A New Species of Loxomerus Chaudoir (Coleoptera: Carabidae: Migadopinae) From the Subantarctic Antipodes Islands, New Zealand: Resurgence of a Flightless Beetle Following Mouse Eradication

Loxomerus antipodes Liebherr and Marris, sp. nov. (Coleoptera: Carabidae), is described from the New Zealand subantarctic Antipodes Islands archipelago. Loxomerus antipodes, sp. nov., was considered conspecific with Loxomerus brevis Blanchard, 1853, from the Auckland Islands, but it is diagnosed from that sister taxon based on numerous anatomical differences, including (1) smaller, externally less convex compound eyes; (2) a more basally constricted pronotum; (3) pronotal and elytral margins contrastingly paler than the more melanised discs; (4) distinctly impressed elytral striae, the associated intervals broadly convex, and sutural intervals upraised, callus‐like in basal half of elytral length; and (5) male aedeagal median lobe apex more elongate. Loxomerus antipodes sp. nov. was initially known only from dead remains collected on Antipodes Island in 1969. In 1995, live specimens were found on neighbouring pest‐free Bollons Island. The species was hypothesised to be locally extirpated on Antipodes Island due to intensive predation by the invasive house mouse, Mus musculus Linnaeus, 1758, present at least since the early 20th century. But following the eradication of mice from Antipodes Island in 2016, the presence of the flightless L. antipodes sp. nov. was documented on the island in 2022 and 2023. Also in 2023, the rarely observed, flightless Pseudhelops antipodensis Watt, 1971 (Coleoptera: Tenebrionidae), was recollected on the main Antipodes Island. Resurgence of these beetles highlights the detrimental effects mice exert on island invertebrate populations and emphasises the beneficial impacts of eradication programmes.