A Field-Based Method to Estimate Densities of Laricobius nigrinus (Coleoptera: Derodontidae), an Introduced Predator of Hemlock Woolly Adelgid (Hemiptera: Adelgidae)

Summary This study investigated the use of emergence traps to assess densities of Laricobius nigrinus Fender (Coleoptera: Derodontidae), a predator of hemlock woolly adelgid (Hemiptera: Adelgidae), in an area of release and establishment. Results indicate that traps effectively collect emerging adults and allow systematic population estimates of L. nigrinus. The incorporation of this method in future monitoring efforts could enable population estimates across the release range of L. nigrinus, thereby enhancing the evaluation of establishment and long-term persistence of this predator.