When I visited my vegetable garden this morning, there was a Gypsy Moth caterpillar cheerfully devouring my kale. There he sat without a care in the world, doing what Gypsy Caterpillars do best and destroying my garden!
Hard to believe that this menace to gardens, trees, shrubs, flowers and anything that grows was actually invited to come to the United States, but it’s the awful truth. Merchants imported the Gypsy Moth in the hopes of producing domestic silk. Unfortunately, many of the moths escaped to become Public Enemy #1 to gardeners across the country.
A bug or an innocuous plant might not look like fearsome invaders, but many are just that. Imported ornamental flowers, plants and trees often grow so well that they crowd their native colleagues out of existence. Weeds that aren’t native to a country take hold and grow like—well, weeds.
Take kudzu. An import from Japan, kudzu was touted at the 1876 Philadelphia Centennial Exposition as being a fine-looking, fast growing plant that could help with soil erosions. It arrived in the south, took root, and rapidly proceeded to envelop every surface it could find. Barns, trees, fences—you name it— were covered in jungle-green during the summer and in awful brown vines during the winter. No possible good could be found in the thing (kudzu jelly, anyone?), so the kudzu bug—when it accidentally arrived on our shores—was considered the answer to a prayer. Alas for the hopes of mice and men! Only 3.5mm in length, olive green with brown speckles, this highly mobile varmint has already made heavy inroads into the soybean crops of farmers in at least four North Carolina counties. It can be encountered almost everywhere, now. If stepped on, kudzu bugs give off a particularly nasty odor and if mashed with bare feet will cause blisters. There’s currently speculation of possibly importing the Paratelenomus saccharalis, a tiny black wasp from Japan to deal with the beastly bug, but there’s fear that the solution may lead to even more problems.
Of course, some imports are harmless and absolutely beautiful, but a significant number cause more problems than they solve. In Turkey, large Guineafowls were brought in from Africa to kill off the ticks that were considered carriers of disease. Instead of doing their job, though, the birds have not only refused to eat the ticks (really, who would want to eat ticks?) but are also actually helping them to spread! And in another part of the world, ‘spread’ is perhaps too mild a word to describe the population explosion of Australia’s rabbits. Introduced into that country by an English farmer called Thomas Austin, the rabbit population has grown so huge that it has not only caused soil erosion but contributed to the demise of much species loss in Australia.
Closer to home in the Everglades, the once vibrant wetland ecosystem is having problems because ‘introduced’ fish species are doing better than the native fish. In the Great Lakes, zebra mussels have made a mess by clogging up water systems. In Hawaii, rats, sheep, cats, goats—all introduced by Polynesians and Europeans—have effectively and completely done away with some of that island’s wildlife. And in California, a fly which had been studied for possibly introduction to control a plant called yellow starthistle escaped and proceeded to damage California safflower crops.
This is just a tiny tip of the iceberg, of course. Invaders seize any chance to travel. Some species can arrive in a ship’s ballast water or in imported products, but they don’t have to be imported; they can even migrate, uninvited, from ecosystems in different neighborhoods. Whether invited or not, the quiet invaders among us continue to cause mischief. To paraphrase the Bard, “Oh, what a tangled web we weave when first we set out to deceive Mother Nature!”
looks so gentle and harmless…
It loves my garden!