UTILIZATION OF TWO LOCALLY SOURCED PLANT POWDERS AS PRESERVATIVES AGAINST SITOPHILUS ZEAMAIS MOTSCHULSKY (COLEOPTERA: CURCULIONIDAE) SUSCEPTIBILITY

Abstract

Due to the unfavourable and dangerous effects of conventional insecticides, protecting stored food grains against insect pest infestation has become a significant issue. Against this back drop, a laboratory experiment arranged in Complete Randomised Design was conducted to evaluate the insecticidal activity of Bridellia micrantha and Chasmanthra dependens against S. zeamais infestation on stored maize. Twenty grams (20g) maize seeds were admixed with 0.5, 1.0, 1.5 and 2.0g of each of the treatments in triplicates. Results showed that both plant materials caused significant adult mortality, suppressed infestation (9.45 – 21.71%), seed damage (6.88 – 21.71%) and reduced weight loss (5.79 – 34.01%) compared to control with increasing dosage rates. However, none of the plant powders was able to guarantee 100% protection against infestation, but both plant powders showed a significant promising effect in suppressing S. zeamais susceptibility to infestation and seed damage. The results obtained suggest that B. micrantha and C. dependens may be explored as a good potential botanical source insecticide as effective and suitable alternative to synthetic insecticides for S. zeamais infestation management on stored maize seeds due to their toxicity, oviposition deterrent, ovicidal activity and seed damage suppression.

Keywords

• adult mortality
• infestation
• insecticidal activity
• oviposition deterrent
• promising effect
• susceptibility