DATCP Orchard Network: Five Key Pests Now Active

Pictured: Obliquebanded leafroller moth. Photo by K. Hamilton DATCP

Apple orchards in DATCP’s pest monitoring network are reporting increased codling moth captures and the onset of flights for two other key pests.

The spring obliquebanded leafroller and dogwood borer flights began last week in a few southern Wisconsin locations, and several more trap sites recorded their first DWB and OBLR trap catches during the May 28-June 4 reporting period.

Obliquebanded Leafroller

For OBLR, inspecting terminals for larvae over the next two to three weeks will help to determine the potential for problems later this season. Although there is no direct correlation between OBLR trap counts and larval populations, scouting is important since orchards that register even low counts (less than five moths per trap) can develop significant larval problems a few weeks after a flight has occurred. Control of OBLR is warranted for populations averaging three or more larvae per tree.

Dogwood Borer

In the case of DWB, trap counts do not indicate the need for control but instead suggest when to start scouting for evidence of larval feeding, such as frass around the graft union of trees. The correct height for traps is 3-4 feet above the ground. Scouting for this pest is most critical for orchards with new trees planted in the last five years.

DATCP cooperators should be aware that the dogwood borer pheromone lure attracts several native clearwing moth species and accurate identification is important. In the photos below, the smaller specimens are male dogwood borers while the larger insects are non-targets. Male dogwood borers can be identified by the two bands on the abdomen.

Photos by Laura Tisch Munchkey Apples.

Codling Moth

Codling moth flights continued for the third week and have been fairly consistent due to warm evening temperatures and dry weather. Initial larvicide treatments will begin June 5-7 in southern Wisconsin locations that have accumulated 250 degree days (base temp 50 degrees Fahrenheit) since the biofix was set May 14-20. For the week ending June 2, 10 of 21 orchard sites reported high or economic counts of five to 23 moths (refer to codling moth map) and, overall, catches increased from the previous week.

Redbanded Leafroller

Lastly, RBLR moth counts fell to an eight-week low at monitoring locations. The weekly total across all orchards was just 89 moths, down from the peak total of 1,103 moths May 7-13. The low number of moths appearing in traps means that the first RBLR flight has ended, and populations are primarily in the larval stages. The second moth flight is expected to begin by mid-June. Apple growers are reminded to refresh pheromone lures in advance of the second flight.

With the exception of apple magot red ball traps which are set in late June, all five pheromone traps supplied by DATCP should now be up in cooperating orchards.

And see more about the lesser peachtree borer: https://widatcp.maps.arcgis.com/apps/mapviewer/index.html?configurableview=true&webmap=03aa63a57dc0487f9e4609d45319a675&theme=light&heading=true&share=true&center=-89.5117795615658%2c44.75555740061336&scale=4622324.434309

Learn more about apple pests: https://datcp.wi.gov/Pages/Programs_Services/AppleOrchardPests.aspx