| Major Insects | Type of Damages | Control |
Aphids
|
-Pressure on seedlings can reduce vigor and stunt plants -Transmit viruses to leafy vegetables, including lettuce mosaic and bidens mottle mosaic. |
-Destruction of crop residues are important for control of all caterpillar, aphid and leafminer pests of leafy vegetables -Natural enemies may control these aphids |
Leaf miners
|
-Larvae mining the leaves |
Disk fields to destroy and cover infested crop residues as soon as possible after harvest to reduce infestation of neighboring fields by emerging adults. -Tiny wasp parasitoids attack the larvae and are quite effective |
Cutworms
|
-Cutworms usually cut seedlings off at or just below the soil line | -Crop rotation -Natural enemies such as parasitic wasps, flies and predacious ground beetles -Insecticides are available for at-plant, pre- and post-emergence broadcast |
Thrips
|
-Large numbers of thrips can damage leaves by excessive feeding -bronzing, downward leaf curling, and extensive tissue necrosis |
-Control weeds prior to their flowering cycle -Use insect and mite predators |
Cabbage looper
|
-Young larvae feed on the lower surface of outer leaves leaving a windowpane of the upper leaf surface. -Older larvae feed through the leaves leaving large holes that frequently penetrate into the heads |
-Looper larvae and pupae are attacked by a large number of insect predators and parasitoids -Insecticides are available for foliar applications |
Armyworm
|
-Can damage lettuce seedlings by feeding in the crown and chewing away the midrib and growing point | -Disc fields immediately following harvest to kill larvae and pupae. Destroy weeds along field borders |
Grasshopper and Cricket
|
-Grasshoppers eat lettuce leaves -Criket can quickly destroy most of a field by eating seedlings; a number of plants in a row
|
-Sweep hand net reduce populations -Use of living insect pathogens as biocontrol agents (Nosema locustae spores ) -Apply chemical treatment for crikets |
