Evolution of resistance to satyrization through reproductive character displacement in populations of invasive dengue vectors

Abstract

Recently, the highly invasive Asian tiger mosquito, Aedes albopictus, rapidly displaced resident populations of the yellow fever mosquito, Aedes aegypti in the southeastern United States and in Bermuda. Although multiple mechanisms of competitive displacement have been hypothesized, recent evidence of cross-insemination between these species in nature and the sterilizing effects of male accessory gland products asymmetrically favoring A. albopictus in interspecific matings support a role for satyrization (a form of reproductive interference) to explain the rapid displacements. Because of the drastic reproductive loss of A. aegypti females satyrized by A. albopictus males, we predicted selection for prezygotic isolation in populations of A. aegypti sympatric with A. albopictus. Exposures in cages demonstrated that female A. aegypti from populations in Florida sympatric with A. albopictus for the past 20 y were significantly less likely than nearby allopatric populations to mate with heterospecific males. Cross-inseminations of A. albopictus females by A. aegypti males were significantly less common, supporting the one-way direction of displacements observed in nature. Our results indicate rapid sexual selection leading to reproductive character displacement and the potential for satyr-resistant A. aegypti to recover from competitive displacements. These results have implications for increased risks of dengue transmission where these vector species meet worldwide.

Ecología de Aedes aegypti y Aedes albopictus en América y la transmisión de enfermedades

“…Aedes albopictus se ha implicado en la transmisión de dengue en varios sitios, entre ellos Hawái (37), Macao (38) y otros lugares donde Ae. aegypti no es común (29).…”

The Effects of Interspecific Courtship on the Mating Success ofAedes aegyptiandAedes albopictus(Diptera: Culicidae) Males

“…albopictus, refractory to further mating (Tripet et al 2011). This satyrizing effect may be a powerful mechanism (Ribeiro and Spielman 1986, Ribeiro 1988, Nasci et al 1989, Lounibos 2007, Tripet et al 2011, Bargielowski et al 2013, Bargielowski and Lounibos 2014 in the displacement of Ae. aegypti populations by invading Ae.…”

“…The selection pressure for Ae. aegypti females to avoid such errant mating is therefore great, and rapid evolution of resistance to satyrization has been documented in previous studies (Bargielowski et al 2013, Bargielowski andLounibos 2014). Female Ae.…”

“…aegypti females being more susceptible to interspecific insemination than Ae. albopictus females (Nasci et al 1989, Bargielowski et al 2013, Bargielowski and Lounibos 2014. The selection pressure for Ae.…”

“…However, recent findings suggest female mate choice (at least in Ae. aegypti) to be important in these species (Cator and Harrington 2011, Bargielowski et al 2013, Bargielowski and Lounibos 2014. Males may therefore not only need to reach a female before their competitors, but also elicit female acceptance once they have located a potential mate.…”