A landscape genetics approach reveals species-specific connectivity patterns for stream insects in fragmented habitats

Dispersal is a critical process in ecology and evolution, shaping global biodiversity patterns. In stream habitats, which often exist within diverse and fragmented landscapes, dispersal ensures population connectivity and survival. For aquatic insects in particular, landscape features may significantly influence the degree of genetic connectivity among populations. Thus, understanding connectivity drivers in such populations is essential for the conservation and management of streams.
We conducted a landscape genetic study using mitochondrial DNA (mtDNA) and genome-wide single nucleotide polymorphism (SNP) markers to assess functional connectivity of stream insects in a fragmented pasture-dominated landscape. We focused on three species with terrestrial winged adults: the mayfly Coloburiscus humeralis, the stonefly Zelandobius confusus, and the caddisfly Hydropsyche fimbriata.
We observed significant spatial genetic structure at larger geographical distances (populations separated by ~3..., Insect Collection
The study sampled aquatic insects at 11 sites across three streams in two neighboring catchments on Mount Pirongia, New Zealand, selected based on land cover, accessibility, and species presence. Sampling occurred at 3–4 sites per stream, spaced at least 490 m apart. Three additional stream sites were included at Mount Karioi (Wainui Stream), approximately 30 km from the main study area, and Mount Taranaki (Katikara & Patea Streams), about 170 km away. All streams had perennial flow, boulder/cobble bottoms, and minimal sediment deposition. Coloburiscus humeralis and Zelandobius confusus nymphs, and Hydropsyche fimbriata larvae were collected via kick-netting or hand-picking and preserved in 95% ethanol.
DNA extraction and SNP sequencing
DNA extraction, sequencing, and SNP genotyping were conducted by Diversity Array Technology (DarTseq™) in Australia. DNA was digested with the PstI-SphI enzyme pair, selected through a pilot study for optimal genome complexity ..., , # A landscape genetics approach reveals species-specific connectivity patterns for stream insects in fragmented habitats

[https://doi.org/10.5061/dryad.rxwdbrvm0](https://doi.org/10.5061/dryad.rxwdbrvm0)

## Description of the data and file structure

#### Dataset Overview

This dataset contains the genomic data used for population genetics analyses in the manuscript, to test the rates of gene flow among aquatic insect populations within streams and between streams across three different regions in the North Island of New Zealand: Pirongia, Karioi and Taranaki. The genomic dataset contains three csv files, each with single nucleotide polymorphisms (SNPs) reports for the three studied species: *Coloburiscus humeralis, Zelandobius confusus* and *Hydropsyche fimbriata. *

The key features of the csv file include SNP position, frequency of genotypes and SNP markers scored as **binary presence/absence data**:

* **\"1\"** → SNP is present in the sample.
* **\"0\"** → SNP is absent in the sample...,