Drippy Blight, a Disease of Red Oaks in Colorado, U.S., Produced from the Combined Effect of the Scale Insect Allokermes galliformis and the Bacterium Lonsdalea quercina subsp. Quercina

Abstract

Drippy blight is an emergent disease of red oaks, caused by the interaction between a kermes scale insect (Allokermes galliformis) and a bacterium (Lonsdalea quercina subsp. quercina). Multi-locus sequence analysis was used to confirm the bacterial pathogen’s identity and its relationship to other phylogenetically related Enterobacteriaceae species. Further, Koch’s postulates were performed on sapling red oaks. Prior to the discovery of drippy blight disease in Colorado, in the United States, the bacterium was reported on oak trees in California but was limited to acorn infections. The scale insect, A. galliformis, was previously known to occur on pin oak in the eastern United States but was not previously associated with either this bacterium or the production of significant branch dieback associated with drippy blight. In addition to a description of this new disease, this research documents a host range expansion of L. quercina subsp. quercina to northern red oak (Quercus rubra), Shumard oak (Q. shumardii), and pin oak (Q. palustris) and extends the reported host range of A. galliformis to include northern red and Shumard oaks.

Bacterial community associated with the ambrosia beetle Platypus cylindrus on declining Quercus suber trees in the Alentejo region of Portugal

“…In recent years bacteria associated with Quercus spp. have been identified worldwide, and especially in several European countries, which play an important role in oak decline (Brady et al, 2017; Denman et al, 2014; González & Ciordia, 2020; Moradi‐Amirabad et al, 2019; Sitz et al, 2018). In Portugal, Brenneria goodwinii was recently found associated with cork oak trees showing symptoms (authors’ unpublished data).…”

“…In Britain, oak trees with acute oak decline (AOD) syndrome were characterized by the presence of a variable community of bacteria, where B. goodwinii, Gibbsiella quercinecans and Rahnella victoriana were consistently found in infected trees (Brady et al, 2017). Moreover, strains of Lonsdalea quercina affecting oak forests were identified in Spain and the United States (Colorado and California; Sitz et al, 2018). Many of these bacteria belong to the Enterobacterales order, which are known to cause a variety of cankers, wilts and necrosis on forest trees (Brady et al, 2014).…”

Declinamiento y muerte de los encinos (Quercus spp.) en México, estado actual del conocimiento

“…A nivel mundial, el declinamiento en encinos ha sido ampliamente estudiado en algunos países (Keèa et al, 2016;Romagnoli et al, 2018;Sitz et al, 2018), en México, sin embargo, después de haber realizado un escrutinio minucioso de la información disponible, encontramos que los estudios son escasos; a continuación, tratamos en orden cronológico los trabajos que han sido desarrollados.…”

Population genomic analysis of an emerging pathogenLonsdalea quercinaaffecting various species of oaks in western North America

“…In the early 2000s a significant dieback of northern red oak, pin oak, and Shumard oak of unknown origin appeared in Colorado and was described as drippy blight disease (13).…”