AbstractAcid lime, Citrus aurantifolia is one of the most consumed citrus fruits in India and is severely affected by the citrus butterfly, Papilio demoleus. The effectiveness of entomopathogenic nematodes (EPN) viz., Heterorhabditis indica and Steinernema glaseri was examined against P. demoleus on C. aurantifolia under greenhouse and field conditions. The EPNs were found effective in controlling the citrus butterfly at all dosages used in the study. The insect mortality increased with an increase in the dose level and exposure time. The highest mortality in the insect (83.7%) occurred with H. indica @ 5 x 109 infective juveniles (IJ), followed by 80.6% with S. glaseri @ 5 x 109 IJ after 72 hrs of treatment under greenhouse conditions. The leaf damage was 19.6% with H. indica @ 5 x 109 IJ. In other treatments, the damage ranged from 28.0 to 43.0 %. In the field, highest mortality in P. demoleus was recorded with H. indica @ 5 x 109 IJ (84.6 %), followed by S. glaseri @ 5 x 109 IJ (82.9%) after 72 hrs of exposure. The least mortality was observed with S. glaseri @ 1.25 x 109 IJ (72.2%). The study demonstrates that both EPN species, particularly H. indica, greatly suppressed P. demoleus populations, and significantly reduced the leaf damage. However, the efficacy was found to be lesser under field condition in comparison to the greenhouse test.
Santhi et al. (Wed,) studied this question.