Reader's question:

Mary and Andrew brought me a large mid-brown beetle-like insect in a jar for identification.

They said that it flew straight into their open kitchen window and landed in the washingup bowl.

Apparently it took Mary several minutes to regain her composure and get her husband to fish it out of the dishwater.

They wondered what on earth it was and whether it was dangerous or damaging to the garden.

THE insect in the jar was a cockchafer. Chafers are beetles, and belong to the same family as the scarab or dung beetles.

The most familiar of our chafers is the cockchafer or ‘maybug’ (Melolontha melolontha). The adult beetle is a night-flier and often comes crashing into lighted windows on warm evenings in early summer. Its large size (1-2 inches long) and buzzing flight make it a little frightening, but the beetle is quite harmless and will not bite or sting.

Adult chafers eat the leaves and flowers of many deciduous trees, shrubs and other plants, but rarely cause any serious damage in the UK.

However, their fat, white grubs (reaching 40-45mm when fully grown) live in the soil and feed on plant roots, especially those of grasses.

The damage to grassland and lawns results in poorly growing patches that quickly turn brown in dry weather. The grubs can be found immediately below the surface, usually lying in a characteristic comma-like position.

The grubs sometimes attack vegetables and other garden plants.

Damage to the roots and rootstock causes small saplings and tender taprooted plants like lettuce, to wilt suddenly or to show stunted growth and a tendency to shed leaves prematurely.

Plants growing in rows are usually attacked in succession as the grubs move along from one plant to the next. Chafer grubs feed below ground for three to four years before changing into adult beetles.

Damage by chafer grubs can be reduced by the use of chemical control, but in small gardens it is often sufficient to simply remove and kill the grubs by hand. Thorough soil cultivation and good weed control will generally ensure that plant losses are minimal.

Infested lawns may benefit from heavy rolling in late spring to kill pupae, and also from adequate watering and feeding to encourage growth of the grass. Covering the lawn with black plastic encourages the larva to come to the surface, upon which groups of starlings will descend and gorge themselves silly.

Jobs this week

■ MOST primroses have finished flowering now. Dig up large clumps and divide into individual plants, each with leaves and roots. Replant into newly-prepared soil.

■ Fuchsias benefit from having their shoot tips pinched out to encourage branching. If left, shoots can grow very long and lanky, while pinching out creates bushier plants with more stems that ultimately carry more blooms.

■ Brigid presents the BBC Tees Gardening show on Sundays from 1pm- 2pm. Questions can be answered on the day by emailing brigidpress@bbc.co.uk anytime during the week, or texting 07786-200995 and phoning 01642-225511 during the show.M/i>