Clay Coloured Weevils are small beetles that feed on leaves and bark, causing problems on tough leaved plants such as Rhododendrons, Camellias, Azaleas and Laurels. They also feed on emerging buds - flower and foliage. In the shrub area, they seem to affect those with leathery leaves most – such as the Camellias and Rhododendrons.
They differ in many respects to the Vine Weevil Beetle, but the main difference – other than visual – is that they feed on the bark of ornamentals as well as the leaves mentioned above.
Clay Coloured Weevils also feed on fruit, in particular Raspberries, causing damage to the canes overall and also directly affecting the fruit, and are normally active through from spring to early autumn.
As with most weevils, they do most of their damage in the night time, climbing into the host plant from their ‘hideaways’ in plant debris nearby or at the base of the plants. They are flightless and transport slowly by crawling.
It causes leaf damage similar to that of the Vine Weevil Beetle - to which it is related. But, also gnaws at bark, sometimes 'ring-barking' the twig or shoot, causing its death.
Clay Coloured Weevils are said to attack conifer varieties as well, and as this is bark rather than foliage damage, severe wilting can occur – normally seen after the damage is done. The fact that it is normally bark damage rather than visible signs of leaf damage, makes it more difficult to spot and treat in the early stages.
Eggs of the Clay Coloured Weevil are laid directly into the soil, and the young larvae then feed on plant roots deep down in the soil – at depths down to 50cm! They feed on plant roots throughout the winter, and wilted plants – as with the Vine Weevil maggot damage will be a sign of activity. For this reason, they are difficult to control chemically. The larvae then emerge from the soil mid-spring as young weevils, and start to feed instantly.
Much of the damage is done to young terminal buds – foliage and flower – which results in severe setback for the plants’ future growth.
Clay colored weevil on Azalea leafThe weevil is brown in colour and little more than 7-8mm long. They have the typical trademark of weevils, by way of two antennae protruding to the front from small downward facing head. The antennae are 'elbowed' rather than straight 'feelers'. They are not quite as big as the ravaging Vine Weevil Beetle, but the damage they can do is not necessarily proportional to their size! Extremely difficult to control by chemical means, so would suggest Provado for best effect.
Raspberry farmers in the US, assess the population – and size of problem – by going out at night, beating the raspberry canes and holding a tray below to catch the falling weevils. For severe isolated known attacks on shrubs, this might in fact be one of the best methods of catching them!