Pests can wreak havoc on our gardening efforts. However, there are steps you can take to help control the problem. In addition to the usual chemical remedies, biological controls (where predators and parasites are introduced to deal with pests) are also effective.
Aphids: Aphids are small soft-bodied insects that are found on all citrus, roses, hibiscus and vegetables. Aphids produce a honeydew residue that can encourage a dusty dark mould to spread all over the plant. Treat plants that are affected with soap or insecticidal spray. Garlic also acts as a repellent to further Aphid attack and you could also try is encouraging aphid-eating insects such as ladybirds, hoverflies, lacewings, spiders and centipedes.
Caterpillars: There are many types of caterpillar and the best known caterpillar pest is the cabbage white butterfly. They eat foliage, stems, vegetables, flowers and fruit. If you see curled leaves and webbing on your plants, it’s likely a cabbage white butterfly is not far away. You will need to firstly pick the insects off the plant and then spray with biological control Bacillus thuringiensis or pesticide. Be sure to cut out any damaged stems.
Earwigs: Earwigs feed at night so they can be hard to spot. They eat the flowers and shred the leaves of clematis, dahlias and chrysanthemums. Inverted flowerpots stuffed with straw or hay on a cane near the plant, will attract and trap earwigs. You’ll then be able to remove them easily. Finally, spray the plant with pesticide to ensure they don’t come back.
Flea beetle: Flea beetles are named for their ability to jump and they love to feed on tomatoes, cabbage, sprouts and many other vegetables. You’ll need to treat the soil as well as the leaves with pesticide and thoroughly clear up any debris. Treat the leaves and also soil, if necessary, with pesticide; clear up debris thoroughly. For an organic alternative to pesticide, try diatomaceous earth. This substance is simply soil composed of fossilised fresh water grass from oceans and lakes. The best part is, while it’s non-toxic to most mammals, it’s fatal to most insects that come into contact with it.
Red spider mites: Red spider mites are generally red in colour in the autumn/winter and the rest of the year can vary from off white to green in colour. If you find a discoloured circle of grass on your lawn that’s a motley coloured yellow, chances are you’ve been visited by a red spider mite, not a UFO. It’s extremely infectious so be careful not to walk through it and don’t mow or fertilise your lawn for some time or you could spread it. Spray the affected area with miticide. You may have to spray your lawn three times in a fortnight to get rid of it. Another option is to use a predatory mite like Phytoseiulus persimilis.
Slugs and snails: These common garden pests can be numerous, especially in damp areas, but are actually quite easy to handle. They tend to be found causing damage to seedlings, young plants and vegetables. Firstly, remove the pests, and then scatter pellets or drenches beneath the plant to keep them at bay. A nematode parasite for slugs can also be effective. A non-toxic alternative that won’t harm children and pets is to mix one part very strong espresso coffee to 10 parts water and spray the plant and surrounding soil. This will dehydrate and kill slugs and snails. It’s important to also cultivate the soil and clear up any debris that may be attracting these pests to the plants.
Vine weevils: These beetles are black with some yellowish or tan markings, their larvae are legless and white to pinkish in colour with brown heads. They are usually found attacking the roots of rhododendrons, azaleas and camellias. Chemicals are rarely successful in controlling vine weevils so it’s best to collect up all the adult beetles and grubs and use a nematode parasite which will feed on the larvae in the soil.