavioural laboratory bioassay. This is taken as further evidence that the male pheromone ofT. ni acts as a sexual stimulant (aphrodisiac) prior to mating. 2-Phenylethanol represents the first identification of a genital scent brush pheromone in the family Noctuidae, and of a male pheromone in the subfamily Plusiinae.Mention of a proprietary product in this paper does not constitute a recommendation or an endorsement of the product by the U. S. Department of Agriculture.     

A sex pheromone from the mandibular glands in bumblebee queens

Summary In this paper it is shown that the mandibular glands of young bumblebee queens produce a species-specific sex pheromone. From our results it becomes obvious that the pheromone is a releaser for the mating attempts made by the conspecific males.Supported by The Netherlands Organisation for the advancement of Pure Research ZWO.     

o-Aminoacetophenone,a pheromone that repels honeybees (Apis mellifera L.)

Summary o-Aminoacetophenone is a pheromone produced by virgin honeybee queens and released with feces. In small social groups, the pheromone repels and is used to terminate agonistic interactions between queens and workers.     

Bombykol biosynthesis from deuterium-labeled (Z)-11-hexadecenoic acid

Summary (Z)-[11,12d ₂]-11-Hexadecenoic acid was applied topically to the pheromone gland of silkworm pupa. After eclosion, the gland components were analyzed by capillary GC-MS. (Z)-11-Hexadecenoic acid, a characteristic fatty acid of the gland, was found to be a precursor of bombykol, (Z)-11-hexadecenol and bombyk acid.We are greatful to Dr Y. Tamaki and Mr H. Sugie of the National Institute of Agricultural Science for mass spectrometric analysis and Dr M. Noda of Kyoto Prefectural University for valuable discussion. This work was supported by a Grant-in-aid for Scientific Research (to K.H. No. 56112011) from the Ministry of Education, Science and Culture of Japan.     

Endogenous suppression of pheromone production in virgin female moths

Summary Sexual receptivity generally is reduced in moths after mating. We found that even in virginHeliothis zea females the titer of pheromone declines after the third night of adult life, although the number of eggs laid increases. Reduction in pheromone titer is not due to reduced amounts of pheromone biosynthesis activating neuropeptide. We have discovered that a substance present in the bursa, ovaries and hemolymph of senescing virgins suppresses pheromone production. A similar factor was found in 2-day-old mated females indicating that both virgin and mated females use this factor to suppress pheromone production.     

Spruce budworm: Effects of different blends of sex pheromone components on disruption of male attraction

Summary Disruption of attraction of maleChoristoneura fumiferana to the natural sex pheromone in an atmosphere permeated by blends of the 2 pheromone components is greatest with ratios of the 2 components close to the natural blend.The (E)- and (Z)-TDALs were obtained from ChemSampCo, Columbus, Ohio, and were further purified by argentation column chromatography on Hi-Flosil-Ag (20% AgNo₃), 60/200 mesh, eluting with 91 pentane: ether. Following formulation, (E)(Z) ratios in the PVC were determined by extracting PVC pellets for 6 h in hexane and analyzing the solvent by GLC. The chemical analyses and purifications were carried out by Ms Linda MacDonald of the Forest Pest Management Institute, Sault Ste. Marie, Ont., to whom I would like to express my thanks.Analyses of the data were done with the help of Dr J. Régnière of the Great Lakes Forest Research Centre, Sault Ste. Marie, Ont. whom I would also like to thank.     

Biosynthesis of a monoene and a conjugated diene sex pheromone component of the lightbrown apple moth by Δ11 desaturation

Summary Fatty acyl moieties present in the female sex pheromone gland of the lightbrown apple moth,Epiphyas postvittana, include the analogues of the two sex pheromone components, (E)-11-tetradecenyl acetate and (E,E)-9,11-tetradecadienyl acetate. Application of deuterium-labelled fatty acids followed by analysis by gas chromatographymass spectrometry showed that biosynthesis of the two pheromone components involved initial 11-desaturation of myristic and palmitic acids respectively.     

