Andrion regensteinense (Herbst, 1797)
Formerly included in Sitona Germar, 1817, this is now the only species of the recently erected genus Andrion Velázquez de Castro, 2007. The distribution includes most of Europe north to southern Scandinavia, northwest Africa; Algeria and Morocco, and parts of western Russia; here it is locally common and often abundant throughout England and Wales, becoming more scattered further north and generally scarce in Scotland. Habitats include almost anywhere the host plants occur, heath and moorland, scrub, wooded margins, parkland and gardens etc. and the beetles may occur in abundance on isolated plants or small patches of plants on calcareous grassland etc. Adults occur on or near the hosts year-round and are generally active from March or April into the autumn, hosts include various species of Ulex (gorse) but most typically U. europeus, Cytisus scoparius (broom) and (probably) species of Genista. Mating occurs over a long period from early spring and pairs in cop. will often be seen among the foliage or flowers in warm weather, eggs are laid in the soil and larvae develop among the roots feeding on root-nodules containing nitrifying bacteria, pupation occurs in the soil and new generation adults appear in late summer and autumn. These new generation adults will overwinter in the soil, occasionally becoming active during mild spells, and emerge in the spring when they will feed upon host foliage and flowers for a while before mating. Adults are readily sampled by sweeping or beating flowering stems or foliage in almost any weather from spring to autumn. Although there are several broadly similar species occurring on these hosts e.g. Charagmus griseus (Fabricius, 1775) and Sitona striatellus (Gyllenhal, 1834), the slender, long-legged and discontinuously-arched form of the present species will soon become familiar.
Andrion regensteinense 1
Andrion regensteinense 2
Andrion regensteinense 3
Andrion regensteinense 4
Andrion regensteinense 5
Andrion regensteinense 6
3-6mm, elongate-oval and discontinuous in dorsal and lateral aspect, dorsal surface with recumbent metallic bronze, green or blue scales which often form contrasting longitudinal rows. Head with round convex eyes and a broad quadrate rostrum, densely and closely punctured and usually densely scaled. Rostrum with a deep central furrow from the antennal insertions to the posterior margin of the eyes, scrobes bent down in front of the eyes and narrowly visible from above. Antennal scape pale, a little shorter than the distance across the eyes and rather abruptly thickened before the apex, funiculus 7-segmented with the basal 2 segments elongate and the remainder quadrate, club elongate and pointed. Pronotum slightly transverse, broadest behind the middle and without borders, coarsely punctured and with scales a little larger than those on the head and elytra, usually with a median longitudinal strip of paler scales. In lateral view the separately convex outline of the pronotum and elytra are characteristic of this species. Scutellum, of which usually only the apex is visible, with uniformly recumbent scales. Elytra elongate and rounded laterally, broader and more robust in the female, a character that is readily appreciated in the field, scales mostly elongate-oval and recumbent, striae very strongly punctured, interstices finely punctured and flat or weakly convex, each with a row of prominent and backwardly-curved raised setae which vary from pale grey to almost black. Legs long and robust, especially so in the male, femora clavate and lacking teeth, dark and variously scaled, tibiae and tarsi generally lighter but variable, claws free and well-developed, especially the anterior pair. Male protibiae strongly curved at the inner apical margin. In most specimens the middle and, especially, the front legs appear disproportionally long, giving them an awkward gangly appearance.