Behavior and management of X-disease vectors

Authors: Marshall, Adrian; Cooper, William

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/25/2026
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: An outbreak of X-disease phytoplasma, which induces production of small unmarketable fruit, has caused the removal of vast amounts of cherry acreage in Washington State. The most abundant X-disease vector in Washington State cherry orchards is Colladonus reductus. For vector and pathogen control growers rely on frequent insecticide applications and removal of infected trees, but these management recommendations originate from California when the last outbreak occurred in the 1980s. The increase in chemical inputs has broken down stone fruit integrated pest management techniques and is neither economically nor environmentally sustainable. To investigate sustainable vector management, we assessed the efficacy of a variety of agricultural and exclusion netting to prevent Colladonus reductus from accessing cherry and peach trees. In 2024 and 2025 we conducted three trials testing four varieties of netting (20% shade, 30% shade, Mesh 25, and Mesh 50) against an unnetted control in commercial cherry orchards in Washington State. In all trials the mesh exclusion netting reduced C. reductus abundance over 99%, and both shade netting types consistently caused a 90% reduction in leafhoppers. The drastic reduction in X-disease vector abundance demonstrates that netting can provide effective season-long protection. Testing netting on production size trees is currently ongoing to examine the impacts on other aspects of the prunus orchard system.