Jul 16, 2020

X-disease phytoplasma vector management for 2020

Managing the leafhopper vectors of X-disease phytoplasma postharvest is important this season to slow the spread of the pathogen. Here we cover basic considerations. Keep in mind there are many unknowns about these leafhoppers and management options will be refined as new research is completed.

Which leafhoppers should I worry about?

Six leafhoppers are known to transmit X-disease phytoplasma: Colladonus montanus, Fiebriella florii, Scaphytopius acutus, Paraphlepsius irroratus, Colladonus reductus, and Colladonus geminatus. The three  most common in Washington are C. reductus, C. geminatus and to a lesser extent C. montanus.

How do I ID the problem leafhoppers?

The leafhoppers which vector X-disease phytoplasma can be tricky to distinguish from the many other leafhoppers hopping around your orchard. There are approximately 20,000 leafhopper species, so it is important to focus on the correct ones. When you trap them on a sticky card for monitoring look for what appears to be a face with a handlebar mustache, a pirate hat and sunglasses on the back of the C. geminatus. and C. reductus has a bright yellow stripe on its back.

Fig 1. C. geminatus left and C. reductus right. Look for the face of a pirate with sunglasses and a handlebar mustache on the back of the C. geminatus. Look for a distinct yellow stripe on the C. reductus. The rarely seen vector C. montanus looks nearly identical to C. reductus, but also has a small yellow patch on the back. Photo: T. Northfield, WSU Entomology.

Trapping basics

• Use yellow sticky cards.
• Deploy post-harvest.
• Hang at 3-5 feet from the orchard floor.
• Place traps on orchard borders, in areas of concern in your block and throughout block. Approx. 1 trap per two acres.
• Check traps every 1-2 weeks.
• Use presence (an average of 1 leafhopper per trap) as a threshold to spray.

To read the complete article including horticulture recommendations and pesticide applications visit http://treefruit.wsu.edu/article/x-disease-phytoplasma-vector-management-for-2020/

For Spanish Gestion de Vectores de Fitoplasma X para 2020

http://treefruit.wsu.edu/article/gestion-de-vectores-de-fitoplasma-x-para-2020/

– Tianna DuPont, WSU Extension; Tobin Northfield, WSU Entomology

Originally published here by Washington State Tree Fruit Extension at treefruit.wsu.edu