Female mating status does not affect male mating behavior in the West Indian sweetpotato weevil, Euscepes postfasciatus

Abstract

Because multiple mating by females encourages sperm competition, the assessment of female mating status before insemination is important for males in order to avoid the risk of sperm competition or to intensify sperm competition. When interacting with females before sperm transfer, males can alter their mating tactics according to the risk or intensity of sperm competition. Information on how mating systems are associated with sperm competition is essential for sterile insect technique eradication programs, which depend on successful mating of released sterile males with wild females. We tested whether males of the West Indian sweetpotato weevil, Euscepes postfasciatus (Fairmaire) (Coleoptera: Curculionidae), adjusted their mating behavior in response to female mating experience and/or age. As virgin/young female weevils accepted males more easily than non‐virgin/old females, assessing females before insemination can be adaptive for male weevils. We found that E. postfasciatus males were unable to adjust their mating tactics in response to female mating status. Although this mating strategy would be costly for individual male weevils, the ability in males to discriminate female mating status can prevent the chance of mating with already‐mated females containing the sperm of wild male(s). Therefore, the mating tactics of male E. postfasciatus are advantageous for sterile insect technique eradication programs.

The Effect of Inbreeding on Mating Behaviour of West Indian Sweet Potato Weevil Euscepes postfasciatus

“…3). In E. postfasciatus, males cannot copulate with females without female acceptance (Kumano et al 2009b. The results suggest that females reject non-kin males and accept full-sib males as mating partners.…”

“…3). In E. postfasciatus , males cannot copulate with females without female acceptance (Kumano et al. 2009b, 2010).…”

“…Euscepes postfasciatus exhibits stereotypical mating behaviour (Sato & Kohama 2007; Kumano et al. 2009a,b; Kumano et al.…”

Effect of low temperature between fractionated-dose irradiation doses on mating of the West Indian sweetpotato weevil, Euscepes postfasciatus (Coleoptera: Curculionidae)

“…Although a single male is able to inseminate up to five females in one night, females become unreceptive for about 1 week after copulation (Sato and Kohama 2007;Kumano et al 2009a). The mating behavior lasts for about 50 min, during which time male weevils mount females both before and after copulation (Kumano et al 2009a(Kumano et al , 2010. Males transfer their sperm within 5 min of initiating copulation (Kumano et al 2010).…”

Intensive resistance by females before copulation induces insemination failure in the West Indian sweet potato weevil Euscepes postfasciatus

“…The West Indian sweet potato weevil Euscepes postfasciatus is an ideal subject for investigating the relationship between female resistance in the pre-copulation period and her decision to fertilize her egg(s). Since males mount the backs of females before and after copulation, mating behavior in E. postfasciatus can be separated into three phases by observation (pre-copulatory mounting, copulation, and post-copulatory mounting) (Sato and Kohama 2007;Kumano et al 2008Kumano et al , 2009Kumano et al , 2010. The duration of mating behavior, including pre-and post-copulatory mounting, is about 40 min in this weevil (Kumano et al 2009(Kumano et al , 2010.…”