Feasibility of monitoring click beetles (Coleoptera: Elateridae) in field headlands with Vernon Pitfall Traps

Larvae of several species of click beetle (Coleoptera: Elateridae) are serious agricultural pests in Canada, including Agriotes sputator L. in Prince Edward Island (PEI). Risk of crop injury can be roughly determined by captures of beetles in pheromone-baited traps. To determine the feasibility of monitoring beetle populations as part of an IPM program for wireworms, we installed traps in 32 fields in eastern PEI and checked them weekly for 9–16 weeks. Data recorded included: the number of beetles captured; the time required to check and service traps; presence of bycatch; incidence of flooding, predation, and disturbance; and the total time required to monitor each field. A mean of 66.6 beetles/trap were collected during 3430 trap checks, with no cleaning or reinstallation required in most (63.6%) instances. Trap checks required <2 min under most common conditions, but longer when cleaning and reinstallation was required, traps were flooded or contained bycatch, or when there was predation on captured beetles. These data are used to predict trap check time based on trap catch condition and the type of service required to traps. Field walking time depended on the distance walked, elevation change during the walk, and the crop present in the field. Together these data suggest it is feasible for crop consultants to monitor click beetle populations in multiple small-medium sized fields per day, and that such monitoring should be considered as part of an IPM program for wireworms in high value crops.