[Animals] Country diary: banking on a beetle bonanza

[Mindsphere.]

 

Langstone, Hampshire: A beetle bank pays dividends in attracting fascinating insects to the garden.

 

I’m used to spotting the most conspicuous and charismatic species in my garden – stag beetles, common cockchafers, seven-spot and harlequin ladybirds – but in the past few weeks something else has been happening. Earlier this year, inspired by the Bring Back Our Beetles campaign run by the Wildlife Trusts and the Royal Horticultural Society, I used branches and twigs to construct dead hedges at the back of my flower borders, mounded soil to create a raised beetle bank, and let the lawn grow wild. Already, my modest patch hosts far more of these fascinating insects than I had appreciated.

There are metallic green leaf weevils (Polydrusus formosus) that drop on to my head from the canopy of the silver birch, common whirligigs (Gyrinus substriatus) that gyrate in schools on the surface of the pond, and glossy blue mint beetles (Chrysolina coerulans), which, along with their globular black larvae, have turned my spearmint leaves to lace.

A quarter of our native species are important pollinators. Pollen beetles (Meligethes aeneus) have a penchant for yellow petals and these tiny black insects are drawn to courgette flowers like iron filings to a magnet, though I also find them sandwiched between the keel and the winged outer petals of sweet pea and runner bean blooms.

On sunny days, I often find thick-legged flower beetles (Oedemera nobilis) feeding on oxeye daisies. Both sexes have slim, iridescent coppery-green elytra, but only the males sport the bulging thighs from which they take their name. The larvae feed and develop inside dried hollow stems – an excellent reason to leave herbaceous plants standing into winter.

Others, like the violet ground beetle (Carabus violaceus) are voracious predators, feeding on molluscs, mites and aphids. In turn, the beetles provide prey for birds, bats and small mammals. While we tend to think of slugs as a hedgehog’s primary food source, research suggests that beetles form the bulk of their diet. Lying in bed at night, I listen to the telltale sound of my prickly visitors crunching through the tough, chitinous carapaces.