The FINANCIAL — Growers in southern New South Wales and the Western District of Victoria are advised to employ measures to reduce crop damage by vegetable weevils which have been attacking canola near Young and Henty in NSW and lupin crops near Lake Bolac in Victoria.
According to PestFacts South-Eastern, a service provided by the National Invertebrate Pest Initiative and supported by growers and the Australian Government through the Grains Research and Development Corporation (GRDC), adult weevils hibernate over summer under debris or tree bark until autumn when they become active.
They may then move into the edges of paddocks soon after crop emergence and are commonly found damaging germinating canola. Cereals and grasses are occasionally attacked. PestFacts co-ordinator Stuart McColl says a border spray at crop emergence can help control vegetable weevils before they move into paddocks. “Controlling capeweed and marshmallow weeds early in the season may also assist in reducing crop damage,” Mr McColl says.
“Rotating crops with non-host plants, implementing a long period of ‘weed-free’ fallow prior to sowing and planting susceptible crops away from previously affected areas may all reduce the risk of invasion by weevils.” Checking seedling crops for the presence of larvae and adults is best achieved at night, when weevils typically feed.
Vegetable weevils are dull brown-grey coloured beetles and have two short white angled ‘v-shaped’ markings near the middle of their back. They are approximately 8 mm long and have a very pronounced snout. Larvae are yellow to green in colour, with a flattened slug like body and a smallish brown head.
Discussion about this post