Induction of insecticide tolerance in German cockroach (Dictyoptera: Blattellidae) due to sublethal doses of imidacloprid, indoxacarb, and lambda-cyhalothrin.

The German cockroach is a global urban pest that causes serious public health problems. The induced levels of insecticide tolerance in the first-generation strains of German cockroach from previous topical treatment of laboratory colonies with LD10 or LD25 doses of imidacloprid, indoxacarb, or lambda-cyhalothrin four times with seven-day interval between each were investigated. Our results showed that the resistant ratios (RR50) at LD50, cytochrome P450 content, and glutathione S-transferase (GSTs) activity in adult cockroaches increased in the first generation when compared to the parental (field) and susceptible strains (SS). Therefore, cockroaches treated with insecticidal sublethal dose are likely to have more insecticide resistance in comparison to untreated ones. [ABSTRACT FROM AUTHOR]