Susceptibility of Two European strains of Stomoxys calcitrans (L.) to Cypermethrin, Deltamethrin, Fenvalerate, λ-cyhalothrin, Permethrin and Phoxim

Susceptibility of two French strains of stable flies Stomoxys calcitrans (L.) to six insecticides was assayed, using an exposure technique (1-hour contact) with treated filter papers. Three replicates per insecticide, per concentration (10 concentrations per insecticide), per fly strain (ENVT, Cabanac) and fly category (blood-engorged – non-bloodengorged) were performed using a total of 14,400 adult flies in this trial. The LD 50 and LD 90 are higher for the blood-engorged flies than the non-blood-engorged flies for both strains of S. calcitrans. The LD 90 (mg/ m²) of the engorged flies for both strains were respectively: cypermethrin (637.9,