Sinodendron cylindricum (Linnaeus, 1758)

Male
Occurs locally in deciduous or mixed woodland and wooded areas throughout the British Isles although rare in the north and Scotland. Adults are active nocturnally when they burrow into rotting wood; typically the male of a pair guards the entrance while the female excavates a branching tunnel, eggs are laid in these branches which are then packed with sawdust. Beech is a common host but a wide range of deciduous trees are attacked, also recorded from pine (Alexander), including stumps. Adults are occassionally seen in flight or are active on timber during bright sunshine.

Unmistakeable. 10-18mm. Shining black but for abdominal sternites which are red and clearly visible when the insect is in flight. Sexually dimorphic; male with pronotum excavate anteriorly and backwardly produced cephalic horn. Female with a single tubercle in place of the horn. Convex and cylindrical. Head, pronotum and elytra coarsely punctured, those on the elytra in irregular rows

Description from 2 Watford specimens at X10


Female

Male

Female

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