Control Flea Beetles Organically
by Marilyn Pokorney
Flea beetles are more of a nuisance than a threat to a healthy garden. But if found on seedlings they can kill the plants. On larger, well-established plants they do little harm. However, in corn and potatoes flea beetles can transmit serious diseases. Potato beetles may transmit early blight. Corn flea beetles can transmit a bacterium called Stewart`s Wilt.
The adults are tiny ranging from 1/16 to 1/4 inch long and are various colors, including black, greenish or bluish black, green or yellow. They have enlarged hind legs which enable them to jump like fleas. The larvae are slender, white grubs which feed on roots, tubers, and lower stems underground.
Flea beetles overwinter as adults among debris in or near fields or host plants. At the end of the year remove plants and surface debris to remove hibernating material.
Eggs are deposited in soil near the bases of host plants and may require a week or more to hatch. Treating the soil with beneficial nematodes can help control the larvae.
Plant later than usual so warmer temperatures can help plants to outgrow the feeding beetles.
Use rotation planting. Don`t plant the same crop in the same bed the next year.
Dusting plants with Diatomaceous earth, ashes, ground limestone, or even flour has been used successfully.
Homemade sticky traps work well. Flea beetles are attracted to the colors of white and yellow. For white traps cut milk jugs sides, other white plastic containers, or styrofoam meat trays into pieces about four to six inches square. Coat the pieces with something sticky. Petroleum jelly, lard, grease and non-setting glue have all been found useful. Wash off the captured beetles and reuse.
For a yellow trap take flypaper and attach it to something solid like a lightweight board that can be set upright or heavy cardboard attached to a wooden stake.
Some people have found beer traps successful.
For plants that don`t need insect pollination, cover beds of seedlings with row covers or gauze-like material to prevent beetle entry.
Flea beetles like hot, dry soil. Misting or fine watering to keep the top soil moist helps as do mulches.
Plant beets, carrots, chard, radishes, spinach and other cool-loving crops a couple of weeks later. These also make effective trap crops to protect other plants.
Natural repellents consist of nicotinia, catnip, and wormwood. Make a tea and spray the affected crop. Another natural repellent is a garlic and hot pepper spray. Flea beetles hate this combination and will quickly leave. Reapply after watering or rain.
If all else fails, insecticides make from plants like Rotenone can be applied.
For more information on organic flea beetle and insect control:
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