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ARS Home » Pacific West Area » Logan, Utah » Pollinating Insect-Biology, Management, Systematics Research » Research » Research Project #436078

Research Project: Blue Orchard Bee Pollination in Washington Pear and Sweet Cherry Orchards

Location: Pollinating Insect-Biology, Management, Systematics Research

Project Number: 2080-21000-019-021-A
Project Type: Cooperative Agreement

Start Date: Mar 15, 2019
End Date: Jul 29, 2021

Growing public interest in wild and alternative bees over the past decade has led to the development of a healthy and competitive blue orchard bee (BOB) industry (Osmia lignaria), from which the necessary quantities of bees are now available for field-scale trials and uses. Due to recent declines in honey bee colony abundance and health, now is an optimal time to target Washington pear and sweet cherry for alternative approaches to commercial pollination. Objective 1: Measure the effect of BOB pollination on fruit set and yield in Washington State pear and cherry orchards over three years. Objective 2: Evaluate whether BOB nesting in commercially managed pear and sweet cherry orchards can result in sustainable rates of bee reproduction over a three-year trial.

This project will entail using blue orchard bees (BOBs) in combination with honey bees to evaluate if the addition of BOBs increases historically “low” yields in Washington sweet cherries and pears. BOBs will be introduced to three separate, 5-acre plots of 1) pears and 2) sweet cherries during their respective bloom periods in 2019, 2020, and 2021. Special care will be taken to ensure that all three replicates for both crops are controlled for age and variety, and subjected to similar orchard management practices. Bees will be released and managed according to current practices. After bloom ends, fruit will be permitted to set and develop naturally over the season. At harvest, we will work with orchardists to determine average fruit yield/acre in experimental plots. Fruit yield/acre will be compared to historical yield averages for the same orchard to examine the relative impact of BOB pollination on orchard performance for each year of the study. Additionally, these yield averages will be compared to fruit production of neighboring orchards that did not receive the added benefit of BOB pollination services (and are located outside the flight range of managed BOB populations). If experimental orchards reveal consistent increases in fruit yield over time and relative to other neighboring orchards in a given year, it will confirm that BOB pollination provides an overall net benefit in orchard blocks where they are introduced. These data will be evaluated using GLIMMIX in SAS, a statistical software program already licensed for use by the USDA ARS. BOB reproduction will also be evaluated over the 3 study years. To evaluate BOB reproduction in orchards, we will collect nests in Washington, and later store completed nests at the USDA-ARS Pollinating Insects Research Unit, where X- radiography can be used to nonlethally count, sex and assess parasitism/diseases of the resultant BOB progeny.