Do Eurasian beavers smear their pelage with castoreum and anal gland secretion?

The scent-matching hypothesis postulates that scent marks provide an olfactory link between a resident owner and his territory, and that this enables intruding animals to recognize the chance of escalated conflicts. However, it is unclear if Eurasian beavers (Castor fiber) mark their own pelage with castoreum from their castor sacs (i.e., the same material used in territorial marking); and/or if beavers mark their pelage with anal gland secretion (AGS) from the anal glands to waterproof the pelage and to act as a living-scent mark. Chemical analysis (gas chromatography and mass spectrometry) of hair samples from 22 live-trapped beavers revealed that castoreum compounds were not present in any samples, AGS compounds were found from 3 animals (13.6%) around the cloaca, and the compound squalene was found in all the samples. Beavers may release castoreum directly into the water when it meets an intruder. Thereby, the scent mark in the water can provide an olfactory link between a resident owner and his territory. Squalene, in contrast to AGS, may be essential for keeping beaver pelts water-repellant.     

Musk deer (Moschus moschiferus): Reinvestigation of main lipid components from preputial gland secretion

The qualitative and quantitative composition of the principal lipid constituents of Siberian musk deer (Moschus moschiferus) preputial gland secretion, main odor carriers and potential precursors of odorous substances, was investigated by means of high-performance liquid chromatography. Free fatty acids and phenols (10%), waxes (38%), and steroids (38%) were found to be the main groups of the secretion lipids. Cholestanol (I), cholesterol (II), androsterone (III), ⁴-3-hydroxy-17-ketoandrostene (IV), 5, 3-hydroxy-17-ketoandrostane (V), 5, 3, 17-dihydroxyandrostane (VI), 5, 3, 17-dihydroxyandrostane (VII), and 5, 3, 17-dihydroxyandrostane (VIII) were isolated from the steroid fraction and their structures confirmed by IR, PMR, and mass spectra. 3-Methylpentadecanone (muscone) was not identified among the secretion lipids. Preputial gland secretion stimulated sex behavior of musk deer females.     

Identification and field testing of additional components of female sex pheromone of African armyworm,Spodoptera exempta (Lepidoptera: Noctuidae)

Ovipositor washings from virgin femaleSpodoptera exempta (Walker) (Lepidoptera: Noctuidae) were analyzed by high-resolution gas chromatography (GC) linked to a male electroantennogram (EAG). GC retention times of the two major EAG responses observed were consistent with their assignment as (Z)-9-tetradecenyl acetate and (Z,E)-9,12-tetradecadienyl acetate, as previously identified. However, three other EAG responses were also noted that had GC retention times consistent with (Z)-9-tetradecenal, (Z)-9-tetradecen-1-o 1, and (Z)-11-hexadecenyl acetate. The components were present in the ratio of 10051.53.54, respectively. Further analysis of the ovipositor washings by GC linked to a mass spectrometer (GC-MS) confirmed these findings and indicated the presence of a sixth component consistent with (Z)-11-tetradecenyl acetate present at 2 % of the major component. In field tests carried out in Kenya, (Z)-11-hexadecenyl acetate was the only newly identified component to enhance the catch of the original two-component mixture when presented in their natural ratio. The addition of (Z)-9-tetradecen-1-ol reduced catch, while (Z)-9-tetradecenal and (Z)-11-tetradecenyl acetate had no apparent effect.     

Sex pheromone of female african white rice stem borer,Maliarpha separatella (Lepidoptera: Pyralidae) from Sierra Leone: Identification and field testing

