New paper!

Polhemus D.A.: "A new species of Rhagovelia (Heteroptera: Veliidae) from Sumba Island, Lesser Sunda Islands with notes on zoogeography".

The new species Rhagovelia sumbana is described from the island of Sumba in the Lesser Sunda Islands. The species possesses character states that place it in the R. sarawakensis group, whose members are otherwise known only from the Sundaland continental platform. The presence of this species on Sumba provides additional supporting evidence for the prevailing tectonic hypothesis that Sumba is a displaced continental fragment rifted from an original position on the southeast margin of Sundaland near Borneo, and the geological evidence for this is briefly reviewed. Photomicrographs of key morphological characters for R. sumbana, a map of its known distribution on Sumba, and a photograph of the type-locality habitat are provided.

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New paper!

Dong X. et al.: "Comparative phylogeography of three Cletus species pairs reveals shared responses to quaternary environmental change".

Understanding how co-distributed species respond to shared environmental histories is a central question in evolutionary biology. Although comparative phylogeography has advanced rapidly in vertebrates, insects—despite comprising most terrestrial biodiversity—remain underrepresented. Here, we conducted a comparative phylogeographic study of three closely related phytophagous insect species pairs in the genus Cletus (Heteroptera: Coreidae) distributed across eastern Asia. Using genome-wide SNPs generated by ddRAD-seq, we integrated coalescent-based demographic modeling, ecological niche modeling, and full-likelihood Bayesian tests to explore patterns of divergence and demographic history. Our results revealed strong phylogeographic structure in all three species pairs, with genetic clusters largely partitioned along a north–south axis. Demographic modeling supported initial divergence during the Early Pleistocene followed by recent secondary contact during Late Pleistocene climatic oscillations. Bayesian model choice identified a single synchronous divergence event among all three lineages, indicating a shared response to Quaternary climatic changes. Species distribution modeling and Stairway Plot analyses further revealed asymmetrical demographic histories between northern and southern species, with northern taxa showing glacial contractions followed by recent expansion. Additionally, isolation-by-distance (IBD) was consistently detected across all lineages, whereas isolation-by-environment (IBE) was significant only in lineage I. Together, these findings suggest that historical climatic change was associated with parallel diversification and lineage-specific traits also contributed to differences in demographic responses. This study advances our understanding of insect diversification in eastern Asia and highlights the value of comparative genomic approaches for resolving complex evolutionary histories.

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