Predation by Hunting Spiders on Citrus Leafminer, Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae)

Abstract

Feeding efficiency of the three species of hunting spiders, Chiracanthium inclusum Hentz, Hibana velox (Becker), and Trachelas volutus (Gertsch), was investigated in laboratory, greenhouse, and field-cage experiments. Results of the laboratory feeding efficiency tests showed that the predation rates of these hunting spiders can be ranked as follows: H. velox > C. inclusum > T. volutus. A similar trend of predation rates was obtained from the feeding efficiency test under greenhouse conditions. The predation efficiency of H. velox was further tested in a field-cage experiment because it was found to be a more efficient predator than C. inclusum and T. volutus from the laboratory and greenhouse feeding efficiency tests. The results of the field-cage experiment indicated that as the population density of the citrus leafminer increases, the number of citrus leafminer consumed by H. velox also increases. In addition, significantly more citrus leafminer larvae were consumed when two to three H. velox were present inside the cage than when only one H. velox was present.