Aspidapion aeneum (Fabricius, 1775)

Female
Generally common and often abundant throughout England and Scotland north to the Lothians, in Wales only from Glamorgan (Morris, 1990). Occurs throughout the Watford area wherever its foodplant, Malva sylvestris (common mallow), is found although this is patchy as the host is absent from the Cassiobury park/Whippendell wood area and from well maintained areas generally. Typical habitat is waste ground, hedgerows, road verges and grassland; the plant is quick to colonise and grows rapidly and so the local occurence of aeneum is likely to be dynamic. Adults are active from early April and, although we have no records, probably earlier as locally the host persists through the winter, they remain active until at least August. In our experience they occur in small numbers, generally up to five on a large plant; even along the canal towards Rickmansworth where common mallow grow huge and A.radiolus is abundant (2006-2008), aeneum has occured only sparingly. Larvae develop within stems and the species probably occurs on other Malvaeae (Morris).

With a little experience aeneum is immediately recognised in the field with a X10 lens, more especially so when associated with the foodplant; it is a little larger and broader than radiolus, more brightly coloured and shining.

2.9-3.6mm. Entirely shining black, elytra vivid metallic dark blue or bronze, front parts appear narrow and elongate against the very convex elytra. Head closely and strongly punctured between moderately convex eyes, some punctures are elongate but they are are not, at least in our specimens, confluent. With sparse short and narrow scales. A deep longitudinal furrow between the eyes is diagnostic; sharply pointed anteriorly and rounded at base, varies in length up to the the longitudinal diameter of an eye. Rostrum shining, puncturation finer and sparser than on head, a little longer and narrower in female. Broadened at antennal insertions which are a little nearer the head in the female. Antennae rufinistic with black club. Pronotum quadrate, widest at base and with front margin weakly raised. Puncturation moderately strong on disc, punctures separated by about their diameter, with a deep, elongate median furrow in front of base. With sparse grey scaling and microsculpture which is just visible at X20. Scutellum black, as pronotum, about twice as long as broad, sides towards base not raised (as in radiolus) but with fine borders. Elytra very convex, broadest at middle and with shoulders only a little broader than width of pronotal base. Less shining towards apex due to dense microsculpture. Striae rather weakly impressed and complete to apex, outer striae not visible from above. Interstices flat and much broader than striae, about five times on disc, with two or in places three rows of very fine punctures. Legs entirely black. Male protibiae bent inwards at apex, all tibiae with an internal tooth at apex. Female protibiae are almost straight and all tibiae lack the apical tooth. Claws appendiculate.

Description taken from three Watford specimens examined at X20.


Male

Female

Female

Furrow on Head

Female

Home