Black vine weevil—Otiorhynchus sulcatus
The black vine weevil feeds on many landscape plants such
as azalea, rhododendron, euonymus, and liquidambar. Adults
have the head elongated into a snout and have elbowed and
clubbed antennae. Adults do not fly.
Larvae are whitish grubs. Other
weevil species may also be present,
but may not cause the extensive root damage caused by black
vine
weevil.
Identification
of species | Life
cycle
Damage
Adults generally feed on foliage. Leaves or flowers appear notched or ragged, and leaves
or needles may be clipped from twigs. The most serious damage is done by larvae, which feed on roots and
can kill or weaken some plants, especially azalea and rhododendron, increasing damage from root diseases
such as Phytophthora. Feeding on branches can cause limb breakage. Feeding galleries may be seen
in the crotches of limbs.
Solutions
Destroy adults to prevent more serious damage.
For rhododendrons, plant less
susceptible species. Provide
cultural care to keep plants vigorous and better able to
tolerate damage. Check roots before planting to make sure
they are free from larvae. Trim branches that provide a
bridge to other plants or the ground
and apply a 6-inch band of sticky material to trunks to prevent
flightless beetles from feeding on foliage.
Trapping may help. Parasitic nematodes may
also be effective in controlling larvae. Timed insecticides applied to leaves can control
adults. | 
Adult
black vine weevil on euonymus leaf
Characteristic
weevil damage
|
