Urinary signaling pheromone and specific behavioral response in tree shrews (Tupaia belangeri)

As soon as they encounter the scent marks made by the urine of fertile male conspecifics, tree shrews of both sexes cover the scent marks with their own sternal-gland secretion by chinning. The urine of other species, female conspecifics, or castrated male conspecifics does not elicit this behavior; that is, overmarking with sternal-gland secretion is a reaction to a specific chemical signal. The intensity of the overmarking reaction, i.e., the chinning score in response to the urine sample, decreases as the urine is diluted. The urine of different male conspecifics elicits overmarking of varying intensity; an animal's own urine is in general not overmarked. This behavioral reaction meets all the criteria for a bioassay of potential use in isolating the tree-shrew pheromone from urine.     

Extraction,characterization, and binding analysis of two pheromonally active ligands associated with major urinary protein of house mouse (Mus musculus)

Mouse urine contains substantial quantities of a family of proteins (MUPs) that are members of the lipocalycin family of proteins and that are potentially capable of binding hydrophobic molecules. We have used gas chromatography-mass spectrometry (GC-MS) to characterize two ligands associated with the MUPs, a thiazole and a brevicomin derivative. Previous work has suggested a role for these two ligands as androgen-dependent pheromones. In urine, nearly all of these ligands are protein bound and fractionation of MUPs on Mono-Q anion exchange chromatography indicated some specificity of ligand binding by the MUP subclasses.     

Alarm pheromone of pentatomid bug,Erthesina fullo Thunberg (Hemiptera: Pentatomidae)

In the pentatomid bug,Erthesina fullo Thunberg, the odor of male metathoracic scent gland elicits an alarm response, making the male individuals of the same species alert and disperse; the alarm response of males is more obvious than that of females. Chemical composition of the glandular secretion was identified by gas chromatography and mass spectrometry data in comparison with authentic compounds. No sexual dimorphism exists in the glandular composition in this species. A total of 9 compounds [(E)-2-hexenal, (E)-4-keto-2-hexenal, (E)-2-hexenyl acetate,n-undecane,n-dodecane, (E)-2-decenal,n-tridecane, (E)-2-decenyl acetate, andn-pentadecane] are identified, among whichn-tridecane and (E)-4-keto-2-hexenal comprised nearly 70% of the total secretion in both females and males.     

Increased scent marking in male Mongolian gerbils by urinary polypeptides of female conspecifics

Male Mongolian gerbils scent mark during a standardized openfield test on an individually different but more-or-less constant level in the absence of females. The presence of females in the same room but without direct contact to the males increases the marking frequencies of the males to an individually different higher level. A similar increase in marking frequency is obtained by application of female urine directly to the nostrils of the males, but not by male gerbil urine or female laboratory mouse urine. This indicates that substances present in female gerbil urine are responsible for the increase in male marking behavior. Using this bioassay, various fractions of female urine were tested for their influence on marking behavior. Our results to date show that the component increasing male scent-marking behavior is hydrophilic and nonvolatile and is contained in the nondialyzable, high-molecular-weight polypeptide fraction of female gerbil urine.     

Determining pheromone content of hairpencils from individual virgin males ofPseudaletia unipuncta (Haw.) (Lepidoptera: Noctuidae)

Levels of benzaldehyde recovered from virginPseudaletia unipuncta (Haw.) males were not influenced by (1) the time hairpencils remained in the solvent (1-72 hr), (2) anesthetization or agitation of males prior to excision of hairpencils, or (3) the time (photophase or scotophase) that hairpencils were excised. Thus the interindividual variability observed is not a methodological artifact. Most males had similar concentrations in both hairpencils, although in some cases only one hairpencil contained pheromone. In one case, a male with partially extruded hairpencils had no benzaldehyde at all. Neither pupal weight nor hairpencil length proved to be reliable indicators of pheromone content.Contribution No. 373, Département de biologie, Université Laval.     

Studies on the nature of chemical signals in scent marks and urine ofSaguinus fuscicollis (Callitricidae,primates)

The circumgenital scent marks ofSaguinus fuscicollis are mixtures of skin gland secretions, urine, and perhaps vaginal discharge. One of their ingredients, urine, is readily investigated by conspecifics. Female tamarins are able to utilize urine to discriminate between the sexes, but it appears that urine, unlike the scent marks, offers no clues for individual discrimination. Moreover, urine is less attractive to conspecifics than complete scent marks, which signal sex and individuality. The sexual identity of marks is recognized even if the tamarins are prevented from contacting the material directly and seems to be retained in a mixture of scent from both sexes.     

