|Barynotus moerens (Fabricius, 1792)|
|Although widely distributed this is a local species with very few modern
records from the west country and much of the southeast, through the midlands, Wales and north to the Scottish
borders there are scattered records (NBN). Joy also includes southern Scotland in the beetles distribution while
Morris adds Stirling and the Western Isles including
the outer Hebrides. Typically associated from Mercurialis perennis (Dog's Mercury), although probably also
polyphagus (Morris), in woodland or wooded situations - which is the natural habitat of Mercurialis -
although sometimes found in more open situations. Locally they occur sporadically throughout Whippendell wood;
although Mercurialis is common throughout the woods the beetle seems to occur, and often in abundance,
where it grows under areas of Betula pendula (Birch). Adults appear during March and persist until at least
June; early in the season we have extracted them from deep moss samples taken from decaying Betula logs
lying among Mercurialis and have found them, singly, under logs. From early April, depending on season,
they may be found among Mercurialis flowers; they are easy to spot even from a distance and may be approached and
observed closely without being startled, in this way we have observed the beetles appearing to feed among the flowers.
Dull and overcast days seem to be the best time to find them and we have observed them among Mercurialis
flowers during lengthy periods of light rain.
These conspicuously large, dull metallic bronze weevils are as likely to be observed on vegetation as in the sweepnet; once found the area should be carefully searched visually as in this way we have found several extensive colonies through the woods. Once observed they will be instantly familiar.
British popualtions are probably parthenogenetic as only females have been found.
8-9mm (Joy) Upper surface, including femora and tibiae but with the exception of the apical area of the rostrum, densely clothed with round, dull metallic scales, the underlying cuticle mostly obscured. Head widened from in front of the eyes to base. Eyes continuous with outline, not convex. Vertex covered with five longitudinal furrows which extend from between eyes onto rostrum. Rostrum slightly elongate (5:4), scrobes visible from above, in side view these are straight and approach the eyes. Antennae brown with club darker, inserted close to apex of rostrum, insertions visible from above. Scape about as long as widest part of rostrum, curved and gradually widened towards apex, funiculus 7-segmented, club elongate, narrow and pointed. Head and pronotum with fine, recumbent pale hairs. Pronotum transverse, broadest in front of middle and without borders. Surface coarsely tuberculate and with a distinct median longitudinal furrow. Elytra rounded laterally, widest behind middle and with well developed shoulders. Striae strongly punctate, alternate insterstices (1,3,5) raised and with two or three rows of pale erect setae. Interstice five strongly raised in apical third, sutural interstice raised at apex. Femora broadest at middle, not toothed. Pro-tibiae sinuate along inner side, expanded to a tooth inside at apex, outer edge more or less straight. Claws smooth and free.