Occurrence of a pheromone-producing gland in female tobacco beetles

Summary A pheromone-producing gland was discovered in the second abdominal segment of virgin female tobacco beetles,Lasioderma serricorne (Fabricius). The gland duct extends to an orifice below the genital pore and is supported by a rigid invagination of the integument. Hexane extracts of intact pheromone glands were found attractive to male tobacco beetles and also induced high receptor potentials in the olfactory sensilla of the antennae of maleL. serricorne. A surface extract of virgin females proved to be significantly more attractive than an extract of pheromone glands.     

Sex pheromone conversion and degradation in antennae of the silkworm mothBombyx mori L.

Summary In living antennae of the silkworm mothBombyx mori L. the pheromone compound (E, Z)-10,12-hexadecadienol and hexadecanol are enzymatically converted to their corresponding fatty aldehydes, acids and long-chain fatty acid esters. The pheromone is completely degraded at high rates in the antennae of freshly hatched moths. The polar volatile [³H]metabolites exclusively consist of tritiated water. The half-life of the pheromone is about 2.5 min in males and 0.5 min in females. Drying inactivates the enzymes responsible for pheromone oxidation.Dedicated to Professor Adolf Butenandt on the occasion of his 85th birthday     

Hormonal control of pheromone responsiveness in the male black cutwormAgrotis ipsilon

In Lepidoptera, reproduction is linked to chemical communication between conspecific partners. When exposed to the female sex pheromone, males respond by exhibiting typical sexual behaviour which leads to mating. Here we show that presence of the juvenile hormone producing gland (corpora allata) of the male black cutworm,Agrotis ipsilon, is necessary for pheromone responsiveness. Allatectomized males do not show any sexual behaviour, although their antennal olfactory system is functional. Allatectomized males implanted with active corpora allata recover full pheromone receptivity. It is suggested that reproductive processes are synchronized in males and females through endocrine control; timing of the mating activity could serve as an adaptive strategy linked to the migratory behaviour of this species.     

Female sex pheromone of the longhorn beetleMigdolus fryanus Westwood: N-(2′S)-methylbutanoyl 2-methylbutylamine

The first known long-range female-released sex pheromone for the family Cerambycidae is reported fromMigdolus fryanus, a sugarcane pest in South America. Although two female-specific compounds, namely, N-(2S)-methylbutanoyl 2-methylbutylamine and N-formyll-isoleucine methyl esters were identified, field tests with synthetic chemicals revealed that only the amide was active and that the amino acid derivative neither increased or decreased trap catches by the amide. This is the first identification of amide as a sex pheromone.     

Influence of larval diapause on pheromone communication in the khapra beetle,Trogoderma granarium everts

Summary InTrogoderma granarium, induction of larval diapause by sub-optimal temperature enhanced the efficiency of pheromone perception by adult males. Such diapause also altered the pattern of pheromone production by females.     

Methoxymercuration-demercuration and mass spectrometry in the identification of the sex pheromones ofPanolis flammea,the pine beauty moth

Summary The major components of the sex pheromone system ofPanolis flammea, pine beauty moth have been identified as (Z)-9-tetradecenyl acetate, (Z)-11-hexadecenyl acetate and (Z)-11-tetradecenyl acetate in the ratio 10051; the double bond position of these derivatives was established by microscale application of a methoxymercuration-demercuration technique and GC-MS followed by multiple ion monitoring.We thank the Science Research Council and Forestry Commission for financial support. We are grateful for the collaboration of Messrs Stoakley and Bevan, Dr C. Longhurst and Mrs J. Edwards.     

Evidence for inhibition of corpora allata activity in workers ofBombus terrestris by a pheromone from the queen's mandibular glands

Summary Queens ofBombus terrestris inhibit the activity of worker corpora allata by means of a pheromone which is produced in their mandibular glands. Exstirpated and homogenized glands as well as an extract of the queen's body surface show the same inhibitory effect as a living unmutilated queen. The pheromone remains on the body only for 1 day after the queen has been killed. The activity of the corpora allata of workers was determined volumetrically as well as by means of a juvenile hormone synthesis in vitro assay.Acknowledgment. The work was supported by the Netherlands Organisation for the advancement of pure research, ZWO.