Mechanisms of Resistance to Organophosphorus Insecticides in Culex tarsalis

$28.00 plus tax (Refund Policy)

Buy Article:


A 55.6-fold level of resistance to parathion in larvae of a multiresistant strain of Culex tarsalis Coquillett was shown to be due to slower penetration and increased metabolism of the toxicant. After 4 h exposure, 1.9× more water-soluble metabolites and 0.4× less intact parathion were recovered from the resistant strain relative to the susceptible. Comparable amounts of paraoxon were isolated from both strains. During the same period, larvae of the susceptible strain absorbed 1.3× as much parathion as resistant larvae.

In vivo tests revealed strong synergism of organophosphorus compounds in the resistant strain by DEF (S,S,S-tributyl phosphorotrithioate) but antagonism or no effect by piperonyl butoxide. In vitro assays indicated that resistance was not due to acetylcholinesterase insensitivity to inhibition by organophosphates.

Document Type: Research Article

Publication date: April 1, 1975

More about this publication?
  • Journal of Economic Entomology is published bimonthly in February, April, June, August, October, and December. The journal publishes articles on the economic significance of insects and is divided into the following sections: apiculture & social insects; arthropods in relation to plant disease; forum; insecticide resistance and resistance management; ecotoxicology; biological and microbial control; ecology and behavior; sampling and biostatistics; household and structural insects; medical entomology; molecular entomology; veterinary entomology; forest entomology; horticultural entomology; field and forage crops, and small grains; stored-product; commodity treatment and quarantine entomology; and plant resistance. In addition to research papers, Journal of Economic Entomology publishes Letters to the Editor, interpretive articles in a Forum section, Short Communications, Rapid Communications, and Book Reviews.
  • Editorial Board
  • Submit a Paper
  • Subscribe to this Title
  • Information for Advertisers
  • Visit this journal's homepage
  • ingentaconnect is not responsible for the content or availability of external websites
Related content



Share Content

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more