Aggregation pheromone ofCarpophilus antiquus (Coleoptera: Nitidulidae) and kairomonal use ofC. lugubris pheromone byC. antiquus

Males ofCarpophilus antiquus Melsheimer (Coleoptera: Nitidulidae) emit an aggregation pheromone that was found to be a novel hydrocarbon, (3E,5E,7E,9E)-6,8-diethyl-4-methyl-3,5,7,9-dodecatetraene. A synthetic scheme and spectra (mass and proton NMR) are given for the compound. Beetles produced the pheromone when feeding on a variety of media, including the brewer's yeast-based artificial diet, fermenting whole-wheat bread dough, corn, and prunes; live baker's yeast was generally added to the food media. Males held individually produced, on average, 25 × more pheromone per beetle than males held in groups of 10 or more. Pheromone was not produced until males were at least 5 days old but was still detected from the oldest beetles tested (47 days). In field tests, the pheromone was attractive to both sexes ofC. antiquus, and it was synergized by food volatiles: A combination of pheromone and fermenting whole wheat dough attracted 2.5× more beetles than pheromone alone, but dough by itself was not significantly more attractive than the control. Semiochemical interactions were studied amongC. antiquus and two other sympatric species for which pheromones are known,C. lugubris Murray andC. freemani Dobson.C. antiquus responded readily to the pheromone ofC. lugubris, but all other interspecific responses to the pheromones were weak. In a sample of naturally infested corn ears, the presence ofC. antiquus was strongly associated with the presence ofC. lugubris, as would be expected if the pheromone ofC. lugubris serves as a kairomone forC. antiquus.     

Residual activity of oviposition-deterring pheromone inRhagoletis pomonella (Diptera: Tephritidae) and female response to infested fruit

Under dry conditions, oviposition-deterring pheromone (ODP) of the apple maggot fly (Rhagoletis pomonella Walsh) on host fruit proved deterrent to ovipositing females for at least three weeks, with a half-life of ca. 11 days. There was no difference in decline of residual activity under lab vs. field conditions or between fly-deposited ODP vs. an application of a water extract of ODP. A decline in pheromone activity resulted from exposure to both natural and simulated rainfall. For natural rainfall, greatest losses (50– 61%) in activity resulted from high-intensity rains, with substantially less activity lost (13–35%) following light or moderate intensity rains.R. pomonella females discriminated against fruit without ODP but with conspecific larvae. Discrimination against infested fruit was manifested within fewer days following infestation of small fruit (9 mm diam.) as compared to larger fruit (15 mm diam.).     

Deterrence of repeated oviposition by fruit-marking pheromone inCeratitis capitata (Diptera: Tephritidae)

During ovipositor dragging on the fruit surface following egg laying in hawthorne fruit,Ceratitis capitata (Wiedemann) females deposit an unidentified pheromone that deters repeated oviposition attempts in that fruit. The pheromone proved water soluble and, when collected and sprayed in aqueous solution onto uninfested fruits in laboratory cages, effectively deterred boring attempts byC. capitata females of wild origin for at least 6 days (termination of test). A laboratory population ofC. capitata cultured on artificial media for more than 200 generations deposited pheromone that proved equally as deterrent to wild fly oviposition as pheromone from wild flies. However, lab fly oviposition was not effectively deterred by the presence of pheromone. The ecological significance of the pheromone is discussed.     

Deterrence of repeated oviposition in sorghum shootflyAtherigona soccata

The sorghum shootfly,Atherigona soccata, under low population density conditions lays one egg per sorghum plant. Possible regulatory mechanisms of this oviposition behavior are reported. The presence of an egg thoroughly washed and reattached to a leaf does not deter further oviposition, indicating the absence of visual cues. When washings from eggs were sprayed on sorghum plants, or when plants from which eggs had been removed were presented to a gravid female, significant deterrence was observed. Apparently a deterrent pheromone is associated with the water-soluble glue with which the females attach their eggs to the leaves. Some deterrent effect persists for at least 7 days.     

