Chemical composition of the frontal gland secretion ofSyntermes soldiers (Isoptera,Termitidae)

The defensive secretions from the frontal glands of soldier termites of the genusSyntermes contain similar mixtures of mono- and sesquiterpene hydrocarbons. The major components inS. dirus, S. molestus, S. brevimalatus, S. peruanus, and a new species (Syntermes sp. n), iscis--ocimene. A substantial amount of aristolochene is found inSyntermes sp. n. and is present at lower levels in all the other species;S. brevimalatus contains onlycis--ocimene and aristolochene. The four other species also contain minor amounts of epi--selinene and germacrene A. The latter compound has been identified on the basis of its rearrangement product -elemene. The termiteS. grandis differed markedly from the otherSyntermes species in that no terpenoid components were found in the soldier extract. With the obvious exception ofS. grandis, the same soldier-specific mono- and sesquiterpenes occurred in all species. The total amount of secretion per unit weight of soldiers varies with the species and is inversely proportional to the development of the mandibular apparatus. InS. molestus smaller gland size is compensated for by a greater number of soldiers foraging trails.     

Isolation,identification, and biological activity of trail-following pheromone of termiteTrinervitermes bettonianus (Sjöstedt) (Termitidae:Nasutitermitinae)

The principal compound which posseses trail-following activity at low concentration has been isolated from workers and from female alates of the grass feeding termiteTrinervitermes bettonianus. Male alates also produce the pheromone but in much smaller quantities than the female. The structure of the pheromone was determined as the diterpene hydrocarbon cembrene-A from spectra and microscale reaction data.     

Soldier defense secretions of malaysian free-ranging termite of the genusLacessititermes (Isoptera,Nasutitermitinae)

Soldiers of free-ranging termites of the genusLacessititermes (Isoptera, Nasutitermitinae) secrete from their frontal glands a mixture of monoterpenes, sesquiterpenes, and diterpenes.Lacessititermes ransoneti, L. laborator, andL. species A produce species-specific secretions, the composition being most complex forL. laborator. Apart from known mono- and dihydroxytrinervitadienes, the following new diterpenes were isolated and tentatively assigned as trinervita-1(15),8(19)-dien-2,3,9,14-tetraol 2,3,14-O-triacetate, trinervita-1(15),8(19)-dien-2,3,9,14-tetraol 2,3,14-O-triacetate, 2,3,9, 14-tetraacetoxy-1 (15), 8(19)-trinervitadiene, and 2,3,11,13-tetraacetoxy-1(15),8(19)-trinervitadiene. Data on intragenus chemical variations were subjected to canonical discriminant analysis and genetic distances among the species were calculated to depict intragenus identities and affinities.     

Interspecific variation in defense secretions of malaysian termites from the genusNasutitermes (Isoptera,nasutitermitinae)

The defense secretions of five species of MalaysianNasutitermes,N. longinasus, N. matangensis, N, havilandi, N. johoricus, andNasutitermes species 01, are compared.N. longinasus andN. species 01 provide trinervitene alcohols,N. havilandi mainly tricyclic trinervitene and tetracyclic kempane alcohols and acetates, whereasN. matangensis furnish acetyl/propionyl derivatives of trinervita-11(12),15(17)-dien-3,9,13-triol (XXI and XXII). A new diterpene, assigned as trinervita-11(12),15(17)-dien-3,13-diol-3,13-O-diacetate (XVII), is isolated fromN. havilandi. The mono- and diterpenoid compositions, being species-specific, are useful for chemotaxonomic and phylogenetic studies.     

Diterpene composition of defense secretion of four west AfricanTrinervitermes soldiers

The diterpene composition of the defensive secretions of minor and major soldiers is described for four sympatricTrinervitermes from the Ivory Coast. The degree of intra- and interspecific similarity between the secretions is assessed and related to available information on soldier behavior. A significant chemical dimorphism is observed between minor and major soldiers ofT. geminatus andT. togoensis. Both species build extensive foraging trails in the open air. During these excursions, the workers are protected by numerous minor soldiers, but only a few major ones. Internest comparison inT. geminatus suggests that the differences between minor and major soldiers is as large within a nest as between different nests. By, contrast, inT. trinervius andT. oeconomus both types of soldiers produce very similar secretions. The foraging habits of those species are far more cryptic. The first species builds earthen tunnels, and the second one forages in close proximity to its nest under cover of vegetation.Maître de Recherche du Fonds National de la Recherche Scientifique de Belgique.     

Behavioral evidence for multicomponent trail pheromone in the termite,Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae)

Evidence is presented for a multicomponent trail pheromone in the eastern subterranean termiteReticulitermes flavipes (Kollar). Choice tests were used to compare strength and persistency of trails made by termites in glass tubes. Tubes connected to termite nests for 24 hr were marked by termites with an extremely long-lasting chemical that persisted for at least one year, and a highly volatile substance that decayed in 15 min. Individual termites varied the trail they deposited under different circumstances. When removed from the nest and placed in a clean tube, they deposited a highly volatile substance. They left stronger and more persistent trails when exploring clean tubes attached to the nest. When they discovered a new food source, they left trails that were more attractive and far more persistent than trails made by exploring or displaced termites. A food trail made by 15 workers was still effective after 24 hr, whereas a trail made by 50 displaced workers, walking one after another through a tube, lasted only 5 min.     

