Weevils
Weevils feed on many flower hosts, including aster, begonia,
carnation, chrysanthemum, dahlia, geranium, impatiens, lily,
primrose, and vinca. Weevils are inconspicuous. Larvae
are whitish or green grubs and live in soil. Adults
are dull gray, blackish, or brown and feed at night, hiding
in litter during the day. The head of adult weevils
is elongated into a snout and their antennae are elbowed
and clubbed. Adults
do not fly.
Identification
of species | Life
cycle
Damage
Adult weevils chew foliage, causing characteristic notching on leaf edges. The serious damage is caused by larvae. Young larvae chew the outer surface of young roots. More mature larvae chew older roots and basal stems, girdling plants near the soil surface and causing decline in mature plants and death in young plants.
Solutions
Destroy adults to prevent more serious damage.
Grow species or cultivars that are less susceptible to weevil
damage, and avoid replanting susceptible crops at infested
sites. Grow older plants that are more likely to be
infested away from younger plants susceptible to weevils. 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. An insecticide
applied to leaves can control adults.
| 
Black vine weevil adult
Feeding damage on viburnum by adult weevils
|