Attraction of bark beetles (Coleoptera: Scolytidae) to a pheromone trap

The movement of bark beetles near an attractive pheromone source is described in terms of mathematical models of the diffusion type. To test the models, two release experiments involving 47,000 marked spruce bark beetles [Ips typographus (L.)] were performed. The attractive source was a pheromone trap, surrounded by eight concentric rings with eight passive trap stations on each ring. Captures were recorded every 2–10 minutes for the pheromone trap and once for the passive traps. The models were fitted to the distribution in time of the central pheromone trap catch and to the spatial distribution of catch among the passive traps. The first model that gives a reasonable fit consists of two phases: Phase one—After release the beetles move according to a diffusion process with drift towards the pheromone trap. The strength of the drift is inversely proportional to the distance from the traps. Phase two—those beetles attracted to, but not caught by, the pheromone trap are no longer influenced by the pheromone, and their movement is described by a diffusion process without drift. In phase two we work with a loss of beetles, whereas the experiment seems to indicate that the loss of beetles in phase one is negligible. As a second model, the following modification of phase one is considered: After release the beetles move according to a diffusion process without drift, until they start responding to the pheromone (with constant probability per unit time), whereafter they start moving according to a diffusion process with drift. This study, like other release experiments, shows that the efficiency of the pheromone trap is rather low. What is specific for the present investigation is that we try to explain this low efficiency in terms of dynamic models for insect movement. Two factors seem to contribute: Some beetles do not respond to pheromone at all, and some beetles disappear again after having been close to the pheromone trap. It also seems that the motility of the beetles decreased after they ceased responding to the pheromone. Furthermore, the data lend some support to the hypothesis that flight exercise increases the response of the beetles to pheromone.     

Field attraction ofBiprorulus bibax Breddin (Hemiptera: Pentatomidae) to synthetic aggregation pheromone and (E)-2-hexenal,a pentatomid defense chemical

A synthetic blend of the aggregation pheromone [(3R,4S,1E)-3,4-bis(1-butenyl)tetrahydro-2-furanol, linalool, farnesol, and nerolidol] of the spined citrus bug,Biprorulus bibax, and the pentatomid defense chemical, (E)-2-hexenal, both attracted adultB. bibax to individual trees in citrus orchards. Lemon trees containing single glass vials with aggregation pheromone or (E)-2-hexenal were colonized by significantly greater numbers of reproductiveB. bibax than unbaited trees. There was no significant difference between the treatments and bug recruitment was not improved by using both treatments.B. bibax did not enter cylinder/funnel traps baited with aggregation pheromone but colonized trees containing the traps. Orange or lemon trees containing aggregation pheromone on orchard perimeters recruited significantly larger populations of emigrating, nonreproductiveB. bibax during fall than untreated trees. Nonreproductive bugs were not attracted to trees containing (E)-2-hexenal. The potential for using these semiochemicals as management tools forB. bibax is discussed.     

Anal gland secretion of European mole: Volatile constituents and significance in territorial maintenance

The chemical composition of the volatile components of the anal gland secretion of mature and immature moles of both sexes was examined by gas chromatography and mass spectrometry. The compounds in the secretion of adult males appear to vary little throughout the year and are similar to those from the adult female outside the breeding season. The secretions are dominated by C₅-C₁₀ carboxylic acids. Female glands regress as they enter proestrus, accompanied by profound changes in the chemical composition of the secretion with early disappearance of the carboxylic acids. In juvenile moles, the composition of the secretion changes as the animal matures, with carboxylic acids becoming dominant only as the animal reaches maturity. Anal gland secretion probably plays an important role in territorial maintenance.     

Response to pheromone traps and disruption of pheromone communication in the lesser peachtree borer and the peachtree borer (Lepidoptera: Sesiidae)

The sex pheromone communication of the lesser peachtree borer,Synanthedon pictipes (Grote and Robinson), and the peachtree borer,Sanninoidea exitiosa (Say), can be disrupted by permeation of the atmosphere with their respective sex pheromones, (E,Z)- and (Z,Z)-3,13-octadecadien-1-ol acetate. The two isomers seemed equally effective against both species. Disruption was greatest when the pheromone was evaporated from the tops of the peach trees; also, pheromone traps placed in the tree tops captured significantly more males than did traps placed lower in the trees. Neither the color nor the directional placement in a tree (NE, NW, SE, SW) of pheromone-baited traps influenced captures of male lesser peachtree borers.Mention of a commercial or proprietary product in this paper does not constitute a recommendation or an endorsement of that product by the USDA.     

