Description: Turnips are very prone to damage from root maggots. Leaves wilt and growth is stunted. Insect is common, white, root feeding maggot. 1/4" long adult flies emerge from the soil about the time cherries bloom and lay eggs at base of plants in surrounding soil. Legless larvae feeds on host plant for three weeks, riddling the roots with brown tunnels before they pupate Two or three generations can occur each growing season.
Control: Use Diazinon before planting as a soil treatment. Rotate from year to year.
Problem: Flea Beetle Affected Area: Leaf and Root
Description: Tiny holes ?pinholes? chewed in leaves by adult insect.
Adult insects are 1/16" long, hard shelled, shiny, dark-colored beetles that jump when disturbed. Slender, whitish, cylindrical larvae feed in or on roots but root damage is generally minimal.
Control: Dust with Rotenone. Keep debris removed. Rotate location of planting from year to year.
Problem: Aphids Affected Area: Leaf and Stem
Description: Small Insects found on new stems and the underside of the leaf. Usually green. They suck fluids from the plant leaving a honey dew substance behind. Leaves turn pale yellow.
Control: Insecticidal soaps or a strong stream of water. Ladybug beetles are natural predators.
* Thiodan or Diazinon ? more than one application may be required.
A layer of aluminum foil under plants reflects light to underside of leaves and may deter aphids.
* Pesticide use and recommendations for various areas are constantly changing. Check with your County agent for current recommendations.