IPM Strategies for Reducing Insect Pest Damage in Midwest Blueberries: Webinar

New methods for both monitoring spotted-wing drosophila (SWD) in blueberries and managing SWD are available. The new monitoring method is focused on larval numbers, and it works for blueberry maggot also. This new, cheap and easy method for detecting SWD fruit infestations can even be done in the field. Management efforts still include traditional spray programs, but additional options involve biological controls (parasitoid wasps) and even a physical control (mylar mulch).

Details are presented by Dr. Rufus Isaacs, professor and extension entomologist at Michigan State University in this webinar: “IPM Strategies for Reducing Insect Pest Damage in Midwest Blueberries.”

Dr. Isaacs begins by discussing multiple options for monitoring SWD in blueberry orchards. Sticky traps or synthetic lure–soapy water traps have been used to detect adults, but the numbers collected do not provide a reliable estimate of the number of eggs that have been laid in developing fruit.

Larval monitoring is better because you gain information about what is happening within the fruit. You can tell whether SWD has already laid eggs and whether first or second larval instars are present. Learn how to create a larval monitoring set-up in the recording.

Larval data provides insights into when to begin spray applications, and it can also be used to determine whether management programs are effective. Resistance to insecticide programs has not been observed in SWD in Michigan, but resistant populations of SWD have been confirmed in California.

Biological controls are being studied to see whether they may help control SWD populations. Two parasitoid wasps, the samba wasp and the ronin wasp, prey on SWD. Only the samba wasp has been approved for release by the USDA so researchers began by releasing samba wasps in Minnesota and Michigan and monitoring wasp and SWD populations. However, while monitoring for samba wasps, researchers actually found higher populations of ronin wasp. The ronin wasp likely hitchhiked to the United States like SWD.

Using a physical control of mylar mulch is also worth exploring. The reflective mylar directs light up in the blueberry canopy, which makes the habitat less suitable for SWD. In addition, the extra light supports photosynthesis and helps the fruit ripen at an even rate.

Presenter