The role of passive migration in the dispersal of resistance genes in Culex pipiens quinquefasciatus within French Polynesia

Abstract

SummaryWe have investigated the distribution of resistance genes in relation to genetic structure and gene flow between various islands of French Polynesia in Culex pipiens quinquefasciatus. We show that (1) resistance to organophosphorous insecticides, mediated by A2–B2 esterases, is present in all islands, (2) A2–B2 frequency decreases as distance from Tahiti increases, and (3) genetic differentiation (measured as estimates of the Fst, parameter from allozyme polymorphism) between islands is significantly correlated to geographic distances which is also correlated to air or sea commercial traffic. These data are discussed in relation to A2–B2 invasion of French Polynesian islands.

Insecticide resistance in Culex pipiens quinquefasciatus and Aedes albopictus mosquitoes from La Réunion Island

“…pipiens populations of a same island, in the temperate (pipiens) and tropical (quinquefasciatus) forms of the species. This was the case for the Mediterranean islands of Sardinia and Corsica , the Polynesian island Tahiti (Pasteur et al, 1995); and the Caribbean island Martinique (Yébakima et al, 2004). Thus, gene flow between Cx.…”

Insecticide resistance in the mosquito Culex pipiens: What have we learned about adaptation?

“…Due to the advantage they provide in OP treated areas, these resistance genes have subsequently spread within populations, and then among populations ( Table 2). The latter phenomenon is considerably facilitated by the fact that most OP treated areas are connected by plane or other transportation systems suitable to passive migration by mosquitoes (Highton & van Someren, 1970;Curtis & White, 1984;Pasteur et al, 1995;Chevillon et al, 1995a). Some resistance alleles such as Ester 2 or Ester B1 are now found on several continents, after their first occurrence in one geographic location probably in the sixties (Raymond et al, 1991;Qiao & Raymond, 1995).…”

Testing the unique amplification event and the worldwide migration hypothesis of insecticide resistance genes with sequence data

“…In addition, there is direct (Highton & Van Someren, 1970) and indirect Pasteur et al, 1995) evidence of large-scale migration of this mosquito by passive transportation by humans, and the presence of one female with A2-B2 in an aircraft has been established (Curtis & White, 1984). The local invasion of A2-B2 in southern France has been documented: A2-B2 was first found near the international Marseille airport and seaport, and has spread within a few years in all surrounding organophosphorous-treated areas (Rivet et a!., 1993).…”