The following list of pest descriptions and control measures provides a good starting point for tackling pest control in gardens throughout the United States and Canada. Control solutions are listed in order of environmental friendliness. Botanical sprays, which can have detrimental effects on beneficial insects and other animals, should be used only as a last resort.
1. Aphids (many species).
Tiny, pear-shaped; long antennae; two tubes projecting rearward from abdomen.
Host/Range: Most fruits and vegetables, flowers, ornamentals, shade trees. Found throughout North America.
Damage: Aphids suck plant sap, causing foliage to distort and leaves to drop; honeydew excreted on leaves supports sooty mold growth; feeding spreads viral diseases.
Control: Wash plants with strong spray of water; encourage native predators and parasites such as aphid midges, lacewings, and lady beetles; when feasible, cover plants with floating row cover; apply hot-pepper or garlic repellent sprays; for severe problems, apply horticultural oil, insecticidal soap, or neem.
2. Cabbage maggot (Delia radicum)
Adults: 1⁄4-inch gray flies. Larvae: white, tapering maggots.
Host/Range: Cabbage-family crops. Found throughout North America.
Damage: Maggots tunnel in roots, killing plants directly or by creating entryways for disease organisms.
Control: Apply floating row covers; set out transplants through slits in tar-paper squares; avoid first generation by delaying planting; apply parasitic nematodes around roots; burn roots from harvested plants; mound wood ashes or red pepper dust around stems.