Analysis of ovipositor washings of femaleMaliarpha separatella from Sierra Leone by high-resolution gas chromatography (GC) linked to a male electroantennograph (EAG) indicated the presence of three electrophysiologically active compounds. The GC retention times of these compounds were consistent with those of (Z)-9-tetradecen-1-ol, (Z,E)-9,12-tetradecadien-1-ol, and (E,E)-10,12-tetradecadien-1-ol. Analysis by El and CI mass spectrometry of ovipositor washings confirmed these identifications and also indicated the presence of the saturated analog, tetradecan-1-ol. There was no evidence, from these analyses, of the corresponding aldehydes or acetates. The EAG-active compounds were present in the ovipositor washings in a ratio of approximately 23.51, with the major component constituting approximately 0.4 ng per ovipositor. GC-MS analysis of entrained female effluvia confirmed that the EAG-active compounds were released by virgin females. Field testing of the EAG-active compounds indicated that (Z,E)-9,12-tetradecadien-1-ol and (E,E)10,12-tetradecadien-1-ol were attractive to male moths in ratios of between 9:1 and 39:1, while (Z)-9-tetradecen-1-ol was found to reduce trap catch when added to blends of the other two compounds.     

Linalool in mandibular gland secretion ofColletes bees (Hymenoptera: Apoidea)

Uinalool was identified as the main component of the mandibular gland secretion in females and males of four species ofColletes bees, viz.,C. cunicularius, C. daviesanus, C. impunctatus andC. succinctus. It was also shown to be the dominant volatile compound in the same gland in maleC. floralis (the female of this species has not yet been investigated). Further, in another species,C. similis, linalool is present in the mandibular gland secretions of females and males, but the dominant volatile component in these secretions is geranial, together with neral. Females of the speciesC. fodiens seem to lack monoterpenes altogether; nonadecane is the dominant volatile compound of the cephalic secretion (based on analysis of a single individual). When linalool is put out in the area of nest aggregation ofC. cunicularius, where the males are patrolling, a distinct increase in flight activity is noted. The function of linalool is discussed on the basis of field observations.This report forms part XXI in the series Studies on Natural Odoriferous Compounds.     

The female sex pheromone of sugarcane stalk borer,Chilo auricilius identification of four components and field tests

Four pheromonal components have been detected in ovipositor washings and volatiles from female sugarcane stalk borers,Chilo auricilius Dudgeon (Lepidoptera: Pyralidae), using combined gas chromatography-electroantennography. The components have been identified as (I) (Z)-7-do-decenyl acetate, (II) (Z)-8-tridecenyl acetate, (III) (Z)-9-tetradecenyl acetate, and (IV) (Z)-10-pentadecenyl acetate by comparison of their gas chromatographic behavior with that of synthetic standards. In field tests carried out in northern India during 1982–1984, a combination of II, III, and IV in their naturally occurring ratio (841) was shown to provide a highly attractive synthetic source for trap use. (Z)-7-Dodecenyl acetate was found to reduce catches of maleC. auricilius, both when dispensed with the other three components and when released from dispensers surrounding a trap baited with the other three components.     

Mammalian exocrine secretions XV. Constituents of secretion of ventral gland of male dwarf hamster, Phodopus sungorus sungorus

In a study aimed at the chemical characterization of constituents of the ventral gland secretion of the male dwarf hamster, Phodopus sungorus sungorus, 48 compounds, including saturated alcohols, saturated and unsaturated ketones, saturated and unsaturated straight-chain carboxylic acids, iso- and anteisocarboxylic acids, 3-phenylpropanoic acid, hydroxyesters, 2-piperidone, and some steroids were identified in the secretion. The position of the double bonds in -icosadienyl--butyrolactone and -henicosadienyl--butyrolactone, and the position of methylbranching in seven C₁₆–C₂₁saturated ketones could not be established. Several constituents with typically steroidal mass spectra also remained unidentified. The female dwarf hamster's ventral gland either does not produce secretion or produced so little secretion that it was impossible to collect enough material for analysis.     

Chemical composition and efficacy of cephalic gland secretion ofArmitermes chagresi (Isoptera: Termitidae)

Soldiers of the neotropical humivorous termiteArmitermes chagresi have large ice-tong-like mandibles for mechanical defense and a moderate length nasus from which cephalic gland defensive secretions are discharged. Soldiers do not eject secretion, but ooze droplets which are held at the nasus tip by hairs. The chemical secretion is composed of C₂₂–C₂₆ macrocyclic lactones, including C₂₄ and C₂₆ and - and -hydroxylated lactones, with C₂₄ macrolides predominating. The cephalic gland secretion has no pheromonal properties and does not induce alarm or attraction in soldiers or workers. Upon application, the secretion repels and is irritating to ants, but does not appear to act as an antihealant. The defensive behavior and chemistry ofA. chagresi is discussed in light of termite ecology and evolution.     

