Oomorphus concolor (Sturm, 1807)

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POLYPHAGA Emery, 1886

CHRYSOMELOIDEA Latreille, 1802

CHRYSOMELIDAE Latreille, 1802

LAMPROSOMATINAE Lacordaire, 1848

OOMORPHUS Curtis, 1831

The only species of the subfamily occurring in the U.K. It is locally distributed across southern England and Wales, including the Isle of Wight and there are scattered records further north; north Wales, the midlands and a few mostly coastal from Yorkshire and Cumberland. Also widespread in the south of Ireland and there are a few records from southwest Scotland. On the continent it occurs from Spain to Greece in the south and from Scandinavia east through the Caucasus to Russia. Adults may be sampled by beating ivy where this is abundant, generally in woodland and wooded borders but also more generally in a range of habitats e.g. parks, downland, meadows and hedgerows. They occur throughout the year, overwintering among ivy etc. and becoming active from late March and persisting into September or later. Both adults and larvae feed on ivy, adults on the leaves while the larvae feed nocturnally on fresh stems. Adults have also been recorded feeding on ground elder, Aegopodium podagraria and astrantia, Astrantia major. Larvae have been recorded feeding on other low herbage. Both stages have been extracted from leaf litter and detritus beneath trees.

A very distinctively shaped species but not immediately obvious as a chrysomelid. The antennae, however, are so distinctive as to assure identification.

2.5-3.5mm. Oval and very convex. Black, and generally with a metallic-bronze reflection. Head deflexed and not, or barely, visible from above. Smooth and very finely punctured. Eyes entire. Antennal insertions widely separated, by about twice the length of the first segment.  Antennae characteristic; segment 2 pale, 8 considerably smaller than 7 and 9-11. Lateral margins of pronotum bordered but these are not visible from above. Surface finely punctured and microsculptured. Broadest a little in front of the right angled hind angles. Scutellum tiny, but visible.  Elytra with large punctures which form rows on the disc but become confused toward the sides and apex, otherwise finely punctured throughout. Epipleura with three depressions (view from below.) Front coxae rounded. Middle and hind tibiae pubescent and dilated; sinuate and smooth on the outer margin.  Outer margin of front tibiae straight. Basal segments of tarsi strongly bilobed. Claws tiny, orange and without a basal tooth.

LAMPROSOMATINAE Lacordaire, 1848

A family of 4 tribes containing 14 genera and around 250 described species with a worldwide distribution.

-CACHIPORRINI Chamorro & Konstantinov, 2011. Contains a single Brazilian genus.

-NEOCHLAMYSINI Monros, 1958. Contains two Afrotropical genera.

-SPHAEROCHARINI Clavateau, 1913. Contains a single Brazilian genus.

-LAMPROSOMATINI Lacordaire, 1848. Contains 10 genera of which only Oomorphus Curtis, 1831 is widespread, with species from all biogeographical regions. The other genera are Oriental, Australasian, Neotropical and Afrotropical.

Most are small species and of the characteristic shape of Oomorphus. 1.8-8mm. Oval or circular to elongate-oval. Head declined and anteriorly flat. Without a median groove or furrows. Eyes entire. Labrum well developed. Antennal grooves present along the prosternal process. Prosternal process variable; parallel, deltoid or truncate (Oomorphus), concave (Lamprosoma), pointed (Neochlamys) or apically bifurcate (Sphaerocharis.) Colour generally black with a metallic reflection but occasionally multicoloured. Larvae build portable fecal sacs like those of Cryptocephalus spp. Larvae sometimes feed on bark and stems of living trees and are often nocturnal. Documented hosts include Bambacaceae, Combretaceae, Fabaceae, Melastomataceae and Myrtaceae. Lamprosoma azureum Germar and other species have been considered as biological control agents in the USA.

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