Colonization abilities of two invasive weevils with different reproductive modes

GUZMAN N. V.; LANTERI A. A.; CONFALONIERI V.A.

EVOLUTIONARY ECOLOGY

SPRINGER

Año: 2012 vol. 26 p. 1371 - 1390

0269-7653

Naupactus leucoloma and N. xanthographus (Coleoptera: Curculionidae: Naupactini) are two flightless weevils native to South America, partially codistributed in that part of the world, that would show asexual and bisexual reproductive modes, respectively. We used two different molecular markers to elucidate the effects of these reproductive modes in the colonization abilities and genetic variability of both species. First, we investigated if clonal reproduction was effectively occurring in the putative parthenogenetic species (i.e. with a significant bias in sex ratio) and second, if this kind of reproduction could be associated with higher colonization abilities and low levels of genetic variability in marginal environments compared to those of the bisexual species. The assessment of central and marginal areas of distribution of these species was performed through ecological niche modeling including environmental variables and through the landscape interpolation of the molecular variability. The results herewith obtained support the idea that insects with parthenogenetic reproduction have the ability to colonize new environments more successfully than bisexual species. In fact, we demonstrate that the apomictic N. leucoloma has recently experienced a significant population growth concomitant with a very important expansion of its geographic range towards distant areas with moderately suitable environments. On the other hand, the bisexual populations of N. xanthographus were maintained in fairly constant sizes, and this species extended its geographic area of distribution to locations not very far from the the proposed ancestral one.