2013 Annual Report
1a.Objectives (from AD-416):
The Spotted Wing Drosophila (SWD) is an invasive pest of small and stone fruits including but not limited to blueberries, blackberries, grapes, strawberries, raspberries, cherries, apple, peach, and plum. SWD is established throughout the west coast of the U.S. and Canada where it has caused significant economic damage to both fresh and processed fruit during 2008 and 2009, and urgent action is needed. The overarching objective of our proposal is to develop an integrated systems-based approach to managing manage SWD. We have created a Pacific Coast North American response team to respond that includes with expertise in entomology, horticulture, genomics, pest management consulting, agricultural production, economics, sociology, extension, and policy-making. The primary questions are based on limited knowledge of SWD biology, physiology and ecology or its economic and social/political impacts.
Objective 1: Evaluate genetic, biological and ecological parameters of SWD.
Objective 2: Develop a SWD management strategy to minimize infestation and reduce risk.
Objective 3: Measure impact and success of SWD project.
Objective 4: Synthesize existing and new information and provide real-time support.
1b.Approach (from AD-416):
Laboratory studies will determine the stage(s) of ripeness the fruits that are most susceptible to SWD, this information will assist growers with the timing of treatments in the field. A common cultivar of each fruit (blueberry, raspberry, blackberry, strawberry, grape, cherry) will be tested at various stages of ripeness in no-choice and choice studies. Tests will compare methyl eugenol, GF 120, fermenting yeast, apple cider vinegar, and ~20 other semiochemicals available for flies. Preliminary screening will first be done by observing 25 male or 25 female flies in a four-arm olfactometer for orientation towards the odor released from one arm and air (control) from the other three arms. Bioassays will be performed using the formulated products of all small fruit and stone fruit insecticides registered in the states of Oregon, Washington, and California with known or suspected activity against Diptera. While laboratory assays cannot determine which pesticides will perform well in the field, they can determine which pesticides lack activity against this pest. Assays will be performed to determine both the direct spray and residual activity of each product. The experiments will be performed in a randomized complete block design with three replicates each containing 10 20 adult SWD. All bioassays will be performed in disposable 100 x 15 mm Petri plates. (Specialty Crops Research Initiative (SCRI). Documents Reimbursable with OSU. Log 40991. Formerly 5358-22000-036-01R (August, 2011).
This research was conducted in support of NP304 objective 2B of the parent project. The spotted wing drosophila (SWD) is a recent invasive insect that infests small and stone fruits that is found in over half of the U.S. Unlike other nuisance flies that infest rotting or damaged fruit, this species will infest ripening fruit on the plant leading to increased pesticide sprays and crop loss. Better knowledge of the biology of the fly will reveal areas where management can be tailored to control the fly while minimizing pesticide inputs.
Studies on traps with various physical designs suggest that red or yellow can be more attractive than clear or white traps (the latter are commonly used now). Also, traps with a larger bait surface area are more attractive. Deli container traps with an entry mesh opening on the side catch more than similar traps with a top mesh opening. The current monitoring trap for SWD is limited in its effectiveness, features known to improve capture of the fly will be incorporated into future trap designs and enable growers to detect the fly earlier in the season. Currently, three studies are underway examining various types of commercially available baits for attractiveness to the fly. Comparisons include the commonly used apple cider vinegar and yeast-sugar-water, lures in development by a commercial company, Chinese vinegar, and other homemade yeast or fermenting solutions, as well as the four-component lure by Cha and Landolt.
Current studies are examining what factors make a blueberry more susceptible to the fly. In laboratory and field cage studies, blueberries of different ripeness stages are exposed to flies. These berries are then examined for egg laying, and then for flesh firmness, skin penetration force, pH and brix. These data are incorporated into a probability model to predict infestation.