Dufour's gland secretion in the cell linings of bees (Hymenoptera: Apoidea)

The volatile chemicals, detectable by coupled capillary gas chromatography-mass spectrometry, in the nest cell linings of four species in the bee generaColletes, Andrena, andLasioglossum are identical with, and limited to, the volatile components present in the Dufour's gland of females, suggesting this source for some of their cell-lining constituents. The extractable material that lines the cells ofTrachusa byssina, in contrast, is derived fromPinus resin, to which it can be chemically traced.Contribution number 1738 from the Department of Entomology, University of Kansas, Lawrence.     

Chemical defense secretions of some species of Malaysian rhinotermitidae (Isoptera,Rhinotermitidae)

The defense secretions of the soldiers of the Malaysian rhinotermitid,Parrhinotermes aequalis (Havilandi) andP. pygmaeus (John),Termitogeton planus (Havilandi) andSchedorhinotermes malaccensis (Holmgren) consist mainly of vinyl ketones, whereas that ofProrhinotermes flavus (Bugnion & Popoff) gives (E)-1-nitropentadecene. The chemistry of the defense secretions ofParrhinotermes andTermitogeton is documented and based on their chemical relationships;Termitogeton shows a closer affinity to the Rhinotermitinae than Heterotermitinae.     

Behavior and survival ofReticulitermes hesperus banks (Isoptera: Rhinotermitidae) on selected sawdusts and wood extracts

Survival ofReticulitermes hesperus workers was assessed inPseudotsuga menziesii, Lysiloma seemanii, andTabebuia ochracea sawdusts; and on heartwood solvent extracts ofP. menziesii, L. seemanii, T. ochracea, Pinus ponderosa, Tabebuia guayacan, and aCentrolobium species. Survival inP. menziesii sawdust was 100% at 5 days and 81–87% at 15 days. Survival inL. seemanii andT. ochracea sawdusts was significantly less over both 5 and 15 days than in the starvation control, indicating toxicity. Survival on filter papers treated with solvent extracts ofT. ochracea andP. ponderosa was significantly less than that on control papers, but onlyP. ponderosa differed significantly from the starvation control. In behavioral assays with groups and with individualR. hesperus workers, extracts ofP. menziesii andP. ponderosa were preferred. In the individual behavioral assays, extracts ofT. guayacan andT. ochracea were repellent. Results of toxicity assays were not predictable from preference assays.     

Interspecific variation of diterpene composition ofCubitermes soldier defense secretions

Soldiers of the humivorous termite generaCubitermes andCrenetermes (Isoptera: Termitidae: Termitinae) secrete a mixture of unusual diterpene hydrocarbons from the fontanellar opening of the frontal gland. The defense secretions of sixCubitermes species and oneCrenetermes species show species-specific distributions of the five chemically identified major components and 12 unidentified minor components. The secretion is also present with its characteric terpene distribution in white presoldiers and newly molted soldiers, but is completely absent in workers.Fellow of the Alfred P. Sloan Foundation (1981–85) and Camille and Henry Dreyfus Teacher-Scholar (1981–86).     

Soldier defense secretions ofTrinervitermes bettonianus (Isoptera,Nasutitermitinae): Chemical variation in allopatric populations

The soldier defense secretions of major and minor soldiers of the East African nasute termiteTrinervitermes bettonianus were analyzed chromatographically and spectrometrically, and the diterpene and monoterpene constituents were determined for three allopatric populations. Incipient colonies from one population raised on food from a second population produced their population-specific terpene pattern independent of food source. Secretion compositions are thus genetically rather than nutritionally determined, in agreement with biosynthetic studies in other nasutes. A minor volatile constitutent, previously proposed to be 3-ethyl-2-octanol was re-identified as (R)-2-decanol.     

Macrocyclic lactones and isopentenyl esters in the Dufour's gland secretion of halictine bees (Hymenoptera: Halictidae)

The volatile components of the Dufour's gland secretion of female halictid bees have been examined in 18 Nearctic species belonging toAgapostemon, Augochlora, Augochlorella, Augochloropsis, Dialictus, Evylaeus, Halictus, andLasioglossum. Nine saturated and unsaturated macrocyclic lactones ranging from C₁₈ to C₂₆ have been identified. Four of these compounds, the saturated C₂₆ and the unsaturated C₂₀, C₂₂, and C₂₄ lactones, are new natural products reported for halictine bees. A series of eight esters containing branched C₅-alkenols and fatty acids has been identified in several species. The cell linings and pollen ball inAugochlora pura pura contain the same major lactones as the Dufour's gland. A discussion of the significance of the Dufour's gland secretion for apoid systematics and its function in the Halictidae is presented.     

