arthropodafotos.de

Further vernacular names:

Willow Leaf Beetle

Classification:

Plagiodera versicolora belongs to the subfamily Chrysomelinae, tribe Chrysomelini.

Distribution:

Palearctic, introduced into North America.

Habitat:

River floodplains, paludal forests, swamps, bogs.

Description:

Length 2.5 - 4.5 mm; body rounded to oval; upper side metallic blue, green or coppery coloured; elytra flat arched with clearly protruding shoulder bulge, at the tip rounded with dimple in the apical angle, irregularly punctured, in the shoulder angles with short longitudinal dimples; elytra somewhat coarser than the pronotum punctured; underside, femora and tibiae black.
Plagiodera versicolora is the only species of the genus in Europe.

Biology:

The Willow Leaf Beetle Plagiodera versicolora lives mostly on willows (Salix), more rarely on poplars (Populus). The species is often found on white willow, crack willow or purple willow. Narrow-leaved, hairless willow species with a relatively low concentration of phenyl glycosides are preferred.
The adults of Plagiodera versicolora appear at the end of April from their winter shelters and feed holes in the leaves of the host plants. They are macropter and well able to fly. The females mate several times. About 7 to 10 days later the yellowish eggs are laid in small groups on the undersides of the leaves. After about 10 days the larvae hatch. These live cannibalistically at first, stay together later in the group, eat together at one leaf and move to the next leaf, if the previous one is skeletonized. The larvae pass through 3 larval stages. The older larvae separate and pupate on the underside of a leaf. The entire development takes about 4 weeks.
In total, about 2 - 3 overlapping generations can be passed through per year. Plagiodera versicolora hibernates in protected places in the leaves layer or under bark.

References, further reading, links:

1. Rheinheimer, Joachim, & Hassler, Michael: Die Blattkäfer Baden-Württembergs, 2018, 928 pages, Kleinsteuber Books (Karlsruhe), ISBN 978-3-9818110-2-5
2. Arved Lompe: Die Käfer Europas - Ein Bestimmungswerk im Internet