Status of thousand cankers disease on eastern black walnut in the eastern United States at two locations over 3 years

Abstract Formulations of entomopathogenic (insect-killing) fungi represent alternatives to synthetic insecticides in the management of forest and shade tree insects. We evaluated bark spray applications of the entomopathogen Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Cordycipitaceae) strain GHA (BotaniGardES), permethrin insecticide (Astro), and water (control) on colonization of black walnut (Juglans nigra L.) (Fagales: Juglandaceae) bolts by the walnut twig beetle (Pityophthorus juglandis Blackman) (Coleoptera: Curculionidae), vector of the fungus that causes thousand cankers disease. Treated bolts were baited with a P. juglandis aggregation pheromone lure and deployed in infested walnut trees. Bark application of permethrin prevented P. juglandis colonization of the phloem. Although treatment of bolts with the B. bassiana suspension did not reduce P. juglandis colonization or short-term emergence relative to the control treatment, it increased the B. bassiana infection rate from 25 to 62% of emerged adults. Results suggest that commercial applications of B. bassiana strain GHA may help augment natural levels of infection by this entomopathogen in the eastern United States, and support continued exploration of entomopathogens for biological control of the walnut twig beetle.

Download Full-text

Thousand cankers disease: Scolytine beetles and phoretic fungal pathogens associated with symptomatic eastern black walnut (Juglans nigra)

10.1603/ice.2016.114692 ◽

2016 ◽

Author(s):

Tyler J Stewart

Keyword(s):

Fungal Pathogens ◽

Black Walnut ◽

Juglans Nigra ◽

Thousand Cankers Disease ◽

Eastern Black Walnut

Download Full-text

Assessment of Alternative Candidate Subcortical Insect Vectors From Walnut Crowns in Habitats Quarantined for Thousand Cankers Disease

Environmental Entomology ◽

10.1093/ee/nvz064 ◽

2019 ◽

Vol 48 (4) ◽

pp. 882-893 ◽

Cited By ~ 1

Author(s):

Karandeep Chahal ◽

Romina Gazis ◽

William Klingeman ◽

Denita Hadziabdic ◽

Paris Lambdin ◽

...

Keyword(s):

United States ◽

Insect Species ◽

Beetle Species ◽

Eastern United States ◽

Geosmithia Morbida ◽

Pityophthorus Juglandis ◽

Thousand Cankers Disease ◽

Baited Traps ◽

Species Specific ◽

Xylosandrus Germanus

Abstract Thousand cankers disease (TCD) results from the combined activity of the fungal pathogen, Geosmithia morbida Kolařík, Freeland, Utley, and Tisserat and its principle vector, Pityophthorus juglandis (Blackman) (Coleoptera: Curculionidae: Scolytinae) in Juglans L. spp. and Pterocarya Kunth spp. host plants. TCD has been reported from the eastern and western United States. To evaluate potential for other beetle species to vector the fungus in east Tennessee, specimens were collected using ethanol-baited traps that were suspended beneath crowns of TCD-symptomatic trees. Associations of G. morbida with insect species collected in traps were assessed in an unsuccessful, preliminary culture-based fungal assay, and then with a molecular-based detection method. For culture-based assays, rinsate from washed, individual insects was plated on nutrient media and growing colonies were subcultured to obtain axenic G. morbida cultures for identification. For the molecular-based method, G. morbida presence was detected by amplifying the previously developed, species-specific microsatellite locus GS004. Capillary electrophoresis was used to detect the amplified amplicons and representative reactions were validated using Sanger sequencing. Eleven beetle species were found to carry G. morbida, including Cnestus mutilatus (Blandford), Dryoxylon onoharaensum (Murayama), Hylocurus rudis (LeConte), Monarthrum fasciatum (Say), Monarthrum mali (Fitch), Xyleborinus saxesenii (Ratzeburg), Xylosandrus crassiusculus (Motschulsky), Xylosandrus germanus (Blandford) (all Coleoptera: Curculionidae: Scolytinae), Stenomimus pallidus (Boheman) (Coleoptera: Curculionidae: Cossoninae), Oxoplatypus quadridentatus (Olivier) (Coleoptera: Curculionidae: Platypodinae), and Xylops basilaris (Say) (Coleoptera: Bostrichidae). These findings raise concerns that alternative subcortical insect species that already occur within quarantined habitats can sustain incidence of introduced G. morbida and contribute to spread within the native range of black walnut, Juglans nigra L., in the eastern United States.

Download Full-text

Thousand Cankers Disease is Widespread in Black Walnut in the Western United States

Plant Health Progress ◽

10.1094/php-2011-0630-01-br ◽

2011 ◽

Vol 12 (1) ◽

pp. 35 ◽

Cited By ~ 25

Author(s):

Ned Tisserat ◽

Whitney Cranshaw ◽

Melodie L. Putnam ◽

Jay Pscheidt ◽

Charles A. Leslie ◽

...

Keyword(s):

United States ◽

New Mexico ◽

Geographic Region ◽

Black Walnut ◽

Western United States ◽

Geosmithia Morbida ◽

Thousand Cankers Disease ◽

Canker Development ◽

Walnut Twig Beetle

Thousand cankers disease of black walnut is caused by aggressive feeding by the walnut twig beetle and subsequent canker development around beetle galleries caused the fungus Geosmithia morbida. The authors We confirmed the presence of G. morbida from symptomatic black walnut or hybrids in California, Colorado, Idaho, New Mexico, Oregon, Utah, and Washington. Thousand cankers disease continues to cause extensive mortality to black walnut over a wide geographic region and is intensifying in the western United States. Accepted for publication 2 June 2011. Published 30 June 2011.

Download Full-text