Genetic and phenotypic variability in Stenoperla prasina (Newman, 1845) (Plecoptera: Eustheniidae) in relation to latitude and altitude in New Zealand

Genetic divergence, body size and variations in external genitalia of the stonefly Stenoperla prasina (Newman, 1845) (Plecoptera: Eustheniidae) were investigated using specimens from 46 locations throughout New Zealand. Sequencing of a 658-bp fragment of the mtCOI gene from 77 individuals collected at 26 locations identified 10 haplotypes, and three geographic haplotype networks. Maximum uncorrected genetic divergence found was 4.3%. Past isolation of populations in northern and southwestern New Zealand was suggested by variations in genitalia. No relationship was found between body size and latitude over the length of New Zealand. However, male or female size was correlated with either latitude or altitude in the North or South Islands, and with altitude on a North Island mountain. The relatively small number of haplotypes found could indicate that they are survivors of an event that caused a bottleneck.