Bees, hoverflies and who does what

Honeybees get the press, but solitary bees do more pollination per insect. The UK has 270 species of solitary bee. Each flies for four to six weeks, nests alone, and specialises in certain flower shapes. Some only visit legumes. Some only work in the morning. You cannot manage them individually, but you can hold 30 species in one garden by offering a range of flower forms and bare ground for nest tunnels. Bumblebees are the cold-weather workhorses — they can forage down to 6°C, and their buzz pollination is essential for tomatoes, peppers and aubergines under glass.

Hoverflies are the unsung predators. The adult feeds on nectar and pollen. The larva is a soft green maggot that eats aphids at extraordinary speed. One hoverfly larva consumes 400 aphids before pupating. They hatch in compost heaps, long grass, and leaf litter. They need flowers within 50 metres of where they emerge, or they disperse. This is why a flowering lawn edge or a patch of self-sown calendula near the compost pays immediate dividends. Phacelia, buckwheat, and fennel are hoverfly magnets.

Ground beetles, ladybirds, lacewings and parasitic wasps complete the beneficial guild. They are drawn to pollen and nectar, but they do not pollinate. They hunt. A garden designed for pollinators is automatically a garden full of pest controllers. The trick is to give them permanent shelter — log piles, dense evergreen hedging, uncut grass through winter. Beetles and ladybirds hibernate. If you tidy everything in autumn, they have nowhere to go.