Incipient speciation in theAnastrepha fraterculuscryptic species complex: reproductive compatibility betweenA. sp.1 aff.fraterculusandA. sp.3 aff.fraterculus

Abstract

Reproductive isolation among biological strains can be detected by analyzing reproductive barriers between populations. The Anastrepha fraterculus Wiedemann (Diptera: Tephritidae) cryptic species complex comprises eight morphotypes defined by morphometric characteristics. The present study analyzed the existence of pre‐ and post‐zygotic isolation among populations of A. sp.1 aff. fraterculus (A. sp.1) and A. sp.3 aff. fraterculus (A. sp.3) determined by tests of sexual compatibility, analyses of the temporal pattern of calling behavior, and the reproductive performance of the offspring of homotypic and heterotypic crosses. Pre‐zygotic tests indicated asymmetric matings with preferences for homotypic crosses. The A. sp.3 population demonstrated distinct characteristics, including low copulation percentages and a high proportion of homotypic copulations under crowded conditions. The females of the A. sp.1 population demonstrated lower copulation latency. The analyzed morphotypes demonstrated two peaks in pheromone emission activity, at the beginning and at the end of the morning and were differentiated in the abundance of males. The calling behavior of the hybrids between A. sp.1 male and A. sp.3 female crosses had an intermediate pattern compared to either parental type. Post‐zygotic compatibility tests indicated low viability of the cross between A. sp.3 males and A. sp.1 females. Pronounced asymmetries were found in the sex ratios of the offspring of heterotypic crosses, and only hybrids from A. sp.1 male vs. A. sp.3 female crosses produced descendants. The observed pre‐ and post‐zygotic incompatibilities reflect the probable occurrence of incipient speciation between A. sp.1 and A. sp.3. A more adequate taxonomic classification of this species complex that considers the distinct characteristics of each morphotype will be needed to improve environmentally wise control methods against this insect pest.

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

“…Data from crossing experiments and behavioural observations among 14 of 28 genetically distinct Bemisia tabaci types revealed a consistent pattern of reproductive isolation among putative species (Liu et al, 2012). A similar outcome has been obtained for cryptic species of the fraterculus species complex where all tested morphologically and genetically distinct type pairs (putative species) have shown some form of reproductive isolation, both at the pre-zygotic and post-zygotic levels (Cáceres et al, 2009;Devescovi et al, 2014;Roriz et al, 2017;Rull et al, 2013;Selivon et al, 1999;Vaníčková, Hernández-Ortiz et al, 2015;Vera et al, 2006).…”

“…() as the Mesoamerican mitochondrial type, our Sinaloa population is well within the area where the Western Mexican type was identified, while the Chiapas populations could belong to the Central American type. In any case, the degree of reproductive compatibility among these types is much greater than the one exhibited by several morphotypes of A. fraterculus (Cáceres et al., ; Devescovi et al., ; Roriz et al., ; Rull et al., ; Selivon et al., ), suggesting, in agreement with Scally et al. (), that at least in Mexico, these types do not represent cryptic species.…”

“…Data from crossing experiments and behavioural observations among 14 of 28 genetically distinct Bemisia tabaci types revealed a consistent pattern of reproductive isolation among putative species (Liu et al., ). A similar outcome has been obtained for cryptic species of the fraterculus species complex where all tested morphologically and genetically distinct type pairs (putative species) have shown some form of reproductive isolation, both at the pre‐zygotic and post‐zygotic levels (Cáceres et al., ; Devescovi et al., ; Roriz et al., ; Rull et al., ; Selivon et al., ; Vaníčková , Hernández‐Ortiz et al., ; Vera et al., ). Conversely, three of the four described species in the Bactrocera dorsalis complex, a serious economic problem for fruit production in Asia and Africa, were fused in a single taxon following review of taxonomic, genetic and reproductive compatibility data (Schutze et al., ).…”

“…Our results suggest that the Chiapas, Oaxaca American type. In any case, the degree of reproductive compatibility among these types is much greater than the one exhibited by several morphotypes of A. fraterculus (Cáceres et al, 2009;Devescovi et al, 2014;Roriz et al, 2017;Rull et al, 2013;Selivon et al, 2005), suggesting, in agreement with Scally et al (2016), that at least in Mexico, these types do not represent cryptic species. There is no apparent barrier to movement between members of these two demes, and in our opinion no obvious environmental differences between the habitats they occupy.…”

“…Such approaches have been successfully applied both, to separate (Cáceres et al, 2009;Dias et al, 2016;Selivon, Vretos, Fontes, & Perondini, 2004;Selivon et al, 2005) or, to cluster (Krosch et al, 2013;Schutze et al, 2012) morphologically cryptic species groups of fruit flies. Among other methods, studying reproductive compatibility, both at pre-zygotic and post-zygotic levels, has contributed to identifying species boundaries and ongoing divergence among cryptic fruit fly taxa (Devescovi et al, 2014;Roriz, Japyassú, & Joachim-Bravo, 2017;Rull, Aluja, & Feder, 2010;Rull et al, 2013;Selivon, Perondini, & Morgante, 1999;Tadeo et al, 2015).…”