Lundy Flea Beetle

Psylliodes luridipennis adults are oblong-ovate, and the same size and build as P. hyoscyami, but not as broad, measuring between 2.8 and 3.6 mm in length. They have a brassy-green head and thorax, shining reddish-brown elytra and brassy-green legs. The hind femora are brassy in colour but paler at the base, and the antennae are brick-red. The adults are fully winged, and are capable of flight. Its brassy colour, smaller size, and more finely and closely punctate-striate elytra distinguish it from its ally, P. chrysocephala, which is also found on Lundy. P. luridipennis is sometimes called the "bronze Lundy cabbage flea beetle" to differentiate it from another beetle found on the Lundy cabbage. This latter beetle, the "blue Lundy cabbage flea beetle", is a short-winged form of the widespread P. napi.

Adult Psylliodes luridipennis beetles are invariably found on the Lundy cabbage (Coincya wrightii), a species endemic to the island of Lundy, where they feed on the leaves. They are not found on other locally occurring plants. However, researchers were also able to lure the beetles onto other crucifers taken from gardens. Two other taxa are known only from Lundy cabbages—the true weevil Ceutorhynchus contractus var. pallipes and an undescribed race of the flea beetle Psylliodes napi—making the plant unique to Britain as the only endemic species which is the exclusive host to endemic insect species. However, the Lundy cabbage is also host to a diverse variety of other invertebrate species. Psylliodes luridipennis is found throughout the highly limited range of the Lundy cabbage, including sheer sea cliffs and further inland at Millcombe House. The insects also found their way to Lundy cabbages artificially seeded within the cabbage's range within a year. It had been hypothesised that P. luridipennis and Ceutorhynchus contractus var. pallipes may help pollinate the Lundy cabbage, but observations of the taxa indicate that neither visit flowers. While there are no honey bees on Lundy, other species of winged insects are present. …