This summer, be on watch for these two pests along the West Coast.
Aphids are a widespread class of destructive garden pests that can be found on a broad variety of plants. They’re sap-suckers, feeding on the phloem vessels that carry nutrients from one part of the plant to the other. In addition to the damage caused by feeding, aphids can sometimes transmit plant virus that may weaken or kill your plants.
Aphids are identifiable by their soft, pear-shaped bodies, and appear in a variety of colors from green to pink to virtually transparent. Their small size—usually less than 1/8th of an inch, may make them difficult to spot, and often their presence is first detectable by the symptoms of aphid damage. Plants that are stunted, yellowing or mottled should be inspected for pests.
Ladybugs are natural predators of aphids, and can be released in gardens to help curb aphid populations. If you’ve spotted a small infestation of aphids, it may be possible to protect your plants by spraying them with a brisk stream of water a couple of times each week. For more stubborn aphid problems, products containing neem oil are effective.
Lygus is a broad genus of insects, but the one most of us have to deal with in our gardens and landscapes is the tarnished plant bug (Lygus lineolaris). This destructive little critter feeds on a wide variety fruit and vegetable plants, including apple, beet, chard, lettuce, stone fruits and strawberry.
The tarnished plant bug is a flat-bodied bug with a distinctive yellow triangle at the base of its wings. The adults grow to about 1/4th inch in length. In the nymph stage, the bug has a greener cast, and lacks wings. As the bug feeds, it secrets a toxic saliva that can leave holes in developing fruit, through which the bug sucks the plant juices, and can leave yellow spots and ultimately stunt the fruit. It can deform leaves and scar stems. The eggs they lay in trees can cause further damage.
Weeds and overgrown grass can serve as host to the tarnished plant bug, so ensuring that your garden is weed-free and your lawn well-tended can help prevent attacks. If you garden stands near a field crop, especially alfalfa, you may have a harder time of it. It’s usually inadvisable to spray insecticides on fruit trees during their blooming period, but during other stages of growth it may be possible to control tarnished plant bugs using a treatment like Spectracide Malathion.