Fiorinia externa
species of insect
Fiorinia externa, the elongate hemlock scale, was accidentally introduced into North America from Japan and is now established in most parts of the north-eastern U.S. It has become a serious pest of hemlock (Tsuga) and some related conifers from the family Pinaceae. Dense colonies of the scale insect result in yellowing, shedding of leaves, dieback and occasional tree death.
Distribution
Fiorinia externa is native to Japan and southern China. It was first reported on Tsuga from New York state in 1908. Compared to other invasive insects, it has spread slowly across the north-eastern U.S. and has reached Georgia in the south, as well as Michigan, Kentucky and Tennessee further west.
While F. externa has not been confirmed to be established in other areas, it is regarded as being of quarantine concern. For example, it has been recorded from other parts of North America like California and Florida on host cuttings. In England, it was reported on a single fir tree imported from the U.S., but subsequently died out on that tree.
Description
The adult female of Fiorinia externa is about 1 mm long. The scale cover of the second instar female is elongated, around 1.5 mm long and has a yellowish-brown, orange-brown or reddish-brown colour.
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This entry incorporates text from “Fiorinia externa” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.