Laboratory and field assessment of cyantraniliprole relative to existing fly baits

BACKGROUND Toxic fly baits are commonly used for fly control in California animal operations. However, resistance development has been a problem. Comprehensive laboratory and field studies were conducted to test commercial baits (imidacloprid, methomyl, dinotefuran, spinosad) and one novel cyantraniliprole bait. A susceptible Musca domestica strain was compared with wild‐type M. domestica and Fannia canicularis strains in the laboratory using choice/no‐choice tests. Field visitation to baits and both short‐ and longer‐term mortality were documented. RESULTS Susceptible Musca suffered high mortality with all baits after 3 days of choice and no‐choice tests. Wild‐type Musca mortality was more variable and higher in no‐choice relative to choice tests. Fannia were most susceptible to spinosad > dinotefuran = cyantraniliprole > methomyl = imidacloprid. Field Musca were most attracted to spinosad > cyantraniliprole > dinotefuran > sugar > methomyl > imidacloprid. Delayed mortality from bait‐fed field flies (captured and held with untreated food and water for 3 days) was ranked spinosad = cyantraniliprole > dinotefuran = methomyl > imidacloprid > sugar. CONCLUSION Behavioral resistance of M. domestica to imidacloprid and methomyl persists. Spinosad and cyantraniliprole baits (delayed mortality) performed best. Speed of action may be a factor in use and misuse of baits. © 2014 Society of Chemical Industry