Location: Temperate Tree Fruit and Vegetable Research
Project Number: 2092-22000-022-040-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Oct 1, 2023
End Date: Aug 31, 2026
Objective:
1. Develop and evaluate non-neonicotinoid pest management programs.
a. Reduced-risk management options for control of key regional insect pests.
b. Non-noenicotinoid management programs for viral pathogens in seed potatoes.
c. New management tools for insect-vectored pathogens in seed potatoes.
d. Evaluating resistance to a novel active ingredient.
2. Develop pest prediction, monitoring, and decision-making tools.
a. Remote sensing for Colorado potato beetle populations.
b. Develop pest prediction, monitoring and decision-making tools.
3. Facilitate adoption of new strategies among growers.
4. Evaluate the social and economic impacts of the new pest management strategies.
Approach:
1.C. New management tools for insect-vectored pathogens in seed potatoes.
We will use PLRV-infected and nonviruliferous (clean) green peach aphid colonies, Lso-infected (haplotype B) and clean colonies of potato psyllids (western haplotype), and a clean colony of beet leafhoppers currently maintained in Wapato, WA, as well as PVYNTN-infected leaf tissue for inoculant. PVY-viruliferous aphids will be generated by confining clean aphids to an infected plant for 10 min. Treatments will include a water control and foliar insecticides representing at least six IRAC groups and one botanical organic, with just one insecticide rated ‘Level I’ on the bee precaution scale (sulfoxaflor) (Table 2). Potato plants (cv. ‘Russet Burbank’) assigned an insecticide treatment will be sprayed following maximum label rates using a CO2-pressurized backpack sprayer.
Transmission assays. We will assess inoculation rates by placing infected insects on treated potato plants for 1 h (PVY) or 48 h (all other pathogens) prior to removal. Acquisition rates will be assessed by placing clean insects on infected, treated plants for 1 h (PVY) or 48 h (all other pathogens) and transferring individuals to untreated, uninfected indicator plants for a similar time interval, two weeks after which inoculated leaves of indicator plants will be collected and tested for pathogen infection using rt-PCR (PLRV, PVY) or qPCR (Lso, phytoplasma).
Behavioral assays. We will quantify vector behaviors known to mediate pathogen spread in the field relative to insecticide treatments using an electropenetrograph (EPG), a choice test, and an immigration/emigration assay. Specifically, we will quantify feeding/probing behaviors using the EPG (Backus & Bennett 2009); intoxication, repellence, attraction, and movement using choice assays and EthoVision software (Noldus 2001); and movement by winged aphids on and off plants with immigration/emigration assays (Eigenbrode et al. 2002, Gadhave et al. 2019). Transmission and behavioral assays will be conducted within the first three years of the project: finishing studies on PLRV and PVY during the first two years, Lso assays during the second and third year, and phytoplasma assays during the third year and, if necessary, the fourth.
