seeds citrus oils (c. sinensis, c. limon and c. reticulata) extraction with hexane in a soxhlet apparatus and through supercritical fluid (co2) were done. besides triglycerides, the oils obtained with hexane comprised volatile compounds such as terpenes and fatty alcohols, esters, and aldehydes. however, the oils obtained by extraction with supercritical fluid presented only triglycerides. these results indicate that the extraction using supercritical fluid presents better selectivity. the activity of the oils on the development of the ant symbiotic fungus, leucoagaricus gongylophorus, showed week activity and the topic insecticide assay showed better activity for the tangerine seed oil.