Sex pheromone of European grapevine moth (Lobesia botrana) its chemical transformations in sunlight and heat

Photo- and radical isomerization of (E, Z)-7,9-dodecadien-1-yl acetate (DDA) leads to an equilibrium mixture of all four possible geometric isomers of 7,9-DDA in the ratio ofE,E, 69–76%;Z,E, 11–13%;E, Z, 12–15%; andZ, Z, 1–3%. Iodine catalysis of the isomerization takes place even in dark at room temperature and is probably a radical reaction.     

Heritable variation in pheromone response of the pink bollworm,Pectinophora gossypiella (Lepidoptera: Gelechiidae)

Heritability of variation in male pheromone response by pink bollworm moths,Pectinophora gossypiella (Saunders), was examined using a still-air, wing-fanning bioassay. Heritability (±SE) of overall responsiveness, as measured by the mean duration of wing fanning to the blend of pheromone components produced by females [4456 ratio of (Z, E)- to (Z, Z)-7,11-hexadecadienyl acetate], was 0.385 ± 0.095. Heritabilities of wingfanning duration to blends with 25 and 65%Z, E isomer were 0.377 ± 0.113 and –0.145 ± 0.103, respectively. These findings indicate an asymmetry in the genetic component of variation in response to pheromone blends with high and low proportions of theZ, E isomer. An index of response specificity for individual males was developed based on the response to an off-blend (either 25 or 65%Z, E isomer) relative to the response to the 44%Z, E blend. Heritabilities of response specificity were 0.117 ± 0.059 and –0.043 ± 0.067 for the 25 and 65%Z, E blends, respectively.     

A new component of the female sex pheromone ofBlattella germanica (L.) (Dictyoptera: Blattellidae) and interaction with other pheromone components

A fourth component, 3,11-dimethyi-2-heptacosanone, was identified as a cuticular contact sex pheromone of the female German cockroach,Blattella germanica. In behavioral assays, higher dosages of 3,11-dimethyl-2-heptacosanone were needed to elicit similar sexual responses in males to those elicited by the major pheromone component, 3,11-dimethyl-2-nonacosanone. A 1585 blend of the C₂₇ and C₂₉ methyl ketone homologs resulted in a dose-response curve intermediate between that of each of the components alone, indicating independence of activity of each component and lack of synergism. Moreover, the activity of 3,11-dimethyl-2-nonacosanone was not enhanced by female cuticular hydrocarbons. The relationship between sexual responses of males to females and to isolated female antennae, and the amount of cuticular pheromone on whole females was investigated. Cuticular sex pheromone found on females increased with the age of the female, as did the male response to whole females. However, a bimodal male response was elicited by isolated female antennae. Differences between behavioral and analytical assays of pheromone are discussed.     

Avoidance response of a terrestrial salamander (Ambystoma macrodactylum) to chemical alarm cues

Organisms from a wide variety of taxonomic groups possess chemical alarm cues that are important in mediating predator avoidance. However, little is known about the presence of such alarm cues in most amphibians, and in particular terrestrial salamanders. In this study we tested whether adult long-toed salamanders (Ambystoma macrodactylum) showed an avoidance response to stimuli from injured conspecifics. Avoidance of stimuli from injured conspecifics could represent avoidance of a chemical alarm cue or, alternatively, avoidance of a territorial pheromone or conspecific predator odor. Consequently, we also tested whether salamanders avoided stimuli from noninjured conspecifics. Salamanders avoided stimuli from injured but not from noninjured conspecifics. Therefore, we concluded that the response to injured conspecifics represents avoidance of a chemical alarm cue and not avoidance of a territorial pheromone or predator cue. This is the first clear demonstration of chemical alarm signaling by a terrestrial amphibian and the first report of chemical alarm signaling in an ambystomatid salamander. By avoiding an area containing stimuli from injured conspecifics, long-toed salamanders may lower their risk of predation by avoiding areas where predators are foraging.     

