Search

Simple Summary: Patterns of variation within a widespread species can provide evidence of population history. Adjacent stable populations with gene flow show clinal genetic divergence forming a pattern of isolation by distance. Populations that have grown due to an increase in potential habitat such as forest cover since the last glacial maximum will have low genetic variation showing patterns of range expansion. The mayfly Acanthophlebia cruentata of Aotearoa, New Zealand, is widespread in streams of North Island but absent from the cooler South Island. Mayfly nymphs are restricted to streams but adults fly, facilitating gene flow among catchments. We detected higher genetic diversity at lower latitudes of this mayfly's range compared to most of its distribution, concordant with predictions of limited forest cover in New Zealand during Pleistocene glacial periods. A signature of recent range expansion was observed in the higher latitudes. Despite initial observation suggesting mayfly size correlated with latitude, we found sex, elevation and sampling date were significant predictors of size, and some size variation is also explained by three regional groups based on haplotype distribution. The mayfly Acanthophlebia cruentata of Aotearoa, New Zealand, is widespread in Te Ika-a-Māui North Island streams, but has never been collected from South Island despite land connection during the last glacial maximum. Population structure of this mayfly might reflect re-colonisation after volcanic eruptions in North Island c1800 years ago, climate cycling or conceal older, cryptic diversity. We collected population samples from 33 locations to estimate levels of population genetic diversity and to document phenotypic variation. Relatively low intraspecific haplotype divergence was recorded among mitochondrial cytb sequences from 492 individuals, but these resolved three geographic-haplotype regions (north, west, east). We detected a signature of isolation by distance at low latitudes (north) but evidence of recent population growth in the west and east. We did not detect an effect of volcanic eruptions but infer range expansion into higher latitudes from a common ancestor during the last glacial period. As judged from wing length, both sexes of adult mayflies were larger at higher elevation and we found that haplotype region was also a significant predictor of Acanthophlebia cruentata size. This suggests that our mitochondrial marker is concordant with nuclear genetic differences that might be explained by founder effect during range expansion. [ABSTRACT FROM AUTHOR]

The Miocene Manuherikia Group in southern New Zealand is well known for its diverse assemblage of plant, invertebrate and vertebrate fossils. Here, we report the first fossil insects from the Manuherikia Group, comprising three isolated wings recovered from leaf beds in the Dunstan Formation near Cromwell, Otago. One partially preserved tegmen is tentatively assigned to Tropiduchidae (Hemiptera: Fulgoroidea), a family of mainly tropical and subtropical planthoppers that is no longer represented in the New Zealand fauna. The brentine weevil Perroudia manuherikia n. sp. (Coleoptera: Brentidae) is the first fossil record of Brentinae from the Southern Hemisphere, with the sole extant species of Perroudia occurring in New Caledonia. A further wing has the typical venation pattern of Polycentropodidae (Trichoptera), a caddisfly family with two genera in the modern New Zealand fauna. These fossil taxa are reported from the Australasian region for the first time. [ABSTRACT FROM AUTHOR]

Three new species of caddis in the endemic New Zealand genus Alloecentrella Wise, 1958 (Trichoptera: Sericostomatoidea) are named and described: A. linearis sp. n., A. cirratus sp. n., and A. incisus sp. n. We report the known distribution of each of the four species in the genus; A. magnicornis and A. incisus appear to be found only in North Island; A. linearis and A. cirratus have been recorded only from South Island. We provide characters to differentiate the larvae (extent of the head carina; the shape of the head capsule in lateral profile) and cases (position of the terminal aperture). We present the results of a phylogenetic analysis of larval, pupal and adult morphological characters which places Alloecentrella in the Helicophidae. [ABSTRACT FROM AUTHOR]