Reproductive compatibility among Mexican populations of Anastrepha obliqua: theoretical and management implications

Abstract

The fraterculus species group, composed of 34 species in the genus Anastrepha (Diptera: Tephritidae), includes the fraterculus cryptic species complex formed by eight reproductively isolated morphotypes. A previous study revealed six genetic mitochondrial types of Anastrepha obliqua, suggesting the existence of a second cryptic species complex. However, marked discrepancies between nuclear and mitochondrial loci rather suggest incomplete lineage sorting or introgression between A. obliqua and A. fraterculus. Such hybridization could nevertheless result in reproductive isolation, an outcome that could affect efficacy of area‐wide management for the most important pest of mangos in America. Two mitochondrial types occur in Mexico, and the limits of a third one, encompassing Central American populations, have not been clearly established. Here, we tested reproductive compatibility among three A. obliqua populations from the Pacific and a population from the Gulf of Mexico. No evidence of pre‐zygotic isolation was found. Flies from the Atlantic mated randomly for equal duration with individuals from three Pacific populations. Homotypic and heterotypic crosses produced similar numbers of eggs, with heterotypic crosses of Pacific males and Atlantic females hatching in lower proportions. Larvae of all cross types developed equally in mangos and exhibited no sex ratio distortion of hybrid F1. The three mitochondrial types identified in Mexico and Central America do not appear to be cryptic species and can be managed using one single strain for the sterile insect technique.

An omics evolutionary perspective on phytophagous insect–host plant interactions in Anastrepha obliqua: a review

“…No less than 30-40% of losses in fruit production in Colombia is related to fruit flies; 70% if adequate pest management is not in place (CONPES, 2008). Mexico uses sterile insect technique (SIT) programs to control populations of A. obliqua in some areas of its distribution (Rull et al, 2018), and Brazil has regulatory laws to quarantine this species (Passos et al, 2018). Being a highly mobile, opportunistic, multivoltine species, A. obliqua is thought to have great dispersive capacity and invasive potential for maintaining populations in new hosts and/or distribution ranges (Tejeda et al, 2016) that can influence diversification patterns.…”

“…It is also occasionally reported in the USA (Fu et al, 2014). It is the most important mango ( Mangifera indica L.) fruit fly pest in Latin America (Aluja et al, 2014; Fu et al, 2014; Rull et al, 2018), but has also been catalogued as a highly polyphagous species, attacking 24 fruit families (Carrejo & González, 1994). The species has an important economic impact on fruit crops (CONPES, 2008; Norrbom, 2008).…”