Sex pheromone of tomato pestScrobipalpuloides absoluta (Lepidoptera: Gelechiidae)

The sex attractant ofScrobipalpuloides absoluta females is a 90:10 mixture of (3E,8Z,11Z)-3,8,11-tetradecatrien-1-yl acetate and (3E,8Z)-3,8-tetradecadien-1-yl acetate. Tetradecadienyl acetates bearing 8Z,11Z; 3E,8Z; and 3E,11Z double bonds were synthesized by stereospecific procedures; the mass spectral and gas chromatographic properties of the 3E,8Z isomer were found to be congruent with those of the tetradecadienyl acetate fromS. absoluta. In wind tunnel bioassays, a 10:1 mixture of synthetic (3E,8Z,11Z)-3,8,11-tetradecatrien-1-yl acetate and (3E,8Z)-3,8-tetradecadien-1-yl acetate was highly attractive toS. absoluta males. Interestingly, the presence of (8Z,11Z)-8,11-tetradecadien-1-yl acetate (10%) inhibited the response to (3E,8Z,11Z)-3,8,11-tetradecatrien-1-yl acetate completely.     

Significance of the pyrrolic nitrogen atom in receptor recognition ofAtta texana (Buckley) (Hymenoptera:Formicidae) trail pheromone and parapheromones

Calculations of the charge of the pyrrolic nitrogen atom in the trail pheromone ofAtta texana, methyl 4-methylpyrrole-2-carboxylate, as well as 17 analogs, showed that the most active compounds all had the same charge of –0.51 electrons on the nitrogen atom. It is suggested that the close value for this charge may be important in recognition by the receptor.This work was supported in part by the University of Iowa Computer Center.     

Field trapping ofMigdolus fryanus westwood (Coleoptera: Cerambycidae) using natural sex pheromone

Migdolus fryanus is a sugarcane pest restricted to South America that is becoming more important due to the inefficacy of control methods against it. The larvae bore into the plant root system and the available insecticides can not give adequate protection. So, the search for alternate control strategies is mandatory. However, the literature on bioethological studies of the species is scarce. This work investigates the attraction of adult males in the field by females that is mediated by a sex pheromone that remains to be identified. Dissected female thoraces were more attractive than other body parts. A trap design for monitoring field populations of this species also is presented.     

Preliminary isolation of male-inhibitory pheromone of the spiderSchizocosa ocreata (Araneae,Lycosidae)

Compounds with pheromone activity were extracted from maleSchizocosa ocreata silk using methanol as the solvent. Behavioral data suggest that these compounds mediate agonistic encounters among male spiders. Preliminary chemical analyses indicate that the pheromones are low-molecular-weight lipids, one being slightly polar, the other nonpolar.     

(R)-acetoin-female sex pheromone of the summer chafer Amphimallon solstitiale (L.)

Extracts of Amphimallon solstitiale (L.), a well known, widely distributed and rather common European scarab beetle, were analyzed by GC-MS and GC-EAD. Acetoin -(R):(S) < 9:1 - as well as 2,3-butanediol -(2R,3R):(2S,3S) :meso = 1:1:9 - were present in extracts of both males and females. Although (2S,3S)-butanediol did not show any EAD activity, the other compounds elicited strong responses exclusively with male antennae. In contrast, several EAD active green leaf volatiles were detected equally well by male and female antennae. During preliminary field bioassays, (R)-acetoin was highly attractive to swarming males, whereas neither rac-acetoin nor the 2,3-butanediols showed activity. Therefore, (R)-acetoin is the female sex pheromone of A. solstitiale.     

Multifunctional communication inRiptortus clavatus (Heteroptera: Alydidae): Conspecific nymphs and egg parasitoidOoencyrtus nezarae use the same adult attractant pheromone as chemical cue

The bean bug,Riptortus clavatus lays scattered eggs (as opposed to the egg masses of pentatomids) on host as well as nonhost plants. Therefore, the first feeding stage (second-instar) nymphs emerging from eggs laid on nonhost plants need a signal that enables them to locate a food source at the lowest energy cost. Male-released (E)-2-hexenyl (E)-2-hexenoate, (E)-2-hexenyl (Z)-3-hexenoate, and myristyl isobutyrate play the double role of attractant pheromone for adults as well as aggregation pheromone, which enables the second-instar nymphs to find the host food plant. These male-specific semiochemicals are released only when foodstuff is available. On the other hand, females ofOoencyrtus nezarae, the most effective parasitoid of the host in Kumamoto, Japan (where the field experiments were conducted), utilize these semiochemicals as kairomones in order to locate the potential host community. Field experiments revealed that the synthetic pheromone rivaled 10 live males in the attraction of adults and second-instar nymphs. Captures of the egg parasitoidO. nezarae females in cylindrical sticky traps were significantly higher in traps baited with the synthetic semiochemicals than in control traps. The number of females captured was significantly higher than the number of males, although the captures in the sticky suction trap system revealed that the populations of male and female were not significantly different.