Evaluating the invasive potential of an exotic scale insect associated with annual Christmas tree harvest and distribution in the southeastern U.S.

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

“…& Dallim. ; or southern eastern red cedar, Juniperus virginiana var silicicola (Small) E. Murray ( 37 ). Fiorinia externa began to feed on all of these plants except Thuja x ‘Green Giant’ and Cupressus x leylandii ; typically, <10% of trees in Cupressaceae - but 57% of J. virginiana var silicicola – had live scales at 19 weeks after infestation ( 37 ).…”

“…; or southern eastern red cedar, Juniperus virginiana var silicicola (Small) E. Murray ( 37 ). Fiorinia externa began to feed on all of these plants except Thuja x ‘Green Giant’ and Cupressus x leylandii ; typically, <10% of trees in Cupressaceae - but 57% of J. virginiana var silicicola – had live scales at 19 weeks after infestation ( 37 ). By 50 weeks after infestation, no Cupressaceae had live scales, except J. virginiana var silicicola whose 3% frequency of infestation was equivalent to a known non-host ( 37 ).…”

“…Fiorinia externa began to feed on all of these plants except Thuja x ‘Green Giant’ and Cupressus x leylandii ; typically, <10% of trees in Cupressaceae - but 57% of J. virginiana var silicicola – had live scales at 19 weeks after infestation ( 37 ). By 50 weeks after infestation, no Cupressaceae had live scales, except J. virginiana var silicicola whose 3% frequency of infestation was equivalent to a known non-host ( 37 ). Members of Cupressaceae have been confirmed as hosts of the congeneric Fiorinia japonica in multiple studies ( 27 ).…”

Morphological and phylogenetic resolution ofConoideocrella luteorostrata(Hypocreales: Clavicipitaceae), a potential biocontrol fungus forFiorinia externain United States Christmas tree production areas

“…The damage inflicted by these insect pests on tree farms and in wild stands is difficult to quantify, but the spread of this insect along with another non-native pest, hemlock woolly adelgid, has been associated with defoliation and decline of hemlocks in the United States (Royle & Lathrop, 2002). These host species are also significant to the Christmas tree production industry, where scale infection can decrease the ability of farmers to transport and sell their products across state lines (McClure & Fergione, 1977), since the transport of Christmas trees is a significant vector for this insect (Dale et al, 2020). The range of these insects was originally limited by their cold sensitivity, but adaptations that increased cold tolerance emerged in the 1970's which allowed for rapid northward expansion (Preisser et al, 2008).…”

“…The damage inflicted by these insect pests on true fir tree farms and on eastern hemlock in native forested stands is challenging to quantify, but the spread of this insect, along with another non-native insect pest hemlock woolly adelgid (HWA; Adelges tsugae ), has been associated with defoliation and decline of hemlocks in the United States (Royle & Lathrop, 2002). Given the broad host range of EHS, this pest poses significant risks to the Christmas tree production industry, where scale infection can decrease the ability of farmers to transport and sell their products across state lines (McClure & Fergione, 1977), since the transport of Christmas trees can contribute to the spread of this and other non-native insect pests (Dale et al, 2020).…”