New research on the maple tip borer

A shoot boring caterpillar, Proteoteras aesculana, destroys new tender shoots of red maple if not killed first. It causes a lot of extra work to train a new central leader. We have learned new information about this insect that we refer to as the maple tip borer.

The window of opportunity appears to be longer than we originally believed following Univ. of Kentucky research by Dr. Potter. Spray once anytime between bud break and when the first two pair of leaves come out (which is usually mid-to late April).

This should greatly facilitate getting this task done. If you spray too late, the critter is protected by the new growth that he tunnels into.

The Talstar Flowable (bifenthrin) label suggests a range of 12-20 fl oz/100 gal/acre. UT only tested 12 fl oz. Dr. Potter only tested 22 fl oz. It is suspected that higher rates would be more residual. Rainfall amounts and intensity should affect the residual period.

I suggest using the lower rate if your able to apply during the narrow window that our research was successful with, but I would use a higher rate if your making the application earlier. I can not legally recommend more than the labeled rate of 20 fl oz per 100 gallons.

I hope Dr. Potter continues his research with several different labeled rates. It is good to know that an earlier application can be effective. Management must decide when to make the application depending on cost of the insecticide, work load, weather and soil conditions. UT Original Recommendation: Talstar Flowable (bifenthrin) mixed at 12 fluid ounces per 100 gallons of water. Spray when the first 2 pair of leaves have come out.

Talstar’s control was far superior to Orthene, Dursban, Merit, Cygon and a few others during 5 years of research done at several Warren County nurseries. Dr. Potter’s 1 year research was done at 2 nurseries in central Ky. Plant growth did begin earlier in 2007 until the April freeze slammed the door.

‘ I have calibration trays for the granular preemergent herbicides that are applied over containers. I have the type needed for Rout & OH2. I also have some for Snapshot & Showcase. These plastic trays are 1 sq. ft. and designed to be laid among the containers. After applying the herbicide, pick the tray up, tilt it and encourage the granules to collect into one of the dimples (either 75, 100 or 150 lbs/acre) in one of the corners. Exercise caution not to puncture the thin plastic dimples. If the first dimple is not full or over filled by the amount in the tray, tilt and shake the contents into another corner dimple. Call 931-473-8484 before coming to ensure someone will be in the office and that I have what you need.