sustainability through science & innovation

More mandalotus weevils

Mandalotus weevils (Mandalotus spp.) have been identified for agronomist, Allan Edis (AGnVET Services), from a canola crop near Henty in the Riverina district of New South Wales. This follows recent observations of Mandalotus weevils causing extensive damage to some canola crops in the Victorian Wimmera and Mallee districts, as well as the Mallee area of South Australia. Allan says approximately 3-4 ha of the paddock was completely bared out as a result of the weevil feeding. Mandalotus weevils are also assumed to be responsible for similar damage in a nearby canola crop, however no weevils (or any other pests) could be found upon visual inspection.

Adult Mandalotus weevils are 3-5 mm long and have a rounded, dull brown coloured body, which can easily be mistaken for a small clod of dirt. Adults actively feed during the night, whilst during the day they can be extremely difficult to detect. Feeding damage is usually first noticed on the leaves of emerging crop plants. In severe cases the seedlings may be ‘ring barked’ just above ground level. This causes the plants to fall to the ground where the weevils continue feeding on the leaves.

Click here for images of Mandalotus weevils and refer to PestFacts Issue No. 3 for more information.


PestFacts is supported by