search
for
 About Bioline  All Journals  Testimonials  Membership  News  Donations


Memórias do Instituto Oswaldo Cruz
Fundação Oswaldo Cruz, Fiocruz
ISSN: 1678-8060
EISSN: 1678-8060
Vol. 108, No. 7, 2013, pp. 894-900
Bioline Code: oc13149
Full paper language: English
Document type: Research Article
Document available free of charge

Memórias do Instituto Oswaldo Cruz, Vol. 108, No. 7, 2013, pp. 894-900

 en Monitoring resistance to Bacillus thuringiensis check for this species in other resources subsp. israelensis in the field by performing bioassays with each Cry toxin separately
Tetreau, Guillaume; Stalinski, Renaud; David, Jean-Philippe & Després, Laurence

Abstract

Bacillus thuringiensis check for this species in other resources subsp. israelensis (Bti) is increasingly used worldwide for mosquito control and is the only larvicide used in the French Rhône-Alpes region since decades. The artificial selection of mosquitoes with field-persistent Bti collected in breeding sites from this region led to a moderate level of resistance to Bti , but to relatively high levels of resistance to individual Bti Cry toxins. Based on this observation, we developed a bioassay procedure using each Bti Cry toxin separately to detect cryptic Bti -resistance evolving in field mosquito populations. Although no resistance to Bti was detected in none of the three mosquito species tested ( Aedes rusticus check for this species in other resources , Aedes sticticus check for this species in other resources and Aedes vexans check for this species in other resources ), an increased tolerance to Cry4Aa (3.5-fold) and Cry11Aa toxins (8-fold) was found in one Ae. sticticus population compared to other populations of the same species, suggesting that resistance to Bti may be arising in this population. This study confirms previous works showing a lack of Bti resistance in field mosquito populations treated for decades with this bioinsecticide. It also provides a first panorama of their susceptibility status to individual Bti Cry toxins. In combination with bioassays with Bti , bioassays with separate Cry toxins allow a more sensitive monitoring of Bti -resistance in the field.

Keywords
Bacillus thuringiensis subsp. israelensis; bioassays; field resistance; Cry toxins; mosquito

 
© Copyright 2013 - Memórias do Instituto Oswaldo Cruz
Alternative site location: http://memorias.ioc.fiocruz.br

Home Faq Resources Email Bioline
© Bioline International, 1989 - 2017, Site last up-dated on 16-Oct-2017.
Site created and maintained by the Reference Center on Environmental Information, CRIA, Brazil
System hosted by the Internet Data Center of Rede Nacional de Ensino e Pesquisa, RNP, Brazil