Chemical cues

Ultra-sound emissions typically occur when male rodents are exposed to female odours or altricial neonates to maternal sources (Whitney, 1974 Conely and Bell, 1978). Without the VNO, sexually inexperienced male mice do not utter emissions at ultra-high frequencies (UHF), whereas those with prior experience vocalise after VN-x, as discussed above (Chap. 5). Female mouse urine contains a unique UHF-eliciting component which is non-volatile but ephemeral (Sipos et al., 1995). The signal is degraded by oxidation and disappears within 15 to 18 hours of deposition. Direct contact with freshly voided urine must occur before males will vocalise (sexually experienced or inexperienced). At least one of the olfactory systems is needed for UHF to be elicited by fresh urine complete deafferentation abolishes the response (Sipos et al., 1993). Exposure to females permits UHF to be elicited by other than chemical cues (Labov and Wysocki, 1989). Nocturnal or cryptic species conceivably use ultrasound to advertise male presence whether this is to deter other males or assist with female location is unclear. 

Block M Volpe L. and Hayes M. (1981). Saliva as a chemical cue in the development of social behavior. Science 211, 1062-1064. 

Johnston R.E. and Rasmussen K. (1984). Individual recognition of female hamsters by males role of chemical cues and of the olfactory and vomeronasal systems. Physiol Behav 33, 95-104. 

Unlike parasitoids of other insect orders that have host-seeking larvae, most parasitic hymenoptera lay their eggs on, in, or very close to a host individual [11]. This requires the adult female to find a suitable host, often with the aid of chemical cues from host frass, pheromones, plant volatiles emitted upon host feeding or egg-deposition, silk, honeydew and other secretions. She may then chemically mark the host following oviposition to reduce superparasitism by herself or intra- and inter-specific insects [11]. 

The queen is usually reproductively dominant within the colony and uses chemical cues as both primer and releaser pheromones to suppress the production or fecundity of other sexuals, inhibit reproduction by worker castes, modulate reproductive behaviors (e.g., inhibit swarming and orient swarms), attract males, regulate worker tasks and worker ontogeny, and produce host repellents in slave-making species. Considering the importance of queen semiochemicals in social hymenoptera, few queen pheromones have been chemically identified. The queens of most social hymenopteran colonies are attractive to workers, allowing them to be properly tended as well as to facilitate the dissemination of other pheromone cues. However, the retinue pheromone has been chemically identified in very few species. In the 1980s, queen pheromone components were identified in the fire ant, Solenopsis invicta [91,92], and in the Pharaoh s ant, Monomoriumpharaonis [93]. 

An example of an uncharacterized chemical cue from ant brood occurs in the obligatory slave-making ant, Polyergus breviceps. Pupae of this species are cared for by their enslaved host worker, while pupae of other species are consumed [125]. 

In addition to their role in chemical defense, DMSP-lyase products may also function as chemical cue in more complex trophic cascades. In the natural environment DMS-production is related to zooplankton herbivory [60] and can thus act as an indicator for the availability of food for planktivorous birds. Indeed, some Antarctic Procellariiform seabirds can detect DMS (22) and are highly attracted to the cue, as was shown with DMS-scented oil slicks on the ocean surface [61]. The odors released during zooplankton grazing (DMS) as well as those of zooplankton itself (e.g., trimethylamine and pyrazines) are attractive to birds [62], thus assisting vertebrate search behavior. 

Even though early success has been demonstrated with the use of polymers for peripheral and central nerve regeneration, it can be enhanced further by providing site-specific release of growth factors and other chemical cues to the regenerating axons, as described in the next section. 

The vomeronasal organ is an accessory chemosensing system that plays a major role in the detection of conspecific chemical cues, also known as pheromones 824... 

Chemosensory neurons of the vomeronasal system are narrowly tuned to specific chemical cues, and utilize a unique mechanism of sensory transduction 824... 

Bloss J., Acree, T.E., Bloss, J.M., Hood, W.R. and Kunz, T.H. (2002) Potential use of chemical cues for colony-mate recognition in the big brown bat, Eptesicus fuscus. J. Chem. Ecol. 28, 819-834. 

Porter, R.H. and Doane, H.M. (1977) Dietary-dependent cross-species similarities in maternal chemical cues. Physiol. Behav. 19, 129-131. 

Cross-dressing in Chemical Cues Exploring She-maleness in Newly-emerged Male Garter Snakes... 

Experimental data suggest that VN stimuli might also play a relevant role in prey-predator interactions by mediating affective responses to prey or predator chemical cues. For instance, one of the preferred prey for the snake Thamnophis sirtalis is earthworms. Halpern (1988) demonstrated that earthworm wash constitutes a VN stimulus that is rewarding for these snakes. On the other hand, it has been shown that rats display defensive reactions to a collar that has been worn by a cat, even if they have no previous experience with cats. For these defensive behavioral responses to occur, direct contact with the collar is needed (Dielenberg and McGregor 2001). 

This suggests a role of the VN organ in detection of the fear-inducing cat s chemical cue, a hypothesis clearly supported by data on c-fos expression (Dielenberg and McGregor 2001). 

Labra, A. (2007) The peculiar case of an insectivorous iguanid lizard that detects chemical cues from prey. Chemoecology 17, in press. 

Hypothesis 3 Females avoid laying eggs into a water body already containing cane toad eggs / tadpoles, they detect this through a chemical cue in the water. 

Arthropods that prey on or parasitize other arthropods frequently employ those chemical cues that reliably indicate the presence of their... 

Stamp N (2003) Out of the quagmire of plant defense hypotheses. Q Rev Biol 78 23-55 Steinberg PD (1988) Effects of quantitative and qualitative variation in phenolic compounds on feeding in 3 species of marine invertebrate herbivores. J Exp Mar Biol Ecol 120 221-237 Steinberg PD, de Nys R, Kjelleberg S (2002) Chemical cues for surface colonization. J Chem Ecol 28 1935-1951... 

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