Laricobius nigrinus Fender (Coleoptera: Derodontidae), a predatory beetle native to western North America, has been released since 2003 for management of hemlock woolly adelgid (HWA), Adelges tsugae Annand (Hemiptera: Adelgidae), a non-native pest killing hemlocks in eastern North America. Over 420,000 L. nigrinus have been released in the eastern USA from field and lab-reared sources, 14,000 of which were deployed in the Commonwealth of Virginia, USA. In order to determine the establishment rates of L. nigrinus in Virginia, surveys were conducted in 2017 and 2018 at all release sites within this state. During the study, stand-level HWA densities were estimated, and hemlock tree health and predator–prey ratios were quantified. The identification of Laricobius spp. recoveries were made using microsatellite analysis. During the period of the study, L. nigrinus were found to have established at 82% of Virginia release sites and were the primary species recovered (80%). Both Laricobius rubidus (18%) and hybrids (2%) were also recovered. Stand-level HWA densities varied greatly over sites and years but showed a general decline in year two of the study. Establishment at such a high percentage of release sites suggests that the climate in Virginia is suitable for the predator and the insect is adaptable to the wide variety of site conditions where hemlocks typically grow.

Laricobius nigrinus Fender（鞘翅目：Derodontidae）是北美西部原产的掠食性甲虫，自2003年以来已被释放，用于管理铁杉毛pest草Adelgid（HWA），Adelges tsugae Annand（半翅目：Adelgidae），这是一种非本地杀虫铁杉。北美东部。在美国东部，已从田间和实验室饲养的源中释放了超过420,000株黑黑麦草，其中14,000株被部署在美国弗吉尼亚州。为了确定黑麦草的建立率在弗吉尼亚州，2017年和2018年在该州所有发布站点进行了调查。在研究过程中，估计了林分水平的HWA密度，并量化了铁杉树的健康状况和捕食者与猎物的比率。Laricobius spp的鉴定。使用微卫星分析进行回收。在研究期间，发现黑灰乳菌已在弗吉尼亚州的82％释放地点建立，是回收的主要物种（80％）。两种Laricobius rubidus（18％）和杂种（2％）也被回收。在站点和年份中，标准水平的HWA密度差异很大，但在研究的第二年中总体下降。在如此高的释放位点上建立表明，弗吉尼亚州的气候适合捕食者，而这种昆虫则可以适应铁杉通常生长的各种场所条件。