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 crawing
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 |
Picture |
| 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 be a nuisance. |
 |
| 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.
|
Found the surface of compost when it is warm and light. |
 |
| 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. |
 |
| 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 bunds - 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 |
Present from July 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. |
 |
|
