Insecticide resistance in Bemisia tabaci (Homoptera: Aleyrodidae) populations from Crete.
The resistance levels to alpha-cypermethrin, bifenthrin, pirimiphos-methyl, endosulfan and imidacloprid were determined in Bemisia tabaci (Gennadius) from Crete. Five B tabaci populations collected from greenhouse and outdoor crops were bioassayed and compared with a reference susceptible strain. Bemisia tabaci collected in a floriculture greenhouse exhibited the highest resistance against all insecticides: at LC50, resistance factors were 23-fold for bifenthrin, 80-fold for alpha-cypermethrin, 18-fold for pirimiphos-methyl, 58-fold for endosulfan and 730-fold for imidacloprid. A population collected on outdoor melons was more susceptible than the reference strain against all insecticides tested, suggesting the occurrence of local highly susceptible B tabaci populations in 'refugia'. In pairwise comparisons of resistance levels, correlation was observed between the LC50 values of the pyrethroid insecticides bifenthrin and alpha-cypermethrin.
Roditakis
Emmanouil
E
Plant Protection Institute of Heraklio, National Agricultural Research Foundation, 71003 Heraklio, Greece. e-roditakis@her.forthnet.gr
Roditakis
Nikos E
NE
Tsagkarakou
Anastasia
A
D000818:Animals; D006115:Greece; D006430:Hemiptera / Q000502:physiology*; D007305:Insecticide Resistance