Foveal glands,source of sex pheromone production in the ixodid tickDermacentor andersoni stiles

The foveal glands of the Rocky Mountain wood tick,Dermacentor andersoni Stiles, are the sex pheromone glands from which the sex pheromone is released via the foveae dorsales. The sex pheromone, 2,6-dichlorophenol, was recovered from extracts of these glands by GLC. Other evidence of the role of these glands in sex pheromone production is described. A³⁶Cl-labelled volatile compound (or compounds) was (were) collected from partially engorged femaleD. andersoni fed in³⁶Cl-labelled hosts, but no labelled compounds were collected when the foveae dorsales were blocked. X-ray analysis revealed unusual concentrations of chlorine in the foveal glands compared to other tissues. Autoradiography also revealed significant accumulations of radiochlorine in the vicinity of these glands.Presumably, the foveal glands of the American dog tick,Dermacentor variabilis (Say), are the sex pheromone glands of that species also, since a³⁶Cl-labelled volatile was collected from female ticks fed on a³⁶Cl-labelled host. However, attempts to recover 2,6-dichlorophenol from gland extracts or volatile emissions fromD. variabilis were unsuccessful.Supported by grants AI 10,986 and AI 10,987 from the National Institute of Allergy and Infectious Diseases, U.S. Public Health Service, U.S. Department of Health, Education and Welfare, Bethesda, Maryland, 20014.     

Male sternal pheromone glands in Acanthosomatid shield bugs from Britain

Pheromone glands are present in the abdominal sternites of the pregenital region in the male adults in all British species of Acanthosomatidae. Secretory units are most numerous in the hawthorn bugAcanthosoma haemorrhoidale and maternal bugElasmucha grisea, next most numerous in the birch bugElasmostethus interstinctus, and least numerous in the juniper bugCyphostethus tristriatus. The largest dorsal abdominal scent glands were found inCyphostetheus. Ordinary dermal glands are also present. They are most numerous along the lateral margins of the abdomen. It is possible that Pendergrast's organ is the source of a female-produced pheromone. Secretory units were numerous in this organ inC. tristriatus female adults.     

Biosynthesis,production site,and emission rates of aggregation-attachment pheromone in males of twoAmblyomma ticks

The aggregation-attachment pheromone componentso-nitrophenol (ONP) and methyl salicylate (MS) in maleAmblyomma variegatum ticks appeared after three days of feeding on the host and reached high values after about six days. Variable quantities of 1.3–7.3 g ONP and about 0.6 g MS were present within ticks. ONP and MS were released at the high rates of 300–1800 ng/hr and 20–600 ng/hr per male tick, respectively. After a temporary decrease, males continued to emit at high rates after nearby attachment of females. InA. hebraeum, ONP showed a similar pattern, but with a delay of about a day. A male, which had fed during 14 days, contained about 2 g and released 225–280 ng/hr. Emission in forcibly detached males of both species dropped rapidly to low levels of less than 10 ng/hr per tick. Host skin and tick feces in the vicinity of feeding males were pheromoneimpregnated. The very high emission rates are consistent with the observations that the pheromone is an important component of the host-location mechanism of conspecifics. ONP and MS are produced in the dermal glands type 2 associated with the ventrolateral cuticle.     

Morphology and chemistry of brown rat,Rattus norvegicus,preputial and clitoral glands

In contrast to previous results from laboratory rats, when sexual dimorphism occurred, clitoral glands from wild female rats were heavier and accounted for a greater proportion of body mass than preputial glands from wild males. Gland length and weight increased with body weight, but gland weight as a proportion of body weight did not. Preputial and clitoral glands showed seasonal differences in size: at one site glands were smaller in December than in April. Maturity, estrus, and pregnancy had no significant effect on clitoral gland size, but immature males had proportionally smaller preputial glands than mature males, and the absolute gland weight, but not gland weight as a proportion of body weight, increased with testes weight. There were no differences between the sexes in lipid production, which increased with preputial or clitoral gland weight. An homologous series of aliphatic acids and their methyl and ethyl esters, plus squalene, cholesterol and lanosterol, was revealed by GC-MS study of the trimethyl silyl derivatized lipid extract. Males and females could be distinguished by principal component analysis of chromatogram peaks.     

The sex pheromone glands ofDermacentor variabilis (Say) andDermacentor andersoni stiles

Evidence is presented indicating the presence of the tick sex pheromone, 2,6-dichlorophenol in lipid droplets in the foveal glands ofDermacentor variabilis (Say) andDermacentor andersoni Stiles. The pheromone appears to be dissolved in the lipid droplets. The droplets consist of neutral lipids, mostly triacylglycerides and cholesterol esters. The esterified fatty acid profiles of foveal gland triacylgylcerides are different from those of other tissues examined or reported for other ticks. The percentage of shorter chain, mostly saturated fatty acids were decreased, while the longer chain polyunsaturated fatty acids were increased. The biological advantages of lipid solution for storage, translocation, and release of the sex pheromone from the female tick are discussed.Supported by grant AI 10986, from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, U.S. Public Health Service, Department of Health, Education and Welfare, Bethesda, Maryland.     

