About This Project

Our lovely soft fruits like strawberries, grapes, and raspberries are in danger from the Spotted Wing Drosophila, a fruit fly that lays its eggs inside the ripening fruit. The fly is very hard to control and when it shows up in new areas, fruit crops are reduced in quantity and quality. Reducing the amount of fruit for sale raises prices, making it unaffordable to many people. My goal to learn more about this introduced pest in South Dakota.

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What is the context of this research?

The Spotted wing drosophila (SWD) was accidentally introduced to California from Asia in 2008. Since then it has move up and down the western coast of the U.S. causing crop losses in California, Oregon and Washington and has been found in the large fruit production areas of the the eastern U.S. It is now moving into the Mid-West states. Because the western and eastern areas were infested first they have done the majority of research on the problem.

In 2013 the fruit fly was positively identified in South Dakota at two locations on opposite side of the state. What we don't know is if it is present in other locations as well, and how fast it is moving across the state. Our growing vineyard and local fruits industries are at risk of SWD infestations damaging crops.

What is the significance of this project?

Spotted Wing Drosophila is a new pest to South Dakota with devastating possibilities. Unlike the standard vinegar fruit fly which lays its eggs on overripe and spoiling fruit, this fly lays its eggs inside healthy fruit. The larvae liquify the fruit's interior making it inedible and unsaleable. Control is difficult because insecticides do not contact the larvae. Non-organic insecticides are available to spray on the fruit killing adult flies; but with many of them the "post harvest interval", or number of days you have to wait before picking and eating is 7 days. Fruit like raspberries and strawberries must be picked every 2-3 days or it will spoil on the plant.

By conducting initial surveys across the state we will fill in the blanks on fly locations and numbers.

What are the goals of the project?

I will be doing an initial survey of South Dakota homeowners and commercial fruit and vegetable producers to determine:

1. Where the Spotted Wing Drosophia is located in 2014.

1a. How far has it spread from the two locations where it was identified in 2013.
1b. Is it present in other areas of the state.

2. Determine infestation levels at specific sites, i.e. is it a heavy or light infestation. Emphasis will be placed on vineyards and commercial sites for this part of the survey due to the economic impact this insect has.

3. Which specific fruit crops are affected in South Dakota.

4. This initial survey will be the basis for more extensive research project starting in 2015.

Budget

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The goal is to have a minimum of 150 participants including Master Gardeners, homeowners and commercial fruit and vegetable producers. South Dakota is a large state and delivering materials to the far corners of the state is an one-way trip of up to 7 hours. Mailing supplies to particpiants will reduce costs.

One of the most important parts to this survey is receiving samples to identify and then use for continuing education. These fruit flies will be mounted as stereoscope slides going to any participants requesting them.

Over half of the requested money will go toward mailing costs to send collection supplies to participants and for them to return the filled vials.

Collection and storage supplies of vials and slides with mounting chemicals are also needed.

Instructions and collection data sheets will be printed and sent to each participant.

To keep costs down, instructions for making collection devices with household containers like peanut butter jars, deli containers, and other large containers will be included. This will allow recycling of plastics that would otherwise be thrown away. Cider vinegar is the collection and shipping medium.

Any extra funds received will go toward adding participants to the study.

Meet the Team

Mary Roduner

Team Bio

I have loved insects since I was about six years old. My Mother showed my brother and I a Mourning Cloak butterfly, and explained the name came from the mourning cloak women in the 1700's wore after a death in the family. I was hooked for life. As a 4-H clubber from ages 9-18, I entered insect collections at the county and state fair most of those years. We also had a large garden when I grew up. My garden now is important to my sanity.

Working with the public as an Extension Field Specialist, I hear the fears of gardeners about this insect and the danger to their fruit. Vineyard owners are fearful they will lose their businesses. My passion is to teach these people and help them make good decisions on pest control.

This isn't my entire life though. I have the three cutest grandkids in the world. I also do needlework, freeze and can what comes out of my garden and am an ancient history buff.