Cuticular hydrocarbons of the eastern subterranean termite,Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae)

Major cuticular hydrocarbon components in several castes ofReticulitermes flavipes (Kollar) have been identified and quantitated. Types of hydrocarbons present includen-alkanes, 2-methylalkanes, 3-methylalkanes, 5-methylalkanes, an alkene, and an alkadiene, with a range in carbon numbers from C₂₁ to C₂₆, This is the first report on insect cuticular hydrocarbons in which both 2- and 3-methylalkanes are present, as well as the first report of an insect with a conjugated alkadiene.     

Identification of trail pheromone precursors from Subterranean termite,Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae)

Whole-body extracts of the termite,Coptotermes formosanus Shiraki served for examining the presence of trail pheromone precursor(s). Three trail pheromone precursor candidates, identified as dodecatrienyl stearate, dodecatrienyl oleate, and dodecatrienyl linoleate, were isolated using various chromatographic methods in conjunction with bioassay and by capillary GC-MS analyses.     

Soldier-specific chemicals of the termiteCurvitermes strictinasus Mathews (Isoptera,Nasutitermitinae)

The defense secretion of the soldier termites ofCurvitermes strictinasus Mathews has been analyzed. Seven components have been isolated and identified, including limonene, terpinolene,p-cymen-8-ol, tridecan-2-one, tridecen-2-onecis,trans-farnesal, andtrans,trans-farnesal.     

Meliaceae and rutaceae limonoids as termite antifeedants evaluated usingReticulitermes speratus kolbe (Isoptera: Rhinotermitidae)

Four limonoids were evaluated by a no-choice bioassay method as termite antifeedants usingReticulitermes speratus Kolbe. Obacunone showed the highest degree of antifeeding potency (PC₉₅=1133 ppm w/w), followed by nomilin (PC₉₅=4475 ppm), azadirachtin (PC₉₅=65,293 ppm), and limonin (with PC⁹⁵ estimates beyond the bioassay limits), which was the least potent. None of the four limonoids exhibited any evidence of acute toxicity towardsR. speratus, although termites fed on obacunone and nomilin at concentrations higher than their PC₉₅ estimates tend to die faster than those in the unfed treatment. Obacunone and nomilin also showed a drastic antifeedant consumption (AC) reduction effect at concentrations higher than 510 and 1360 ppm, respectively. With azadirachtin and limonin, such an effect was not observed. The present data suggest that both obacunone and nomilin have an absolute antifeeding activity towardsR. speratus.     

Evidence for trail-pheromone precursor in termiteReticulitermes speratus (Kolbe) (Rhinotermitidae: Isoptera)

Whole body extracts of the termite,Reticulitermes speratus, were subjected to various chemical operations and bioassays to examine the presence of trail-pheromone precursor. Fractions that mainly contained fatty acid esters were obtained from hexane extracts by means of silica gel column chromatography. Trail-following activity of the fractions was activated by alkaline hydrolysis, while the original fractions did not show any conspicuous activity. Bioassay showed that the activity of hydrolyzed product was approximately 20 times as high as the original hexane extract. This suggests that the precursor candidate could be stored in termite bodies as an esterified form. Chemical analyses revealed that the complete structure of the hydrolyzed product was coincident with that of the native pheromone ((Z,Z,E)-3,6,8-dodecatrien-1-ol).     

Soldier frontal glands of the termiteMacrotermes subhyalinus: Morphology,chemical composition,and use in defense

Soldiers of the East African fungus-growing termiteMacrotermes subhyalinus (Rambur) (Termitidae: Macrotermitinae) employ both mechanical and chemical defenses. Soldiers release a chemical secretion composed of long-chain saturated and monounsaturated hydrocarbons into wounds inflicted by their powerful mandibles. Chemical analysis of the secretion shows the paraffin fraction to consist primarily ofn-tricosane,n-pentacosane, 3- and 5-methylpentacosane, and 5-methylheptacosane. The major oleflns were identified as (Z)-9-heptacosene and (Z)-9-nonacosene. The secretion originates from the frontal glands of both major and minor soldiers; however, the hypertrophied gland of the major soldiers contains 500-fold more secretion than that of the minor soldiers. This secretion appears to impair the healing of wounds in test ants, and thus could represent a valuable supplement to the mechanical defense mechanism.     

Chemical constituents of the chest gland secretion of the thick-tailed galago (Galago crassicaudatus)

The naturally exuded chest gland secretions of adult male and female thick-tailed bush babies were collected directly in capillary tubes. The pure secretion was subjected to GC-MS analysis which revealed three major components. These were identified by comparison with the appropriate standard compounds: benzyl cyanide,p-hydroxybenzyl cyanide, and 2-(p-hydroxyphenyl)ethanol. Analysis of a male and a female secretion indicated that some sexual dimorphism in the relative concentrations of these components may exist.     

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.