Induced mimicry of colony odors in ants

The cuticular hydrocarbons ofFormica selysi (Formicinae) andMonica rubida (Myrmicinae) reared in single species and in mixed species colonies were determined using gas chromatography (GC) and GC-mass spectrometry. In colonies containing both species, each species modified its species-specific recognition odor. This odor is composed, at least partly, of cuticular hydrocarbons. The cuticular hydrocarbons ofM. rubida consist only of saturated alkanes (n-alkanes and branched alkanes). InF. selysi the mixture also contains unsaturated compounds (monoenes and dienes). In hetero-specific colonies, a new chemical signature developed. This signature resulted from qualitative and quantitative changes in the spectrum of hydrocarbons produced by each species and permitted the two species to inhabit the same nest without displaying interspecific aggression. The readjustment seemed to be more an active synthesis or an active transfer than simply a passive transfer from one species to the other. This may imply that the ants synthesized some components of the hydrocarbon signature of the other species. These synthesizing processes may be activated under particular social environmental conditions.     

Compared behavioral responses of maleDrosophila melanogaster (Canton S) to natural and synthetic aphrodisiacs

Cuticular aphrodisiacs fromD. melanogaster females were further characterized and the male response specificity towards such natural and synthetic unsaturated hydrocarbons was investigated. The behavioral activity seems to be correlated with some chain-length requirement and double-bond position; at least one double bond in position 7 seems necessary. This position is more abundant among natural monoenes, and among dienes which also bear a second double bond in position 11, whatever the chain length. Bioassays of the synthetic (Z,Z)-7,11-heptacosadiene yielded a dose-response curve close to that of the natural mixture of heptacosadienes in which the 7–11 isomer is predominant. This female specific 7,11 heptacosadiene appears to be the most potent aphrodisiac for males of the species. Its threshold is lower than that of both 7,11-nonacosadiene and 7-pentacosene which might also play a role in sex and species recognition.     

Hydrogenation of linolenate. VII. Separation and identification of isomeric dienes and monoenes

Isomeric dienes and monoenes produced by partial hydrogenation of linolenic acid have been separated by the combined use of low-temp crystallization and countercurrent distribution.Cis, trans dienes have been separated fromcis, cis dienes.Cis, cis conjugatable dienes have been partially separated fromcis,cis nonconjugatable dienes. Dienes with onetrans double bond were separated by gas chromatography into two groups:cis, trans andtrans, cis. Individual positional isomers could not be separated. Cis-9 monoene was separated fromcis-12,cis-15, andtrans monoenes by low-temp crystallization. Countercurrent distribution at 3,000 transfers only partially separated this mixture ofcis-12,cis-15, andtrans monoenes. The double bond in bothcis andtrans monoenes was found in all carbon positions, 7 through 16, showing for the first time that the 15, 16 bond of linolenic acid had moved away from the carboxyl. The majorcis bonds remained at carbons 9, 12, and 15. Combination of countercurrent distribution fractions has produced samples containing 95%cis, cis dienes; 90%cis, trans ortrans, cis dienes; 95%cis monoenes; and 90%trans monoenes. Presented at the AOCS meeting at Chicago, Ill., 1961. A laboratory of the No. Utiliz. Res. & Dev. Div., ARS, U.S.D.A.     

Mating stimulant pheromone and cuticular lipid constituents ofFannia pusio (Wiedemann) (Diptera: Muscidae)

Chromatograms of the cuticular lipids washed from newly emerged male and femaleFannia pusio were nearly identical. By the time the flies were 1 day old, the chromatographic profiles for the sexes were different. Mature females contained more C₃₁- and C₃₃-hydrocarbons than the males. The double bonds of the female monoolefins were mostly at the eleventh and thirteenth carbons, but those of the males were predominantly at the ninth carbon. Most active in stimulating copulation by males were the unbranched monoolefins with 31 and 33 carbons from the females. When they were synthesized and tested, the most active compound was (Z)-11-hentriacontene.A portion of a dissertation intended for submission by the first author to the Graduate School of the University of Maryland in partial fulfillment of the requirements for the Ph.D. degree.Mention of a proprietary or commercial product in this paper does not constitute an endorsement of this product by the U.S. Department of Agriculture or the University of Maryland.     