Effects of relative humidity,temperature, and population density on production of cuticular hydrocarbons in housefly Musca domestica L

The production of cuticular hydrocarbons by both males and females of Musca domestica L. under very wet conditions (90% relative humidity) compared to the production at 50 and 20% relative humidity is delayed up to at least 3 days after emergence from the pupae. Eight days after emergence, however, males contain the same amounts of hydrocarbons at 90, 50, and 20% relative humidity, whereas females at 90% still possess less of these substances than at 50 and 20%. It is suggested that this is due to the fact that males, being more active than females, need more cuticular hydrocarbons to prevent water loss. No indication is found that relative humidity has a different effect on the production of the sex pheromone, muscalure [(Z)-9-tricosene] by females than on the production of the other hydrocarbons. Male and female flies produce more hydrocarbons at 35°C than at 20°C. On females, the relative amounts of nonacosane and methyl- and dimethylnonacosanes are significantly higher at 35°C than at 20°C. Female flies produce some (Z)-9-tricosene after eight generations at low population density in contrast to females at high population density, which did not produce muscalure. We suggest that because of the relatively large contribution to the total population, the properties of a small number of females are likely to be expressed sooner in the next generations of small populations than in those of large populations.     

Evidence for the controlled release of a crustacean sex pheromone

Evidence for the controlled release of a crustacean sex pheromone: mature malePortunus sanguinolentus (Herbst) did not give the characteristic display described by Ryan (1966) to water from a container with a carried or artificially restrained premolt female. However, the sex pheromone was still present in the urine of the restrained female, suggesting that she inhibits the emission of the sex pheromone by regulating her urine flow.Based on part of a dissertation presented by the author in partial fulfillment of the requirements for the doctoral degree in zoology at the University of Hawaii.     

Transfer of the sea anemone pheromone,anthopleurine, by the nudibranchAeolidia papillosa

After the nudibranchAeolidia papillosa eats the sea anemoneAnthopleura elegantissima, anthopleurine, an alarm pheromone from the sea anemone, persists in the tissues of the nudibranch. For at least five days following such a meal, nudibranchs are capable of evoking alarm responses in anemones without touching them, presumably by releasing anthopleurine into the water. The anemone's alarm response to anthopleurine is to withdraw the tentacles and oral disk, the preferred sites of attack forAeolidia. This leaves exposed to attack the anemone body regions with the highest anthopleurine concentrations. Specimens ofAeolidia collected near sources ofAnthopleura are more likely to contain detectable amounts of anthopleurine than those more distant; some nudibranchs collected 0.5 m fromAnthopleura contained enough anthopleurine to evoke alarm responses in anemones they approached. These findings suggest that the predator helps in the transmission of anthopleurine, which may reduce the severity of predation onAnthopleura.     

Pheromone-mediated responses of male cabbage looper moths,Trichoplusia ni,following various exposures to sex pheromone or (Z)-7-dodecenol

Prolonged preexposure (three days) of maleTrichoplusia ni to its six-component sex pheromone blend or its major pheromone component, (Z)-7-dodecenyl acetate, reduced subsequent upwind flight responses to a pheromone source. Preexposure to (Z)-7-dodecenol increased upwind flight responses to a pheromone source combined with (Z)-7-dodecenol. The impact of long-term preexposures was moderate when compared to the more immediate effects of background noise. When (Z)-7-dodecenyl acetate was presented as background noise, all maleT. ni failed to respond to a plume of the full pheromone blend. However, most moths succeeded in locking on to the pheromone plume and contacting the pheromone source in the presence of the five minor pheromone components as background noise. When (Z)-7-dodecenol was released as background noise the response rate to a pheromone source containing (Z)-7-dodecenol was increased dramatically. This indicates that males became adapted to (Z)-7-dodecenol while responding to the pheromone source. The results of this study indicate that both long-term preexposure treatments and immediate exposure to background noise can limit the ability of maleT. ni to respond to sex pheromone sources.     

