The Lari-Leuco Container: A Novel Collection Arena for Separating Insects Ascending or Descending From a Plant Foliage Sample.

Abstract

Efficient separation of insects from plant material for quantification and collection is an important component of entomological research. This paper reports on a novel, easily replicable container designed to efficiently collect two different biological control agents dispersing from hemlock (Tsuga spp.) foliage infested with the invasive hemlock woolly adelgid (HWA), Adelges tsugae Annand (Hemiptera: Adelgidae). The container utilizes a simplified Berlese-style funnel design to collect Laricobius spp. (Coleoptera: Derodontidae) larvae dropping from the foliage into a removable bottom jar, a central jar to house the foliage sample, and a removable top jar to collect adult silver flies (Leucopis spp., Diptera: Chamaemyiidae) emerging from puparia on the twigs. The efficacy of two designs (with and without a funnel leading to the top collection jar) was evaluated using western hemlock [Tsuga heterophylla (Raf.) Sarg.] foliage naturally colonized with HWA and the two predator genera. All Laricobius larvae were effectively collected in the bottom jar, and the addition of an inverted funnel leading to the top collection jar increased the proportion of Leucopis flies reaching the target jar from 60% to 94%. This 'Lari-Leuco' container is presented as a research and motoring tool to benefit the integrated pest management program for HWA in eastern North America and for potential use in simultaneously separating ascending and descending life stages in other insect-plant or predator-prey systems.