2016-17 Rapid Ag: Creating a Risk-based Decision Support Tool and Early-warning System for Spotted-wing Drosophila

November 1, 2015

Principal Leader

Christopher R. Philips


Department of Entomology

Funding Awarded

  • 2016 Fiscal Year: $75,953
  • 2017 Fiscal Year: $76,028

The Problem

The emergence of Spotted-wing Drosophila (SWD) in Minnesota is seen by many as a "game changer" for raspberry and blueberry production in the state. Increased use of pesticides to combat SWD has led to a need for a more detailed integrated pest management plan that takes into account host plants and seasonality.


The ability of an invasive insect to establish in a novel environment and become a major pest depends, in part, on its dispersal ability and its ability to utilize available host plants. Knowledge of these interactions can aid in optimizing control strategies such as fine-tuning spatial and temporal control measures. Spatial optimization of control may be particularly important when early season infestations are likely to occur due to the emigration of overwintering individuals from other areas. Dispersal and movement from crop and noncrop hosts remains one of the most challenging variables to characterize, particularly for insects of small size in natural settings. Nevertheless, it is also one of the most important variables in designing monitoring and control programs for invasive pests.

Among the recent invasive species in Minnesota, SWD: Drosophila suzukii, has emerged as the most devastating pest of soft fruits including blackberry, raspberry, blueberry, cherry, peach, grape, and strawberry, and some reports of infestations in cherry tomato. Unlike most Drosophila species, SWD females oviposit primarily in ripening fruits, presenting a major threat to U.S. fruit industries. Since its first detection in California in 2008, SWD has spread throughout the U.S. causing significant yield losses, often reaching 100% and increased pesticide use at an estimated cost approaching $1 billion annually. The presence of SWD can be viewed as a “game changer” to raspberry and blueberry production, as these crops historically required very little insecticide use, but now incur the highest infestation levels, with yield losses often reaching 100%. Currently SWD management consists of insecticide applications on a 4-5 day schedule. Increased chemical inputs add substantial new costs to growing operations and increased risks to surrounding ecosystems, leading to numerous growers abandoning these crops, and substantial economic losses.


  1. Identify and evaluate non-crop host plants.

  2. Correlate seasonal phenology of crop and non-crop hosts with SWD populations, and pesticide application timing.

  3. Develop a risk-based IPM decision support tool and early warning system for Minnesota growers.

SWD damage.

Examples of damage done by SWD to blueberries (A), cherries (B & C) and raspberries(D).