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Pests: find out more VINE WEEVIL
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The Pest
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The Black Vine Weevil (Otiorhynchus sulcatus) is a pest of many crops, and is a major pest where polythene or containers are used.
Adults are 8-12mm long and dull black in colour with patches of tiny yellow bristles. The C-shaped larvae are 10-14mm long, very bristly, cream in colour with a shiny brown head and no legs. Adults feed at night, and are therefore rarely seen, they leave rounded notches at the edges of leaves and flowers. It is the damage done to the plant roots by larval feeding which causes crop losses and attacked plants often show few symptoms above ground until they are severely weakened and dying.
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Vine Weevil Adult
Vine Weevil Larvae
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Life Cycle
The vine weevil has four easy to identify life cycle stages: Adult-Egg-Larvae-Pupa. Outdoors adult vine weevils lay eggs from May to October, a single vine weevil adult can lay as many as 1500 eggs, and will lay her eggs in several locations to try to ensure that at least some hatch successfully. Newly laid eggs are white turning brown as they mature and take between 8.4 days at 27°C and 56 days at 9°C to hatch into larvae. At this stage the larvae are about 1mm in length, creamy white with a dark head, they will curl into a "C" shape when touched, these larvae can grow to 14 mm in length after feeding on root material and fleshy stems. Vine weevil larvae over-winter in the soil as larvae, in late spring they burrow deeper into the soil to pupate. The life cycle is governed by temperature, which means that it follows a seasonal pattern outdoors but in a protected environment, with less temperature fluctuation, there is no seasonal pattern - any stage being found at one time.
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