Melandrya caraboides (Linnaeus, 1760)
POLYPHAGA Emery, 1886
TENEBRIONOIDEA Latreille, 1802
MELANDRYINAE Leach, 1815
Melandrya Fabricius, 1801
A widespread though very local and generally scarce Western Palaearctic species which extends east into Siberia, in Europe the distribution is rather patchy; it occurs from lowlands to lower mountain altitudes from Spain to The Black Sea in the south, although it is absent from Greece and some of the Balkan countries, and north into the UK, Denmark and southern provinces of Fennoscandia where it is very rare and has probably declined since the middle of the twentieth century. In the UK it was formerly classified as nationally scarce but has now been removed from the list; it is locally common in suitable habitats throughout England and Wales north to the Humber and more local and scarce further north into southern Scotland and in Ireland. Typical habitats are broadleaf woodland and wooded parkland and pasture with plenty of fallen and decaying wood, but they also occur on trees on heaths and moors and are often associated with carr and permanently wet or frequently flooded wood in marginal wetland situations. Adults are active over a short season from April until August or September although specimens have been recorded throughout the year, they are mostly crepuscular and nocturnal and spend the day under damp logs or among moss but they are sometimes active during the day and may take flight during very warm weather. Breeding occurs in the summer and eggs are laid in decaying timber where the larvae will develop. A wide range of trees have been recorded as hosting the larvae, in the UK often willows (Salix L.), beech (Fagus L.) and ash (Fraxinus L.), and on the continent often in birch (Betula L.), but otherwise from hazel (Corylus L.), elm (Ulmus L.), hornbeam (Carpinus L.), plum and cherry (Prunus L.) among others. Adults are sometimes associated with large decaying sporocarps developing on decaying wood but larvae are xylophagous, consuming fairly hard dead wood inside stumps, dead trunks and fallen timber, they develop through the summer and may overwinter but this is not known for sure, nor is it known how long the larvae take to develop but pupae have been found during June, and teneral adults occur from April or May, suggesting overwintering larvae or pupae although autumn pupation is more likely as adults are occasionally recorded through the winter. Adults may be sampled by searching among dead wood or under logs or fallen timber, they often occur as pairs but very occasionally they swarm at night and large numbers may be found on a single stump.
Melandrya caraboides 1
Melandrya caraboides 2
10-16 mm. Elongate and discontinuous in outline with the pronotum as wide as the base of the elytra, body black with a blue or green reflection, dorsal surface with fine, dark pubescence throughout, appendages black with the tarsi and terminal antennomere reddish. Head broadest across convex and strongly transverse eyes, surface finely punctured but for a smooth transverse line between the eyes in males, in females entirely punctured and transversely impressed between the eyes. Antennae 11-segmented and filiform; slightly broader in males, insertions visible from above. Terminal maxillary palpomere securiform in males, gradually expanded from the base and truncate apically in females. Pronotum broadest at rounded posterior angles and narrowed to a rounded apical margin, lateral margins without raised borders, surface finely punctured and with deep basal fovea, usually with a smooth longitudinal line but not longitudinally impressed. Elytra weakly dilated from rounded shoulders to a continuous apical margin, surface finely punctured and with 8-10 broad, slightly sinuate longitudinal impressions. Femora unarmed, all tibiae with paired apical spurs, those on the middle and hind tibiae much shorter than the basal tarsomere. Tarsi 5-5-4 in both sexes.