Biological and Genetic Aspects of Crosses Between Phylogenetically Close Species of Mexican Triatomines (Hemiptera: Reduviidae)

Abstract

Reproductive isolation between Triatoma mexicana (Herrich-Scaeffer) and the six species of the Phyllosoma complex, belonging to the genus Meccus, was examined by analyzing the fertility of experimental hybrids. The percentage of couples with offspring was highest in the set of crosses between Meccus phyllosomus (Burmeister) and T. mexicana, and lowest in those between Meccus pallidipennis (Stål) and Meccus bassolsae (Alejandre-Aguilar, Nogueda-Torres, Cortés-Jiménez, Jurberg, Galvão, and Carcavallo) with respect to T. mexicana. Crosses between Meccus mazzottii (Usinger), Meccus picturatus (Usinger), and Meccus longipennis (Usinger) and T. mexicana had scarce offspring, whereas offspring from crosses between M. phyllosomus and T. mexicana were abundant. However, all F1 nymphs died in different instars before reaching sexual maturity. The biological evidence in this study suggests that different degrees of reproductive isolation exist between T mexicana and the different species of Meccus. Our data also support the current status of T. mexicana as a separate species.

Biological aspects of crosses between Triatoma recurva (Stål), 1868 (Hemiptera: Reduviidae: Triatominae) and other members of the Phyllosoma complex

“…Meccus species alleles (particularly those for size, overall color, and hair type and size) may therefore have Mendelian‐dominant/recessive relationships with the corresponding T. recurva alleles. Similar results were recorded in a previous study, when alleles of M. pallidipennis, M. longipennis, M. picturatus , and M. mazzottii were dominant over those of M. phyllosomus and M. bassolsae (Martínez‐Ibarra et al ). A similar phenomenom has been reported about morphological features of the F1 offspring from crosses of T. lenti and T. sherlocki (Mendonça et al ).…”

“…The effects of some post‐zygotic mechanisms have also been reported, such as non‐viability of the first generation (hybrid), exemplified by crosses of T. mexicana and the six species of Meccus spp. (Martínez‐Ibarra et al ), genetic sterility of hybrids, such as that observed in the crosses of M. mazzottii x M. pallidipennis, M. mazzottii x M. picturatus , and M. mazzottii x M. bassolsae (Martínez‐Ibarra et al ), and the collapse of the hybrid, recorded for crosses of different sympatric taxonomic groups of T. dimidiata (Latreille) (Herrera‐Aguilar et al ) and in crosses of T. lenti Sherlock and Serafim x T. sherlocki Papa, Jurberg, Carcavallo, Cerqueir and Barata (Mendonça et al ).…”

“…Triatoma recurva was crossed to the six species of Meccus and to T. mexicana according to established methodologies (Martínez‐Ibarra et al ). Briefly, five couples of each set of crosses were placed in plastic jars (5 cm diameter × 10 cm height).…”

Triatoma mexicana Herrich-Schaeffer (Hemiptera: Reduviidae: Triatominae) Descripción de la Genitalia Externa del Macho y Morfología Externa de la Hembra.

“…Así T. mexicana presenta un tasa de eclosión del 60%, comparada con el 70% de las especies del complejo; el promedio de tiempo para alcanzar la etapa adulta fue más corto en T mexicana coincidiendo con los tiempos de Meccus picturatus Usinger y Meccus pallidipennis Stål; el promedio del tiempo de desarrollo en los ejemplares alimentados en conejo fue sobre los 255 días igual que en Meccus bassolsae Alejandre, pero diferente para Meccus phyllosomus Burmeister y M. pallidipennis; el promedio de ingesta de sangre antes de la muda fue más alto cuando se usó un protocolo con temperatura y humedad relativa bajo, coincidiendo con los resultados obtenidos para M. pallidipennis; la mortalidad fue más alta en las ninfas de primero y segundo estadio, coincidiendo con todas las especies del complejo; el promedio del tiempo de defecación fue sobre los 18 minutos en T. mexicana a diferencia de todas las especies del complejo las cuales presentan un tiempo de menos de 10 minutos, comportamiento que las hace diferentes y por lo tanto mejores transmisores de T. cruzi, razón por la cual los autores no la consideran como una especie del complejo Phyllosoma (Martínez-iBarra et al 2008). El mismo autor comprobó el aislamiento reproductivo de T. mexicana y las especies del complejo Phyllosoma, al realizar cruzas parentales, que aunque las hembras ovipositaron, ninguno de los estadios ninfales logró alcanzar el estado adulto (Martínez-iBarra et al 2011). …”

Comparison of biological fitness in crosses between subspecies of Meccus phyllosomus (Hemiptera: Reduviidae: Triatominae) in southern Mexico

“…Triatoma. mexicana [Herrich‐Scaeffer] with respect to all the species of Meccus ) (Martínez‐Ibarra et al ., ), apparently, hybridization is a common phenomenon between different species/subspecies of triatomines. For example, laboratory hybrids of Triatoma juazeirensis Costa & Felix and T. sherlocki Papa, Jurberg, Carcavallo, Cerqueira, & Barata have shown intermediate characteristics or outstanding biological parameters that may confer on them higher fitness compared with their parental species (Almeida et al ., ).…”