- Time to Consider
- A spectacle of winter
- Berried treasure
- Bounty all year round
- Bring garden to life
- Caring for a garden's soul
- Cascade of colour
- Cheer in the winter garden
- Fancy a Chinese?
- Herbs for the hot sun
- Jewel of September
- Leafing through salad choices
- Love of our roses
- Magic of meadows
- Nation's favourite
- Nurturing growth
- Planning new dawn
- Pots in the portfolio
- Secrets for the summer
- Signs of spring
- Taste of the season
- The Cape of good tastes
- Turn up the heat
- Upsetting the apple cart
- Consider the wildlife
- Hardy ferns for winter interest
- Magnificent sedums
- Natural Principles
- Old-fashioned roses
- Stripe Action
- The importance of gardens
- The Lady is a champ
The Lady is a champ
If you do spray your aphids in early summer, any ladybird that comes into contact with the chemical (be it an insecticide or a soft soap) will probably die. This is serious for the gardener, because most species of ladybird produce only one generation a year. Killing them now will mean that there will be none for the rest of this year or the next.
The 7-spot (Coccinella 7-punctata), one of our most common ladybirds, can get through 70 aphids a day in a six-month foraging season. It will lay 1,500 eggs during its year-long life, grouped together in ranks of 20 to 40 close to aphid colonies. These hatch in about a week, producing larvae that will eat up to 500 aphids during its three-week life. Each larva will then turn into pupa, or chrysalis, emerging into the fully formed adult about a week later.
An absence of aphid colonies means no ladybird eggs. Meanwhile the aphids, with no predators around, will happily produce a generation a week during warm weather. Commercial growers have long appreciated the efficiency of the ladybird as a biological control for aphids. They have been using the most voracious one, the multicoloured Asian ladybird (Harmonia axyridis) or harlequin, because it eats up to a 100 aphids a day. Though kept under glass, they inevitably escape and breed. This large, round ladybird has already caused problems in America. During the early 1990s, swarms invaded houses in Ohio looking for hibernation sites. They squirt strong-smelling, yellow liquid over curtains and furnishings - they also bite. The harlequin is used as a biological control in France, the Netherlands and in Belgium, just across the Channel. On September 19, 2004, one was identified in the garden of the White Lion pub at Sible Hedingham in Essex. It was thought to have been carried on the wind from Holland. This, the first British sighting, was verified by Dr Michael Majerus, an expert based at Cambridge University.
Dr Majerus' concerns are not for our soft furnishings, however. When aphids are in short supply, the hungry harlequin turns cannibal and eats other ladybirds, their larva and pupae, lacewing and hoverfly larvae, plus moth and butterfly eggs. Majerus believes that we are in danger of losing half of our 40 ladybird species. "Given that 12 species are already on the Red Data List because they are endangered this is obviously worrying news," he says. "Now many of our native ladybirds will be in direct competition with this aggressively invasive species, and some will simply not cope."
Further informationTwo new websites have now been set up in response to the possible threat to our native ladybirds. One will monitor the spread of the harlequin (www.harlequin-survey.org) and the other (www.ladybird-survey.org) will record our native species. A map recording new harlequin sightings already shows many clusters in the south and east, but the harlequin can disperse over long distances and has the potential for rapid geographic expansion.
Dr Majerus asks people to send odd-looking ladybirds - preferably alive - in a clean plastic container to: The Harlequin Ladybird Project Officer, Biological Records Centre, CEH Monks Wood, Abbots, Ripton, Cambs PE28 2LS. Digital photos can also be submitted on-line.
Many gardening shops sell special ladybird shelters and hibernaculums, but these are not always the best way to encourage them into the garden. Ladybirds like to hibernate at ground level and often next in leaf litter, or dead, hollow stems, so a cheaper and more suitable alternative shelter is old shrub prunings. Strip the shrub prunings of foliage, tie a dozen or so stems together, and stand them in a sheltered part of your garden. Online-store Green Gardener (01394 420087; www.greengardener.co.uk) sells a range of ladybird-related products, including ladybirds by post.
Identifying the harlequinThe harlequin is larger and rounder (8mm or 3/4in) than the native 7-spot (6mm). Colour and pattern vary, but the most common forms are either orange with 15 to 21 black spots, or black with two or four orange or red spots. It has two distinct black false eyes and football-shaped white markings on either side of its head.
Common native speciesThe two-spot ladybird (Adalia 2-punctata): often seen eating aphids on roses in urban gardens. Colour and pattern vary, but it is often red with two large round black spots, one on each side, or black with red spots. It hibernates close to buildings in little groups, and will nestle in the corners of window frames.
The seven-spot ladybird (Coccinella 7-punctata, pictured right): the most widespread, found on herbaceous plants. The seven-spot always has a bright-red back and seven distinctive black spots, three on each side with one centrally placed. It hibernates close to the ground.
The 10-spot ladybird (Adalia 10-punctata): a small ladybird with variable markings that can range from completely black to all red - usually identified by its pale legs. It lives in trees and hedges, and is rarely seen on herbaceous plants. It hibernates in leaf litter, plant debris, bark, on tree trunks and in ivy. This species may produce two generations per year.
The 14-spot ladybird (Propylea 14-punctata): a creamy-yellow ladybird with 14 squarish spots often fused together, it feeds on at least 200 plant species. This species hibernates at ground level in leaf litter, plant debris, grassy tussocks and plant stems, often clusters in large groups.
The 22-spot ladybird (Psyllobora 22-punctata): this yellow ladybird has 22 round black spots that don't join up. It feeds on mildew, not aphids, and is usually found close to the ground, often on hogweed or creeping thistle, but can also be found on hedges and coppiced trees. All three stages, the larval, pupal and adult, are black and yellow, and the larvae appear later in the year, when mildew is more prevalent. It hibernates in long grass close to young trees, or in ivy.
'The Natural Gardener' by Val Bourne (Frances Lincoln) is available for £14.99, plus £2.25 p&p, from Telegraph Books Direct (0870 155 7222).