Sexual Isolation and Cuticular Hydrocarbon Differences between <Emphasis Type="Italic">Drosophila santomea</Emphasis> and <Emphasis Type="Italic">Drosophila yakuba</Emphasis>

Drosophila santomea and Drosophila yakuba are two sister species inhabiting Saõ Tomé island. Previous studies showed that both species display strong reproductive isolation, although they can produce a few viable hybrids. Our study tried to understand the mechanism of this ethological isolation between two allopatric strains. A strong sexual isolation was confirmed, with a marked asymmetry. Comparisons of latency times to either courtship or copulation suggest that males do not discriminate females, whereas D. yakuba females, but not D. santomea females, accept their homospecifics more quickly. Cuticular hydrocarbon compositions of both species and sexes were also established with gas chromatography (GC) and GC/mass spectrometry analysis. All have (Z)-7-tricosene as their major compound. There are several quantitative differences between species for few minor compounds. The largest difference concerns n-heneicosane, which is more abundant in D. santomea than in D. yakuba flies (up to seven times more between males). A similar quantitative difference was also found in a pair of sympatric strains. Furthermore, D. yakuba males artificially perfumed with n-heneicosane were discriminated negatively by D. yakuba females, suggesting a role for this compound in the sexual isolation between these two species.     

Aggregation pheromones inDrosophila borealis andDrosophila littoralis

Mature males ofDrosophila borealis andD. littoralis (Diptera: Drosophilidae) produce pheromones that attract both males and females in a wind-tunnel bioassay. Ethyl tiglate is a major pheromone component in both species. Isopropyl tiglate is a minor component, as active as ethyl tiglate on an equal-weight basis, but less abundant in the flies. Both species respond to (Z)-9-heneicosene, a compound they do not possess, but which is a pheromone component in closely related species.D. borealis andD. littoralis are also able to discriminate among various heneicosene isomers. These responses to hydrocarbons may represent artifacts of evolution in this group. For both species, the pheromone was strongly synergized by an extract of fermenting aspen bark, a host material ofD. borealis. Benzyl alcohol was identified as one active component, although it did not account for all the activity of the extract. In nature, the flies probably respond to mixtures of fly-derived and host-derived volatiles.     

Cuticular Hydrocarbons of Buffalo Fly, <Emphasis Type="Italic">Haematobia exigua</Emphasis>, and Chemotaxonomic Differentiation from Horn Fly, <Emphasis Type="Italic">H. irritans</Emphasis>

We determined the quantity and chemical composition of cuticular hydrocarbons of different strains, sexes, and ages of buffalo flies, Haematobia exigua. The quantity of cuticular hydrocarbons increased from less than 1 μg/fly for newly emerged flies to over 11 μg/fly in 13-d-old flies. The hydrocarbon chain length varied from C₂₁ to C₂₉, with unbranched alkanes and monounsaturated alkenes the major components. Newly emerged flies contained almost exclusively C₂₇ hydrocarbons. Increasing age was accompanied by the appearance of hydrocarbons with shorter carbon chains and an increase in the proportion of alkenes. 11-Tricosene and 7-tricosene were the most abundant hydrocarbons in mature H. exigua. Cuticular hydrocarbons of H. exigua are distinctly different from those of horn flies, Haematobia irritans. The most noticeable differences were in the C₂₃ alkenes, with the major isomers 11- and 7-tricosene in H. exigua and (Z)-9- and (Z)-5-tricosene in H. irritans, respectively. Cuticular hydrocarbon analysis provides a reliable method to differentiate the two species, which are morphologically difficult to separate. The differences in cuticular hydrocarbons also support their recognition as separate species, H. exigua and H. irritans, rather than as subspecies.     

