SCREENING OF ASTERACEAE (COMPOSITAE) PLANT-EXTRACTS FOR LARVICIDAL ACTIVITY AGAINST AEDES-FLUVIATILIS (DIPTERA, CULICIDAE)

Ethanol extracts of 83 plants species belonging to the Asteraceae (Com positae) family, collected in the State of Minas Gerais, Brazil, were tested for larvicidal activity against the mosquito Aedes fluviatilis - Diptera. Culicidae). The extract from Tagetes minuta was the most ac tive with a LC90 of 1.5 mg/l and LC50 of 1.0 mg/l. This plant has been the object of several studies by other groups and its active componen ts have already been identified as thiophene derivatives, a class of c ompounds present in man), Asteraceae species. The extract of Eclipta p aniculata was also significantly active, with a LC90 of 17.2 mg/l and LC50 of 3.3 mg/l and no previous studies on its larvicidal activity or chemical composition could be found in the literature. Extracts of Ac hryrocline satureoides, Gnaphalium spicatum, Senecio brasiliensis, Tri xis vauthieri Tagetes patula and Vernonia ammophila were less active, killing more than 50% of the larvae only at the higher dose tested (10 0 mg/l).