Tuesday, July 21, 2020 8:34 AM
As if it’s not bad enough to be under threat of pestilence, this year we have an unusually high number of pests in the garden. Pestilences, be they bubonic plague, Ebola or coronavirus, are by their very description epidemic diseases, whose advance we are unable to halt. Pests, on the other hand, be they slugs, various and sundry beetles or caterpillars, should be something we can control — or so I once thought. Now I’m not so sure. In this year’s garden — in addition to the ever-present tiny snails, so much a part of the landscape that I smoosh them between my fingers without even thinking — we are under attack by potato bugs and, most puzzling of all, earwigs. As I haven’t seen a potato bug in at least 15 years, to find them skeletonizing our blooming plants was a shock. And it took me a long time to connect the presence of tiny, pincer-wielding earwigs all over inside the house — scurrying along in the bathtub and sink, crawling out of bouquets on the dining table and, once, out of a garden salad — to connect their presence to the huge bites taken out of the basil and nasturtiums in the kitchen garden, but I’ve ruled most other predators out.
It’s not easy to identify earwigs as your latest pest, because they’re nocturnal, hiding in cool, moist places during the day and feeding at night. Earwig damage mimics damage from caterpillars and slugs, so to be sure you’ve identified the real culprits you have to lurk about your garden after dark, checking for feeding earwigs on your plants. This is not one of my post-dinner activities, so I’ve pretty much decided to live with the limited damage I’m seeing and confine my counterattacks to eliminating the tiny ones I find when rinsing greens or stepping into the shower. If you are seeing a lot of earwigs, or have had a problem with them in your garden before, you can sprinkle a two-inch-wide circle of diatomaceous earth around beds or the base of plants where earwigs commonly travel, reapplying after it rains. However, it’s a subject of some debate as to how safe diatomaceous earth is when it comes to pollinator bees, so we’ve ruled that out as a method of control. Alternatively, you can fill cat food or other shallow containers with a quarter-inch of oil (preferably fish oil) and sink them into the ground near plants. The earwigs will be attracted and you can empty the cans every day.
Earwigs are not all bad. Aside from their chewing damage, they’re beneficial in compost piles and as predators because they eat nuisances like aphids, mites, and undesirable nematodes, as well as other insect larvae. Earwigs are omnivorous, primarily feeding on decaying organic matter as well as those pest insects, so it would be nice if they could hang around and just be helpful, but gardening is a constant balancing act. As the earwig’s only insect predator in North America is the tachinid fly, you can try to attract and encourage this fly in your garden by planting alyssum, calendula, dill, and fennel, then hope that the two populations will somehow balance out and your plants be spared.
As for potato bugs or, more accurately, Colorado potato beetles, the adults, which are about the size of my pinkie fingernail, are rounded and a yellowish-orange color with black stripes on their wings and black spots just behind the head. Their larvae, which range in size from a grain of rice to a dried lentil, are red with black head and legs, becoming yellowish-red or orange with two rows of black spots on each side of the body as they grow. If you have an infestation of these pests, you have to eliminate the larvae as well as the adults, because each of those can reproduce quickly and lay dozens of eggs. You may be tempted to use a spray such as neem oil or spiniosad, which purportedly have low toxicity to pollinators, but the jury is still debating their safety. So the only organic way to attack potato bugs, alas, is mano a mano. If you get out early in the morning, you can shake adult beetles from the plants onto a ground cloth and dump them into soapy water. I’m not certain, but I think they don’t fly as readily when their wings are damp with dew. At other times, you’ll have to brush the bugs into the jar of soapy water.
When I was a child, my grandmother would give me a similar jar of soapy water and send me out to brush Japanese beetles from her roses and into the jar. She would pay me a penny for every drowned beetle. In those days, a good morning harvest of soapy beetles meant I could race out to the Good Humor truck as it made its daily afternoon rounds and have my pick of popsicles or ice cream confections — a win-win all around. These days, my reward for picking off beetles in the potato patch is the knowledge that by saving the plants we will soon have a bountiful crop of waxy new potatoes for salads or boiling and serving with lashings of butter and sprinklings of chives and parsley — another win-win, but of the adult variety.
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