Gardening – Bugged by bugs

Well, if there was ever a year that I was grateful for my bore, it’s this one. With lawns, paddocks and even mature trees around us taking on a distinct crispy look, my green oasis is a lush haven! The tropical conditions are bringing out the bugs though, particularly those that love hot, dry conditions. Unfortunately, many of these bugs are too small to see (well, for anyone over 50), so the outbreak is often not spotted until the damage is well underway.

Chief among the culprits this season seem to be mites, which attack a very wide range of plants. These are very tiny, less than a millimetre in size, but when magnified look like tiny fat spiders. Indeed, they are related to spiders and some of the many species are known as spider mites. They will usually only become apparent when the leaves lose their gloss and look dusty and yellowed. On inspection, you may notice a fine webbing between the leaves and stems with the mites moving along the strands.

Another of the tiny terrors are thrips. These are also less than one millimetre in size, but more  slender than mites and have wings, although they are poor fliers. They feed by inserting their mouthparts into the plants and sucking out the contents, often in the process transmitting various viruses into the plant to add insult to injury. The leaves take on a distinctive silvery-grey appearance, which is usually the first indication you have a problem.

Slightly larger, but no less destructive, are the tomato potato psyllid (often just known as TPP in the horticultural world). Looking like mini-cicadas, TPP also love hot weather and by now most tomatoes, potatoes, capsicum and eggplants in this area will be infested, unless they are grown under insect proof mesh. Like Thrips, they inject a pathogen (a virus-like organism call psyllid yellows) into the plant as they feed, weakening the plant so much it eventually dies.

Although this may sound like the roll call from hell for keen gardeners, there is a relatively simple solution. All these pests are controlled quite well with sprays of neem oil, mixed with insecticidal soap (for example, Yates Nature’s Way Natrasoap) plus seaweed extract for maximum effectiveness. This combination controls insects in several ways: it smothers them if in direct contact, it breaks down their exoskeleton causing the insects bleed to death, it interrupts their lifecycle by preventing the insects from growing from one stage into another, it causes the insects to stop feeding so they starve to death, and it repels insects from the sprayed plants.

On a micro-scale it’s all pretty gruesome really, but in the battle between gardeners and bugs, all is fair in love and war. However, this does come with a warning: Don’t spray your entire garden indiscriminately all season long, as this will kill too many of the good bugs and unbalance your ecosystem, leading to more pest outbreaks. Instead, try to target spray plants that are infested, or that from experience you know are most likely to become infested. Roses and tomatoes are the best examples. Also make sure you spray in the evening. Spraying on hot days, such as the ones we are currently experiencing, will result in scorching on the leaves, not to mention a very hot and sweaty gardener.

Andrew Steens