Assortative mating among Anastrepha fraterculus (Diptera: Tephritidae) hybrids as a possible route to radiation of the fraterculus cryptic species complex

Abstract

Reproductive isolation among populations of Anastrepha fraterculus has been found acting at the pre-and post-zygotic levels. Differences in timing of sexual activity and male sexual pheromone composition among populations could partially account for prezygotic isolation. Hybrid males were found to produce a novel pheromone, which is a mix of parental pheromones. In the present study, we found that the hybrid females showed a significant preference to mate with hybrid males than with parental males. Male location during pheromone emission is associated with its reproductive success and, thus, differences in the location of males during courtship could also play a role in isolation. We found evidence that reproductive isolation is also related to the location of males during courtship. Hybrid male behaviour regarding location during pheromone release was found to be influenced by the maternal lineage. If these populations hybridized in the field, the hybrid females would tend to mate with hybrid males probably leading to the formation of a new entity within the A. fraterculus complex. This simple and fast process could be one reason explaining the high number of taxonomic entities within this complex. Further studies on other members of the fraterculus species group may reveal whether this can be considered as an example of homoploid hybrid speciation.

Evaluating mating compatibility within fruit fly cryptic species complexes and the potential role of sex pheromones in pre-mating isolation

“…For example, male hybrids obtained under such conditions from matings between Anastrepha fraterculus populations from Peru and Argentina produced a pheromone that was a mix of the parental pheromones (Cáceres et al 2009), and the hybrid females preferred mating with hybrid males rather than with males of the parental populations (Segura et al 2011). Interestingly, parental females did not discriminate between the males of their own morphotype and the hybrid males (Cáceres et al 2009), probably indicating that parental females from both morphotypes use the compounds present in the pheromones of their con-specific males to recognize them, even when hybrid males’ pheromone had different proportions of these compounds and, what is more, the presence of additional compounds that are not part of the parental pheromone.…”

Taxonomy and phenotypic relationships of the Anastrepha fraterculus complex in the Mesoamerican and Pacific Neotropical dominions (Diptera, Tephritidae)

“…In several papers it is assumed that reproductive isolation between cryptic species of the Af complex has recently evolved, leaving implicit the idea that those morphospecies had direct relationships, and at some time of its evolutionary history there was an interpopulation divergence among them (Cáceres et al 2009, Segura et al 2011, Rull et al 2013, Devescovi et al 2014). This is probably true among morphospecies related within each phenotypic lineage that could have a common origin and most likely a more recent evolution.…”

“…For instance, high levels of pre- and post-zygotic isolation, karyotypic and polytene chromosome differences, and qualitative and quantitative differences in male pheromones were found in two laboratory strains from Argentina and Peru (Cáceres et al 2009, Segura et al 2011) which belong to the Brazilian and Andean lineages, respectively. In addition, pre-zygotic reproductive isolation resulted in strong assortative mating to gene flow among the Mexican morphotype and other populations classified in the Brazilian-1 and Peruvian morphotypes (Rull et al 2013), all of them belonging to three distinct phenotypic lineages described herein.…”

Diversity of fruit fly (Diptera: Tephritidae) species in French Guiana: their main host plants and associated parasitoids during the period 1994–2003 and prospects for management

“…This group is also considered to be the most derived one [13]. Anastrepha fraterculus is a complex of cryptic species which shows physiological and morphological differences [25,26]. In fact, the actual number of putative species within the A. fraterculus complex and their associated biogeography is still uncertain.…”