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

Abstract

The study of sexual behavior and the identification of the signals involved in mate recognition between con-specifics are key components that can shed some light, as part of an integrative taxonomic approach, in delimitating species within species complexes. In the Tephritidae family several species complexes have received particular attention as they include important agricultural pests such as the Ceratitis fasciventris (Bezzi), Ceratitis anonae (Graham) and Ceratitis rosa Karsch (FAR) complex, the Bactrocera dorsalis (Hendel) complex and the Anastrepha fraterculus (Wiedemann) complex. Here the value and usefulness of a methodology that uses walk-in field cages with host trees to assess, under semi-natural conditions, mating compatibility within these complexes is reviewed, and the same methodology to study the role of chemical communication in pre-mating isolation among Anastrepha fraterculus populations is used. Results showed that under the same experimental conditions it was possible to distinguish an entire range of different outcomes: from full mating compatibility among some populations to complete assortative mating among others. The effectiveness of the methodology in contributing to defining species limits was shown in two species complexes: Anastrepha fraterculus and Bactrocera dorsalis, and in the case of the latter the synonymization of several established species was published. We conclude that walk-in field cages constitute a powerful tool to measure mating compatibility, which is also useful to determine the role of chemical signals in species recognition. Overall, this experimental approach provides a good source of information about reproductive boundaries to delimit species. However, it needs to be applied as part of an integrative taxonomic approach that simultaneously assesses cytogenetic, molecular, physiological and morphological traits in order to reach more robust species delimitations.

Gut bacterial diversity and physiological traits of Anastrepha fraterculus Brazilian-1 morphotype males are affected by antibiotic treatment

“…The diets were colored with a food dye (FLEIBOR, Laboratorios Fleibor, Buenos Aires, Argentina) to allow the differentiation between those males that had been fed with AB and those that had not. This marking system does not present any detrimental effect on A. fraterculus [48, 83].…”

Evidence for Introgression Among Three Species of the Anastrepha fraterculus Group, a Radiating Species Complex of Fruit Flies

“…These species encompass some of the most economically relevant in the genus, which is composed of 34 recognized species and includes some closely related species that show enough morphological similarities ( Norrbom et al, 1999 , 2012 ) to render species identification a difficult task. Despite their morphological lability, there are several differences in host preference, reproductive behavior ( Aluja, 1994 ; Aluja et al, 1999 ; Sivinski et al, 1999 ; Juárez et al, 2015 ) and morphometry ( Selivon and Perondini, 1998 ; Hernández-Ortiz et al, 2012 , 2015 ; Perre et al, 2014 , 2016 ) that suggest incipient speciation, so much so that A. fraterculus in particular has been considered a species complex, composed of several entities, three of them in Brazil ( Hernández-Ortiz et al, 2004 , 2015 ; Hendrichs et al, 2015 ; Vaníèková et al, 2015 ). Even though these studies have used data from a range of methods, including behavior, morphometrics, karyotype, isozymes, pheromone, cuticular hydrocarbons, mtDNA and reproductive studies, they lack a comprehensive sampling across the species’ range and fail to fully integrate molecular and phenotypic data, which complicates their use in species identification.…”

Individual variation in male pheromone production inXylocopa sonorinacorrelates with size and gland color

“…They are often species-specific signals, maintaining reproductive isolation by reducing hybridization between sympatric species (Daimon et al 2012). Sex pheromones can also play key roles in intraspecific mate choice and/or signaling mate quality to the receiver, two roles that are not mutually exclusive (Juárez et al 2015). Sex pheromones are thought to act as honest signals of mate quality, as diet can impact pheromone production (Darragh et al 2019), with males fed a higher quality diet showing increased reproductive success (Rantala et al 2003; Liedo et al 2013).…”