Evaluation the efficiency of five inorganic salts on the cowpea beetle Callosobruchus maculatus (Coleoptera : Chrysomelidae)‎ \

Abstract EN

The experiment was conducted to determine the efficacy of five inorganic salts viz., sodium chloride (NaCl), sodium fluoride (NaF), sodium phosphate (NaH2PO4), potassium chloride (KCl) and potassium phosphate (KH2PO4) against cowpea beetle, Callosobruchus maculatus (Fabricius) (Coleoptera: Chrysomelidae) .

The effect of the salts was evaluated based on toxicity, oviposition, adult emergence and percentages of weight loss.

After period 96 hrs, sodium fluoride showed the highest efficiency salt (LC50 0.39 and LC90 1.23%), followed by sodium chloride (0.42 and 2.33%) and potassium phosphate (0.43 and 1.39%).

Sodium phosphate was the least toxic salt against the adult beetle (0.79 and 4.84%), whereas potassium chloride showed moderate toxicity (0.50 and 2.23%).

The mean number of cowpea beetle eggs laid on cowpea seed treated with four concentrations of five inorganic salts, was significantly low as compared with control.

Potassium phosphate and sodium fluoride affected oviposition of C.

maculatus significantly.

Results of adult emergence showed the same trend of oviposition, potassium phosphate and sodium fluoride showed high efficiency on adult emergence, sodium phosphate exhibited the lowest effective salt, whereas potassium chloride and sodium chloride were inbetween.

Generally, based on direct toxicity, effect on oviposition, adult emergence and loss in seed weight, potassium phosphate and sodium fluoride showed great efficiency against the cowpea beetle, C.

maculatus.

So, it may be recommended to use these salts in control programme of this pest.