ANTIMITE ACTIVITY OF Capsicum chinense L. FRUIT EXTRACT AGAINST Tetranychus urticae KOCH (ACARI: TETRANYCHIDAE)
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Abstract
Two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) is a destructive pest that causes significant damage to vegetables, flowers, fruits and ornamental crops worldwide. The acaricidal, ovicidal, repellent and oviposition deterrent activities of Capsicum chinense L. against T. urticae were evaluated under laboratory conditions. The ethanolic fruit extract of C. chinense was tested at 0.25, 0.5, 1.0, 1.5 and 2.0% concentrations. The result showed that all the concentrations had toxic, ovicidal activity, repellent, and oviposition deterrent effects on T. urticae. With increasing doses and time, the mortality percentage of adults and nymphs (after 24, 48 and 72 h) gradually increased. Extracts at 2.0% concentration showed the highest mortality of adults (80.0%) and nymphs (93.0%) after 72 h exposure. Mortality was greater in nymphs (29.0 – 93.0%) than in adult females (12.0 – 80.0%) when treated with different concentrations. Ovicidal activity (after 7 days) results showed that the lowest egg hatchability was (59.0%) at 2% concentration with the highest corresponding efficacy (37.23%). The LD50 values for adults were 3.39, 2.24 and 0.50 and for nymphs were 1.29, 0.38 and 0.23 after 24 h, 48 h and 72 h respectively whereas for eggs were 5.63 after 7days. The ethanolic fruit extract of C. chinense was also found to be effective as a repellent and oviposition deterrence against T. urticae, with the repellency and oviposition deterrent rate increasing with doses and time, and showed a significant effect at the highest concentration (2.0%) in both cases. The oviposition deterrent was shown to be more prominent than the repellent effect. According to the findings, the ethanolic fruit extract of C. chinense has great potential to develop as a bio-acaricide for T. urticae management.
