Morphometric Analysis of the Developmental Stages and Insecticidal Efficacy of Three Botanical Oils Against Adult Callosobruchus analis

Abstract

The developmental stages of Callosobruchus analis were observed under laboratory conditions at 28 ± 2 °C and 72 ± 5% relative humidity. The results showed that female C. analis began to lay eggs within 24 hours and have an oviposition period of 8.50 ± 0.70 days and an average of 13.00 ± 0.50 eggs were laid by individual C. analis throughout their lifetime. The mean developmental periods from egg to larva and larva to pupa were observed to be 8.50 ± 0.79 and 4.50 ± 0.70 days, respectively. The unmated bruchids were observed to have lived longer than the mated bruchids as the unmated bruchids lifespan was on average 10.50 ± 0.81 days, as opposed to 2.50 ± 0.75 days for mated females. Adult male C. analis have an average antenna length of 2.96 ± 0.08 mm which is slightly longer than 2.42 ± 0.12 mm on average for female bruchids. The three botanical oil extracts from Capsicum frutescens, Anacardium occidentale and Xylopia aethiopica used at 10.0% concentration were not effective, as none of them resulted in a mortality rate of 50% when recorded 3 days after treatment.

Keywords

• morphometric records
• mortality
• plant oils