Male Mating Competitiveness of a Wolbachia-Introgressed Aedes polynesiensis Strain under Semi-Field Conditions

Abstract

BackgroundLymphatic filariasis (LF), a global public health problem affecting approximately 120 million people worldwide, is a leading cause of disability in the developing world including the South Pacific. Despite decades of ongoing mass drug administration (MDA) in the region, some island nations have not yet achieved the threshold levels of microfilaremia established by the World Health Organization for eliminating transmission. Previously, the generation of a novel Aedes polynesiensis strain (CP) infected with an exogenous type of Wolbachia has been described. The CP mosquito is cytoplasmically incompatible (i.e., effectively sterile) when mated with wildtype mosquitoes, and a strategy was proposed for the control of A. polynesiensis populations by repeated, inundative releases of CP males to disrupt fertility of wild females. Such a strategy could lead to suppression of the vector population and subsequently lead to a reduction in the transmission of filarial worms.Methodology/Principal FindingsCP males and F1 male offspring from wild-caught A. polynesiensis females exhibit near equal mating competitiveness with F1 females under semi-field conditions.Conclusions/SignificanceWhile laboratory experiments are important, prior projects have demonstrated the need for additional testing under semi-field conditions in order to recognize problems before field implementation. The results reported here from semi-field experiments encourage forward progression toward small-scale field releases.

Evidence of Polyandry for Aedes aegypti in Semifield Enclosures

“…aegypti. [6][7][8][9][10][11]52,53 The data gathered here will inform genetic control programs to optimize the spread of desired genotypes. Contrary to earlier interpretations, 54 monogamy of females is not a prerequisite for effective genetic control strategies.…”

Genetic control ofAedesmosquitoes

“…polynesiensis; specific characteristics of this vector may have contributed to the failure of drug-based control programmes in the region. 7,8 A vaccine has long been available for yellow fever, but remains some way off for dengue, following disappointing results from a recent large trial of the leading candidate. 9,10 With no licensed vaccine or specific drug (whether prophylactic or therapeutic), dengue control focuses on the major mosquito vector, Ae.…”

“…Several key Aedes species have now been transformed, either by recombinant DNA methods using transposon vectors, [14][15][16][17][18] or by artificial infection with various Wolbachia, a diverse group of intracellular bacteria. 7,19,20 This opens the door to the development of powerful new genetics-based tools with which to control major vector-borne diseases.…”

Determinants of Male <I>Aedes aegypti</I> and <I>Aedes polynesiensis</I> (Diptera: Culicidae) Response to Sound: Efficacy and Considerations for Use of Sound Traps in the Field

“…A version of the sterile insect technique that is based on Wolbachia-induced cytoplasmic incompatibility (Laven 1967), resulting in karyogamy failure and embryonic arrest when a female mates with a male harboring a different Wolbachia type than her own (Werren 1997), has been proposed as a potential vector control tool to be integrated with MDA programs aimed at eliminating Þlariasis (Brelsfoard et al 2008). The mating competitiveness of males from a strain in which a different Wolbachia type has been introgressed has been studied in both laboratory and Þeld cages (Brelsfoard et al 2008, Chambers et al 2011, but Þeld studies on male Ae. polynesiensis ecology and Þtness have been stymied by the low catch numbers of males using traditional femalebased traps (Schmaedick et al 2008, Mercer et al 2012.…”