Translator Disclaimer
1 October 2012 The Gall Midge Asphondylia Borrichiae (Diptera: Cecidomyiidae) : An Indigenous Example of Host-Associated Genetic Divergence in Sympatry
K. Stokes, P. Stiling, M. R. Gilg, A. M. Rossi
Author Affiliations +

Speciation usually is conceptualized as occurring via three biogeographic modes: allopatry, parapatry, and sympatry. Sympatric speciation has been the most controversial because of the difficulty of developing plausible theoretical models in which the homogenizing effects of gene flow are sufficiently overcome to permit genetic divergence to occur in the absence of geographic barriers restricting gene flow. Recently, a number of hypothetical models for sympatric speciation have been advanced and several candidate study systems have provided evidence of sympatric divergence, although many of the systems so identified involve introduced species, especially in the cases of host-race formation in phytophagous insects, which expand their host range and use a novel host. Although these cases demonstrate the reality of sympatric divergence, they do not address which mode of speciation predominates in indigenous communities. Asphondylia borrichiae Rossi & Strong has been proposed as a potential example of sympatric divergence in a fully indigenous system, based on the results of a host-choice experiment involving three host-plant species. In the current study, we report significant differences in the genetic composition of midge populations collected from each host in situ, supporting the hypothesis of sympatric genetic divergence among the morphologically identical host-associated populations of A. borrichiae and consistent with host fidelity in oviposition choice.

©2012 Entomological Society of America
K. Stokes, P. Stiling, M. R. Gilg, and A. M. Rossi "The Gall Midge Asphondylia Borrichiae (Diptera: Cecidomyiidae) : An Indigenous Example of Host-Associated Genetic Divergence in Sympatry," Environmental Entomology 41(5), 1246-1254, (1 October 2012).
Received: 9 February 2012; Accepted: 3 July 2012; Published: 1 October 2012

This article is only available to subscribers.
It is not available for individual sale.

Asphondylia borrichiae
host-associated divergence
host-race formation
sympatric speciation
Get copyright permission
Back to Top