Physical and Mechanical Control

Sometimes the most efficient way to kill insects is to stomp on them, literally or figuratively! Physical or mechanical control methods can be as simple as hand-picking the bagworms from a juniper bush, cutting tent caterpillars out of a shade tree, or using a fly swatter and window screens to keep your home free of flying insects. At the other end of the technology spectrum are the electronic bug killers. These high-tech fly swatters produce an ultraviolet glow that attracts flying insects to an untimely death on an electrified grid. Although bug zappers probably kill more beneficial insects than pests, their owners seem to sleep better at night with the reassuring sound of bugs sizzling on the grill. From its inception in the late 1970's, the market for these devices has grown into an industry with annual sales approaching $100 million.
Yellowsticky trap Simple entrapment devices work quite well to control some types of insects. Fly paper and sticky boards, for example, are often used in greenhouses to control whiteflies or leafhoppers. Fruit and shade trees can be protected from various pests (e.g., plum curculio, gypsy moth, and codling moth) by tying a band of folded burlap around the trunk with its open side facing down. As insects climb up the trunk, they are waylaid in the folds of burlap which can be treated with insecticide or inspected daily to collect the pests. Ditches or moats with steep vertical walls are occasionally used as barriers to keep crawling insects (e.g., chinch bugs or whitefringed beetles) from migrating out of one field and into another. Pitfall traps are dug at 3-5 meter intervals in the ditch and filled with kerosene or creosote to kill the pests.