AUTHOR=Venette Robert C. , Ambourn Angie , Aukema Brian H. , Jetton Robert M. , Petrice Toby R. 

TITLE=Hosts and impacts of elongate hemlock scale (Hemiptera: Diaspididae): A critical review

JOURNAL=Frontiers in Insect Science

VOLUME=4

YEAR=2024

URL=https://www.frontiersin.org/journals/insect-science/articles/10.3389/finsc.2024.1356036

DOI=10.3389/finsc.2024.1356036

ISSN=2673-8600

ABSTRACT=<p><italic>Fiorinia externa</italic> Ferris, elongate hemlock scale, was inadvertently introduced to North America from Japan. This insect is particularly problematic on hemlock, <italic>Tsuga</italic> spp., though it has been reported in association with several other conifers. The evidence that other conifers might be hosts, capable of supporting growing populations of the insect, has not been previously reviewed. Our review confirms that <italic>F. externa</italic> is an oligophagous pest of members of Pinaceae. Although species of Cupressaceae and Taxaceae have been reported as hosts of <italic>F. externa</italic>, they seem unable to support population growth of this pest. Evidence of the tree-killing potential of the insect, even on suitable hosts, is remarkably scant. The degree of pest risk posed by <italic>F. externa</italic> with respect to tree mortality in areas beyond the geographic range of hemlock seems modest, but uncertain.</p>