उष्णकटिबंधीय रोग और सार्वजनिक स्वास्थ्य जर्नल

अमूर्त

Mosquitocidal Properties of Three Essential Oil Plants Tested against Anopheles gambiae Sensu Stricto, Giles 1902 (Diptera: Culicidae,Anophelinae), Main Malarial Vector

Nanga Woulsou Maurice, Saotoing Pierre, Nukenine Elias Nchiwan

Objective: The efficacy of essential oils of Lantana camara, Ricinus comminus and Securidaca longepedunculata; three medicinal plants from Northern Cameroon has been assessed against malarial vector, Anopheles gambiae Sensu Stricto (An. gambiae s.s.). The synthetic chemicals Delthamethrin (DEET), was used as positive control, and water and hexan were used as negative control.

Methods: The insecticidal effect of the essential oils from leaves was tested in old adult An. gambiae s.s. aged three to four days at five concentrations (35, 45, 55, 100 and 150 ppm). The adult mortality was observed after 24 hours under the laboratory conditions according to WHO (2020) bottle method.

Results: All of bioassay; the maximum efficacy was recorded in the three essential oils after 24 hours exposure. The LC50 values against adults of An. gambiae s.s. were 66.72 ppm, 72.67 ppm, 79.63 ppm and 59.49 ppm, respectively for Securidaca longepedunculata, Lantana camara, Ricinus comminus and T+ (DEET). However there was no significant difference between these letal concentrations (P ≤ 0.05). Elswhere, the LC95 values were 111.40 ppm, 113.4 ppm 1, 105.35 ppm and 99.08 ppm for L. camara, R. comminus, S. longepedunculata, and DEET respectively. Six percent (6%) mortality was observed in negative control (hexan). The HC50 were 3h40, 4h38 and 7h34 for S. longepedunculat; L. camara and R. comminus respectively. The HC50 of positive control was 1h49. Between DEET HC50 and HC50 of all essential oils, difference was significant.

Conclusion: At the end of our experiments, we realized that there are local means to fight against vector agent of malaria. Essential oils of Lantana camara, Ricinus comminus and Securidaca longepedunculata are potential for controlling malarial vector.