A high-efficiency collection device for quantifying sex pheromone volatilized from female glands and synthetic sources

A high-efficiency collection device for sex pheromones volatized from forcibly extruded female glands is described. Filtered nitrogen gas is the carrier and glass wool the adsorbent. Small quantities of distilled carbon disulfide are used to rinse the glass wool. Recovery efficiency of synthetic compounds was usually 90–100%, and a mean of 2.4 ± 0.65 SD ng/min of (Z)-7-dodecenyl acetate was recovered in emissions from individualTrichoplusia ni (Hubner) glands.     

The attractivity of the female sex pheromone ofPeriplaneta americana and its components for conspecific males and males ofPeriplaneta australasiae in the field

The attractivity of virgin female odors of the American cockroach was examined in field experiments. Crude extracts of the female odor, the isolated sex pheromone fractions, periplanone-A and periplanone-B, and other compounds obtained during the isolation served as stimulants. An extract of male odors, obtained by identical collection methods, was used as a control. Males ofPeriplaneta americana were attracted by the crude extract and periplanone-B; males of the sympatric species,P. Australasiae, by periplanone-A. Experiments in which these components were presented subsequently and as mixtures indicate that, under certain conditions, periplanone-A may also function as an attracting substance forP. americana males and that periplanone-B and possibly some other components act as an inhibitor for males ofP. australasiae.     

Production of pheromone by hairpencil glands of males obtained from interspecific hybridization betweenHeliothis virescens andH. subflexa (Lepidoptera: Noctuidae)

Pheromone produced by the hairpencil glands of interspecific hybrid- and backcross-generation males from crosses betweenHeliothis virescens (F.) withH. subflexa (Gn.) was studied. Males of reciprocal F₁ hybrids, all of which had hairpencil glands morphologically similar to those ofH. virescens, produced neither the same pheromone blend nor amounts of pheromone that were produced by males ofH. virescens. Instead, these hybrid males produced pheromone that was quantitatively and qualitatively similar to that produced byH. subflexa. Hairpencil gland extracts from males obtained from backcrossing F₁ females of either cross to males ofH. subflexa were the same as those ofH. subflexa. However, extracts from backcross males of crosses between F₁ females andH. virescens were variable. Some extracts from these backcross males were like those ofH. virescens while others were either likeH. subflexa or were intermediate between those of the parent species. These results showed that the production of pheromone by the hairpencil glands of hybrid and backcross males is under the dominant regulation of autosomal genes of theH. subflexa genome.     

Patterns of deposition of urine containing chemosignals that affect puberty and reproduction by wild stock male and female house mice (Mus domesticus)

House mice release chemosignals in their urine that influence the timing of puberty and reproductive condition in conspecific females. These experiments tested the possibility that mice depositing urine containing chemosignals that affect puberty and reproduction do so differentially with respect to urine cues from conspecifics. Mice were tested in cages containing samples of urine or water on cotton in wire mesh capsules protruding from the cage floor. Their urine deposition patterns were recorded on squares of filter paper positioned below the cages. Males deposited more urine than females housed in groups, estrous females, diestrous females, or prepubertal females. All groups of mice deposited urine in a nonrandom fashion with regard to urine cues from conspecifics. Male mice deposited more urine near locations previously soiled by females than near water or other males. Grouped females deposited more urine near male urine cues and avoided depositing urine near urine from other group-housed females. Both estrous and diestrous female mice deposited more urine near males than near other urine cues or water, possibly to attract mates. Prepubertal females avoided depositing their urine near male urine and urinated more near urine from grouped females than near other urine types or water. Young females may be avoiding possible male mates until they have attained puberty. This avoidance behavior may enhance the long-term reproductive success of the females that otherwise might mature and mate at too young an age.     

Influence of lectins on female sex pheromone reception byHeterodera schachtii (Nematoda: Heteroderidae) males

A bioassay was developed in which the chemotactic behavior of males of the sugarbeet cyst nematodeHeterodera schachtii towards the female sex pheromone can be observed and documented at any time. The standardized test, performed under sterile conditions, gives reproducible results within 1–2 hr. Incubation of males with the lectins fromCanavalia ensiformis, Triticum vulgare, Arachis hypogaea, Helix pomatia, andLimax flavus did not affect chemotactic attraction to the sex pheromone. Supplementing the bioassay medium with the lectin fromC. ensiformis also had no effect.C. ensiformis lectin binding to the surface of the exudate produced by the secretory gland cell of the amphids, the main chemoreceptors, did not inhibit the passage of fluorochrome fluorescein isothiocyanate into the amphidial canals, where the receptor dendrites are localized. Amphidial exudate synthesis was enhanced during pheromone reception.     

