Pest Identification - above ground

You need to keep a watchful eye on the insects that crawl and fly around your plants. Some are feeding elsewhere, or feeding on other creatures, or dead matter. Others are looking for a meal from your plants, or to lay their eggs so that their offspring can feed on your plants. To help you identify the common threats we have divided them into crawling insects and flying insects. Many are very small, and you will need a magnifying glass. If you are growing in a greenhouse or indoors then hang up some sticky traps to catch your suspects so that you can monitor them. Remember that the place they are in, and the signs of damage, are the most important clues....

Flying Pests

Insect	Appearance	Haunts
Cabbage White Butterflies	Butterflies with white wings and black spots.	Fluttering around in summer from April to September, they can be seen hunting for cabbages and other large brassicas where they can lay eggs.
Shore Fly	Tiny flies buzzing around on the surface of the soil.They look like miniature house flies but are only 3mm long.	Found the surface of wet compost when it is warm and light, particularly when there is algae, they don't feed on plants, although they can carry pathogens. The young chew at tender roots.
Sciarid Fly	Tiny black flies about 2.5mm long running around on the surface of the soil.They look like miniature mosquitoes. They are thinner and smaller than shore flies and move in a different way. Often a nuisance near compost bins.	Found the surface of compost when it is warm and light.The young chew at tender roots.
Crane Fly	Aptly named "Daddy Long Legs" most people can recognise these gangly-looking insects.	Typically found flying around in Autumn, where they are often found inside. Also found outside on lawns looking for somewhere to lay their eggs.
Vine Weevil	Small black flying beetles	Visible at night, feeding among the leaves of shrubs and other tough plants.
May Bug	Brown flying beetles about 25mm in size. The top pair of wing shields are reddish brown but there are large lacy translucent flying wings underneath, and when in full flight they make the bug look twice as large.	Common in gardens and often attracted into houses with the light in early summer.
Leaf miners	Tiny flies whose young burrow through the leaf surface and leave unsightly marks	Found on tomatoes, chrysanthemums, herbs, kale.
Whitefly	Clouds of small white flying insects	Typically found in greenhouses around tomatoes, aubergines,courgettes
Thrips	Minute cigar-shaped insects about 2mm long. There are rose thrips, gladiolus thrips, western flower thrips, etc, and they are all slightly different in colour and size. The larvae crawl but the adults have wings.	Found in summer in flowers and around buds and leaves.

Crawling Pests

Aphids	Small soft bodied insects making visible clusters under the leaves. They often drop white skins onto the leaves below.	Different species favour different plants - they can be pale coloured, cream or transparent, or they can be black, or green (see below).
Greenfly	Small green wingless aphids	Found at the tips of shoots and round buds - often roses.
Blackfly	Large black wingless aphids	Found on beans, maize, etc, in clusters or swarms
Spider Mite	Minute mites on underneath of leaves - larger clusters are associated with webbing which they use to crawl between stems. The "red" is misleading because they are only red in winter. They are also called "two-spotted mites" but you would need a microscope to view them properly.	Found in dry hot spells they favour particular leaves such as broad beans, day lilies, begonias.
Caterpillars	Multi-segmented crawlers with distinctive head and many legs. Found with eggs and droppings (should perhaps be categorised under 'flyers' because the adults are moths and butterflies.)	Present from June to September outside, or even beyond these times in warm weather. Favourite places are large brassicas where the two to look out for are the caterpillar of the large white butterfly and the cabbage white butterfly.