Marking pheromone

Fig. 1. Three behavior patterns of Plethodon cinereus (A) normal walking posture, (B) tapping the nasolabial cirri to the substrate, and (C) chin scraping," which may be involved in pheromonal marking. 

Fig. 1.5 Tip recordings from a tarsal D-hair of Rhagoletis cerasi (cherry fruit fly) in response to surface extracts of fruits with female pheromone markings and of fruits which had only contact with an equal number of males.

Territorial pheromones These pheromones mark the boundaries of an organism s territory. In dogs, these pheromones are present in the urine. Dogs can thus mark out their territory. 

Behavioural testing of protein fractions has not kept pace with semiochemical studies. Belcher et al. (1990) found that the mixed scent marks of the Saddle-backed Tamarin (S. fusicollis) comprise urine and genital/suprapubic gland secretions. Both sexes deposit mixtures of pheromonally active large molecules at, for example, exudate feeding... 

Regier F. and Goodwin M. (1977). On the chemical and environmental modulation of pheromone release from vertebrate scent marks. In Chemical Signals in Vertebrates 1 (Muller-Schwarze D. and Mozell M.M., eds.), pp. 115-134. 

Thiesen D., Regnier F., Rice M., Goodwin M., et al. (1974). Identification of a ventral scent marking pheromone in the male Mongolian Gerbil (Meriones unguiculatus). Science 184, 83-85. 

Many different functions of pheromones have been found since Butenandt. Aggregation pheromones attract both sexes to a special location, while sex pheromones are offered by one sex only to attract or arouse the other one. Trail pheromones used by ants mark food trails and alarm pheromones change the state of alertness of conspecifics. These are only some of the functions pheromones can have, and similar different functions can be found in allelochemicals as well. 

Fig. 2 Taxonomy and pheromone studies of insects in the superfamily of Noctuoidea. The numbers before and after + in parenthesis of each group indicates the total number of species whose female sex pheromone and male attractant have been reported respectively. Each mark after the group name indicates that some species within the group produces a pheromone component of Type I ( with a common functional group, with a novel functional group), Type II (A), or others )...

All of the suborder Symphyta and many species in the superfamily Aculeata in the suborder Apocrita are solitary insects. Although not requiring the complex semiochemistry of parasitic or social insects, solitary insects employ pheromones for mating, territorial marking, and host marking. Unfortunately, very few of these have been chemically identified. The pheromones of sawflies and seed wasps were extensively reviewed in 1999 [ 14]. The semiochemicals recently identified in solitary hymenoptera, discussed below, are summarized in Table 2 and Fig. 1. 

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]. 

Tetratrophic interactions between a host plant, a phytophagous pest (primary host), a hymenopteran parasitoid or symbiont (secondary host) and a hymenopteran hyperparasitoid (which parasitizes the secondary host) are of considerable importance, because hyperparasitism can significantly reduce populations of economically beneficial parasitoids [11]. Hyperparasitoids use host-marking (=spacing) pheromones, sex pheromones [12], and host-detection cues [42], but they also show additional chemically mediated interactions with the other partners. These include detection of the primary host s secretions by the hyperparasitoid [43], detection of plant volatiles by the hyperparasitoid [44], and detection of the hyperparasitoid s secretions by the primary host [45] or by the secondary host. The latter causes the secondary host to avoid locations where the hyperparasitoid is foraging [46]. 

Several long-range attractant sex pheromones have been identified (Table 3) or evidence for such a pheromone has been obtained in the past 13 years. The parasitoid Ascogaster reticulatus produces (9Z)-hexadec-9-enal 9 in a tibial gland [47]. The pheromone is spread by the females much like a trail on the substrate, and the males follow the mark to the source by close antennal contact with the substrate [48]. EAG studies have revealed that the males respond much more strongly to (9Z)-hexadec-9-enal than the females and that the response to the... 

Host marking pheromones are important in many species of parasitic hymen-optera, because they ensure that a female parasitoid focuses on non-parasitized hosts. This, in turn, ensures a more effective use of limited host resources. Marking pheromones can be internal (injected into the host at the time of oviposition) or external (applied to the host during inspection and/or ovipo-sition). The internal markers can be detected by sensory hairs on the parasitoid ovipositor [11]. The internal markers often also delay the development of the host. 

Wyatt, T.D. (2003) Pheromones and Animal Behaviour. Cambridge University Press, Cambridge. Yahr, P. (1983) Hormonal influences on territorial marking behavior. In B.B. Svare (Ed.), Hormones and Aggressive Behavior, New York, pp. 145-175. 

Hudson, R., Gonzalez-Mariscal, G. and Beyer, C. (1990) Chin marking behavior, sexual receptivity, and pheromone emission in steroid-treated, ovariectomized rabbits. Hormones Behav. 24, 1-13. 

---