Sex pheromone communication in the nematode,Rhabditis pellio

Both males and females ofRhabditis pellio release pheromones that attract the opposite sex prior to copulation. A quantitative bioassay for the female-produced pheromone was designed, based on male movement toward a pheromone source placed at one end of a 10-mm strip of bacterial material maintained on nutrient agar in a petri plate. Females produced pheromone from the age at which they attained the adult stage (3 days following hatching from the egg) and maintained a relatively constant production level until at least the ninth day of life. Similarly, males became responsive to the female pheromone by the third day and remained responsive through the ninth day, although the time required for the males to migrate toward a female pheromone source increased with increasing age. No daily rhythm of pheromone responsiveness by males or pheromone production by females was observed when the nematodes were conditioned to a 1212 h light-dark cycle.     

Prolonged Adaptation as Possible Mating Disruption Mechanism in Oriental Fruit MothCydia (=Grapholita) molesta

The effects of pheromone preexposure on flight behavior of male Oriental fruit mothCydia molestawere investigated in laboratory experiments using a wind-tunnel and in an orchard through insect releases at the center of a grid of pheromone traps. In the wind-tunnel experiments, the proportion of insects performing various behavioral phases was found to depend on the intensity and duration of the adapting stimulus and the recovery time allowed between exposure and measurement, indicating adaptation of at least some elements of the sensory system. The orchard experiments exhibited similar adaptation effects at similar exposure levels, causing the entry of treated insects into the traps to be delayed compared to controls and a reduction in insects caught for the highest preexposure concentration. The levels of pheromone exposure required to produce significant adaptation were, however, found to be much higher than could be expected under conditions of release of synthetic pheromone for insect control through mating disruption.     

Reproductive Character Displacement in Lymantria monacha from Northern Japan?

Our objective was to test the hypothesis that the pheromone blend and/or diel periodicity of pheromonal communication differ in populations of the nun moth, Lymantria monacha(Lepidoptera: Lymantriidae), from eastern Asia (northern Honshu, Japan) and Central Europe (Bohemia, Czech Republic). Coupled gas chromatographic–electroantennographic detection (GC-EAD) analyses of pheromone gland extract of female L. monachafrom Japan confirmed the presence of compounds previously identified in pheromone extracts of L. monachafrom Bohemia, as follows: (Z)-7-octadecene, 2-methyl-(Z)-7-octadecene (2me-Z7–18Hy), cis-7,8-epoxy-octadecane (monachalure), and cis-7,8-epoxy-2-methyloctadecane (disparlure). Field experiments in Honshu suggested that (+)-monachalure is the major pheromone component of L. monacha. 2me-Z7–18Hy significantly enhanced attractiveness of (+)-monachalure. Addition of (+)-disparlure to (+)-monachalure plus 2me-Z7–18Hy in Honshu and Bohemia increased attractiveness of lures by 1.2 and 20 times, respectively, indicating that (+)-disparlure is of least and most significance in the respective L. monachapopulations. Moreover, capture of male L. monachain pheromone-baited traps between 18:00 and 24:00 hr in Bohemia and 2:00 and 5:00 hr in Honshu revealed a markedly different diel periodicity of pheromonal communication. Pheromonal communication late at night and use of (+)-monachalure, rather than (+)-disparlure, as the major pheromone component by L. monachain Honshu may have resulted from interspecific competition with coseasonal L. fumida, which uses the early night for pheromonal communication and (+)-disparlure as major pheromone component. Whether communication channel divergence of L. monachain Honshu indeed constitutes a case of reproductive character displacement is difficult to prove. The evolution of such divergence in sympatricpopulations of L. fumidaand L. monachawould have to be demonstrated.     