Lectin studies of surface carbohydrates and induction of gland secretion in the free-living stages ofSchistosoma mansoni

Secretion from glands was observed when cercariae ofSchistosoma mansoni were exposed to certain lectins. Lectins fromMaclura pomifera, Pisum sativum, andTriticum vulgaris, were effective at 7.5 /ml. The effects of cercarial gland secretion caused byT. vulgaris agglutinin andArachis hypogaea agglutinin were blocked by pretreatment with the inhibiting glycan. Discharge of glands was not visualized after exposure of miracidia to lectins. The distribution of five labeled lectins was determined on live miracidia and cercariae. OnlyT. vulgaris agglutinin generally labeled the cercarial and miracidial bodies. Specific labeling occurred with the other lectins on the anterior, in glands or on their secretions, in flame cells in both stages, and on an unidentified ring of cells in miracidia. The possible mechanisms involved in changes caused by the lectins are discussed.     

Pentatomid natural products

In addition to the primarily defensive metathoracic glands, adult Pentatomoidea possess a pair of active exocrine glands that open between the III and IV abdominal tergites. In the southern green stink bug,Nezara viridula, and other phytophagous species examined, the glands are small (< 10 g secretion/individual) and of approximately equal size in both sexes. In some, but not all, of the predaceous pentatomids (Asopinae), the III-IV dorsal abdominal glands are small in females (< 10 g secretion/individual) and extremely large in males (>500 g secretion/individual). Using a GC-MS system, the secretion from both males and females ofN. viridula (Pentatominae) was found to contain (E)-2-hexenal, hexanal, 1-hexanol, andn-tridecane. Females contained about three times moren-tridecane than males. The capacious glands ofPodisus maculiventris (Asopinae) males produce (E)-2-hexenal, benzyl alcohol, -terpineol, linalool, terpinen-4-ol, andcis-piperitol. The composition of the previously unanalyzed secretions from the adult III-IV dorsal abdominal glands is compared and contrasted to that of secretions from the metathoricic gland, and the role of coexisting exocrine glands in adult Heteroptera is discussed.     

Identification of Volatiles from the Secretions and Excretions of African Wild Dogs (Lycaon pictus)

Gas chromatography/mass spectrometry was used to identify 103 organic compounds from urine, feces, anal glands, and preputial glands of free-ranging African wild dogs, Lycaon pictus. Aliphatic acids were the dominant class of compound in all materials. In addition to aliphatic acids, urine contained dimethyl sulfone, 1,3-propanediol, benzoic acid, 1-methyl-2,4-imidazolidinedione, and squalene as major components: feces contained indole and cholesterol; and both contained 2-piperidone, phenol, 4-methyl phenol, benzeneacetic acid, and benzenepropanoic acid and other compounds. Anal gland secretion was particularly rich in cholesterol and fatty acids, and preputial gland secretion rich in squalene. A large majority of the identified compounds have been reported from other mammals, including species sympatric with African wild dogs. Eleven of the African wild dog components have not been reported previously from mammals and have not been found in sympatric species; one component, 1-methylimidazole-5-carboxaldehyde has not been reported previously as a natural product. In the chemical profiles of their urine, feces, and anal gland secretion African wild dogs differ markedly from other canids.     

Marking urine and preputial gland secretion of male bank voles (Clethrionomys glareolus L.) chemical analyses and behavioral tests

Urine and preputial gland secretion of male bank voles were analyzed by gas chromatography (GC) and mass spectrometry (MS) (selected ion monitoring, SIM). GC-MS analyses showed the presence of hexadecyl acetate in preputial gland secretion and in marking urine but not in metabolic urine. Female bank voles responded more strongly to marking urine of males than to metabolic urine, and they responded more to preputial gland secretion (pure or added to urine) than to metabolic urine. Dominant males spent more time and marked more frequently in response to hexadecyl acetate-enriched urine than to urine alone. The opposite reaction was shown by subordinate males. The results suggest that the acetate functions in the bank voles' dominance interactions.     

