Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: November 1, 2009
Publication Date: N/A
Technical Abstract: More than 1 million human cases of Chikungunya were recently reported in India. Aedes aegypti (the yellow fever mosquito) is an important disease vector in India where it transmits Chikungunya, dengue, and yellow fever viruses to humans. In this study, scientists from Bharathiar University in Coimbatore and ARS in Gainesville, FL determined the larvicidal effects of extracts of Orthosiphon thymiflorus, a member of the mint family, against Aedes aegypti. The extracts of O. thymiflorus caused morbidity and delayed development in mosquito larvae and prevented adult emergence. When combined with a microbial pesticide (Bacillus thuringiensis israelensis [Bti]), the extract caused high mortality in mosquito larvae. Field trials of the extract combined with a microbial pesticide showed the former to significantly increase larval mortality (compared with the microbial pesticide alone) when applied to the water surface in cisterns, discarded tires, and mud pots. The results suggest that O. thymiflora extracts synergize with Bti-produced toxins to increase mosquito mortality and that such plant extracts are a potentially important source of natural product-based mosquitocides.