Selective hydrogenation of soybean oil: IV. Fatty acid isomers formed with copper catalysts

Two samples of soybean oil hydrogenated with copper-containing catalysts at 170 and 200 C were analyzed for their natural and isomeric fatty acids. Methyl esters of the hydrogenated oils were separated into saturates, monoenes, dienes and trienes by countercurrent distribution between acetonitrile and pentane-hexane. Monoenes were further separated intocis- andtrans-isomers on a silver-saturated resin column. Double bond location in these fractions was determined by a microozonolysis-pyrolysis technique. The diene fraction was separated with an argentation countercurrent distribution method, and linoleate was identified by infrared, ozonolysis and alkaliisomerization data. The double bonds in thecis-monoenes were located in the 9-position almost exclusively. However, the double bonds in thetrans-monoene were quite scattered with 10- and 11-isomers predominating. About 86% to 92% of the dienes consisted of linoleate as measured by alkali isomerization. Other isomers identified as minor components includecis,trans andtrans, trans conjugated dienes and dienes whose double bonds are separated by more than one methylene group. No. Utiliz. Res. Dev. Div., ARS, USDA.     

Mating stimulant pheromone and cuticular lipid constituents ofFannia femoralis (Stein) (Diptera: Muscidae)

The cuticular lipids of male and femaleFannia femoralis were similar for recently emerged insects but soon began to develop chromatographic patterns characteristic of each sex. Mature females contained more C₃₁ and C₃₃ monoolefin in the cuticular lipid than males. Also, the double bonds in the monoolefins of the female lipid were situated predominantly at the eleventh and thirteenth carbons, while most of those from the males were centrally located in the molecule or at the ninth carbon.The female C₃₁ monoolefin stimulated copulation by the males, but more mating activity occurred when the saturated hydrocarbons present in the female cuticular lipids were added. The synthetic monoolefin most active as a mating stimulant pheromone was (Z)-11-hentriacontene, but the addition of female alkanes or of syntheticn-alkanes to (Z)-11-hentriacontene increased the activity of the synthetic pheromone.A portion of a dissertation intended for submission by the first author to the Graduate School of the University of Maryland in partial fulfillment of the requirements for the Ph.D. degree.Mention of a proprietary or commercial product in this paper does not constitute an endorsement of this product by the U.S. Department of Agriculture or the University of Maryland.     

Homogeneous hydrogenation of methylcis-9,cis-15-octadecadienoate catalyzed by platinum-tin,palladium and nickel complexes

Methylcis-9,cis-15-octadecadienoate was used as a model for the hydrogenation of methyl linolenate. Homogeneous catalysis by platinum, palladium and nickel complexes produced a mixture of isomeric monoenes similar to that from the hydrogenation of methyl linolenate. These catalysts are, therefore, capable of promoting isomerization of isolated double bonds and of producing conjugated dienes which are necessary for the formation of monoenes. N. Market, and Nutr. Res. Div., ARS, USDA.     

Evidence for an attractant in cuticular lipids of femaleLucilia cuprina (Wied.), Australian sheep blowfly

Various nonpolar and weakly polar organic solvent extracts of femaleLucilia cuprina caused more flies to be trapped in conical flasks, placed in cages of blowflies, than in untreated flasks or in flasks treated with similar extracts of maleL. cuprina. This is attributed to an attractant present in the extracts of female flies, and since more females than males tended to be trapped, the attractant (or pheromone) possibly plays a role in the group oviposition behavior exhibited by this species. The data from experiments and gas-liquid chromatography (GLC) examinations of dichloromethane and hexane extracts of flies suggest that the attractant is a cuticular lipid.     

Homogeneous catalytic hydrogenation of unsaturated fats: Metal acetylacetonates

Hydrogenation of linseed and soybean methyl esters was achieved at 100–180C, 100–1000 psi H₂ and 0.05–0.25 moles catalyst per mole of ester. The relative activity of metal acetylacetonates in decreasing order was: nickel (III), cobalt (III), copper (II) and iron (III). Reduction occurred readily in methanol solution but only slowly in dimethylformamide and acetic acid. No reduction occurred in the absence of solvents. Soybean oil was also hydrogenated rapidly with nickel (III) acetylacetonate in methanol, but in this system the triglycerides were converted to methyl esters. Nickel (III) acetylacetonate was the most selective catalyst toward linolenate hydrogenation. Methyl linoleate and linolenate hydrogenated with nickel(III) acetylacetonate were fractionated into monoenes, dienes and trienes. Thecis monoenes separated in 62 to 68% yield had double bonds in the original position. The remainingtrans monoenes had extensively scattered unsaturation. The dienes and trienes showed no conjugation, but some of the double bonds in the dienes were not conjugatable with alkali. Little stearate was formed. Presented at AOCS meeting in Chicago, 1964 No. Util. Res. and Dev. Div. ARS, USDA     

