Control of Callosobruchus maculatus Fabricius (Coleoptera: Chrysomelidae: Bruchinae) using triglycerides from animal sources

Abstract

Bioassays were conducted to investigate the insecticidal potentials of beef tallow, fish oil, and pork lard against Callosobruchus maculatus (F.). Doses used were 9.50, 7.25, 5.00, 2.75, and 0.50 mLkg⁻¹ of cowpea. Untreated seeds served as the control. A completely randomised design in factorial arrangement (3 triglycerides × 6 doses) with four replicates was adopted. Results showed that the triglycerides were effective in protecting cowpea seeds against C. maculatus. However, fish oil seems to be the most toxic, with adult mortality surpassing 50% at 72 hours after exposure. All the doses had significant effect on C. maculatus, but additional insecticidal activities were not significant at doses beyond 5.00 mLkg⁻¹. Compared with the control, the triglycerides deterred oviposition by 41.63-99.31%, suppressed F₁ progeny by 55.94-100.00%, reduced seed damage by 50.66-100.00% and germination was not impaired. Our results suggest that fish oil, at 5.00 mLkg⁻¹ of cowpea, could be a potent control alternative for C. maculatus.

Keywords:

• Fish oil
• cowpea
• pest control
• Callosobruchus maculatus
• seed damage
• effective dose

Acknowledgements

The authors are grateful to the Department of Crop and Environmental Protection, FUAM, NG for the provision of laboratory space and facilities, Dr. Samuel Adelani Babarinde, of the Department of Crop and Environmental Protection, Ladoke Akintola University of Technology, Ogbomoso, NG for technical assistance.

Disclosure statement

No potential conflict of interest was reported by the author(s).