Flea beetles relish many of the same vegetable crops organic gardeners grow, but their diminutive size often allows their destruction to progress unchecked until the plants are hobbled or killed. With close monitoring, gardeners can control these insects early using natural, organic pest control methods.
When vegetable gardeners discover flea beetle damage in their organic gardens, the only evidence may be a smattering of tiny holes in the leaves of their eggplants, peppers, broccoli, beans, cabbage, potatoes, and spinach. Flea beetles are about the size of a pinhead, with an appearance and movement similar to the fleas that plague cats and dogs.
Flea beetles are most active early in the growing season, when they emerge from winter hibernation from plant debris. Although flea beetles make tiny holes, their large numbers can quickly cause enough damage to lead to plant death. The tiny white grubs further the pest’s dirty work underground, feeding on vegetable plant roots. Adding insult to injury, flea beetles can transmit diseases to the vegetable garden, such as potato blight and corn wilt.
Hot Pepper Wax is an effective, natural organic spray that gardeners can use to deter flea beetles. The spray consists of cayenne pepper concentrate mixed with food grade paraffin wax, which extends the product through rain and irrigation. Gardeners can easily wash the wax away at harvest time.
Pyrethrins are derived from chrysanthemum flowers, and function as a broad-spectrum organic pesticide spray against many pests, including flea beetles.
Gardeners must take care not to purchase sprays made from manufactured pyrethroids, which are structurally similar to pyrethrins but are harmful to mammals and not considered organic.
Organic gardeners with repeat flea beetle offenders can stop the destructive cycle with parasitic nematodes. These microscopic worms migrate through moist soil searching for their prey, which includes many types of garden grub pests.
Gardeners can shop for the commercially available Heterorhabditis bacteriophora, which targets flea beetles. The nematodes arrive in an impregnated sponge, which gardeners can add to a backpack sprayer for application.
Floating row covers are effective flea beetle repellents, provided the gardener install them at the same time the vegetables plants go into the garden.
Gardeners who start seeds directly in the garden should erect row cover barriers before germination, or risk the inadvertent creation of a flea beetle habitat beneath the fabric. Mature plants are less susceptible to flea beetle damage, so remove the covers to allow for pollination when flowers appear.