Evaluation of the pyrrole insecticide chlorfenapyr for the control of Culex quinquefasciatus Say.

Abstract:

:Culex quinquefasciatus Say (Diptera: Culicidae) is a widely distributed mosquito vector species in India and also in other tropical regions of the world. This species is implicated in the transmission of lymphatic filariasis in many countries. This species is reported to be widely resistant to insecticides of different classes in current use. In the present study, bio-efficacy of chlorfenapyr, an insecticide of pyrrole class with a novel mode of action was tested for the control of Cx. quinquefasciatus. Studies were performed to determine the diagnostic dosage; residual efficacy on different artificially fabricated substrates, namely wood, mud, mud+lime, cement and cement+distemper; to assess cross-resistance with different insecticides; and synergism/antagonism using piperonyl butoxide (PBO). A dosage of 5.0% chlorfenapyr was determined as diagnostic dosage with 2 h exposure and 48 h holding period for assessing the susceptibility of mosquitoes. The residual efficacy was observed up to 34 weeks on wood and mud+lime substrates while on other substrates, it was about 15 weeks at a dosage of 400mg a.i./m(2). Laboratory-reared strains of Cx. quinquefasciatus showed cross-resistance, whereas field-collected mosquitoes showed absence of cross-resistance to chlorfenapyr. Potentiation bioassays showed antagonistic effect of PBO to chlorfenapyr toxicity owing to the involvement of oxidases in the initial step of a conversion of pro-insecticide chlorfenapyr to toxic form CL 303268. The present study results have shown that chlorfenapyr can be a potential insecticide for the control of multiple insecticide resistant strains of Cx. quinquefasciatus. However, in countries where indoor residual spray (IRS) is not targeted for the control of this species, like in India, chlorfenapyr used in IRS for the control of malaria vectors in rural and peri-urban areas can additionally provide control of Cx. quinquefasciatus also.

journal_name

Acta Trop

journal_title

Acta tropica

authors

Raghavendra K,Barik TK,Bhatt RM,Srivastava HC,Sreehari U,Dash AP

doi

10.1016/j.actatropica.2011.02.001

subject

Has Abstract

pub_date

2011-04-01 00:00:00

pages

50-5

issue

1

eissn

0001-706X

issn

1873-6254

pii

S0001-706X(11)00026-X

journal_volume

118

pub_type

杂志文章