Sex Pheromone Response Research Articles

Antennal receptor response to sex pheromone mimics in the American cockroach

THE essential oils D-bornyl acetate, α- and β-santalol and several plant sesquiterpene hydrocarbons have been shown to induce sexual excitement in male American cockroaches1, and thus seem to mimic the cockroach sex pheromone. Tahara et al.2 have identified one of the active sesquiterpene hydrocarbon species obtained from Compositae plants as germacrene D. The contrast in structures of these various active compounds poses a serious problem as to the specificity of the sex pheromone receptor. To resolve this we have undertaken an electrophysiological study of the antennal receptors of both male and female cockroaches. The electroantennogram (EAG) responses of both sexes were examined during exposure to the compounds in question. Theoretically the sex specific receptors of the male antennae should respond singularly to natural sex-pheromone (and stereochemical mimics) whereas the female antennae should be unresponsive other than to general irritants and/or to food odours. In fact, the EAG response to the female sex attractant has been obtained in males but not in females3,4.

Correlation of moth sex pheromone activities with molecular characteristics involved in conformers of bombykol and its derivatives.

Molecular characteristics of bombykol and its 11 derivatives, which reveal significant correlations with biological activities for single sex pheromone receptor cells of four moth species, Bombyx mori, Aglia tau, Endromis versicolora, and Deilephila euphorbiae, were examined on the assumption of the "bifunctional unit model." Probabilities of bifunctional unit formations of those 12 compounds were assessed with frequency distribution patterns of distances between the proton acceptor, the proton donor, and the methyl group involved in a total of 1,200 conformers. A highly significant correlation exists between biological activity for each species and the probability of a particular bifunctional unit formation: a proton acceptor (A)--a methyl group (Me) unit (A--Me distances: about 6 A) for Deilephila (r = 0.94); a proton acceptor (A)--a proton donor (D)(A--D: about 11 A) for Aglia (r = 0.83); two antagonistic proton donor--methyl units (D--Me: about 14 and 5 A for favorable and adverse unit, respectively) for Bombyx (r = 0.94) and Endromis (r = 0.92).

A Model of Pheromone Molecule-Acceptor Interaction

Multiple binding interactions between odor molecules and acceptors are formulated by means of the Boltzmann statistics and intermolecular bond energies. Number, spatial arrangement and electronic properties of binding positions of the acceptor can be defined such that the specificity of sex pheromone receptors in male noctuid moths is quantitatively described.

DIEL PERIODICITY OF MALE SEX PHEROMONE RESPONSE AND FEMALE ATTRACTIVENESS IN THE GYPSY MOTH (LEPIDOPTERA: LYMANTRIIDAE)

AbstractIn field studies gypsy moth males were attracted to synthetic cis-7,8-epoxy-2-methyloctadecane (disparlure), the female sex pheromone, and virgin females from 0900 to 2000 (Eastern Standard Time). The greatest numbers of males were lured to the synthetic attractant or the calling female from 1100 to 1500. These periods of male response are longer than reported in previous (1896 and 1932) New England investigations and suggest the possible recent evolution of a new diel rhythm of male sex pheromone response.

Perception of Olfactory Stimuli That Inhibit the Responses of Male Phycitid Moths to Sex Pheromones

Male Plodia interpunctella (Hübner) or Cadra cautella (Walker) became habituated to inhibitors of the sex pheromone response while maintaining their responsiveness to the sex pheromones. From these data we conclude that the inhibitors and the sex pheromones are perceived via separate sensors. Inhibition is a direct and immediate result of sensory input via the appropriate sensors.

Scanning Electron Microscopy of Antennal Sensilla of the European Corn Borer, Ostrinia nubilalis1

Scanning electron microscopy of the antennae of Ostrinia nubilalis (Hubner) moths was used to compare morphological classes and numbers of external sensilla typical of the sexes. These observations are correlated with previous studies of sex pheromone receptor sensilla in Bombyx mori L. for assessment of the physical apparatus responsible for sex pheromone detection in the corn borer. Sensillar classes found on antennae of both male and female corn borers include sensilla styloconica, sensilla chaetica, sensilla coeloconica, sensilla auricillica, sensilla basiconica, and sensilla trichodea. The sensilla trichodea are further subdivided into two distinct types (designated A and B) on criteria of surface substructure and length. Sensilla trichodea are more numerous on the antennae of male moths than on those of females, with the excess surface area of Type A sensilla trichodea estimated at 100% greater in the males. Estimates of numerical totals and distribution along the antennal flagelluni are compared for the sensilla trichodea types for both sexes. The other sensilla of male and female corn borer moths also have been compared with respect to location on the antennae and relative frequency. Complete descriptions of sensillar and antennal morphology as observed with this technique are included.

Natural Inhibitor of the Gypsy Moth Sex Attractant

INHIBITION or masking of sex pheromone response by natural products occurring in the pheromone producing gland has been described in the gypsy moth1, Porihetria dispar (L.), other Lepidoptera2,3 and insects in additional orders4,5 but none of the inhibitors has been identified. We report here that an olefin, 2-methyl-cis-7-octadecene, present6 in the female sex pheromone gland of the gypsy moth, inhibits male attraction to the female sex attractant pheromone, which was identified as cis-7,8-epoxy-2-methyloctadecane6.

Antennal proteins of saturniid moths—Their possible rôle in olfaction

Reception of female sex pheromone is reversibly blocked by exposing male silkmoths ( Antheraea pernyi) to formaldehyde vapours or by bathing their antennae in saline solution. Electrophoretograms of proteins eluted from the male antennae show two major bands. One of these may correspond to the ‘receptor protein’ for the female sex pheromone. An analogous component is present in electrophoretograms of the proteins eluted from the male antennae of two other species, Antheraea polyphemus and Hyalophora cecropia.

Sex pheromones of noctuid moths. XV. Timing of development of pheromone-responsiveness and other indicators of reproductive age in males of eight species.

Three indicators of reproductive maturity—sperm storage, sex pheromone responsiveness, and mating—were examined for males of the following 8 species of the family Noctuidae: subfamily Plusiinae; Trichoplusia ni (Hubner), Autographa californica (Speyer), Pseudoplusia includens (Walker), and Rachiplusia ou (Guenee) ; subfamily Amphipyrinae; Prodenia ornithogalli Guenee and Spodoptera exigua (Hubner) ; subfamily Heliothinae; Heliothis zea (Boddie) and H. virescens (F.). On an average, for the 8 species, movement of sperm bundles from the testes into the ductus ejaculatorius duplex occurred about 1.3 days before the systems for pheromone responsiveness or mating had matured. The 2 last-mentioned systems matured about the same time. In 5 of the species, more than ⅔ of the males contained sperm in the ductus ejaculatorius duplex at the time of emergence from the pupa.