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How to recognise it
These small, shiny beetles are about 2-3mm long and black or green/bronze in colour. They can be found in the flowers of plants, usually in large numbers, feeding on and destroying the flowers.
Lifecycle
Adults lay eggs on unopened flower buds in April/May. White larvae with brown heads hatch from the eggs and they, along with the adults, feed on flower pollen. After about three weeks of feeding the larvae burrow into the soil to pupate, overwintering there and emerging as adults in spring.
Why it’s a problem
Flowers are damaged and sometimes destroyed completely by the feeding larvae and adults. This is a particular problem when the plants are being grown for cut flowers or exhibition.
Where you are likely to find it
The flowers of the following plants are particularly susceptible; brassicas, narcissi (daffodils), dahlias, marrows, runner beans, roses, shasta daisies (Leucanthemum x superbum) and sweet peas.
How to deter it
Protect valuable flowers (eg for exhibitions) by creating a ‘tent’ of horticultural fleece over them to prevent the beetles reaching the flower to lay eggs.
How to get rid of it
Gentle shaking of cut flowers, or putting them in a shaded place for three hours, should remove the beetles.
It is preferable not to use insecticides on flowers as other pollinating insects will be affected, plus it will only stave off the pollen beetle attack for a short time.
Is it good for anything?!
No.
Other useful information
Large populations of pollen beetles develop on oil seed rape crops, which may be the source of the infestation for some gardens. There are many different species of pollen beetle, two of the more common being Meligethes aeneus and M. viridescens.