(7<Emphasis Type="Italic">Z</Emphasis>,9<Emphasis Type="Italic">E</Emphasis>)-2-Methyl-7,9-Octadecadiene: A Sex Pheromone Component of <Emphasis Type="Italic">Lymantria Bantaizana</Emphasis>

Our objective was to identify the sex pheromone of Lymantria bantaizana (Lepidoptera: Lymantriidae) whose larvae feed exclusively on walnut, Juglans spp., in China, and Japan. Coupled gas chromatographic–electroantennographic detection (GC-EAD) analyses of pheromone gland extracts revealed a single EAD-active component. Retention index calculations of this compound on four GC columns suggested that it was a methyl-branched octadecadiene with conjugated double bonds. In GC-EAD analyses of 2-methyloctadecenes, (Z)-2-methyl-7-octadecene and (E)-2-methyl-7-octadecene elicited the strongest antennal responses, suggesting that the double bond positions were at C7 and C9. In comparative GC-EAD analyses of pheromone gland extract and stereoselectively synthesized isomers (E,E; E,Z; Z,E; Z,Z) of 2-methyl-7,9-octadecadiene, the (E,Z)- and (Z,E)-isomer had retention times identical to that of the candidate pheromone, but only the latter isomer elicited strong EAD activity. Results of field experiments in Japan substantiated that (7Z,9E)-2-methyl-7,9-octadecadiene is the L. bantaizana sex pheromone, a compound previously unknown in the Lepidoptera. Detection surveys in North America for exotic Eurasian forest defoliators could include traps baited with the L. bantaizana pheromone.     

Behavioral and electrophysiological evidence for volatile sex pheromones in Parcoblatta wood cockroaches

Species within the cockroach genus Parcoblatta are sexually dimorphic for wing length; females have reduced wings and are flightless, while males have long wings that are used in flight. We predicted that Parcoblatta females would release a volatile sex pheromone to attract the more mobile males. Nymphs of the broad wood cockroach, P. lata, and the Caudell's wood cockroach, P. caudelli, were collected in forested areas in North Carolina, USA, and reared in the laboratory for observations of sexual behavior and for pheromone analysis. After several days of sexual maturation, virgin females of both species exhibited distinct calling behaviors. In females of P. lata, calling commenced 6 days after adult emergence. Under a light–dark photoperiod regime, calling behavior in both species was restricted to the scotophase. Calling consisted of a repeated pattern of raising and lowering the abdomen with occasional exposure of the genital vestibulum. To test whether calling behavior is associated with the release of pheromone, volatiles from calling and noncalling females were collected on Super-Q and tested by electroantennogram (EAG) and behavioral assays. Volatile collections from calling females elicited higher male-specific EAG responses than collections from noncalling females of the same physiological stage. In an olfactometer choice test (Y-tube), males preferred volatiles from calling females over those from noncalling females. To determine the anatomical source of the pheromone, solvent extracts of various body parts were analyzed by EAG. The first through seventh tergites were the only body parts that elicited male-specific EAG responses in both species. In P. lata, the activity of the extract increased from 1- to 7-day-old females, but was lower in mated than in virgin females of the same age. The putative pheromone gland appears to consist of numerous class-3 secretory units, each composed of a secretory cell connected to a cuticular pore via a tubular duct. We conclude that female P. lata and P. caudelli produce sex-specific volatile pheromones that are emitted during calling behavior.     

Developmental and environmental sources of pheromone variation inColias eurytheme butterflies

Body size, age, ambient temperature, wing wear, and flight activity were investigated as possible sources of variation in the quantities and relative proportions of the three chemical components [n-heptacosane (C27), 13-methylheptacosane (13MH), andn-nonacosane (C29)] of the male courtship pheromone ofColias eurytheme butterflies. Size of the male has very little influence on the amount of any of the pheromone components present on the wings. Most of the deposition of all three components onto the surface of the hindwing occurs between 3 and 9 hr after emergence from the pupa. 13MH is deposited more rapidly than C27 and C29, and C27 more rapidly than C29. After the first 12 hr posteclosion, the pheromone phenotype of an individual male remains relatively constant through at least 96 hr of age. Experiments showed that none of the three chemicals volatilize to any appreciable extent at temperatures likely to be experienced in the field. The pheromones of actively searching and courting males did not differ from those of less-active feeding and resting males, suggesting that volatilization induced by flight activity is not an important source of pheromone variation. Loss of scales with age does seem to affect pheromone phenotype, but not in a readily interpretable way. Although the quantity of 13MH was lower in worn males than in fresh, C27 was higher.Lepidoptera: Pieridae.     