Identification and Function of Prothoracic Exocrine Gland Steroids of the Dytiscid Beetles Graphoderus cinereus and Laccophilus minutus

The chemical composition of the prothoracic defensive secretion of the water beetles Graphoderus cinereus and Laccophilus minutus was examined by gas chromatographic–mass spectrometric analysis of trimethylsilylated gland extracts. The main components are 3,11-dihydroxy-5-pregnan-20-one in G. cinereus and 3,12-dihydroxy-5-pregnan20-one in L. minutus. Fully saturated pregnanes have not been found in the prothoracic defensive glands of dytiscids before. Based on tests with synthetic compounds, their biological role was examined in a feeding assay with the minnow Phoxinus phoxinus. Agar pellets containing either steroid strongly deterred feeding.     

Chemistry and Defensive Efficacy of Secretion of Burrowing Bug (Sehirus cinctus cinctus)

Adult Sehirus cinctus cinctus emit a volatile secretion from their metathoracic scent glands when tactually stimulated. We identified the volatile components by gas chromatography, high-performance liquid chromatography, and mass spectrometry. The secretion of both sexes contained (1R)-(+)--pinene, (1S)-(–)--pinene, -myrcene, (R)-(+)-limonene, and -terpinolene. Two additional compounds were found in only female secretions: (E)-2-hexenyl acetate and (E)-2-octenal. We also tested the defensive capability of this insect by offering it to various predators. Anoles, starlings, and a killdeer rejected S. c. cinctus after an initial sampling. These findings suggest that the secretion plays a defensive role.     

Female sex pheromone of oriental tobacco budworm,Helicoverpa assulta (Guenee) (Lepidoptera: Noctuidae): Identification and field testing

Analysis of ovipositor washings from virgin femaleHelicoverpa assulta (Guenée) (Lepidoptere: Noctuidae) from Korea by gas chromatography (GC) linked to electroantennography and GC linked to mass spectrometry resulted in the identification of nine compounds, hexadecanal, (Z)-9-hexadecenal, (Z)-11-hexadecenal, hexadecyl acetate, (Z)-9-hexadecenyl acetate, (Z)-11-hexadecenyl acetate, hexadecan-l-ol, (Z)-9-hexadecen-l-ol, and (Z)-11-hexadecen-1-ol. However, ovipositor washings from females from Thailand contained mainly the 16-carbon aldehydes with very small amounts of (Z)-9-hexadecenyl acetate. Field tests conducted in Korea, China, and Thailand indicated that a binary blend of (Z)-9-hexadecenal and (Z)-11-hexadecenal was sufficient for attraction, although the most attractive ratio of compounds varied with location. In Korea a 201 blend of compounds was the most attractive, while in Thailand a 7.51 blend was most attractive. In China both blends of hexadecenal isomers were equally attractive. Addition of the hexadecenyl acetates to the 201 blend of hexadecenals in the ratio of 13.3 increased the trap catch of maleH. assulta compared to lures containing the aldehydes alone in Korea but reduced trap catch in China. Addition of the hexadecenyl acetates to the 7.51 blend of hexadecenals had no significant effect on trap catch in Thailand or China compared to the aldehydes alone. The addition of the 16-carbon alcohols to the aldehydes had a significantly inhibitory effect in all three countries, suggesting they are not pheromone components. Taken together these results indicate thatH. assulta is polymorphic with at least two populations responding to different sex pheromones.     

