Distribution of two pine processionary moth species inTurkey evidences a contact zone

Abstract

The pine processionary moths Thaumetopoea pityocampa and T. wilkinsoni are among the most important Mediterranean pine defoliators. Although recent studies suggest that the two species may coexist in Turkey, the relevant literature lacks precise information on the occurrence and exact distribution of the two species in this country. In particular, whether the two sister taxa form a contact zone is still unknown. In this study, we aimed to reveal the limits of the ranges of the two species in Turkey by using nuclear (ITS-1, photolyase) and mitochondrial markers (COI). Multilocus molecular characterization of the two species showed for the first time that the two species co-occur in some of the sampling sites. In addition, we determined clear signatures of mitochondrial introgression between the two species, and therefore the existence of a possible hybrid zone within Turkey. These results bring up interesting questions relating to the evolution of the identified hybrid zone.

Evidence of potential hybridization in the Thaumetopoea pityocampa‐wilkinsoni complex

“…Recently, İpekdal et al . () and El Mokhefi et al . () explored these contact zones in Turkey and Algeria, respectively, identifying signs of introgression.…”

“…To date, a low frequency of hybrids between the Th. pityocampa‐wilkinsoni has been observed in the putative contact zone in W Turkey (İpekdal et al ., ). A more intensive study of trait variability would be required, especially in the contact zones, for the evaluation of the possible presence of reproductive barriers apart from phenology.…”

“…The pattern of genetic diversity was typical of species that have experienced marked glaciation cycles with the main divergence times within the complex dating back to the end of the Miocene (Kerdelhué et al ., ). In addition, a contact zone between species was hypothesized and partly supported by molecular data from north‐western Turkey (İpekdal et al ., ). Further differences could be identified in the phenology because Th.…”

From refugia to contact: Pine processionary moth hybrid zone in a complex biogeographic setting

“…We sampled 174 larvae from 27 localities in Greece, Bulgaria, Turkey, Cyprus, and Lebanon (major regions related to the suspected hybrid zone and regions that were ignored or insufficiently studied previously) between 2002 and 2012. Fifty specimens from İpekdal et al () were also included; thus, we obtained 224 individuals from 42 localities in total (Figure ; Table ). Larvae (first–fifth instars) were collected from different host trees to avoid sampling siblings and stored at −20°C in 70% ethanol.…”

“…A contact zone between T. pityocampa and T. wilkinsoni was recently discovered in western Turkey with some evidence of introgression (İpekdal, Burban, Kerdelhué, & Çağlar, 2015). However, this result was based on sparse sampling and a limited number of mitochondrial and nuclear markers.…”