Description

The Apioninae includes most of the European and North American species of the family. All are small weevils <5mm with an elongate and discontinuous outline; the elytral base is usually distinctly broader than the pronotal base and often abruptly and widely so, where the shoulders are broadly rounded and convex this often indicates a fully-winged condition. The name Apion means pear in Greek and obviously refers to the shape of the elytra which are typically pyriform but vary from elongate and rather parallel e.g. in Stenopterapion Bokor, 1923 or Squamapion Bokor, 1923, to broadly expanded as in Protopirapion Alonso-Zarazaga, 1990. Convexity varies; most species are moderately convex but some are flattened e.g. some Squamapion while species of Protapion Schilsky, 1908 and some Exapion Bedel, 1885 have highly arched elytra. The entire upper surface is usually pubescent, often only very finely so, but this may be dense and form distinct patterns e.g. in Ixapion Roudier & Tempére, 1973 or Taeniapion Schilsky, 1906. Colour varies but most species are dark, grey to black, and many have a distinct and often vivid metallic reflection, a few are pale and members of Apion Herbst, 1797 are completely bright red. The head is generally quadrate and variously punctured and microsculptured, sometimes glabrous and variously striate towards the base and behind eyes which are entire, round or elliptical and vary from almost flat to very convex and discontinuous with the outline. The vertex is sometimes impressed, sometimes strongly so e.g. in Aspidapion Schilsky, 1901 or Diplapion Reitter, 1916, or may have longitudinal keels. The ventral margin of the eyes is often clothed with a distinct margin of scale-like pubescence. The rostrum is usually long and downward curved, least so in some male Perapion Wagner, 1907 and most developed in female Rhopalapion Schilsky, 1906. It is often dilated near the antennal insertions and sometimes toothed or characteristically narrowed e.g. in species of Oxystoma Duméril, 1806. The scrobes are usually low down on the lateral surface, and in some genera e.g. Cynapion and Oxystoma they are enlarged. The antennae are 11-segmented and inserted laterally, only rarely appearing to be geniculate e.g. in some Protapion species, the second segment is usually larger and expanded apically, forming a scape, the funiculus is 7-segmented and the club 3-segmented and compact; it sometimes appears 4-segmented as the apical segment may be subapically constricted. The pronotum is generally quadrate or nearly so and always lacks lateral borders, it is often constricted before the anterior and posterior angles and the sides are generally straight or weakly curved, the dorsal surface is variously convex and usually has a median  basal fovea which may extend to the middle or even the apex. The punctation varies from very faint, as in Acentrotypus Alonso-Zarazaga, 1990, to strong, dense and confluent. The scutellum is usually visible, an exception is Synapion Schilsky, 1902, and sometimes the surface is carinate or longitudinally grooved e.g. in Aspidapion. The abdomen has five visible sternites although the first two are fused and generally longer than the others combined. The procoxae are close together and closed behind, the prosternum being broadly visible anterior to these, the mesocoxae are close together but distinctly separate. The elytra are usually free and many species are fully winged; they completely cover the abdomen and are either continuously or separately rounded, elongate and usually broadest about or behind the middle. The striae are usually distinct and often strongly punctured, especially towards the base, the sutural striae usually does not reach the base, being abbreviated near the apex of the scutellum, and the outer striae, 6-8 are usually absent below the humerus, the ninth stria is always short; ending at the level of the metacoxae. Rarely they may be very fine or almost obsolete e.g. in Acentrotypus. The interstices vary in width and may almost equal the striae e.g. in Kalcapion Schilsky, 1906, although in general they are broad, well defined and lack large punctures, the surface varies from weakly concave to flat or convex and they are variously punctured and microsculptured. Legs usually long and slender with smooth femora . Tarsi 5-5-5 with the third segment strongly bilobed and the fourth tiny and likely to be overlooked. Claws equal in length and free, sometimes with a basal tooth. Males are generally narrower than females and in some species they are consistently smaller, sometimes there are colour differences between the sexes and in females the rostrum is usually longer.