Presented at the National Meeting of the Entomological Society of America, Symposium: Biorational Insecticides—Mechanism and Application, November 2002.
Identification of biochemical markers linked to neonicotinoid cross resistance in Bemisia tabaci (Hemiptera: Aleyrodidae) †
Article first published online: 18 NOV 2003
Copyright © 2003 Wiley-Liss, Inc.
Archives of Insect Biochemistry and Physiology
Special Issue: Biorational Insecticides—Mechanism and Application
Volume 54, Issue 4, pages 165–176, December 2003
How to Cite
Rauch, N. and Nauen, R. (2003), Identification of biochemical markers linked to neonicotinoid cross resistance in Bemisia tabaci (Hemiptera: Aleyrodidae) . Arch. Insect Biochem. Physiol., 54: 165–176. doi: 10.1002/arch.10114
- Issue published online: 18 NOV 2003
- Article first published online: 18 NOV 2003
- Bemisia tabaci;
- cytochrome P450;
The whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), is a serious pest in many cropping systems world-wide and occurs in different biotypes. The most widespread one is the B-type, whereas the Q-biotype is nowadays still mostly restricted to Southern Spain. Neonicotinoid cross-resistance is known at a high level in Q-types from Spain and individual samples collected in Italy and Germany. Now we detected for the first time high neonicotinoid cross-resistance in a B-type from Israel. Target site resistance to imidacloprid using [3H]imidacloprid in nicotinic acetylcholine receptor (nAChR) binding assays could not be detected in any of these highly resistant strains. The impact of metabolizing enzymes such as esterases, glutathione S-transferases, and cytochrome P450-dependent monooxygenases in neonicotinoid resistance was studied biochemically with artificial substrates. Monooxygenase activity was increased 2–3-fold in moderately resistant strains (RF ∼30) and even 5–6-fold in highly resistant strains (RF ∼1,000). Only monooxygenase activity correlated with imidacloprid, thiamethoxam and acetamiprid resistance and, therefore, monooxygenases seem to be the only enzyme system responsible for neonicotinoid resistance in B. tabaci Q- and B-types. The oxidative degradation of imidacloprid in resistant Q-type strains could be confirmed by metabolism studies of [14C]imidacloprid in vivo. Five-hydroxy-imidacloprid could be detected as the only main metabolite. The insecticidal activity and binding affinity to nAChR of this compound was 10 times lower than imidacloprid itself in B. tabaci. Arch. Insect Biochem. Physiol. 54:165–176, 2003. © 2003 Wiley-Liss, Inc.