Interactions Between Host-plant Volatiles and the Sex Pheromones of the Bird Cherry-oat Aphid, <Emphasis Type="Italic">Rhopalosiphum padi</Emphasis> and the Damson-hop Aphid, <Emphasis Type="Italic">Phorodon humuli</Emphasis>

The bird cherry-oat aphid, Rhopalosiphum padi (L.), and the damson-hop aphid, Phorodon humuli (Schrank), migrate at the same time of year and colonize closely related Prunus spp. as primary hosts, but utilize (1R,4aS,7S,7aR)-nepetalactol and (1RS,4aR,7S,7aS)-nepetalactol, respectively, as sex pheromones. Interactions between these sex pheromones and benzaldehyde and methyl salicylate, plant volatiles common to primary hosts of both species, were investigated to assess whether they confer reproductive isolation between these species. Female autumn migrants (gynoparae) and males of these two species were caught in the field with water traps baited with their respective sex pheromones. Rhopalosiphum padi gynoparae and males also responded positively to benzaldehyde. Release of either benzaldehyde or methyl salicylate with the conspecific sex pheromone increased catches of both species of aphid. However, releasing both plant volatiles with the sex pheromone of R. padi increased catches of gynoparae and males, but reduced those with the sex pheromone of P. humuli. These results support the hypothesis that specific plant volatiles synergize responses of autumn migrating aphids to their sex pheromone. Because these interactions are species-specific, they may be important in allowing males to discriminate between conspecific sexual females (oviparae) and those of other aphid species.     

Identification, Synthesis, and Field Testing of the Sex Pheromone of the Citrus Leafminer, Phyllocnistis citrella

The citrus leafminer is an important vector of citrus canker in many of the major citrus production areas of the world. (7Z,11Z)-Hexadecadienal was reported as a sex attractant for this insect in the 1980s, based on trap catches during pheromone screening trials in Japan. However, attempts to reproduce this work in other areas of the world have not been successful. We report here that (7Z,11Z)-hexadecadienal is only one component of the pheromone, with the other critical component being the analogous trienal, (7Z,11Z,13E)-hexadecatrienal. Both compounds were identified in the effluvia from live female moths by coupled gas chromatography (GC)-electroantennography using nonpolar and polar GC columns, and the identifications were confirmed by comparisons of mass spectra with those of authentic standards. Stereoisomers of the two compounds, and a number of analogs, were synthesized to confirm the identifications. In field trials, neither compound alone was attractive to male moths, but blends of the two were highly attractive, with thousands of insects being caught per trial. Addition of the isomeric (7Z,11Z,13Z)-hexadecatrienal inhibited attraction to the two-component blend. Electronic Supplementary Material Supplementary material is available for this article at and accessible for authorized users. This paper and the preceding paper (Leal et al.) were submitted within a few days of each other. The editors and the authors agreed that they should be published in tandem.     

New Pheromone Components of the Grapevine Moth <Emphasis Type="Italic">Lobesia botrana</Emphasis>

Analysis of extracts of sex pheromone glands of grapevine moth females Lobesia botrana showed three previously unidentified compounds, (E)-7-dodecenyl acetate and the (E,E)- and (Z,E)-isomers of 7,9,11-dodecatrienyl acetate. This is the first account of a triply unsaturated pheromone component in a tortricid moth. The monoenic acetate (E)-7-dodecenyl acetate and the trienic acetate (7Z,9E,11)-dodecatrienyl acetate significantly enhanced responses of males to the main pheromone compound, (7E,9Z)-7,9-dodecadienyl acetate, in the wind tunnel. The identification of sex pheromone synergists in L. botrana may be of practical importance for the development of integrated pest management systems. Electronic supplementary material Supplementary material to this paper is available in electronic form at and accessible for authorised users.     

