Invasive species are a potential menace to people and to our native species. While some pests from foreign lands can be managed naturally, or by effective control methods - others are very difficult to control. With few, if any, natural predators, and in some cases no present means of effective control; some of these out of town uninvited pests threaten our landscape, industry, and even much of our country as we know it. Here are two of them that have become particularly problematic.
Japanese beetles - cause large scale plant destruction for farmers, gardeners and homeowners, in both the adult and larval stages. This is a very different situation from that which exists in its native home of Japan, where natural predators help to control it. In Japan, intestinal parasites, nematodes, and several species of parasitic wasps and flies keep this voracious insect under control. But they are not here in numbers sufficient to manage our beetle problem.
The problem with Japanese beetles isn't that each one eats a lot, but that there are so many of them, and together they can devastate an areas' plants. Starting at the top of a plant and eating their way down, they can leave a plant that looks like a green skeleton. The grubs on the other hand can ruin turf grasses, and damage many other plants by eating the roots. And the beetles aren't that selective in what they will consume. They will eat hundreds of different plant species: damage from these insects totals in the hundreds of millions of dollars.
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It's not hard to identify an adult beetle. They're metallic green, about 3/8" long with bronze wing covers (and usually there's more than one). The grubs, which are only found by digging, are white and curled up and about 1" long. Two of the natural controls from Japan, nematodes and Milky Spore disease can be purchased in this country, and applied to the ground. This can help to control grubs, and to a lesser extent adults since they must first go through the larval stage. But since beetles can fly in and out of feeding areas, these controls are only effective if surrounding homes use them as well.
The natural pest control product, neem oil, is believed to repel Japanese beetles. Like any product that's applied by spraying - it must be applied on a regular basis to replenish it. It is however less toxic than chemical sprays, for those who have children and pets, or would like to impact the environmental as little as possible.
Fire ants - which are native to South America, have become a serious pest in some parts of the United States. They were inadvertently introduced into the U.S. in the 1930's in Mobile, Alabama, and have since spread throughout the southeastern part of the country and California. These ants are pests because they deliver a painful and venomous sting that burns the unfortunate person who steps in their midst: and because their large mounds can damage plants and crops. Being stung by a fire ant is a particularly painful experience because of the way they deliver their stings. They will anchor themselves to a victim with their mandibles, and sting continuously until stopped.
Fire ants will sometimes attack and kill small animals. They can be difficult to control, but there are products available to do so. There are both baits and insecticides designed to control fire ants on lawns and in yards. Also effective is a species of fly that's native to S. America, which lays its eggs in an ant's head. When the young hatch, they eat the inside of the head and kill the ant. This species of fly, called the ant decapitating fly, has been successfully introduced in a number of states with a fire ant problem. However, not all introductions of it have been successful.
The sting of the fire ant is painful and will usually form a bump similar to an acne outbreak a day later. The bites are a problem not only because they are irritating and unattractive but because they can also become infected. And some people are allergic to the venom from fire ants, and need emergency attention because of anaphylaxis.
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