Detection of female mating status using chemical signals and cues

Abstract

Males of many species choose their mate according to the female's reproductive status, and there is now increasing evidence that male fitness can depend on this discrimination. However, females will also aim to regulate their mating activity so as to maximize their own fitness. As such, both sexes may attempt to dictate the frequency and timing of female mating, reflecting the potentially different costs of female signaling to both sexes. Here, I review evidence that chemical cues and signals are used widely by males to discriminate between mated and unmated females, and explore the mechanisms by which female odour changes post-mating. There is substantial empirical evidence that mated and unmated females differ in their chemical profile, and that this variation provides males with information on a female's mating status. Although there appears to be large variation among species regarding the mechanisms by which female odour is altered post-mating, the transfer of male substances to females during or subsequent to copulation appear to play a major role. This transfer of substances by males may be part of their strategy to suppress reproduction by competing males, particularly in species where females mate more than once.

Signal Honesty through Differential Quantity in the Female-Produced Sex Pheromone of the Moth Heliothis virescens

“…However, almond moth females are considered mostly monandrous (McNamara et al, 2008) and, therefore, age-related mate selection would be effective only if high proportions of old females were unmated, which is unlikely. Males may also be capable of assessing the mating status of females through differences in female chemical signals (Thomas, 2011). For monandrous moth species, such as the almond moth, this is somewhat trivial, as sex pheromone production is probably permanently shut down in mated females (e.g., Foster, 1993).…”

Short-term phenotypic plasticity in long-chain cuticular hydrocarbons

“…Although the original function of cuticular hydrocarbons is thought to be protection against desiccation, it is now widely accepted that these chemicals are also used in short-range communication [11]. In females, changes in cuticular hydrocarbons have been widely reported, with mated females more often than not displaying a significantly different cuticular hydrocarbon profile than their unmated counterparts [12]. In males, it has recently been demonstrated that the social environment can influence the expression of cuticular hydrocarbons [13], and that changes in cuticular hydrocarbon expression can occur rapidly [14].…”

Silk-mediated male courtship effort in the monandrous wolf spider Pardosa astrigera (Araneae: Lycosidae)

“…However, most sex pheromones in spiders are contact chemicals associated with the web or draglines released by females during locomotion (Huber 2005;Gaskett 2007;Schulz 2013). Although many studies have shown that males generally prefer the silk from virgin females over those from immature and/or mated females Roberts and Uetz 2005;Stoltz et al 2007;Uetz and Norton 2007;Costa 2010, 2014;Thomas 2011;Tuni and Berger-Tal 2012), relatively less is known about whether male spiders are able to discriminate silk cues from virgin females varying in postmaturation ages (but see Roberts and Uetz 2005;Shamble et al 2009;Costa 2010, 2014;Klein et al 2012). From a male's perspective, chemical advertisement of the female receptivity may not minimize its searching costs by avoiding unavailable mates, but may reduce its risk of being cannibalized.…”