Susceptibility Levels of Periplaneta Americana (Dyctioptera: Blattidae) To Two Different Insecticides in Populations From Southwest Colombia
  Key Words  
  Biochemical assay, insecticide resistance, organophosphate, phyrethroid
  Gloria Isabel Jaramillo, Ranulfo Gonzalez, Clara Ocampo and Graham Moores
  The levels of susceptibility to a pyrethroid (deltamethrin) and an organophosphate (malathion) and metabolic enzyme activities of adult Periplaneta americana females from populations collected in three cities of south western Colombia (Cali, Popayan, and Buenaventura), were characterized by bottle bioassays and biochemical tests. All populations were susceptible to both insecticides, with resistance ratios(RR) lower than 3. Although the control (Univalle) population, presented the lowest protein level, perhaps due to the smaller size and weight of the individuals kept in laboratory conditions for a long time, levels of esterases and oxidases did not show differences between the populations evaluated. Such baseline data will be valuable for reference and could help to control problems that arise in this pest in the future.