PEST

NAME
Vine Weevil, Black Vine Weevil
Otiorbyncbus sulactus

ORDER
Coleoptera

Description of the Pest
The adult weevil is black with small brownish dots on its wing covers and is up to 9mm long. The white fleshy larva is legless up to 12mm long and both adult and larva have chewing mouth parts.
These insects have a Holometabolouslife cycle, ie. When metamorphosisis observed during the pupalstage.

     

Appearance and Distribution of the Pest
This insect is found in Europe, North America and Australia and tends to appear in localised areas. The adult is distributed by flying with wind assistance and the larvae can infest other areas by soil movement or in infected stock.

Period of Activity
The adult is active during the warmer months of the year and normally have one generation per year. The larvae overwinter in the soil and the adults lay its eggs in soil surrounding the host plant.

Damage Caused
The adult chew on the leaves of the host plant and the larvae forms tunnels in corms or tubers. It also attacks roots particularly potted plants. Affected plants have a loss of colour in the foliage and stems die back or the plant collapses. Secondary infection enters the plant where weevil damage occurs.

Susceptible Plants
There is a wide range of plants attacked including Rhododendronspecies, Hydrangeaspecies, Vitisspecies, blueberries, hops, apples,Cyclamen, Pelargonium, Sedum, Fuchsia and Begoniaspecies. Plants that are already damaged, stressed or older are more likely to be attacked.

Cultural Control
Stressed plants can have there culture improved, but once the symptoms are seen and the plant collapses removal is the main course of action.

BiologicalControl
The larva may be attacked by patristic nematodes.

Chemical Control
There in no practical chemical control.