Do sexual pheromone traps provide biased information of the local gene pool in the pine processionary moth?

Abstract

1 Sexual pheromone traps are commonly used to monitor populations of the pine processionary moth, Thaumetopoea pityocampa, assuming that trapped males are representative of the breeding population. 2 For seven Italian populations, mitochondrial haplotypes (COI and COII) of adult males caught in traps were compared with those of larvae obtained from egg batches laid in the same year, to test whether the males trapped were representative of the local populations. 3 The distribution of haplotype frequencies revealed substantial homogeneity between adult males and larvae samples from the same population, except for Aosta Ruines Verres, a population recently expanding in the south-western Alps. In this case, the results suggested that trapped males were recruited over a wider area than local moths because haplotype diversity was higher than that of larvae. 4 A further analysis of this population using nuclear markers (AFLP) confirmed that adults, collected in pheromone traps, were genetically different from the larvae emerging in the same stand. 5 In conclusion, the assumption that trapped males are representative of breeding populations was confirmed for core populations, but has not been verified for the recently established population of Aosta Ruines Verres. This should encourage discussion with respect to the reliability of pheromone traps in monitoring programmes of the pest, especially at the range's edge

Comparative population genetic study of two oligophagous insects associated with the same hosts

“…The dispersal capacities of both sexes could nonetheless play a role in the founding and success of expanding populations, which should be tested experimentally in the future. A recent study comparing the genetic diversity of males caught in pheromone traps to larvae hatched in the same location showed substantial homogeneity between adults and caterpillars in core populations but not in expanding zones (Salvato et al, 2005), which corroborates our hypothesis.…”

Genetic differentiation of the pine processionary moth at the southern edge of its range: contrasting patterns between mitochondrial and nuclear markers

“…In this study, the discordance could be the result of a sex‐biased dispersal, with males spreading longer distances than females as shown in other populations for both T. pityocampa and T. wilkinsoni (Salvato et al. , ; Simonato et al. ), leading to a nuclear gene flow higher than the mitochondrial one.…”

Population monitoring of the pine processionary moth (Lepidoptera: Thaumetopoeidae) with pheromone-baited traps

“…A sensitive monitoring design based on few pheromone traps deployment may help solving this problem. Recently, Salvato et al (2005) questioned the reliability of pheromone traps to monitor T. pityocampa populations at the range margins after finding genetic differences between adults collected in pheromone traps and larvae sampled in the same stand. However, assuming that the number of males recruited from a wider area is proportional to the number of local moths (a likely scenario in isolated populations, such as those at the range margins), the overall trap captures can still be significantly correlated with local population densities.…”