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In vivo distribution and metabolisation of 14 C‐imidacloprid in different compartments of Apis mellifera L
Author(s) -
Suchail Séverine,
De Sousa Georges,
Rahmani Roger,
Belzunces Luc P
Publication year - 2004
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/ps.895
Subject(s) - imidacloprid , hemolymph , toxicokinetics , midgut , biology , neonicotinoid , in vivo , toxicology , chemistry , pharmacology , biochemistry , pharmacokinetics , pesticide , botany , larva , microbiology and biotechnology , agronomy
In vivo distribution of the neonicotinoid insecticide, imidacloprid, was followed during 72 h in six biological compartments of Apis mellifera L: head, thorax, abdomen, haemolymph, midgut and rectum. Honeybees were treated orally with 100 µg of 14 C‐imidacloprid per kg of bee, a dose close to the median lethal dose. Elimination half‐life of total radioactivity in honeybee was 25 h. Haemolymph was the compartment with the lowest and rectum that with the highest level of total radioactivity during the whole study, with a maximum 24 h after treatment. Elimination half‐life of imidacloprid in whole honeybee was 5 h. Imidacloprid was readily distributed and metabolised only by Phase I enzymes into five metabolites: 4/5‐hydroxy‐imidacloprid, 4,5‐dihydroxy‐imidacloprid, 6‐chloronicotinic acid, and olefin and urea derivatives. The guanidine derivative was not detected. The urea derivative and 6‐chloronicotinic acid were the main metabolites and appeared particularly in midgut and rectum. The olefin derivative and 4/5‐hydroxy‐imidacloprid preferentially occurred in head, thorax and abdomen, which are nicotinic acetylcholine receptor‐rich tissues. Moreover, they presented a peak value around 4 h after imidacloprid ingestion. These results explain the prolongation of imidacloprid action in bees, and particularly the differences between rapid intoxication symptoms and late mortality. Copyright © 2004 Society of Chemical Industry