Prionus laticollis (Drury, 1773) (Coleoptera: Cerambycidae), the broad necked root borer, is a known pest of numerous woody plant species. Larvae feed on and can severely damage roots and lower trunks, causing decline or structural weakness. It has been documented infesting commercial apple plantings in New York and New England, notably in recent years when infestations caused tree decline and death in an established orchard in Northport, New York. As with other Prionus species found in the U.S.A., males are attracted to all four isomers of 3,5-dimethyldodecanoic acid, the female-produced sex pheromone of the related species, P. californicus Motschulsky, 1845. We conducted field trials using a commercial mix of this pheromone to monitor occurrence, phenology and abundance of P. laticollis in several orchard and mixed hardwood habitats in New York from 2010–2015. Male beetles were readily captured in all locations using pitfall traps baited with a commercial synthetic pheromone blend of all possible isomers, with maximum seasonal totals of 112–145 beetles per site. The first beetles were captured from 19 June to 4 July, corresponding to 436–691 degree-days (base 10°C) from 1 January, depending on year and location. A 2012 lure comparison between the single-isomer natural pheromone and the four-isomer blend showed no significant differences in numbers of beetles captured. Beetle catch generally peaked within two weeks of initial flight each year, with most activity occurring throughout July. A distinct decrease in beetle numbers was noted at the Geneva location over the course of repeated annual trapping trials, possibly reflecting a negative impact on the local population.