Susceptibility of Hide Beetle, Dermestes maculatus (De Geer) [Coleoptera: Dermestidae] to Powder and Extract of Two Species of Capsicum Fruits on Smoke-Dried Catfish, Clarias gariepinus (Burchell) [Pisces: Clariidae

Abstract

Meat consumption is expensive and highly blood pressure prone amongst elderly Nigerians. In lieu of this, smoke-dried catfish consumption becomes a better alternative in reducing cholesterols that cause high blood pressure amongst elders. However, the nutritional values and health benefits of smoke-dried catfish have greatly reduced during postharvest due to hide beetle, Dermestes maculatus infestation. Susceptibility of hide beetle, Dermestes maculatus to Capsicum annum, and Capsicum frutescens fruits onsmoke-dried catfish, claria gariepinns were investigated in the laboratory at mean temperature and relative humidity of 29.6oC and 76.8%, respectively. Capsicum fruits powders were admixed at 2g, 4g, 6g, 8g, and 10g/50g of smoke-dried catfish while extracts were tested at concentrations 2%, 4%, 6%, 8% and 10% for mortality, adult emergence, progeny inhibition, and weight loss effects. Capsicum frutescens powder was more toxic to D. maculatus larvae. It achieved 100% larvae mortality throughout the period of exposure at dose 10.0g. Capsicum frutescens was also found to be more toxic than C. annum to D. maculatus adult that caused 82.50% mortality at concentration 10.0 g within 24 h of application and were significantly different (P < 0.05) from all other treatments within the same period. The two plant powders were able to prevent adult emergence except for the powder of C. annum which recorded 32.50% adult emergence at concentration 2.0 g and was significantly different (P<0.05) from other treatments. A similar trend of results was observed on the toxicity of fruits extracts to D. maculatus larvae and adults. Capsicum frutescens was more lethal to D. maculatus larvae. The plant materials significantly reduced adult emergence and weight loss when compared with the control experiment. Capsicum annum and C. frutescens offered an effective protection against infestation and damage cause by D. maculatus on smoke-dried fish.