Continuing on about bugs in your garden, it is time to look at some of the “bad” bugs gardeners have to contend with. Insects can do a great deal of damage to all types of plants and trees. They can eat away leaves, cut through stems, nibble on roots, bore into trees to deposit eggs which hatch into destructive larvae, and even infiltrate fruit and vegetables while or after they have matured. Insects do most of their damage while eating. Their mouthparts are either chewing or sucking. While it would be impossible to look at all the bad insects in a blog of readable length, here are some of the most common insect pests in the United States. In Part 3 we will focus on “bad” bugs in Florida as certain insects prefer the warmer climates and plants, trees, and produce grown in this state.
Leaf miners chew their way through leaves, living them looking like a piece of lace or filled with tiny tunnels. They include sawflies, dipteran flies, rose slugs, lepidopteran moths, and coleopteran beetles.
Defoliators feed on plants and can strip them bare of leaves, sometimes in a matter of hours. Tomato hornworm, most caterpillars (larvae of butterflies and moths), may beetle, and flea beetles are in this category.
Gall makers are insects who create abnormal looking growths on plants and trees of every kind. These growths, called “gals,” can appear on a twig, leaf, root, stem, or bud. And, interestingly, each type of gall maker consistently attacks just one part of a host and each time leaves a gall similar in shape, color, and size. Six groups of insects are included in the gall maker category and are moths, wasps, beetles, flies, adelgids, and aphids.
Wood borers are insects of the beetle and moth species that lay their eggs in branches, stems, and trunks of woody plants. The eggs then hatch into larvae which eat their way around and through their hosts. Wood borers usually attack already weakened trees or trees in stress, but sometimes will attack healthy trees, often young ones, as well. Depending on the degree of the infestation, a tree can become diseased from the introduction of wood rotting organisms, through the boring holes, weakened, so the trees are vulnerable to wind damage, or even death when nutrient or water supply is cut off by grinding the insides of life-giving parts. Examples of these pests include metallic wood-boring beetle, locust beetle, cottonwood borer beetle, elm borer beetle, carpenter borer moth, and Lilac/ash borer moth.
Scale insects suck juices from stems which can cause discoloration and drying of leaves. If the scale insects are not eliminated the plant will eventually die. Oyster shell scale, soft brown scale, and San Jose scale are included in the scale species.
As is readily seen, insect pests are indeed “bad bugs.” No garden is without one kind or another and usually many more than one. In our next blog, Part 3 in the series of “The Good and the Bad” the focus will be on Florida insects. And, if you stay with us until Part 4, you will learn some of the ways unwanted insects can be controlled and in some cases eliminated. Chemical treatments will be considered, but the emphasis will be on natural, environmentally friendly methods of control and elimination.