PMC

Relationship between difference in flight period and genetic isolation among weekly cohorts of I. punctigera. (a) Disrupted flight period site (Gifu). Closed circles indicate F_st for weekly cohort pairs within the same flight periods, and open circles represent pairs between the two flight periods. (b) Continuous flight period site (Kyoto). Molecular markers are (i) AFLPs and (ii) mitochondrial COI haplotypes.

Mitochondrial and nuclear gene trees of Inurois. (a) Mitochondrial COI gene. Red represents the early-winter group and blue represents the late-winter group. The trees are neighbour-joining trees. Node supports are bootstrap percentages in NJ and ML analyses followed by Bayesian posterior probability (shown when>70% for NJ). (b) Nuclear elongation factor 1α. For I. punctigera, collection site (SD, Sendai; KB, Kobuchizawa; GF, Gifu; KY, Kyoto), flight period (red, early winter; blue, late winter; grey, continuous flight period site), and mitochondrial clades (yellow, A; green, B) of the specimen are indicated.

Geometrid winter moths and their life-history variation along a climatic gradient. (a) Copulating Inurois tenuis male and female. (b) Seasonal life cycles of Inurois punctigera at (i) continuous flight period site and (ii) disrupted flight period site (modified from ). (c,d) Collection date of moths plotted against the mean temperature of the coldest month at the collection site for (c) I. punctigera and (d) other Inurois species in Japan. Orange diamonds, I. nikkoensis; green diamonds, I. kobayashii; red diamonds, I. kyushuensis; orange pluses, I. asahinai; green pluses, I. fumosa; red pluses, I. fletcheri; and blue pluses, I. tenuis.

(a) Statistical parsimony tree with geographical distribution of haplotypes. The size of each haplotype reflects the number of samples, and the pie graph indicates the proportions of individuals from different regions distinguished by colours as in (b). Internal haplotypes immediately on both sides of the connection path of clades A and B are encircled by a broken line. (b) Sampling areas in Japan. Locality codes are those used in the electronic supplementary material, table S2, which gives exact distributions of haplotypes. Filled circles, continuous flight period site; open circles, disrupted flight period site.

Genetic difference among individual moths in different allochronic cohorts at four study sites. Genetic difference is expressed by first and second PCO scores based on AFLPs. Differences in flight date are indicated by different colours and symbols. (a–c) Disrupted flight period sites: (a) Sendai (red diamonds, early; blue diamonds, late); (b) Kobuchizawa (red diamonds, early; blue diamonds, late); (c) Gifu (red diamonds, 10 December; red triangles, 16 December; red circles, 21 December; red squares, 29 December; pink diamonds, 4 January; blue diamonds, 26 January; blue triangles, 1 February; blue circles, 8 February; blue squares, 15 February; light blue diamonds, 22 February; light blue triangles, 29 February). (d) Continuous flight period site: Kyoto (red diamonds, 31 December; red triangles, 7 January; red circles, 14 January; red squares, 21 January; pink diamonds, 27 January; blue diamonds, 4 February; blue triangles, 18 February; blue circles, 18 February; blue squares, 25 February; light blue diamonds, 3 March; light blue triangles, 10 March).

Geographic pattern of genetic differentiation between six allochronic populations at three disrupted flight period sites and a population at continuous flight period site of I. punctigera. (a) Four study sites (open circles) and geographic pattern of winter coldness in Japan. Insets show the seasonal prevalence of I. punctigera moths at each site. For Sendai and Kobuchizawa, flight periods are indicated by bars based on collection records in the 2007–2008 winter. For Gifu and Kyoto, the number of males collected every 1 hour is shown based on weekly census during the 2007–2008 winter. Mean temperature of the coldest month: blue, below 0°C; yellow, 0–3°C; pink, above 3°C. (b, c) Population trees based on (b) mitochondrial COI gene sequence and (c) amplified fragment length polymorphisms. The unrooted trees were constructed based on Nei's genetic distance between populations. Node supports are bootstrap values (shown when>50%). Sample sizes and haplotype diversity (b) or average heterozygosity (c) are indicated for each population. Genetic divergences between sympatric allochronic populations are indicated by F_st values (^**p<0.001).