Lack of post-mating isolation between two populations of Anastrepha fraterculus from different ecological regions in Argentina

It is alleged Anastrepha fraterculus (Wiedemann), a Neotropical pest of fruit, is a complex of cryptic species rather than a single biological entity. The objective of the present work was to evaluate the post-mating compatibility between two populations of A. fraterculus from different ecological regions of Argentina: Yuto (YU) from northwest and Concordia (CO) from the northeast. We have previously shown that there is no pre-mating isolation between these two populations. Mating couples, obtained during a field-cage experiment, were individually placed in vials, and females were allowed to lay eggs in artificial fruits. Eggs, pupae, and adults (males and females) of the four possible crosses (YU × YU, CO × CO, YU × CO, and CO × YU) were recovered from the first (F1) and second (F2) generation. In both F1 and F2, the estimates of sex ratio, egg-to-pupa viability, and pupa-to-adult viability were not significantly different among crosses. These results indicate a lack of any post-mating isolation between theses two populations. Considered together with a previous experiment indicating absence of pre-mating isolation, the evidence strongly supports the assumption that these two populations of A. fraterculus from Argentina belong to only one species.