Aggregation pheromone components inDrosophila mulleri

Existence of an aggregation pheromone was demonstrated inDrosophila mulleri. Mature males produce at least two compounds that are lacking from females and newly emerged males and that attract both males and females in a wind-tunnel bioassay. These compounds are (S)-(+)-2-tridecanol acetate and (Z)-10-heptadecen-2-one. Both were synthesized, and the flies responded to the synthetic compounds as well as to fly-derived preparations. The flies also responded to racemic 2-tridecanol acetate but not to the pureR enantiomer. A more polar, very volatile attractant was also extracted from both sexes ofD. mulleri but was not identified.     

(Z,Z)-5,27-Tritriacontadiene: Major sex pheromone ofDrosophila pallidosa (Diptera; Drosophilidae)

A crude cuticular extract from both sexes of 3660 fruit flies (Drosophila pallidosa) was subjected to SiO₂ and AgNO₃/SiO₂ column chromatography, accompanied by bioassay for the sex pheromone activity. After three chromatographic steps, the active fraction was obtained. The main component of the active fraction was determined to be (Z,Z)-5,27-tritriacontadiene [(Z,Z)-5,27-C_33:2, on the basis of gas-liquid chromatographic analysis, chemical derivatization and gas chromatography-mass spectrometry. Synthetic (Z,Z)-5,27-C_33:2 at 5 female equivalents (FE) elicited a clear courtship response with a high courtship index amongD. pallidosa males. Therefore it was concluded that (Z,Z)-5,27-C_33:2 was a major sex pheromone component in this species.     

A rapid method for the analysis of hydrogenated fats by GC with IR detection

A rapid method for analysis of trans and cis FA in hydrogenated fats has been developed. The method is based on a single anlaysis by CG with IR detection. Multivariate partial least squares regression is applied on the IR spectra to predict the number of cis and trans double bonds. For each chain length the method provides information about the amount of the saturated FA, the amount of trans monoenes, the amount of cis monoenes, the amount of PUFA, and the average number of cis and trans double bonds in PUFA. The method has been validated by summing the values to a total trans value and total unsaturation. These sum values were compared with total trans unsaturation, as determined by AOCS method Cd 14-95, and iodine value, as determined by AOCS Cd 1d-92.     

Deuteration of methyl linoleate with nickel,palladium, platinum and copper-chromite catalysts

Samples taken during deuteration of methyl linoleate with the title catalysts were separated into saturate, monoene and diene fractions. Monoenes were further separated intocis andtrans fractions. A comparison of the double bond distribution in monoenes with those from hydrogenation of alkaliconjugated linoleate indicated that up to 59% of the linoleate was reduced through a conjugated intermediate with nickel catalyst. The respective percentages for palladium and platinum catalysts were 51 and 23. Copper catalysts have previously been shown to reduce linoleate solely through conjugated intermediates. Copper-chromite catalyst showed infinite selectivity for the reduction of linoleate, because stearate did not form. The decreasing order of various catalysts for the selective reduction was copper-chromite>>>Ni at 195 C>Pd>Ni at 100 C>Pt. Computer simulation of platinum reduction indicated that ca. 20% of the linoleate was directly reduced to stearate through a shunt. Geometrical isomers of linoleate were formed during reduction with all catalysts except copper-chromite. Nickel catalyst formed bothtrans,trans- andcis,trans-isomers, as well as nonconjugatable dienes. These isomers were favored at the higher temperature and deuterium was incorporated into them. Palladium and platinum did not isomerize linoleate to nonconjugatable dienes. Because conjugated dienes are more reactive than linoleate, they were not found in appreciable amounts during reduction. Conjugated dienes were the only isomers formed with copper-chromite catalyst. Deuterium was found in these conjugated dienes, which were also extensively isomerized. As a result of isomerization and exchange during reduction of linoleate-as well as further exchange between deuterium and monoenes-a wide distribution of isotopic isomers in monoenes was found with nickel, palladium and platinum catalysts. Since isomerization of monoenes with copper-chromite is negligible, the isotopic distribution of monoenes must be due to exchange of intermediate conjugated dienes followed by addition. Presented at the AOCS Meeting, Ottawa, September 1972. ARS, USDA.     

