LARVICIDAL AND REPELLENT ACTIVITIES OF ETHANOLIC EXTRACT OF ARTEMISIA ANNUA (ASTERACEAE) AND CARICA PAPAYA LINN (CARICACEAE) LEAVES IN MALARIA VECTOR CONTROL IN DOGBO DISTRICT IN SOUTH-WESTERN BENIN, WEST AFRICA

Nazaire Aïzoun*, Gustave Djèdatin, Omédine Koukoui and Daniel Chougourou

ABSTRACT

Background: The use of chemical insecticides causes important damages to environment and human health and there is a need to search for alternative solutions. Objective: The current study was aimed to evaluate the larvicidal and repellent activities of ethanolic extract of Artemisia annua (Asteraceae) and Carica papaya Linn. (Caricaceae) leaves on larvae of Anopheles gambiae s.l mosquitoes in malaria vector control in Dogbo district in south-western Republic of Benin. Methodology: Larvae of Anopheles gambiae s.l mosquitoes were collected from breeding sites using the dipping method from April to July 2022 during the great rainy season in Dogbo district. A batch of twenty (20) larvae of fourth instar were exposed to ethanolic extracts of Artemisia annua and Carica papaya Linn leaves with different concentrations of 1 mg/liter, 2mg/liter, 3 mg/liter, 4 mg/liter and 5 mg/liter in some glass jars or plastic test cups of same dimensions covered with small cutting untreated net and in some control jars containing no trace of these ethanolic extracts. Larval mortality was recorded after 24 hours, 48 hours and 72hours exposure. Repellent activities of ethanolic extracts of both tree leaves were also measured. Phytochemical screening was also done with the leaves of both trees. Results: The results showed that the concentration of 1 mg/liter of ethanolic extracts of Artemisia annua and Carica papaya Linn kills 100% of Anopheles gambiae s.l. larvae after only 24 hours exposure. The leaves of both trees have repellent effects on Anopheles gambiae sensu lato adult mosquitoes. Several compounds are present in leaves of both trees such as alcaloids, tannins, flavonoïds and so on, and contributed to the mortality of larvae of Anopheles gambiae sensu lato. Conclusion: Both ethanolic extracts of Artemisia annua and Carica papaya leaves have larvicidal and repellent activities against Anopheles gambiae sensu lato mosquitoes.

Keywords: Artemisia annua, Carica papaya Linn, malaria control, Benin.