Gardening with Daphne: Pollen beetle is a nasty little bug

Bug off: The pollen beetle decimates plants.
Bug off: The pollen beetle decimates plants.
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I had a desperate email from my friend Carol last weekend.

She has grown Iceland poppies in the border for the first time this year, but they are rapidly being ruined by what she described as ‘flower fleas’.

This is a great name for the nasty little bug more known as the pollen beetle.

Both the adults and larvae feed on the buds and flowers of a wide range of flowers in search of pollen.

They make holes in developing buds to reach the stamens, cause flower deformity and bud abortion and can ruin ornamental flowers as well as reducing the yield of many agricultural crops.

I was surprised to hear that Carol was being troubled by pollen beetle so late in the summer.

The adults usually emerge from late March to May, and are often first noticed when oilseed rape is in flower, particularly when it grows in the headlands of farm fields that are untreated by insecticides.

However, a second generation may occur in late summer and early autumn, which appears to be the case with my friend’s poppies.

The adults lay their eggs in flower buds; these hatch after seven to ten days to produce larvae that when fully developed pupate in the soil.

These emerge the following summer to continue their devastation.

I have had the first flush of roses decimated in the past with pollen beetles, although this has thankfully not occurred in recent years.

They can be a particular nuisance on cut flowers, and I usually recommend standing the vase on a brightly coloured – preferably yellow – piece of paper or cloth; the beetles usually migrate to this and the flowers should be clean after an hour or two.

Alternatively, place the cut flowers in a container of water in a dark place with a bright window nearby, and you will find all the beetles on the glass after a little time.

You can control pollen beetle with an insecticide – organic or inorganic depending on your persuasion, but in recent years they have started to show some resistance.

If a second generation is around, which seems to be the case, it is wise to fleece cauliflowers as the heads develop, as they can also spoil these if allowed to move in.