Capsicum chinensis (Hot Pepper) Powder Larvicidal Activity Against Mosquitoes Larvae in Lafia Local Government Area, Nasarawa State, Nigeria

Abstract

Mosquitoes spread more diseases than other known arthropod and have shown resistance to conventional insecticides despite several control efforts, prompting the need to explore alternative control measures such as the use of bio-larvicides which are environmentally friendly. To this end, a study on larvicidal activity of the powder of Capsicum chinensis against mosquitoes larvae in Lafia Local Government Area, Nasarawa State, Nigeria was carried out through collection of wild field mosquitoes larvae from April to July 2018. Fresh Capsicum chinensis fruits were collected from farmlands and dried under room temperature and further processed to fine powder from which varying concentrations were used against the larvae. The larvae were exposed at 24, 48 and 72 hours, respectively. Anopheles gambiae larvae were susceptible (100% mortality) to the various concentrations of the powder at the end of the 72 hours exposure period while Culex quinquefasciatus were resistant (0% mortality). There was a very high significant difference (P < 0.0001) in mortality rate of An. gambiae larvae in relation to concentrations while there was no significant difference (P = 1) in mortality rate of Cx. quinquefasciatus across concentrations. LD 50 and LD 90 values for An. gambiae at 24 hours were 21.88mg/ mL and 52.48mg/mL respectively; 16.98mg/mL and 38.90mg/mL respectively at 48 hours and 13.80mg/mL and 30.19mg/mL respectively ay 72 hours. This study shows that Capsicum chinensis is a promising bio-larvicide for controlling An. gambiae. Also, Cx. quinquefasciatus may possibly require higher multiple doses of Capsicum chinensis to influence mortality.