Gardening > Vegetable Pests In Your Garden

Vegetable Pests In Your Garden

Faced with a row of holey, leaf-stripped or generally sickly-looking crops or ornamental plants it can be difficult to decide which particular garden pest has wreaked the damage. If slugs and snails can be eliminated from the list of suspects there are several other creatures that may be causing the problem.

Caterpillars, which are the larvae of the moths and butterflies, are very well known garden pests, especially the bright green caterpillar, which is the larva of the cabbage white butterfly. These can completely destroy leafy vegetables, especially those of the brassica family. The caterpillars of various other butterflies and moths live and feed on leaves or stems and some live in the soil where they eat roots. Cut worms are actually the caterpillar of several species of noctuid moths. They are fat squashy larva, green grey or brown in colour, feeding on brassica, carrots, beetroot, celery and potatoes. Cut worms usually live at the base of these plants, coming out at night leaving behind wilting and often cut off seedlings. The pea moth lays its eggs while the pea plant is in bloom. The larvae of this moth spoil the peas often making them inedible.

The larvae of the onion fly live in the soil around the roots of onions. These larvae are white and fat and they can do considerable damage to the crop. Carrot flies lay their eggs at the base of carrots, parsley, parsnips and celery. As they develop the yellow grubs burrow into the vegetables spoiling them with holes and brown marks. Another fly, the cabbage root fly, lays its eggs in the soil next to the stem which the newly-hatched larvae burrows into. As the white, cigar-shaped grubs feed the plants wilt and collapse.

Leatherjackets and wireworms are also larvae. Leatherjackets are the larvae of the cranefly and wireworms of the click beetle. Wireworms will attack any plant but are especially fond of potatoes and carrots which they riddle with holes. These larvae are thin and shiny with a yellowish skin. Leatherjackets are fat, white larvae which live just below the soil and eat roots and sometimes stems.

Earwigs, a brown, shiny insect, do not tend to do a great deal of damage but they can threaten the perfection of a prize chrysanthemum or dahlia by nibbling on the buds and leaves. Aphids by contrast can do a lot of damage. These are commonly known as blackfly and greenfly and they suck the sap from plants which causes distortion. They also compromise the health of plants by transmitting viruses and by leaving behind 'honeydew', a sticky excretion which can encourage sooty mould. Whitefly, tiny white flies which when disturbed rise up in a cloud, also suck sap. The variety which attacks brassicas is a particular nuisance and other types of whitefly can invade greenhouses.

If you find a mass of tiny holes in your brassica seedling leaves this is likely to be the work of the flea beetle. The worst case scenario with the damage of this pest, especially if the weather is cold and wet, is the total destruction of the seedlings. However sometimes plants can overcome an attack especially if growing conditions are good. Woodlice also like seedlings and young tender plants and tend to attack at night leaving stems and leaves nibbled.

Lastly millipedes which are small and black with short legs live beneath the surface of the soil. They like to eat the roots of plants. It is essential that you learn to distinguish millipedes (harmful) from centipedes (beneficial) because centipedes are extremely useful, coming out at night and eating insect pests and even slugs.

Caterpillars - Butterflies and Moths lay tiny eggs on the underside of leaves. These can be removed by hand. Pick off caterpillars.

Pea Moth -

Carrot Fly - Use a physical barrier like enviromesh.

Onion Fly - Grow onions from sets to avoid the need for thinning out seedlings. The fly is attracted to the scent released from the bruised plants. Hoe to expose the grubs to birds.

Leatherjackets - Squash the grubs, Have ground cover plants to attract ground beetles which eat leatherjackets.

Wireworm - Bury bits of potato or carrot in marked positions. These will attract wireworms. After a few weeks remove and burn and repeat the process. Grow wheat between the crops. Wheat attracts wireworms and after a few weeks dig up wheat and destroy it.

Earwigs - Fill a small flower pot with straw. Put it upside down on a stick in the flowerbed. The earwigs will crawl into it. Clear out and replace once a week.

Aphids - Release ladybirds or lacewing larvae into the garden. Attract hoverflies with poached egg plant. Try garlic insect spray as well.

White Fly - Use a yellow sticky board in the greenhouse. Outside clear up all garden rubbish in autumn so the whitefly have no food. During the summer you can use a cordless vacuum cleaner to hoover them up as they rise from the plants.

Flea Beetle - Grease a piece of board with heavy engine grease. Hold the board over the affected plant and when the beetles jump up they will become trapped on the grease.

Woodlice- Keep the garden very tidy and free of old stones, old bits of wood and debris so they do not have a hiding place. Hoe around plants to expose woodlice to birds.

Millipede - Same as for Woodlice.