Ladybirds and Lacewings ....
Insects can be the organic grower’s best friend. Whether pollinators or predators, they will help manage pests and keep your garden healthy.
See here for further advice on how to introduce wildlife into your organic growing area.
We have chosen 7 friendly insect favourites for each day of the week. Whatever you do, don’t spray or squash them ……
Often confused with wasps because of their similar yellow and black colouring. However, unlike wasps, hoverflies do not sting (nor do they have long antennae, angry eyes and a bulgy abdomen with a wasp waist – that’s how you tell the difference). More than 85 species have been found in a single garden. They can fly in bursts of up to 40km per hour. The adult hoverfly feeds on nectar and pollen, and their larvae are voracious predators of aphids and other garden pests. As a result, hoverflies should be welcome in any organic growing area, acting both as pollinators and pest controllers. How do you tell the sex of a hoverfly? It’s all in the eyes - the male's eyes meet at the top of the head, whereas the female's are separated by a gap.
Plants to attract hoverflies: yarrow, alyssum, dill, cosmos, mallow, poached egg plant, lemon balm, potentilla, marigold
These beetles are carnivores, feeding almost exclusively on aphids (green and black fly) and red spider mites. Which is why the organic grower loves them. Ladybirds lay hundreds of eggs in the colonies of aphids and other plant-eating pests. When they hatch, the ladybird larvae will eat up to 5,000 aphids. A ladybird can only live up to 3 years – assuming it can dodge its predators, which it does by exuding a toxic yellow substance (reflex blood). Interestingly swifts and swallows are immune to these defensive chemicals. The ladybird’s distinctive shell is often red or orange, and the number of spots can vary from 2 to 18.
Plants to attract ladybirds: yarrow, carpet bugleweed (ajuga reptans), alyssum, penstemon, fennel, cinquefoil and tansy
Parasitic wasps (Hymenoptera)
These wasps also do not sting. They lay their eggs on or in other insects. Although their life cycle is gruesome - after the egg hatches, the parasitoid larva eats the host alive before emerging as an adult - these insects have an important role to play. They kill enormous numbers of garden pests, from brassica-munching caterpillars to sawflies, ants and aphids.
Ichneumonidae is one of the largest families of organisms in the world, with over 100,000 species. Indeed, parasitoid wasps are produced on an industrial scale by several firms, for release in fields and greenhouses as a pest control. A female wasp can identify the sex of her eggs, and will only lay female eggs if she finds a good quality host, providing lots of food.
Plants to attract parasitic wasps: yarrow, dill, mallow, cosmos, lobelia, alyssum, cinquefoil, marigold
Butterflies and moths
There are 2500 species of Lepidoptera(butterflies and moths) in Britain. Admittedly their larva (caterpillars) can be pests in the garden – eating brassicas, fruits and other plants. But the adults are beautiful and busy pollinators. How do you tell the difference between a moth and a butterfly? The latter are usually brightly coloured day-flying insects, have clubbed antennae and hold their wings vertically above the body at rest. Most moths are nocturnal, hold their wings flat at rest and have either hair-like or feathery antennae.
Butterflies drink nectar from flowers through their tongues, which function like straws. As well as being pollinators, and visually attractive in the garden, moths and butterflies are an important element of the food chain, as prey for birds, bats and other insectivorous animals (for example, in Britain and Ireland, Blue Tits eat an estimated 50 billion moth caterpillars each year). Individual butterflies have developed their own chemicals to deter predators and parasites, to find a mate, and to overcome the chemical defences of a host plant. Powerful antibiotics, for instance, have been found in the Meadow Brown, one of the UK’s most widespread species.
Plants to attract butterflies: buddleia, marjoram, lavendar, perennial wallflower Plants to attract moths: jasmine, evening primrose, honeysuckle, sweet rocket and night scented stock
These beautiful and common insects in British gardens and are easy to recognise by their transparent lace-like wings, which are nearly twice as long as the abdomen. Both the adult and larvae are voracious consumers of aphids and insect eggs. The larvae have specialised mouthparts with large jaws that interlock to form pincers. Once impaled on these pincers, a prey's body contents are sucked out through hollow food channels running between the jaws.
Lacewings court by 'tremulation', a low frequency sound produced by both males and females vibrating their abdomens. This duet causes the surface they are standing on to vibrate. These courtship ‘songs’ differentiate lacewing species.
Plants to attract lacewings: yarrow, dill, angelica, coriander, cosmos, fennel and dandelion
Ground beetles (Coleoptera, carabidae)
These are voracious predators. Organic growers should cultivate and protect them, as they love slugs and snails! They eat by vomiting on their prey and waiting for their digestive enzymes to make their food more fluid and easier to eat. As the name suggests, many ground beetles spend their time on the ground and few can fly. So when you put down your slug beer traps, make sure there is a lip to prevent the poor beetle climbing in and drowning.
Many ground beetles are nocturnal and need some form of shade during the day, such as a log pile, leaf litter or large stones. When threatened, ground beetles discharge a noxious, highly irritant fluid (harmless to humans) from the tip of their abdomen. Females also use this as their own can of 'pepper spray' to deter over-amorous males. This beetle illustrated is a violet ground beetle carabus violaceus.
Solitary bees (Hymenoptera)
Unlike honeybees and bumblebees, the solitary bee lives up to its name and does not live in colonies. There are more than 200 species of solitary bee in Britain, including the mason bee (pictured), which makes its nest in hollow reeds or holes bored in wood. (You can make your own bee 'hotel' with small hollow stems and twigs bound together.) Some solitary bees look like honeybees, and although they carry pollen on their legs, unlike honey bees, they don't have pollen baskets on their hind legs. The female will dig the nest, stock it with nectar and pollen and then seal it, leaving the young to fend for themselves. Some build nests in the ground, although there is also one species of solitary bee, Ceratina cyanea, that excavates its own aerial nest, usually in bramble stems. And another group which build nests in empty snail shells, sealing the entrance with chewed leaves and saliva. Then there are the leaf-cutter bees, which cut neat circles out of rose leaves and petals to build nests in dead plant stems or sometimes in stacks of old flowerpots. All solitary bees are excellent pollinators and should be encouraged into your garden.
Plants to attract solitary bees: lavender, fuschia, heather, viburnum, marjoram, cat mint