Repellant effects, odor

The repellent effect depends on hunger, as in female elk (Andelt etal, 1992) and less-preferred plants are better protected by predator urine odors (Swihart etal, 1991). 

There is growing evidence that repellents interact with odorants and odorant receptors (ORs), thereby interfering with the odorant-driven host-seeking process. - Bohbot et al. tested the molecular effects of different insect repellents and one novel synthetic pyrethroid with known repellent properties on Aedes aegypti ORs. The pyrethroid inhibited the OR response to an attractant in a similar way to 3,8-pflra-menthane-diol or nepetalactone. Results indicated that repellent effects of pyrethroids may be due to a combination of sublethal neurotoxic excitement and interactions with the olfactory system. ... 

We examined the effect of a series of potential botanical repellents on Diaphorina citri in behavioral assays. Repellents were also evaluated in combination with citrus odors to verify their repellency in the presence of these attractive compounds. Finally, we examined the repellent effects of a select number of plant volatiles formulated in SPLAT. 

Feeding repellents for pest birds are the most important application of chemical stimuli to manipulate bird behavior. Methyl anthranilate (Fig. 13.1) and dimethyl anthranilate, esters of benzoic acid, are found in concord grapes and are used as artificial flavorings. Starlings, Sturnus vulgaris, have an aversion to methyl anthranilate, which irritates the trigeminal nerve, and they feed less on food flavored with a variety of anthranilates. They avoid the more volatile anthranilates most. The odor is partly responsible for the effect contact is not necessary. In one particular experiment, only volatile compounds were aversive (Mason and Clark, 1987). If only anthranilate-treated food is offered, the birds will accept more of the flavored food than they do if they offered a choice between... 

Predator odors are also effective area repellents for lagomorphs. A rabbit warren sprayed with an extract from lion feces had as many as 80% fewer animals than before the treatment and also fewer than a control warren. Adult rabbits stayed away from the treated warren longer than young ones. The effect lasted up to 5 months (Boag, 1991 Boag and Mlotkiewicz, 1994). 

For odors to work, certain environmental conditions have to be met. Townsend s voles, Microtus townsendii, avoid a repellent odor if no cover is available. With cover present, they feed whether or not the area is scented. Therefore, for effective area repellents, the pest rodent should be able to retreat to unscented areas in preferred habitat such as sufficient cover (Merkens etal, 1991 Table 13.2). 

Melchiors, M. A. and Leslie, C. A. (1985). Effectiveness of predator fecal odors as blacktailed deer repellents. JournalofWildlifeManagement 49,358-362. 

Resell F (2001) Effectiveness of predator odors as gray squirrel repellents. Can J Zool 79 1719-1723... 

Chemical alarm responses in frog tadpoles Responses of rodents to cat nrine Responses of rats and mice to predatory snake odors Comparison of effects of commercial sqnirrel repellents with fox urine Oil of Citronella as repellent for dogs and cats Camphor as repellent for cats Predator odors as squirrel repellents Natnrally occnrring contraceptive componnds in plants Attractiveness rating of photos of men and women with and withont fragrance present... 

Compared to the thus far discussed emphasis on drug discovery applications, olfactory receptors play an important role in the perfume and cosmetic industry the screening and design of new odorants is an economically interesting application. The discovery that the malaria transmitting mosquitos Anopheles, which is responsible for the death of more than one million people each year, possesses odorant receptors for particular components of human sweat means that different ligands could be screened for their activation or inhibition of these receptors, potentially leading to new, more effective insect traps and repellents [126]. 

Melchiors, M.A. Lesli, C.A. 1985. Effectiveness of predator fecal odors as black-tailed deer repellents. J. Wildl. Manage., 49, 358—362. 

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