Management of Carpophilus spp. beetles (Nitidulidae) in stone fruit orchards by reducing the number of attract-and-kill traps in neighbouring areas

Owing to variation in susceptibility of different stone fruit varieties to nitidulid beetles (Carpophilus spp.), growers generally use attract-and-kill traps to treat only the most susceptible fruit tree varieties. Carpophilus populations often tend to build up in the untreated, less-susceptible varieties and then migrate to ripening, more-susceptible varieties in neighbouring areas. This compromises the ability of attract-and-kill traps to control the pest in the treated orchards. The use of attract-and-kill traps at the standard rate of 3 traps/ha in less-susceptible varieties is also expensive. Field experiments were conducted over two consecutive growing seasons in stone fruit orchards to test whether treating neighbouring less-susceptible varieties with a reduced number of attract-and-kill traps (2 traps/ha) would compromise control of the pest in susceptible target plots (treated with 3 attract-and-kill traps/ha). Each of the target plots with susceptible varieties had a history of high levels of da...