Dispersal of females and differentiation between populations of Epirrita autumnata (Lepidoptera: Geometridae) inferred from variation in mitochondrial DNA

Abstract

Abstract. Analysis of the mitochondrial DNA (mtDNA) control region (CR) was used to examine the dispersal of females of a geometrid moth, Epirrita autumnata, in Fennoscandia. A 542-bp-portion of the CR of 200 individuals from four northern and four southern localities was sequenced. The mtDNA CR of E. autumnata contains a substantial amount of variation as a total of 108 mtDNA haplotypes were observed. Between the northern and the southern localities (~1100 km), there was a moderate level of genetic differentiation (FST = 0.128). The amount of variation in the mtDNA CR of E. autumnata was lower in the north than in the south. The reduction in genetic variability may result from a combination of historical bottlenecks that date back to the post-glacial recolonization of Fennoscandia and, present-day bottlenecks due to the northern E. autumnata populations experiencing repeated outbreaks followed by collapse in population size. On a small spatial scale (0.6-19 km), within the northern and southern areas, no genetic differentiation was detected suggesting ongoing gene flow due to the dispersal of E. autumnata females among the localities. This finding was contrary to our earlier expectation of poor flying ability of E. autumnata females.

Deep sympatric mtDNA divergence in the autumnal moth (Epirrita autumnata)

“…They found less variation in northern‐ compared with southern populations, which they argue might be a result of the northern moths' cyclic population dynamics (Futuyma ; Snäll et al. ). Their results also revealed moderate levels of divergence between the northern and southern populations.…”

“…Snäll et al. () analyzed the mtDNA control region investigating the dispersal of E. autumnata females and differentiation between northern‐ (Norwegian samples) and southern (Finnish samples) E. autumnata populations. They found less variation in northern‐ compared with southern populations, which they argue might be a result of the northern moths' cyclic population dynamics (Futuyma ; Snäll et al.…”

“…Hence, one might expect to find relatively low levels of genetic variation within this species (Futuyma ; Snäll et al. ). However, preliminary results from DNA barcoding of Scandinavian moths and butterflies (Lepidoptera) revealed discrepancy between present division to species and sequence divergence in the genus Epirrita (Johnsen, Aarvik & Lifjeld, unpublished data).…”

Genetic structure of the green oak leaf roller (Tortrix viridana L.) and one of its hosts, Quercus robur L.

“…Du Merle (1999) and Horstmann (1984) indicate a high dispersal activity in line with our laboratory observations for males, where males showed a much higher activity than females (data not shown). A recent study on gene flow in a geometrid species (Epirrita autumnata) yielded similar results (Snä ll et al, 2004). Snä ll et al (2004) observed that the females of E. autumnata are weak flyers and expected genetic differences already in a small area (up to 19 km 2 ) using mitochondrial markers, but they found no genetic differences in a small area and only a moderate amount of genetic differences in a large area of about 1000 km 2 .…”

“…A recent study on gene flow in a geometrid species (Epirrita autumnata) yielded similar results (Snä ll et al, 2004). Snä ll et al (2004) observed that the females of E. autumnata are weak flyers and expected genetic differences already in a small area (up to 19 km 2 ) using mitochondrial markers, but they found no genetic differences in a small area and only a moderate amount of genetic differences in a large area of about 1000 km 2 . These results were attributed to high gene flow, either because the adult females had a high rate of dispersal or because the historical gene flow was high.…”