Avian Repellency of Coniferyl and Cinnamyl Derivatives

Abstract

Phenylpropanoids, a class of common phenolic compounds in plants, may potentially be useful as pest repellents. We investigated the relationship between the chemical structure of coniferyl benzoate and its repellency to birds by comparing coniferyl benzoate to two analogous natural esters, corresponding alcohols, and benzoic acid. The absolute and relative feeding repellency of these compounds were assessed in choice (two-cup) and no-choice (one-cup) tests using European Starlings (Sturnus vulgaris). In addition, benzoin Siam (= gum benzoin Siam) was compared to coniferyl benzoate to ascertain if phenolics that naturally occur with coniferyl benzoate in benzoin Siam enhance its repellency. Two-cup tests suggested that coniferyl alcohol was the most repellent compound followed by 3,4-dimethoxycinnamyl alcohol, 3,4-dimethoxycinnamyl benzoate, cinnamyl alcohol, cinnamyl benzoate, coniferyl benzoate, and benzoic acid. The repellency of most alcohols relative to their corresponding ester reversed in the one-cup tests. One-cup tests suggested that 3,4-dimethoxycinnamyl benzoate was the most repellent substance followed by cinnamyl benzoate, benzoin Siam, 3,4-dimethoxycinnamylalcohol, cinnamyl alcohol, coniferyl alcohol, coniferyl benzoate, and benzoic acid. Three conclusions on structure-activity relationships were inferred from these data. First, benzoate esters are more repellent than their corresponding alcohols.Second, repellency is increased by electron-donating groups. Third, acidic functions decrease repellency. We suggest that one function of naturally occurring coniferyl and cinnamyl derivatives may be chemical defense. Genetically engineering agricultural crops to produce analogs of coniferyl alcohol, as an inherent defense against pests and pathogens, may be possible.

Visual and taste cues for minimising native bird interactions with toxic 1080 baits – a review of current practices

“…Both these compounds and some of the other constituents that occur in low concentrations are known to have bird repellent effects (e.g. Jakubas et al 1992;Clark 1995;Watkins et al 1999). Cinnamaldehyde was the most effective bird repellent of 14 cinnamic acid derivatives tested by Watkins et al (1999), including cinnamamide, which has been extensively evaluated for field use (Cowan et al 2016).…”

Human food flavor additives as bird repellents: I. Conjugated aromatic compounds

“…Solutions were then sprayed onto the surface of maintenance chow (50 ml solution:100 g chow), and the alcohol was allowed to evaporate under a hood overnight. 25 On a percentage by weight basis, the range of concentrations tested across compounds was 0.3±0.4% (wt/wt). This concentration range corresponds to the 50% reduction in feed consumption by starlings presented with food treated with methyl anthranilate.…”

Male endogenous pheromonal component of Bactrocera carambolae (Diptera: Tephritidae) deterred gecko predation

“…Grains treated with individual compounds of CF and DMP were shown to deter avian consumption (Nishida & Fukami 1990;Jakubas et al 1992). ME-fed B. papayae males, which contained both DMP and CF in the rectal gland, were also demonstrated to avert predation by hungry gecko that have been conditioned to feed on untreated fruit flies (Tan & Nishida 1998;Wee & Tan 2001).…”

“…ME-fed B. papayae males, which contained both DMP and CF in the rectal gland, were also demonstrated to avert predation by hungry gecko that have been conditioned to feed on untreated fruit flies (Tan & Nishida 1998;Wee & Tan 2001). When assayed individually, CF was shown to be a weaker deterrent than DMP in deterring vertebrate predators (Nishida & Fukami 1990;Jakubas et al 1992). Therefore, a question arises as to whether ME-fed B. carambolae male would be able to deter vertebrate predation?…”