title: Malathion resistance in Aedes aegypti of Puerto Rico induced by selection pressure on larvae.
abstract: A high level of tolerance to malathion occurred in Aedes aegypti larvae of San Juan, Puerto Rico in 1978. The tolerance was 7-fold when compared with a susceptible strain. Malathion selection pressure in the laboratory on this tolerant strain resulted in resistance after only six filial generations. The resistance of the F6 generation as 10-fold when compared with the strain as it was in the field in 1969, and 19-fold when compared with a susceptible laboratory strain. The results, together with those of previous studies suggest that resistance may be a major factor in situations in Puerto Rico in which malathion failed to control Ae. aegypti.
mesh_terms: D000330:Aedes / Q000235:genetics*; D000818:Animals; D007305:Insecticide Resistance; D007814:Larva; D008294:Malathion; D011647:Puerto Rico; D012641:Selection, Genetic
chemical_list: D008294:Malathion