Influence ofHeliothis virescens sex pheromone dispensers on captures ofH. zea males in pheromone traps relative to distance and wind direction

Evaluations conducted by placingHeliothis virescens (F.) sex pheromone (virelure) dispensers at different distances in the predominant downwind and upwind directions fromHeliothis zea (Boddie) pheromone traps indicated that reductions inH. zea male captures were greatest relative to distance when theH. zea traps were located downwind from the virelure dispensers than when the traps were located upwind. When operating traps for both species at the same site, the influence of virelure dispensers on captures inH. zea pheromone traps would be minimized by placing theH. zea traps upwind of theH. virescens traps and, if wind direction is variable, the traps should be spaced at least 75 m apart.Lepidoptera: Noctuidae.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 commercial or proprietary product in this paper does not constitute an endorsement of this product by USDA.     

Courtship pheromone production and body size as correlates of larval diet in males of the arctiid moth,Utetheisa ornatrix

Hydroxydanaidal, the corematal courtship pheromone of maleUtetheisa ornatrix, shows pronounced quantitative variation in natural populations of the moth. Males that, as larvae, fed on seed-bearing rather than immature food plants (Crotalaria spectabilis orC. mucronata) produce higher levels of hydroxydanaidal. Such males also have higher systemic loads of pyrrolizidine alkaloid, the known metabolic precursor of hydroxydanaidal, whichUtetheisa sequester from their larval diet and which is concentrated in the seeds ofCrotalaria. Males raised on seed-bearing plants also achieve higher adult weight. In the context of sexual selection, therefore, femaleUtetheisa could, through assessment of male hydroxydanaidal levels, gauge both the alkaloid content and body weight of their suitors.     

Rhythms of maleAntheraea polyphemus Attraction and female attractiveness,and an improved pheromone sythesis

WildAntheraea polyphemus (Cramer) (Lepidoptera:Saturniidae) males were attracted to synthetic pheromone and to laboratory-reared females from 2300 (EDT) until dawn. Males were attracted to the synthetic pheromone at a mean time of 01:33 and to the females at 0323 (EDT). Synthetic traps accumulated the most males (61 compared to 19 in the female-baited traps), but there was no large difference in catch during the main interval of female attractiveness. Pheromone used in the study was prepared by an improved synthesis that utilizescis-4-nonen-1-yl bromide as a key intermediate.Lepidoptera:Saturniidae.     

Responsiveness ofPseudaletia unipuncta (Lepidoptera: Noctuidae) males,maintained as adults under different temperature and photoperiodic conditions,to female sex pheromone

Different-agedPseudaletia unipuncta (Haworth) males, maintained as adults at 10 and 25°C under 16∶8 and 12∶12 light-dark photoperiodic regimes, were flown to a 30-μg pheromone source in a wind tunnel at 20°C. While the responsiveness of individuals reared under both photoperiodic conditions at 25 °C was similar by day 5 (65–75%), response levels of younger males showed that those reared at 16∶8 light-dark matured more rapidly than those under 12∶12 light-dark. A significant delay in the onset of responsiveness was observed for males reared under 10°C with less than 25% of individuals responding to the pheromone, even at 25 days old. At this temperature, photoperiodic conditions had no significant effect on male receptivity. When males are transferred from 10°C to 25°C 16∶ 8 light-dark, their level of responsiveness after five days was similar to control 5-day-old males reared at 25°C, 16∶8 light-dark. These results are discussed relative to the hypothesis that this species migrates in response to seasonal cues that indicate a predictable habitat deterioration.     

Evidence for a short-range sex pheromone in female Maladera matrida beetle

Laboratory studies with live and frozen Maladera matrida female and male beetles showed that males were attracted to chemical substances emanating from the females at dusk. Beetles exhibited sexual activity (including mating) at dusk towards frozen females but not towards frozen males. Frozen females that had been extracted with methanol together with either hexane or dichloromethane or with a mixture of all three solvents did not elicit male sexual activity. Activity was fully restored when a concentrate of the extract was applied to the previously extracted frozen females. Males also responded with vigorous sexual activity to frozen males to which female extract had been applied. Deterrent chemicals appear to be absent from the male body. Males exposed to females that had been frozen during the morning displayed weak sexual activity, indicating that females lack active semiochemicals. Differences between dusk and morning extracts were found with respect to more than 20 compounds, some of which were present in much higher concentrations at dusk than in the morning, while others were not detected in the morning extract. The active component(s) of the short-range sex pheromone of female M. matrida is (are) presumably to be found among these compounds.     

