Project Number: 8080-21000-032-015-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Oct 1, 2018
End Date: Aug 31, 2022
The objectives of this project are to: 1) identify movement and damage patterns of plum curculio (PC) within peach, apple and blueberry; 2) evaluate management tactics that exploit PC distribution within fruit farms; and 3) disseminate materials on PC behavior and management to stakeholders.
We will utilize a mark-capture technique to track colonization and dispersal of PC within peach, apple, and blueberry across generations. Fruit trees/bushes will be marked with two unique protein markers with a multiple row buffer zone between treated areas to prevent contamination of protein markers. Weevils will be directly ‘marked’ during protein application or will become ‘marked’ in situ as they encounter protein covered plant material during movement within the crop. At each site, weevils will be sampled by gently beating three, randomly selected terminal branches from three adjacent trees/bushes. Transects of peach and apple orchards will be sampled weekly during activity periods for PC using beat samples and/or circle traps during years one and two. Circle traps will also be placed around the trunk of the tree to intercept adults moving into the canopy. Additionally, two unbaited black pyramid traps (4’ high) will be placed per two-acre block to intercept adults. A mid-season and harvest sample each of 25 fruit per plant will be assessed for PC feeding and/or damage. We will also evaluate the following treatments: 1) border spray beginning at petal fall and continuing weekly for the first generation activity period, usually two to four weeks; 2) grower standard involving insecticide application on a 10-14 day interval using the same insecticide as in Treatment 1; and 3) untreated control. At mid-season and again at harvest, fruit damage assessment will be done by picking 25 fruits and recording PC feeding or oviposition scars. Additionally, natural enemies will be monitored using yellow sticky cards and relative PC population pressure will be examined through beat samples and monitoring traps. Based on the findings of objectives 1a and b, we will evaluate the integration spatially refined PC management at the field scale to determine reduction in fruit damage in years two and three. We will compare four treatments. At mid-season and again at harvest, fruit damage assessment will be done by picking 25 fruits from 12 sites along the perimeter and 12 in the interior, and recording PC feeding or oviposition scars. We will evaluate changes in PC populations and the impact of management tactics through the development of a stage-structured model, which will simulate mortality on specific life stages. This model will predict how our developed integrated pest management (IPM) strategy affects long-term PC pressure over successive generations. Finally, we will facilitate grower implementation by conducting trials of spatially refined application of EPNs on commercial farms in collaboration with fruit growers, and then develop and disseminate extension materials on PC management.