Production of a Non-Toxic Plant-Based Bio-Remediant to Repel Mosquitoes and Prevent Allergy Caused by the Bite of African malaria mosquito (Anopheles gambiae)

Abstract

Increasingly mosquitoes are becoming more resistant to synthetic repellents particularly pyrethroids and DEET (N,N-Dimethyl-meta toluamide). This calls for development of alternative Bio-repellents that are biodegradable and non-toxic. Therefore, a study was carried out to produce a non-toxic plant-based bio-remediant against the allergy caused by the bite of Anopheles gambiae.  Mosquitoes were reared under laboratory conditions in wooden cages according to renowned methods. Tests were performed in cages, with a 12:12 (Light: Dark) photoperiod and controlled temperatures of about 27^oC. Knockdown effects of the repellent formulations and susceptibility tests were done according to WHO protocols to establish the stability of the repellent cream, sensitivity of human skin to the repellent, and effectiveness of the repellent to prevent mosquito bites. Peppermint oil had the lowest mean value of mosquitoes aligned to the left side of volunteers, with 2.5, and the highest was 21.0 for turmeric oil. ANOVA indicated a significant difference between the means (p>0.05). Peppermint oil had the highest repellency of 95% and the lowest was 21% for turmeric oil. A cream was formulated by mixing the oils of peppermint and ginger, and it gave 4 hours of protection. Comparison of Knockdown times (KdT50 and KdT90), showed that peppermint oil inflicted 99% mortality (ED₅₀ = 0.04), equivalent to deltamethrin, while ginger oil achieved a high mortality of 80% (ED₅₀ = 0.05). It is recommended that the cream be utilised as a repellent against mosquito bite allergy and for the control of malaria.