Sex pheromone of oriental beetle,Exomala orientalis: Identification and field evaluation

A gas chromatograph coupled with a behavioral bioassay was used to identify two sex pheromone components, 7-(Z)- and 7-(E)-tetradecen-2-one of the Oriental beetle (OB),Exomala orientalis. Field experiments showed that the blend of the two isomers (Z:E, 7:1) was not significantly more attractive than theZ component alone. The best performance of traps baited with the synthetic sex pheromone was achieved when they were set with the pheromone device at 30 cm above the ground. Catches in traps baited with 1 and 10 mg were not significantly different, but they were higher (2.9-fold) than captures in traps loaded with 0.1 mg of the pheromone. Further investigations by GC-EAD revealed the presence of a possible minor component, but the small amount of material prevented its identification. 2-(E)-Nonenol, with the same retention time as the natural product, did not affect the attractancy of the synthetic sex pheromone. GC-EAD screening of previously identified sex pheromones of scarab beetles showed that male antennae of the Oriental beetle responded to japonilure, but it showed neither synergism nor inhibition to the OB sex pheromone.     

Biology of pheromone release by male caribbean fruit flies,Anastrepha suspensa (Diptera: Tephritidae)

Males of the Caribbean fruit fly,Anastrepha suspensa (Loew), typically form leks and attract females by releasing a multicomponent volatile pheromone. Previous reports have identified two nine-carbon alcohols, three lactones, a sesquiterpene, and a monoterpene in the volatiles. The present report is a study of the physiology of male pheromone release and of ecological and social interactions that influence pheromone release by laboratoryreared flies. Volatiles released by males were trapped on Tenax, eluted, separated, and quantitatively measured by gas chromatography. Experiments showed that the volatiles were primarily released from mouth and anus. Sealing the anal opening or the mouth with melted beeswax resulted in up to 40% or greater reduction in most components, and sealing both mouth and anus further reduced release of volatiles, but some volatiles are possibly still released directly from the cuticle. An anal pouch of everted tissue played a major role as a large evaporative surface for release of some of the volatile components. Male flies entrained to a 1410 light-dark cycle showed a peak release of volatiles at 11–12 hr into the photophase, but smaller quantities of the same volatiles were released over a broad period during the daylight hours. Laboratory-reared males peaked in pheromone release at 7–10 days and production and release continued through 35 days of age. Single males released significantly more of all components measured than did groups of males. The reduction by aggregations of males may be related to lekking behavior in this fruit fly. The pheromone probably serves to attract females to a lek site, but additional parameters are likely to enter into the choice of male made by the arriving female.This is University of Florida Agricultural Experiment Station Journal Series No. 9589.     

Dodecyl acetate,a second pheromone component of the cabbage looper moth,Trichoplusia ni

Dodecyl acetate was identified as a second component of the sex pheromone ofTrichoplusia ni (Hübner). Dodecyl acetate comprised 9.6% by weight of the total pheromone [(Z)-7-dodecenyl acetate plus dodecyl acetate] extracted from glands and 7.3% by weight of the total pheromone evaporated from the surfaces of glands. Dodecyl acetate appears to function as a short-range pheromone component. Evaporation at female release rates of a 1090 mixture of dodecyl acetate and (Z)-7-dodecenyl acetate in the field caused a significantly greater percentage of males to land on the pheromone source, increased significantly the time they spent on the source, but decreased significantly the time they spent searching for the source when within 50 cm, as compared to (Z)-7-dodecenyl acetate alone.Lepidoptera: Noctuidae.