An epizootic has been reported in Fiorinia externa populations in New York, Connecticut, Pennsylvania and New Jersey. Infected insects have profuse sclerotial masses enclosing their bodies. The mos...

Pests and pathogens are a continuous threat to the health of Western honey bee Apis mellifera L. Monitoring honey bee colonies for arthropod pests, disease‐causing bacteria and fungi, and early detection of new invasions is essential to maintain the pollination services provided by honey bees. We investigated the feasibility of using eDNA metabarcoding to detect pests and pathogens in bee hives and across their foraging environment. We sampled 13 sources for eDNA within and outside hives from our test apiary to determine where the most informative eDNA could be obtained, with most sources sampled thrice. This resulted in 61 samples, 20 negative controls, and three positive controls. Furthermore, we compared two eDNA collection techniques—wiping surfaces with moistened forensic swabs and using a spray/wash technique that aggregated surface eDNA into a container, before collecting the eDNA on a filter. We used DNA metabarcoding with universal primer sets to target arthropod, bacterial, and fungal communities. Our results showed that most sources yielded sufficient eDNA and that results of the swab and spray/wash methods were similar when they could be applied to the same surface. We detected DNA from honey bee bacterial symbionts, mycotoxin‐producing fungi and Brachymyrmex sp. rover ants. Common pests and pathogens of concern to honey bees (i.e., [small hive beetle (Aethina tumida), Varroa destructor, and Melissococcus plutonius]) were detected. This matched our visual observations of clinical signs of these pests and pathogens in the hives we tested. DNA from some species was source specific, which has implications for using eDNA as a monitoring tool. Collectively, our data show that eDNA metabarcoding can accurately detect DNA from arthropods and microbes honey bees contact and can be used as a comprehensive molecular predictor tool for colony health surveys.

Mycopathogens of economically important exotic invasive insects in forests of northeastern USA have been the subject of research at the Entomology Research Laboratory, University of Vermont, for the last 20 years. Elongate hemlock scale, European fruit lecanium, hemlock woolly adelgid and pear thrips were analyzed for the presence of mycopathogens, in order to consider the potential for managing these pests with biological control. Fungal cultures isolated from insects with signs of fungal infection were identified based on morphological characters and DNA profiling. Mycopathogens recovered from infected insects were subdivided into three groups, i.e., specialized entomopathogenic; facultative entomopathogens; ubiquitous opportunistic contaminants. Epizootics were caused by fungi in the specialized group with the exception of M. microspora, P. marquandii and I. farinosa. Inoculation of insects in laboratory and field conditions with B. bassiana, L. muscarium and Myriangium sp. caused insect mortality of 45 to 95%. Although pest populations in the field seemed severely compromised after treatment, the remnant populations re-established themselves after the winter. Although capable of inducing high mortality, a single localized aerial application of a soil-dwelling fungus does not maintain long-time suppression of pests. However, it can halt their range expansion and maintain populations below the economic threshold level without the use of expensive insecticides which have a negative impact on the environment.

A fungal epizootic has been detected in populations of the scale Fiorinia externa Ferris (Hemiptera: Diaspididae) in the eastern hemlock, Tsuga canad