Abstract

The concern for environmental safety and increased development of resistance to chemical insecticides by major arthropod vectors is rekindling interest in the search for botanical products that may be used against major vectors. Essential oils of 11 local plants were evaluated for larvicidal activities against laboratory colonies ofAnopheles arabiensis and Aedes aegypti early fourth instar larvae. Those oils which induced higher larvicidal activities in the laboratory were also evaluated in the field. In the laboratory, the LC50 values of the oils ranged from 17.5 to 85.9 ppm againstA. arabiensis and from 9.1 to 67.8 ppm against A. aegypti. Similarly, the LC90values of the oils ranged from 33.2 to 128.4 ppm and from 14.3 to 96.4 ppm against the respective mosquito species. However, Chenopodium ambrosioides Linnaeus oil with LC50 of 17.5 and 9.1 ppm against A. arabiensis and A. aegypti, respectively, and Ocimum lamiifolium Hochst oil with LC 50 of 20.9 and 8.6 ppm against A. arabiensis and A. aegypti, respectively, were the most effective oils. A. aegypti,were more sensitive to most oils than A. arabiensis larvae. Of the five essential oils which exhibited relatively strong larvicidal effects in the laboratory and further tested in the field against wild-collected anopheline larvae, the LC50 and LC 90 values ranged from 35 to 110 ppm, and from 63.7 to 162.9 ppm, respectively. O. lamiifolium and C. ambrosioides still induced the highest larvicidal effects with LC50= 34 ppm; LC90 = 97. 9 ppm and LC50 = 47.3 ppm; LC90 = 97.9 ppm, respectively. However, it was revealed that laboratory bred mosquito larvae were more sensitive to the essential oils than wild-collected larvae. Key words: Anopheles arabiensis, Aedes aegypti, essential oils, botanical larvicides.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.