Common Australian Garden Pests & Pest Control
Aphids are small (usually 1 – 4mm), soft-bodied insects that can be found on a wide range of garden plants, including roses, hibiscus, all citrus, impatiens and vegetables. Species range from yellow, to green to black. Aphids can stunt the growth of the plant, distorted or wilted leaves, cause buds to drop, and can result in a poor flower and fruit yield. They are sap suckers, and will digest the plants’ sap to create a sweet residue called honeydew.
This sweet substance attracts Ants, and Ants will “farm” Aphids in order to harvest the honeydew produced by these insects. They will “colonize” the plants stems and leaves, growing in number. The Ants will give the Aphids protection, and will literally pick up and carry the Aphids all over the plant. The honeydew residue the Aphids produce can also be detrimental to the plant, as this encourages Sooty Mould (a dusty dark mould) to spread all over the plant.
Eliminating the Aphids from your plant will also get rid of the Sooty Mould.
There is a range of chemical treatments that you can get from your local garden centre or hardware store. Home made remedies include a spray made from 100g of fresh garlic and/or chilli, crushed and fermented for 2 days in 2 tablespoons vegetable oil and 2 tablespoons of liquid soap or soap powder. Strain into a garden sprayer and dilute 1 part to 50 parts water. Garlic acts as a repellent to further Aphid attack. Blasting aphids with a jet of water from your garden hose also works, however this is only a temporary solution and needs to be repeated every 2-3 days.
Black Scale can usually be found on citrus plants, olive trees and vines. These small black insects cover the plants’ leaves and stems. This can reach a level where they can stunt the growth of the plant, as the plant is denied the necessary sunlight it requires to grow. In addition to this, Black Scale will sap the nutrients from the plant, excreting the residue honeydew. Like the Aphids, these sap suckers create honeydew, which attracts Ants and Sooty Mould.
Black Scale Control
For small amounts of Black Scale, you can get of this simply by brushing it off the stem or leaf with a toothbrush or knife. For larger infestations, spray the plant with a special treatment for this pest, or alternatively, you can spray oil on the plant which will suffocate the Black Scale within a few days. You can mix regular vegetable oil with liquid soap, dilute this with water and spray on your plants, however be sure not to spray oil during hot sunny weather, as this could end up burning the plants’ leaves.
The Mealy Bug is another common garden pest, and favoring shade, can be found in sheltered spots in your garden, patio areas and even on indoor plants. Like the Aphids and Black Scale, the Mealy Bug sucks the sap from the plant, causing it damage to health and growth. The plants’ leaves will usually wilt and distort. Also like the other sap suckers, the Mealy Bug produces honeydew, which leads to the same conditions of Ants harvesting from them, and Sooty Mould fungus. Again, eliminating the producer of the honeydew will help control the Sooty Mould.
Mealy Bug Control
One sure way to eliminate this pest is to dab methylated spirits on them. This will dissolve their waxy coating, and they will dry out and die.
Citrus Leaf Miner
This pest targets all citrus plants (as the name suggests). The larvae burrows into the leaf, leaving silvery paths. Once grown, the larvae will curl the edges of the leaf together to help form the cocoon. Inside the cocoon, it will pupate into its final form as a small moth (roughly 5mm long). This pest distorts the leaves of the plant, which can stunt growth and reduce yield. It can be especially damaging to the tender new growth of the plant.
Citrus Leaf Miner Control
Remove any leaves that are effected and show the silvery paths of Citrus Leaf Miner. You can also protect new growth by spraying the new growth with oil (again mixing vegetable oil with liquid soap will do the trick). As Citrus Leaf Miner prefers hot, sunny weather, you can avoid attacks to your new growth by planting your citrus plants during the autumn months.
Slugs and Snails
These common garden pests can cause damage to young plants, seedlings, and vegetables. While they can be numerous (especially in damp areas of the garden), these pests are quite easy to handle.
Slugs and Snails Control
Slug pellets scattered beneath the plant will help keep slugs and snails at bay, however these pellets might be harmful for pets or children. You can also try the method of spraying salt-water on the plant (be careful not to spray to much, as this could dry your plant out!), the salt will dehydrate the slug or snail, and they will die. Also, another clever way to eliminate this pest is to use a coffee spray. Mix one part espresso coffee (very strong -0 the stronger the better) to 10 parts water, and spray the plant and surrounding soil. This again will dehydrate and kill the pest.
For chronic pest problems, you can contact a gardener in your local area. They will be able to give your garden treatment against pests and mites, and allow your garden to recover.