An extreme locust infestation threatens crops and jobs in East Africa, Reuters reported. The swarms have affected unknown amounts of harvests in Ethiopia, Kenya, Uganda, and Somalia. Even in your home garden, bugs need controlling.
East Africa is no stranger to locusts, but the current infestation is believed to be larger than several previous generations, according to the article. “Locust swarms have been recorded in the region since biblical times, but unusual weather patterns exacerbated by climate change have created ideal conditions for insect numbers to surge,” the article said. “Warmer seas are creating more rain, wakening dormant eggs, and cyclones that disperse the swarms are getting stronger and more frequent.”
The article went on to state that Kenya temporarily ran out of pesticides for over a week, while Ethiopia can’t afford to rent as many airplanes as it needs to spray them on crops. Bugs can ruin crops on a large scale or a small one; fortunately they’re much more manageable for the home gardener—even without pesticides.
Three Kinds of Cultural Control
Minimally invasive cultural control can reduce the number of problematic insects feeding on gardens. First, increasing landscape diversity can be used “as a way of increasing insect diversity—especially beneficial insects, [like] those parasites, predators, parasitoids, things that can help control the insects that we don’t want in our gardens,” said Dr. Linda Chalker-Scott, Extension Specialist in Urban Horticulture and an Associate Professor of Horticulture at Washington State University. “So, for instance, remember that you should use ground covers. That’s going to protect the soil as well as provide a habitat for a lot of those predators and parasitoids, many of which are small, and any of which live on the ground.”
Dr. Chalker-Scott said that in places where using ground covers isn’t possible, spread coarse, woody mulches to cultivate helpful insects.
Second, she advised using polyculture or intercropping, which are agricultural terms. “Rather than having the rows of carrots and lettuce and radishes, where it’s more or less a smorgasbord for insects that like those particular vegetables, mix it up,” she said. “Plant them in pods, intersperse them with the rest of your landscape, rather than just having a vegetable garden. This confuses pests that will have to actively search for these plants rather than having all of their host plants right there.”
Third is using trap plants, which are less desirable crops you can plant to feed insects. Dr. Chalker-Scott said that trap plants are often specific to which bug has found your garden and will require research on your part.
“Yes, that means you’re going to be supporting that pest, but remember, we’re not trying to wipe it out; we’re just trying to manage it,” she said. “And if you can manage it by allowing it to eat something you don’t care about—a trap plant—then perhaps it won’t attack the things you do care about.”
Depending on what you wish to grow, mechanical methods of managing pests may prove more effective. Physical removal of bugs can include the use of a spray hose, which does double duty as it also provides your plants with water. There are other physical repellants as well. One is kaolin clay.
“This is something that gets mixed up and sprayed directly into the leaves of plants, and it repels insects in a variety of ways,” Dr. Chalker-Scott said. “Obviously, something that’s covered in clay is not going to be very appetizing; so insects, even if they can take a bite, are going to be repelled by the taste of the clay and they’ll leave it alone. Also, that layer of clay on the leaf surface keeps a lot of insects from being able to lay their eggs on leaves.”
Finally, there are also oils. Various oils can be used for gardening, which, like kaolin clay, will make the taste of your plants unappealing to insects and hinder their ability to lay eggs in your plants. “But you have to be careful with the oils, especially in summertime, because they can be phytotoxic and can cause burn,” Dr. Chalker-Scott said.
The locust problem in Africa is serious and in desperate need of strong pesticides. This will save harvests on a considerable part of the continent and prevent starvation. However, in your own garden, milder pest solutions can easily be found.
Dr. Linda Chalker-Scott contributed to this article. Dr. Chalker-Scott is an Extension Specialist in Urban Horticulture and an Associate Professor of Horticulture at Washington State University. She received her Ph.D. in Horticulture from Oregon State University, focusing on environmental stress physiology of woody plants.