Mosquitoes are responsible for more diseases than any other group of arthropods. The mosquito Aedes aegypti is the world's most important vector of yellow fever and dengue viruses. Plants and lichens have evolved an array of defense mechanisms to protect themselves against the wide variety of pathogens and pests with which they are confronted. Included in these defense mechanisms are the proteins and secondary metabolites. Attempts to eradicate mosquitoes have proven unsuccessful requiring search for more powerful alternatives. O objective of this work is to purify the toxic proteins and secondary metabolites from the plant Phoradendron quadrangulare and from the lichen Teloschistes flavicans against Ae. Aegypti larvae. Aqueous and methanol extracts of the P.  quadrangulare caused 100% of mortality in Ae. aegypti larvae. Aqueous extract was submitted to an ion-exchange chromatography (DEAE-Sepharose). The peak eluted by the equilibrium buffer (Tris-HCl 20mM pH=8,0) caused 80% of larval mortality.  In the other hand, the methanol extract was further fractioned resulting in three fractions:  dichloromethane, ethyl acetate and the methanol/water. The fraction methanol/water promoted 100% of mortality.  Methanol extracts from the lichen T. flavicans was fractioned and five fractions were obtained and tested. Two fractions presented high larval mortality: etil acetate and dichloromethane.  By Thin Layer Chromatography (TLC) was verified that both fractions had similar composition. However, the solvent dichloromethane was more efficient to promote the extraction of the secondary metabolites. Chromatography procedures will be made to further purify the active substances from the both extracts. Synergic effects of these substances against  Ae. aegypti larvae will be investigated.