Evaluation of visual damage thresholds for management of cabbage caterpillars in Florida and Georgia [Trichoplusia ni, Plutella xylostella, Artogeia rapae, cabbage looper, diamondback moth, imported cabbageworm]

Action thresholds consisting of 2.5, 5.0, and 10.0% of plants with new damage, 0.2 and 0.5 new hole or window per plant, and 0.1 medium to large larvae per plant were evaluated at four locations for the management of the cabbage caterpillar complex: cabbage looper, Trichoplusia ni (Huebner), diamondback moth, Plutella xylostella (L.), and imported cabbageworm, Artogeia rapae (L.). The thresholds were successful at two of the four locations. Where successful, all thresholds gave similar results based on marketability. The percentage of new damage thresholds resulted in more insecticide applications than the other thresholds. Weaknesses in the use of the action thresholds were evident in this experiment when the insect pressure was abnormally high, the relative abundance of each species varied, or atypical species were present.