Efficiency of Unitraps in Capturing Corn Earworm Moths, Helicoverpa zea (Lepidoptera: Noctuidae), in the Field

Pheromone-baited traps are commonly used to monitor and detect moths. Traps and lures are often compared to each other to identify the optimum set up and lure dosage. However, it is also important to understand the efficiency of a trap in capturing the moths that are attracted to it. In the present study, three pheromone-baited traps were placed at the edge of a cornfield to determine the one with the highest capture rate of <i>Helicoverpa zea</i> (Lepidoptera: Noctuidae): Scentry Heliothis traps, clear Unitraps, and green Unitraps. Once it was determined that green Unitraps captured more <i>H. zea</i>, field observations determined the number of moths captured in the traps compared to the number approaching, i.e., trap efficiency. Green Unitraps had a capture efficiency ranged from 5 to 11%, with an average of 11%. Unitraps, although useful for monitoring existing populations, may not be effective in detecting an invasive incursion. The implications of low capture efficiency in the surveillance of <i>H. zea</i> are considered, including possible explanations and next steps to improve monitoring efforts of heliothine moths.