Anyone tidying their garden over the coming weeks is set to encounter countless ladybirds amongst foliage and debris as these creatures hunt for cosy hideaways with autumn’s arrival. It’s been an exceptional year for these helpful insects, courtesy of the balmy spring and summer temperatures that have caused aphid numbers to soar – the primary food source for ladybirds.
Aphids multiply rapidly during warmer spells as elevated temperatures accelerate both their growth and breeding cycles, creating abundant sustenance for ladybirds. Horticultural charity Garden Organic has documented a massive surge in populations continuing into September at its demonstration site in Ryton, Coventry.
Ladybird specialist Professor Helen Roy, from the UK Centre for Ecology and Hydrology and honorary fellow of the Royal Entomological Society, reveals the UK Ladybird Survey, which encourages recording of all ladybird species discovered across Britain, has logged substantial numbers of seven-spot, 14-spot and harlequin ladybirds, plus rare varieties like the hieroglyphic ladybird – a bronze-brown creature inhabiting heathlands.
“Aphid-feeding ladybirds such as seven-spot ladybirds and two-spot ladybirds are able to use various cues to determine whether the aphid colony is increasing or about to crash – and will lay their eggs near a population that’s going to increase and sustain their larvae through their development.”
Harlequin ladybirds, initially spotted in Britain during 2004, could potentially impact population figures, though. “They spread very rapidly and are now found across the UK in high numbers throughout the year. Harlequin ladybirds are voracious predators and while they will eat lots of aphids, they also feed on other insects including ladybird larvae, hoverfly larvae and other insects that are beneficial to gardeners,” says Roy.
“Our studies have shown they cause declines of some other species including, as an example, dramatic declines in two-spot ladybird in the UK.”
Ladybirds undergo four developmental phases. The journey from egg to larva, then pupa, before finally emerging as an adult takes approximately two months.
Reproduction commences in May with the subsequent generation appearing in August – though you’ll likely observe them in substantial numbers until late October. The newly emerged adults have merely a few months to accumulate sufficient fat reserves within their bodies for winter survival.
How can we help ladybirds during the colder months?
Avoid excessive tidying
Consider establishing a well-balanced, biodiverse environment with abundant habitats, recommends Garden Organic gardener Jules Duncan. “Now the nights are drawing in and there is the temptation to tidy up the garden and retreat indoors – but resist that temptation.
“Fallen leaves, dry sticks and hollow stems are the perfect hiding place for these gardener’s friends. They particularly like flat-topped flowers such as fennel, yarrow, angelica, alyssum and dandelions.
“In our organic garden, the seven-spot likes nothing better than leaf litter to weather the storms and we regularly find two-spots nesting in groups in the crevices of our compost bays.”
Construct log piles
Log piles are straightforward to assemble and offer another excellent area for ladybirds to cluster together for protection, Duncan suggests. Should you discover them indoors, avoid ejecting them into the harsh weather, instead move them to a shed corner or peaceful garden spot.
Establish a nettle patch
Maintain a small nettle area to supply food for aphids – a key food source for ladybirds – when they appear next spring, allowing the entire cycle to restart, Duncan recommends.
Cease using pesticides
“If you want to encourage two-spot and seven-spot ladybirds, we recommend stopping using pesticides because they can be non-discriminatory, attacking the pests as well as the beneficial insects,” says Duncan. Through spraying you eliminate the food source for the ladybirds, which consequently will diminish their populations.