Insects - Pests of Ornamental Trees, Shrubs and Flowers - page 151

335

Otiorhynchus clavipes (Bonsdorff) ( 337 )
syn. O . fuscipes (Olivier); O . lugdunensis
Boheman
Red-legged weevil
Adults attack various woody hosts, including Japanese
laurel ( Aucuba japonica ), honeysuckle ( Lonicera ) and
lilac ( Syringa ); the larvae are associated with the
roots of soft-fruit crops, especially raspberry, and
ornamentals such as lilac, maple ( Acer ), Viburnum and
Weigelia . Locally common in Europe, including south-
western England, Belgium, France, Germany, the
Netherlands and Switzerland, particularly on light soils.

335 Larval mine of birch leaf-mining weevil ( Orchestes rusci )
on Quercus .

DESCRIPTION
Adult: 8-12 mm long; body blackish, oval and
distinctly pointed posteriorly; sculpturing on thorax and
elytra shallow; wingless; legs long and reddish. Egg:
0.5

336

0.6 mm; more or less spherical; whitish when laid
but soon becoming black. Larva: up to 12 mm long;
creamy white, with a brown head; body plump,
wrinkled and strongly C-shaped.

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LIFE HISTORY
Adults appear from late spring to August, the period of
appearance varying according to the timing of pupation.
They are active at night, feeding on leaves and other
aerial parts of various woody plants. During the daytime
they hide in grass tussocks, under stones and in other
shelter. Eggs are laid in the soil, scattered at random
close to the surface beneath host plants, each female
depositing up to 300. Eggs hatch in about three weeks.
The larvae then feed on plant roots, each passing
through five instars. Larvae overwinter either as fully
fed individuals or as young individuals which complete
their development in the following spring; the former
pupate in spring and the latter in the summer.
Reproduction is either sexual or parthenogenetic.

336 Remains of larval mine of birch leaf-mining weevil
( Orchestes rusci ) on Betula .

337

DAMAGE
Adults notch the leaves. They also damage blossoms
and unopened buds, and check the growth of young
shoots by gnawing at the bases. Larvae are more
important; they feed on roots, attacked plants wilting
and sometimes dying.

337 Red-legged weevil ( Otiorhynchus clavipes ).