Melandrya caraboides (Linnaeus, 1761)       Notable B

Male
A widespread species found throughout the UK except for the far north; local across England and Wales but rare in Scotland and Ireland (Alexander). The NBN website shows the species to occur continuously around the borders of Greater London.

Adults occur between april and july or august depending on season and are associated with a wide range of decaying broad leaved trees including Oak, Beech, Birch, Hornbeam, Ash, Elm, cultivated Plum and Cherry among others (Hyman and Parsons). They may prefer Salix spp. (Hyman and Parsons) or Beech and Ash (Alexander). The larvae, 15-25mm when mature (Hurka) develop in the rotting timber, more especially the soft and moist white-rotted heartwood of boughs, trunks and shrubs (Alexander). The species may be found in a variety of habitats e.g. ancient broadleaved woodland, wooded pastures and heaths, river margins and bogs. In our experience they prefer moist habitats; we have found them on several occasions (1987) beneath large Willow logs beside freshly excavated gravel pits around Uxbridge and Denham, these logs were lying on the water margin on sand and gravel completely devoid of vegetation, these specimens probably hatched from the logs as several were found through the spring and summer. More locally they have been found under the bark and in the soft xylem of rotten Willow stumps by the river Gade below Cassiobury park, these stumps were covered in thick moss, grass tussocks and various fungal fruiting bodies, mostly bracket types. According to Harde they are associated with 'Fungus infected rotten wood of deciduous trees', he also describes how the adults 'flips' or 'somersaults' when handled but we have yet to see this behaviour.

A huge, shining species which may be confused with a Carabid or tenebrionid.

9-16mm. (Male 13mm., Female 16mm.). Black with tarsi, at least apical segments, apical half of terminal antennal segment and palpi reddish brown. Elytra metallic black with strong blue lustre. Upper surface with very fine recumbent pubescence throughout. Head broadest at eyes which are strongly transverse. Finely punctate but for a smooth transverse area between eyes in male, in female entirely punctate with transverse impressions between eyes. Antennal insertions visible from above. Pronotum widest before base, not bordered laterally and with strong basal fovea. Hind angles obtuse and hind margin strongly sinuate. Puncturation finer than that on head, with a narrow smooth area along centre, lateral margins with fine outstanding dark setae like pubescence . Scutellum black, as pronotum. Elytra widest behind middle, sinuate laterally, width across humeral prominences a little larger than base of pronotum. With well developed striae which are evanescent towards base, third and fifth unite subapically to form a single, more prominent striae which extends towards apex. Puncturation fine, the apical area weakly rugose. All tibiae with two apical spurs on inner surface, those on meso and meta tibiae much shorter than basal tarsal segment. Tarsi 5-5-4, penultimate segment bilobed, claws smooth, weakly toothed at base

In our other species, M.barbata (Fab.), the pronotal pubescence is fine throughout, the pronotum more strongly narrowed anteriorly and the insect is smaller, 10-12mm. The NBN shows only three records for this very rare species, 2 from s Hants. and 1 from Surrey.

Description from 2 Watford specimens at X10


Female

Male

Female

Male Palp

Female Palp

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