Multichemical defense of plant bugHotea gambiae (Westwood) (Heteroptera: Scutelleridae): (E)-2-hexenol from abdominal gland in adults

The occurrence inHotea gambia adults of a sexual dimorphism in the divided dorsal abdominal scent gland (dg 1)is reported. Counts made of ducted secretory units indicate that female dg 1 regresses at the end of larval development, unlike male dg 1 which undergoes no regression. Other dorsal abdominal scent glands (dg 2, dg 3) which function in the larvae cease to function during the imaginai moult. From gas chromatographic, mass spectrometric and [¹H]NMR data, the identity of the secretion from male adult dg 1 was established as virtually pure (E)-2-hexenol (a 100-mg mature male adult contains 0.5–1 l of secretion). 2-Hexenol was also found in the reduced female adult dg 1. In the sexually monomorphic metathoracic scent gland, (E)-2-alkenals (C₆, C₈) and (E)-4-oxohex-2-enal, together with monoterpenes (-pinene, limonene) but not 2-hexenol, were identified. The vapor of (E)-2-hexenol is repellent to both sexes ofHotea adults and toxic to blowfly (Calliphora) eggs.     

Dufour's gland and its role in secretion of nest cell lining in bees of the genusColletes (Hymenoptera: Colletidae)

The liquid secretion of the Dufour's gland in mated females comprises a mixture of macrocyclic lactones, straight chain mono- and dicarboxylic acids, together with trace amounts of di- and trihydroxy monocarboxylic acids and a series ofn-alkanes. Polymerization of the liquid to form the membranous nest cell lining, which also contains alanine and glutamic acid as major constituents, may be mediated by an enzyme from the thoracic salivary gland and voided via the mouth. The composition and structure of the cell linings are similar to those of Wigglesworth's cuticulin.     

Chemical defense secretions of the termite soldiers ofAcorhinotermes andRhinotermes (Isoptera,Rhinotermitinae)

The defense secretions of advanced nasutoid rhinotermitine soldiers from the New World contain enolic -ketoaldehydes as the major components. The secretions of minor soldiers ofRhinotermes hispidus (Emerson) andR. marginalis (Emerson) consist primarily of 3-keto-13-tetradecenal and 3-ketotetradecanal, but possess in addition C₁₃, C₁₄, C₁₅, and C₁₇ saturated and unsaturated ketones. Major soldiers lacked these compounds and in fact had virtually no frontal gland secretion. The defense secretion of the monomorphic soldiers ofAcorhinotermes subfusciceps (Emerson) contains mostly 3-keto-(Z)-9-hexadecenal and (Z)-8-pentadecen-2-one. Biosynthetic origins and interrelationships are postulated for these compounds, and the concomitant evolution of chemical weaponry and the modified labral brush is discussed.Fellow of the Alfred P. Sloan Foundation (1981–1983).     

The dufour gland and the secretion placed on eggs of two species of social wasps,Liostenogaster flavolineata andParischnogaster jacobsoni (vespidae: Stenogastrinae)

The secretion placed on eggs and fed to larvae and the ant guard placed on the nest stalk ofParischnogaster jacobsoni contain the same hydrocarbons and in approximately the same proportions as is found in the Dufour gland. The secretion on eggs is a mixture of the contents of the Dufour gland and nectar. The emulsifying agent is a palmitic acid salt. Similarly, inLiostenogaster flavolineata, the egg secretion is an emulsion of nectar and Dufour gland secretion, which contains alkoxyethanol emulsifiers, found in nature for the first time.     

Sex pheromone chemistry of the western spruce budwormChoristoneura occidentalis Free

SCOT capillary Chromatographic and SCOT capillary chromatographic-mass spectrometic analyses of gland washes and effluvia of virgin femaleChoristoneura occidentalis Free, have been conducted with both a diapausing and nondiapausing strain of this insect. The following compounds were identified in gland washes and effluvia in both strains:E andZ11–14Ald,E andZ11–14Ac,E andZ11–14OH and 14Ald, 14Ac, and 14OH. The average aldehyde: acetate: alcohol ratio found by analysis of single glands by virgin females (nondiapausing strain) was 170.73. Analysis of virgin female effluvia gave this ratio as 1038 (diapausing strain: %Z=8, 11, 15, respectively) and 1036 (nondiapausing strain: %Z=8, 11, 12, respectively). The saturated components were generally 1–2% of theE isomer in each case. Comparisons of EAG responses of bothC. occidentalis andC. fumiferana toE11–14Ald,E11–14Ac andE11–14OH were made. Correlations with both laboratory and field data previously published were also made betweenC. fumiferana andC. occidentalis.Lepidoptera: Tortricidae.