Resistance to insecticides of housefly Musca domestica in the center of the European part of Russia

Under laboratory conditions, resistance to insecticides from various chemical classes of several strains of the housefly, Musca domestica, obtained from populations collected at facilities in the Moscow and Kaluga regions (KSK-1 in a cowshed and KSK-2 in the stable of an equestrian sports club, Krasnogorsk – at a food facility, Kaluga – in the compost of a garden non-profit partnership). It was found that when insecticides were applied topically, houseflies of all the studied strains hadthe highest resistance to cypermethrin (RF=75–900x) and to neonicotinoid compounds thiamethoxam and clothianidin (RF=95–330x). High resistance to fipronil was found in two strains of fly (RF= 46–75x). Strain KSK-1 was weakly tolerant to chlorpyrifos (RF=3.7x), while the other strains were susceptible. All the studied house fly strains were more susceptible to indoxacarb and chlorfenapyr than the laboratory strain S-NIID. The data indicate that studied housefly strains are multiresistant to almost all commonly used insecticides. Possible mechanisms of insect resistance to insecticides are discussed. Frequent use of insecticides of various chemical classes led to resistance in the target pest. Widespread use of pyrethroids in animal facilities has led to high resistance to them in the house fly because places where larvae hatch are constantly polluted with these insecticides. High resistance to neonicotinoids is also due to their frequent use as poisoned baits in livestock facilities. To the contrary, the studied housefly strains remained susceptible to the tested oxadiazines and pyrroles, chemical classes that were recently introduced to Russia.