Cuticular hydrocarbons ofAedes hendersoni cockerell andA. triseriatus (SAY)

Field-caught adult male and femaleAedes hendersoni are difficult to distinguish from the sibling speciesA. triseriatus. We found that mosquitoes from the same sex of the sibling species can not be readily separated either by unique cuticular hydrocarbon components or by differences in percent composition of those components. Multivariate analysis of the cuticular hydrocarbon data does not provide good separation. Cuticular hydrocarbons were identified using gas chromatography electron-impact mass spectrometry and gas chromatography chemical-ionization mass spectrometry. Flame-ionization capillary gas chromatography was used for quantitative analysis of individual mosquitoes. Sixty-four hydrocarbons with chain lengths from C₁₆ to greater than C₄₆ were common to both species. Identified hydrocarbon components weren-alkanes, monomethylalkanes, dimethylalkanes, trimethylalkanes, and alkenes.Diptera: Culicidae.     

(S)-2-pentadecyl acetate and 2-pentadecanone Components of aggregation pheromone ofDrosophila busckii

(S)-2-Pentadecyl acetate and 2-pentadecanone were identified as the major aggregation pheromone components, inDrosophila busckii. Both sexes of flies were attracted equally in a wind-tunnel olfactometer. The flies also responded to racemic 2-pentadecyl acetate but not to the pureR enantiomer. In bioassay, (S)-2-pentadecyl acetate and 2-pentadecanone were each active alone, and a mixture of both increased the number of flies responding ca. twofold. The aggregation pheromone components are found in the ejaculatory bulb of sexually mature males and are transferred primarily to the female cuticle during mating. One third of the pheromone transferred is released by the female to the surrounding environment in a few hours after mating. None of the aggregation pheromone components remained on the mated female's cuticle, leaving two thirds unaccounted for. The same results were obtained when racemic 2-pentadecyl acetate was topically applied to immature and mature virgin males and females. BothD. mulleri andD. busckii were attracted to (S)-2-acetates of 13, 14 and 15 carbons, butD. mulleri preferred (S)-2-tridecyl acetate andD. busckii preferred (S)-2-pentadecyl acetate.     

Mating-stimulant pheromone and cuticular lipid constituents of the little house fly,Fannia canicularis (L.)

Chromatograms of the cuticular lipids washed from recently emerged female and maleFannia canicularis (L.) flies were nearly identical, but by the time the flies were 5 days old, the cuticular components of the two sexes differed considerably. A monoolefin which constituted 66% of the cuticular lipid from 5-day-old females stimulated a copulatory response from males and was identified as (Z)-9-pentacosene. The cuticular lipid of the same age males contained only 1% of this compound. Although all the major constituents of the cuticular lipid from mature females were hydrocarbons, 27% of the lipid washed from 5-day-old males was a nonhydrocarbon material that was represented by a single GLC peak. This material was identified as heneicosan-8-ol acetate.Diptera: Muscidae.A portion of a dissertation intended for submission by the first author to the Graduate School of the University of Maryland in partial fulfillment of the requirements for the Ph.D. degree.Mention of a proprietary or commercial product in this paper does not constitute an endorsement of this product by the U.S. Department of Agriculture or the University of Maryland.     

Aggregation pheromones ofDrosophila immigrans,D. phalerata,andD. subobscura

Aggregation pheromones ofDrosophila immigrans, D. phalerata andD. subobscura were demonstrated by testing attraction of adult flies to hexane extracts of the flies in a windtunnel bioassay. Extracts of adult males of all species attracted conspecific males and females. However,D. subobscura flies were attracted only when the extract (cVA) in the extracts of adult maleD. immigrans andD. phalerata. Both species were attracted to synthetic cVA. Male and femaleD. phalerata. Both species were attracted to synthetic cVA. Male and femaleD. subobscura produced 5,9-pentacosadiene, 5-pentacosene, 2-methylhexacosene and 5,9-heptacosadiene, while only maleD. subobscura produced (Z)-5-tricosene and minor amounts of cVA.