Vertebrate pheromones and other semiochemicals: the potential for accommodating complexity in signalling by volatile compounds for vertebrate management

Abstract

The interaction between volatile and non-volatile, e.g. proteinaceous, components of pheromone and other semiochemical-based signalling systems presents a daunting set of problems for exploitation in the management of vertebrates, good or bad. Aggravating this is the complexity of the mixtures involved with pheromones, not only by definition associated with each species, but also with individual members of that species and their positions within their immediate communities. Nonetheless, already in some contexts, particularly where signals are perceived at other trophic levels from those of the vertebrates, e.g. by arthropods, reductionist approaches can be applied whereby the integrity of complex volatile mixtures is maintained, but perturbed by augmentation with individual components. In the present article, this is illustrated for cattle husbandry, fish farming and human health. So far, crude formulations have been used to imitate volatile semiochemical interactions with non-volatile components, but new approaches must be developed to accommodate more sophisticated interactions and not least the activities of the non-volatile, particularly proteinaceous components, currently being deduced.

Protecting cows in small holder farms in East Africa from tsetse flies by mimicking the odor profile of a non-host bovid

“…Our WRC may be one such effective synthetic combination for protecting people and their livestock from tsetse and other arthropod pathogen vectors attracted to cattle. Moreover, the response of vectors to compounds from related non-host species may be of more adaptive value in their behavioral ecology than their response to botanically derived repellents [ 34 ]. The high performance of the WRCs is likely to relate to the potential role of these compounds as stress cues associated with traits making prospective hosts unsuitable [ 34 , 35 ].…”

“…Moreover, the response of vectors to compounds from related non-host species may be of more adaptive value in their behavioral ecology than their response to botanically derived repellents [ 34 ]. The high performance of the WRCs is likely to relate to the potential role of these compounds as stress cues associated with traits making prospective hosts unsuitable [ 34 , 35 ]. Added advantages include minimum maintenance and no harmful effects on environmental, human or other animal health as the repellent compounds are natural products already present in tsetse habitats and importantly, also drastically reduce the reliance of livestock keepers and pastoralists in Africa on trypanocides.…”

An evolutionary conserved olfactory receptor for foodborne and semiochemical alkylpyrazines

“…[12][13][14][15] Pyrazines function both intraspecies, for example, as pheromones sensu stricto, [16][17][18] as well as interspecies, for example, as allomones (to the benefit of the "sender") 7,8 and kairomones (to the benefit of the "receiver"). 9,10,19 Despite pyrazines' eminent role as information carriers for the chemical senses of humans and other animals, the molecular chemoreceptive mechanisms of their chemosensory perception remained largely unknown, so far.…”

Characterizing human odorant signals: insights from insect semiochemistry and in silico modelling

“…This involves the insect detecting the presence, or heightened levels, of certain compounds which, in the context of normal host semiochemicals, cause avoidance or even repulsion. This phenomenon is an example of contextual repellency [18,19]. Thus, the tsetse flies, Glossina species, comprising the vectors of trypanosomes causing animal trypanosomiasis or nagana in sub-Saharan Africa, are known to avoid the non-host waterbuck, Kobus ellipsiprymnus defassa, although the livestock cattle hosts are in the same family (Bovidae).…”