I've been asked about these today. It's been a good summer for these critters. Have any of you suffered from them? The first signs most people see is when birds start pecking away at the lawn.
Chafer larvae attack the roots of lawns and some ornamental plants, fruit and vegetables, while adult chafers feed on the leaves of a range of different shrubs, plants and immature deciduous trees. However the adults rarely cause much damage.
About Chafer grubs Adult chafers range in size, the biggest at 30mm in length being the Cockchafer, and the smallest the Welsh chafer at 11mm.
The adult chafers are mainly reddish brown in colour with distinctive large antennae. Chafers have strong, hard cases that protect their delicate wings, when in flight these cases make a distinctive whirring sound.
The creamy, white larvae or grubs are often found curled up just below the soil surface, feeding especially on roots, mainly in August and September. Larvae have distinctive grey ends to their abdomens, and brown heads. Some species remain as larvae for up to three years. Plant damage is mostly caused by the larvae although the adults can also seriously damage the upper parts of the plants.
Chafers overwinter below ground as pupae and the adults emerge in spring. Adults often return to the same location to lay their eggs over a two week period during early summer. Chafer predators such as foxes, badgers, rooks, crows, jays and magpies often damage lawns and community greens searching for grubs. Treatment
Organic Try natural pest controls, such as the parasitic nematode, Heterorhabditis megidis. Where possible eradicate the larval stages by lifting sections of turf and disposing of the larvae. Encourage birds that prey on the beetles and their larvae. Use barrier methods such as fleece, to keep adults away from plants at risk.
Prevention Check regularly for signs of chafer infestation and quickly deal with them. Scarify and aerate lawns in autumn. Where lawns have a history of infestation try to compress the turf by rolling it heavily during spring.
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