Effect of Dennettia Tripetala Powder and Reduced Rates of Pirimiphos-Methyl Singly and Combined in Management of Callosobruchus Maculatus (F.) [Coleoptera: Bruchidae]

Dennettia tripetala powder and reduced rates of pirimiphos-methyl dust were tested on cowpea against C.
maculatus for their effective management. The study was conducted under ambient conditions of 250C – 280C
and 65% - 75% relative humidity in the laboratory for a period of 3 months. Powder of D. tripetala and dust of
pirimiphos-methyl were tested sole at 0.4g and 0.1g per 20g of cowpea seeds respectively while various
combinations at 0.2g DT + 0.05g PM, 0.2g DT+ 0.025g PM, and 0.2g DT + 0.0013g PM were also tested on 20g
of cowpea seed. D. tripetala powder was more effective at 0.4g when applied singly. Adult mortality of more
than 80% occurred in less than 3 days. It also caused a significant reduction in oviposition, adult emergence and
weight loss after emergence. Effect of sole application of pirimiphos-methyl dust at 0.1g per 20g of cowpea seed
was less when compared with 0.4g of D. tripetala. The combined treatments of D. tripetala and pirimiphosmethyl
slightly reduce adult emergence and weight loss. This study revealed better performance of D. tripetala
powder when applied singly over reduced rates or even when combined with pirimiphos-methyl against cowpea
seed beetle.