Biological Studies of a Predator, Sycanus indagator II. Field Survival and Predation Potential

Abstract

Studies of Pseudoplusia includens (Walker) larvae as prey and an imported predator, Sycanus indagator (Stal) were made in field cages over soybean plants. Predation by 3rd and 4th nymphal instars accounted for 6 to 20% larval mortality after 2 days. Other tests showed about equal results 4 days after introduction of prey and predator on soybeans. Survival of S. indagator in soybean fields was below 50% and nymphs consumed about 1 soybean looper/day with a mean of 29 larvae during predator development. Egg hatch for S. indagator was 93% in the laboratory and was 42% when egg masses were pinned to soybean plants in the field. Predation by S. indagator on cabbage looper larvae, Trichoplusia ni (Hubner), ranged from 29 to 79% in field cages over cabbage plants. Observations of S. indagator feeding on T. ni larvae on cabbage plants showed 48.5% of the larvae were successfully attacked in cages compared to 69% in plastic containers. Survival and larval consumption was too low to suggest success of this predator in Florida cabbage or soybean fields.