Diagnosing and Treating This Tree Pest
Recently we’ve received a lot of questions regarding aphids, and because we want your fruit trees to be as healthy as possible, we did a little research on this particular tree pest.
Aphids are these tiny, pear-shaped guys that come in a variety of colours, most commonly green, red, black, yellow, or white. They may appear pretty harmless, but in reality they’re nasty buggers, and definitely not something you want inhabiting your tree. Aphids suck the sap from the leaves, twigs, stems, and roots of trees, leaving behind a sticky sap to attract other pests. This detrimental activity results in damage like leaf curling, bud distortion, gall formation in leaves, and twig dieback.
Before worrying about the potential damage your tree can experience, you have to diagnose how serious the problem is. Most of the key markers in determining if you have aphids can be found in the leaves; aphids cause a discolouration in leaves, making the undersides of the leaves yellow, as well as curling, wilting, or drying out of the leaves. Aphid presence also results in the formation of galls, which are small, round swellings that contain many aphids. As mentioned before, aphids also leave behind a telltale sap called “honeydew” which drips from the underside of leaves making them stickier than normal.
Luckily there are a few ways you can solve this problem. If you don’t notice any clear, visible signs of aphid colonies forming on your fruit tree, you can take certain precautions to prevent future infestation. These include spraying the undersides of your leaves with a strong jet of water, promoting natural predators of the aphid such as ladybugs, lacewing flies, and syrphid flies, and by constant monitoring of your tree. To promote natural predators in your garden, purchasing flowering plants that attract them is a pretty sure way to guarantee their presence. Some examples of flowers that attract these predators include angelica, calendula, and caraway. To further prevent future aphid infestation, it’s also a good idea to avoid the use of nitrogen-heavy fertilizers and broad-spectrum insecticides.
If you do notice an infestation, first determine if it’s localized (in one area of the tree) or if it’s spread to various areas in your tree. If your aphids are still local, pruning or destroying the infected leaves is often an effective method to prevent spreading. Aphids are also attracted to the colour yellow, so placing a dish of yellow-coloured water near the tree can also draw the aphids away from your tree. Another method of treating aphids is by using certain insecticides. For major infestations, the best insecticides are Bug Buster and Trounce, while for smaller infections, Insecticidal Soap and dormant oil spray are quite effective. Every product mentioned can be found in most gardening stores.
Hopefully this has helped broaden your knowledge on aphids and how to prevent the spread of them in your tree. If you’re interested in learning more about pests and diseases, then today’s your day! We’re hosting a preventing pests and diseases in fruit trees workshop on August 12th, 2017. For tickets and information, click here.