April Pest of the Month: Xylella fastidiosa

Xylella fastidiosa is Australia’s number one national priority plant pest. It is a bacterial pathogen that can cause disease on many host plants, most notably Pierce’s disease on grapevine. It is known to infect hundreds of host plant species across nearly 100 families and is recognised as priority pests for a number of industries in Australia including production nurseries, cherries, citrus, tree nuts, summerfruit, viticulture and others.

Other hosts include, but are not limited to golden wattle, big leaf maple, scotch broom, green couch, Duranta erecta, fuchsia, French broom, English ivy, olive, hydrangea, sweet marjoram, evening primrose, sycamore, California wild rose, blackberry and rosemary (see links below).

Symptoms typically include leaf scorch, veinal chlorosis, wilt and dwarfing; initial symptoms may not be immediately recognised as those caused by Xylella. If you suspect a plant is infected with Xylella it is important to report it immediately. Even if the plant is not infected with Xylella, it is recommended to send plants with unusual symptoms to a diagnostic laboratory for identification of any pathogens present.

For more information refer to the following factsheets:

https://www.cabi.org/isc/datasheet/57195

https://nurseryproductionfms.com.au/download/pest-and-disease-fact-sheet-pierces-disease/

Figure caption: Oleander leaf scorch caused by Xylella fastidiosa. Photo by Jack Kelly Clark, University of California Statewide IPM Program.