SciELO - Scientific Electronic Library Online

vol.32 issue1Succession of Scarabaeidae on bovine dung in Itumbiara, Goiás, Brazil author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand




Related links


Neotropical Entomology

Print version ISSN 1519-566XOn-line version ISSN 1678-8052


SALMERON, Eloisa  and  OMOTO, Celso. Characterization of deltamethrin and chlorpyirifos resistance in Blattella germanica (L.) (Dictyoptera: Blattellidae) and Cross-Resistance relationships to fipronil. Neotrop. Entomol. [online]. 2003, vol.32, n.1, pp.177-181. ISSN 1519-566X.

The objectives of this study were to characterize the resistance of Blattella germanica (L.) to deltamethrin and chlorpyrifos and to evaluate their cross-resistance relationships to fipronil. The isolation of resistance was done under laboratory conditions from field-collected populations. Three cycles of selection pressure with deltamethrin and chlorpyrifos were conducted to obtain the Deltamethrin-R and Chlorpyrifos-R strains. The estimated LD50 for the susceptible (SUS) strain was 0.24 (IC 95% 0.18 - 0.31) and for Deltamethrin-R strain was 10.26 (IC 95% 7.28 - 14.17) mg deltametrina/mg. For chlorpyrifos, LD50 for the SUS strain was 4.16 (IC 95% 2.80 - 5.33) and for Chlorpyrifos-R strain was 24.98 (IC 95% 20.90 - 30.28) mg chlorpyrifos/mg. Therefore, the resistance ratios were approximately 43- and 6-fold to deltamethrin and chlorpyrifos, respectively. A low intensity of cross-resistance (approximately 2-fold) was observed between fipronil and the insecticides deltamethrin and chlorpyrifos. Thus, fipronil can be used as a good candidate in resistance management programs of B. germanica to deltamethrin and chlorpyrifos.

Keywords : Insecta; German cockroach; urban pest; insecticide.

        · abstract in Portuguese     · text in Portuguese     · Portuguese ( pdf epdf )


Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License