Production and release of (Z,E)-9,12-tetradecadienal by sex pheromone glands of females ofPlodia interpunctella (lepidoptera: pyralidae)

Extracts of sex pheromone glands obtained from females ofPloida interpunctella contained detectable amounts of (Z,E,)-9,12-tetradecadien-1-ol acetate (Z9,E12–14:Ac) and (Z,E.)-9,12-tetradecadien-1-ol (Z9,E12–14:OH) 4 hr prior to the first scotophase after adult emergence. The amount of pheromone increased during the first 4 hr of the scotophase and then declined to low levels during the subsequent photophase. Decapitation of females immediately after emergence, prior to expansion of the wings, inhibited production of pheromone during the subsequent 48 hr. Injection of extracts of the heads of 1-day-old females ofP. interpunctella of partially purified extracts of the cephalic ganglia of females of the corn earworm moth into decapitated females stimulated production of bothZ9,E12–14:Ac andZ9,E12–14:OH as well as production of (Z,E)-9,12-tetradecadienal (Z9,E12–14:Al). This aldehyde was subsequently identified from extracts of pheromone glands obtained from naturally calling females as well as from volatiles emitted by calling females. Studies on the terminal steps in biosynthesis of the pheromone showed thatZ9,E12–14:OH was produced from the corresponding acetate and thatZ9,E12–14:Al was produced from the alcohol via the action of an oxidase(s).     

Interspecific attractivity of female sex pheromone components ofPeriplaneta americana

Female sex pheromones ofPeriplaneta americana, P. australasiae, andBlatta orientalis elicit locomotion and upwind orientation in conspecific males. Interspecific attraction between these species was observed in a wind tunnel assay for most species combinations, with the exception ofP. australasiae males not being attracted toP americana females. The role of twoP. americana sex pheromone components, periplanone-A (PA) and periplanone-B (PB) in male attraction was analyzed. PA induced locomotion in males of all three species, with highest threshold concentration inP. americana. PB was effective inP. americana andB. orientalis, but not inP. australasiae. Experiments with mixtures of both components confirmed an inhibitory influence of PB onP. australasiae males when it was added to PA in a ratio of 31 or higher. SinceP. americana andP. australasiae have been found to be syntopous, and their daily mating periods overlap, the female sex pheromone ofP. americana is discussed as an isolating factor between both species.     

Response of male codling moths (Cydia pomonella) to components of conspecific female sex pheromone glands in flight tunnel tests

In flight tunnel tests, the percentages of oriented upwind flights of male codling moths culminating in contacting a source of different compositions of female sex pheromone gland components were determined over a dosage range of 0.1–100,000g. The following compositions were tested: (1) (E,E)-8,10-dodecadien-1-ol of 99.7% isomeric purity; (2) 1 + dodecanl-ol + tetradecan-1-ol; (3) 2 + decan-1-ol + (E)-9-dodecen-1-ol; and (4) an equilibrium mixture of 8,10-dodecadien-1-ol isomers (61%EE, 5%ZZ, 14%ZE, and 20%EZ). The ratios of the components in compositions 2 and 3 were chosen to produce vapor ratios equal to the natural ratios found in the female effluvium by Arn and coworkers. As the dose of composition 1 was increased from 0.1 to 10g, response increased from 0 to about 80% and then was approximately constant from 10 to 300g. Over the range 0.1–300g, the percentage of males contacting the septum was virtually the same as the percentage flying upwind. From 300 to 100,000g, the percentage of males flying upwind and contacting the source steadily decreased from about 80 to 0%. The male responses to compositions 2 and 3 were virtually identical to the response to 1. These results indicate, contrary to published reports, that dodecan-1-ol and tetradecan-1-ol in combination with 1 do not increase the responses of the behavioral modes determining degree of attractancy and disruption of sexual communication over that of 1 alone. These results also show that decan-1-ol and (E)-9-dodecen-1-ol do not enhance response in the five-component mixture. The response to composition 4 increased from 0% at a dose of 0.3g to 26% at a dose of 30g and then decreased to 0% at a dose of 3000g. Thus, the inhibiting effect of the isomers on response was greater at the higher doses.     

Evidence for presence and nature of female sex pheromone ofBrithys crini fabricius (Lepidoptera: Noctuidae)

The existence of a female sex pheromone of the noctuid mothBrithys crini Fabricius was confirmed in both laboratory bioassay and field tests. Crude extracts and airborne volatiles from females were analyzed by gas chromatography and mass spectrometry and the data compared with authentic compounds. The primary sex pheromonal compound was Z11-16: Ald. Scanning electron microscopy showed that the external surface of the sex pheromone gland was covered with folds that might increase the sex pheromone evaporation area.