Parasitoid infestation changes female mating preferences

Abstract

Females often adjust their mating preference to environmental and social conditions. This plasticity of preference can be adaptive for females and can have important consequences for the evolution of male traits. While predation and parasitism are widespread, their effects on female preferences have rarely been investigated. Females of the cricket Gryllus lineaticeps are parasitized by the parasitoid fly Ormia ochracea. Infestation with fly larvae substantially reduces female life span and thus reproductive opportunities of the cricket. Both female G. lineaticeps and flies orient to male song and both prefer male songs with faster chirp rates to songs with slower chirp rates. We tested the effect of parasitic infestation on female responsiveness to male song and female chirp rate preferences. The proportion of individuals responding to male songs did not differ between infested and control females. Control females preferred intermediate chirp rates to slow chirp rates and did not discriminate between fast and intermediate chirp rates. In contrast, infested females showed no preferences in the choice trials, indicating reduced chirp rate selectivity. This plasticity in female preferences may be adaptive; parasitized females may have a higher probability of reproducing before they are killed by the parasitoids if they are less selective (i.e. there will be a larger pool of males considered acceptable). The change in preferences suggests relaxed selection on male chirp rate during times of parasitism.

Men With a Terminal Illness Relax Their Criteria for Facial Attractiveness

“…According to Lopez (1998) energetic costs related to infection may prohibit females from more energy-consuming discriminatory mate choice. A similar disease-dependent pattern of mate preferences was reported in female crickets Gryllus lineaticeps ( Beckers & Wagner, 2013 ), where parasitized females showed no preferences towards males with attractive male characteristics ( Beckers & Wagner, 2013 ). The authors suggested that in life-threatening situations, mate selection criteria are less strict to facilitate rapid reproduction.…”

Female mate choice plasticity is affected by the interaction between male density and female age in a field cricket

“…As a result, females may adjust their choosiness based on their ability to afford perceived search costs. Many studies have manipulated the costs of choosiness and have found that females adjust choosiness in response to changes in a variety of factors such as parasitism (Beckers & Wagner, 2013), age (Richard, Lecomte, De Fraipont, & Clobert, 2005;Ronald, Fern andez-Juricic, & Lucas, 2012), body condition and diet (Hebets, Wesson, & Shamble, 2008;Moskalik & Uetz, 2011;Vitousek, 2009), predation (Karino, Kuwamura, Nakashima, & Sakai, 2000;Willis, Rosenthal, & Ryan, 2012), male density and trait variability (Fowler-Finn & Rodríguez, 2012a;Lehmann, 2007), and previous experiences with certain male phenotypes (FowlerFinn & Rodríguez, 2012b;Hebets, 2003;Wagner, Smeds, & Wiegmann, 2001). …”

Female pipefish can detect the immune status of their mates

“…This finding correlates with the sexual immune dimorphism in the system, where males have a more efficient immune response than females (Roth et al 2011). The plasticity of mate preference upon immune activation of males and females is still poorly understood (Beckers and Wagner 2013). It is becoming clear, however, that a change in the strength of mate preference in response to condition can have severe implications for the evolution of secondary sexual traits (Cotton et al 2006).…”

“…Upon immune challenge, females might invest more resources into the current reproduction event as a last-ditch attempt to increase their reproductive success (Rolff 1999;Pfennig and Tinsley 2002;Roth et al 2012b;Beckers and Wagner 2013). Previous results already indicate that challenged females produce larger offspring with an induced immune defense compared to offspring of unchallenged females (Roth et al 2012b).…”

“…Therefore, these studies cannot disentangle whether a change in mate preference is the result of a behavioral plasticity by the host or it is caused by the parasite virulence (Poulin 1994;Poulin and Vickery 1996;Pfennig and Tinsley 2002;Mazzi 2004;Beckers and Wagner 2013). We therefore used heat-killed bacteria to dismiss a possible host-parasite interaction, i.e., to control for the cost of virulent infection.…”