נגישות
menu      
Advanced Search
Syntax
Search...
Volcani treasures
About
Terms of use
Manage
Community:
אסיף מאגר המחקר החקלאי
Powered by ClearMash Solutions Ltd -
Insect detoxifying enzymes: Their importance in pesticide synergism and resistance
Year:
1993
Authors :
Ishaaya, Isaac
;
.
Volume :
22
Co-Authors:
Ishaaya, I., Department of Entomology, Agricultural Research Organization, Volcani Center, Bet Dagan, Israel
Facilitators :
From page:
263
To page:
276
(
Total pages:
14
)
Abstract:
Pyrethroid esterases of Trichoplusiani, Spodoptera littoralis and Bemisia tabaci hydrolyze the trans‐isomers of various pyrethroids more extensively than the cis‐isomers. Profenofos fed to T. ni larvae at a level inhibiting the gut pyrethroid esterases by 65% with trans‐permethrin and of 95% with cis‐cypermethrin increased the toxicity of topically applied trans‐permethrin by fourfold and cis‐cypermethrin by 20‐fold. Similar assays with S. littoralis resulted in an increase of about threefold in the toxicity of both compounds. Monocrotophos, profenofos, acephate, and methidathion inhibited pyrethroid esterase activity in B. tabaci and synergized considerably the toxicity of cypermethrin. The remarkable tolerance of the predator Chrysopa carnea to pyrethroids is attributed to the presence of a high level of pyrethroid esterase activity with a unique specificity for hydrolyzing the cis‐isomer. Phenyl saligenin cyclic phosphonate, a potent inhibitor for larval pyrethroid esterases synergized the toxicity of trans‐permethrin by 68‐fold from an LD50 of 17,000 μg/g to 250 μg/g. In contrast, oxidase inhibitors such as piperonyl butoxide, SV‐1, and MPP synergized considerably the toxicity of pyrethroids in Tribolium castaneum and Musca domestica. Hence the predominant pathway for pyrethroid detoxification in insects, whether hydrolytic or oxidative, depends largely on the insect species. The high toxicity of the recent developed acylureas results from their high retention in the insects. Assays using radiolabeled diflubenzuron and chlorfluazuron applied to fourth instar T. castaneum larvae revealed a rapid elimination of diflubenzuron (T1/2 ≅ 7 h) as compared with chlorfluazuron (T1/2 > 100 h). Addition of 100 ppm DEF to the diet increased both the retention time and the toxicity of diflubenzuron in both T. castaneum and S. littoralis, which was due probably to the inhibition of diflubenzuron hydrolase activity. Esterases, hydrolyzing pyrethroids, and acylureas may serve as tools for evaluating potential synergists and for monitoring resistance in various agricultural pests due to increased metabolism. © 1993 Wiley‐Liss, Inc. Copyright © 1993 Wiley‐Liss, Inc.
Note:
Related Files :
Animal
benzoylphenyl urea detoxification
insecticide resistance
insecticides
insects
metabolism
Pesticide Synergists
Review
Show More
Related Content
More details
DOI :
10.1002/arch.940220119
Article number:
Affiliations:
Database:
Scopus
Publication Type:
article
;
.
Language:
English
Editors' remarks:
ID:
29678
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:48
You may also be interested in
Scientific Publication
Insect detoxifying enzymes: Their importance in pesticide synergism and resistance
22
Ishaaya, I., Department of Entomology, Agricultural Research Organization, Volcani Center, Bet Dagan, Israel
Insect detoxifying enzymes: Their importance in pesticide synergism and resistance
Pyrethroid esterases of Trichoplusiani, Spodoptera littoralis and Bemisia tabaci hydrolyze the trans‐isomers of various pyrethroids more extensively than the cis‐isomers. Profenofos fed to T. ni larvae at a level inhibiting the gut pyrethroid esterases by 65% with trans‐permethrin and of 95% with cis‐cypermethrin increased the toxicity of topically applied trans‐permethrin by fourfold and cis‐cypermethrin by 20‐fold. Similar assays with S. littoralis resulted in an increase of about threefold in the toxicity of both compounds. Monocrotophos, profenofos, acephate, and methidathion inhibited pyrethroid esterase activity in B. tabaci and synergized considerably the toxicity of cypermethrin. The remarkable tolerance of the predator Chrysopa carnea to pyrethroids is attributed to the presence of a high level of pyrethroid esterase activity with a unique specificity for hydrolyzing the cis‐isomer. Phenyl saligenin cyclic phosphonate, a potent inhibitor for larval pyrethroid esterases synergized the toxicity of trans‐permethrin by 68‐fold from an LD50 of 17,000 μg/g to 250 μg/g. In contrast, oxidase inhibitors such as piperonyl butoxide, SV‐1, and MPP synergized considerably the toxicity of pyrethroids in Tribolium castaneum and Musca domestica. Hence the predominant pathway for pyrethroid detoxification in insects, whether hydrolytic or oxidative, depends largely on the insect species. The high toxicity of the recent developed acylureas results from their high retention in the insects. Assays using radiolabeled diflubenzuron and chlorfluazuron applied to fourth instar T. castaneum larvae revealed a rapid elimination of diflubenzuron (T1/2 ≅ 7 h) as compared with chlorfluazuron (T1/2 > 100 h). Addition of 100 ppm DEF to the diet increased both the retention time and the toxicity of diflubenzuron in both T. castaneum and S. littoralis, which was due probably to the inhibition of diflubenzuron hydrolase activity. Esterases, hydrolyzing pyrethroids, and acylureas may serve as tools for evaluating potential synergists and for monitoring resistance in various agricultural pests due to increased metabolism. © 1993 Wiley‐Liss, Inc. Copyright © 1993 Wiley‐Liss, Inc.
Scientific Publication
You may also be interested in