Bagous limosus (Gyllenhal, 1827)

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POLYPHAGA Emery, 1886

CURCULIONOIDEA Latreille, 1802

CURCULIONIDAE Latreille, 1802

BAGOINAE Thomson, C.G., 1859

Bagous Germar, 1817

A widespread though very local and generally rare species across southern and central Europe, extending north into the UK, Denmark and some southern provinces of Fennoscandia, also recorded from North Africa (Algeria), Asia Minor, Iran and Central Asia. Throughout this range it occurs in wetland margins, mostly in lowlands but sometimes in low mountain valleys, especially in the north. In the UK the species has a very scattered distribution, mostly along eastern England from Kent to Yorkshire, also from the New Forest and the Severn Estuary, there are older records from Cumberland and Lundy Island and it is known from a few records in southwest Ireland, it is very local and rare throughout but nonetheless one of our most frequently recorded members of the genus. Adults have been recorded throughout the year; they are generally active from April until September and peak in abundance during May. Typical habitats are marshes, bogs and well-vegetated margins of slow-moving stretches of rivers and ditches etc. Adults are diurnal, slow-moving and spend much of their time on damp or wet substrate but they also climb stems and may be found under matted algae etc. on dry pond margins. Mating has been observed in the spring and larvae feed through the summer, overwinter and complete their development in the spring. Little is known of the biology but larvae are known to bore into host stems and petioles or mine fleshy leaves, they overwinter in stems and pupate within stems or petioles in the spring. Host plants include Curly-leaf pondweed (Potamageton crispus L.), Shining pondweed (P. lucens L.) and Broad-leaved pondweed (P. natans L.), and probably other members of the genus, and (on the continent) adults have been observed feeding on the leaves of Frogbit (Hydrocharis morsus-ranae L) and Water milfoil (Myriophyllum sp.) It is likely that winter is mostly passed in the larval stage but at least some adults overwinter as they sometimes occur in flood refuse, in soil or within stems. The species is univoltine throughout the range.

Bagous limosus

Bagous limosus

2.7-3.5 mm. Broadly elongate and rather flattened, body pale grey to sandy-brown, usually with paler stripes to the pronotum, a paler marking across the shoulders, behind the middle of the elytra and sometimes another towards the lateral margin, but these soon become worn and older specimens may appear substantially dark grey or black. Dorsal surface with dense flattened granules and often appearing to have a slimy or wet secretion. Head flat between weakly convex eyes which continue to the base of the rostrum, without impressions or sculpture, rostrum shorter than the pronotum in both sexes, gently curved and widened from the middle to the base and apex, scrobes situated laterally but very narrowly visible from above towards the apex. Antennae short and robust, the scape as long as the anterior interocular distance, funicular segments mostly transverse and the club pubescent, broad and pointed apically. Pronotum transverse, broadest in front of the middle, constricted subapically and narrowed in an almost straight line to obtuse posterior angles, apical margin with lateral post-ocular lobes that are narrowly visible from above. Pronotal surface constricted across the apical quarter, otherwise smooth and without a median longitudinal impression. Elytra much wider than the pronotum across broadly-rounded shoulders, almost straight laterally to a rather strong subapical constriction and a continuous apical margin, surface uneven between strongly punctured striae; the punctures large, discrete and for the most part well-separated, interstices with scattered extremely fine pale setae. Legs variable in colour but usually with dark femora and pale tibiae and tarsi. Tibiae bent inwards subapically and produced into a sharp inward pointing spine. Tarsi glabrous, long and narrow, all with segments 1-3 elongate and of similar width, segment 4 diminutive and the terminal segment longer than 1 & 2 Combined. Claws smooth, free at the base and without a basal tooth.