Scaffolds 03 index

Upcoming Pest Events | Trap Catches | Insects | General Info

Return to top

Upcoming Pest Events | Trap Catches | Insects | General Info

Return to top

Upcoming Pest Events | Trap Catches | Insects | General Info

FALL BORER CONTROL CONSIDERATIONS

(Dave Kain and Art Agnello, Entomology, Geneva)

[Ed. note: We're printing this article as an update from last year's version on borer management because of its timeliness and applicability to the situation in many commercial orchards recently.]

There is increasing concern throughout the Northeast about damage done to apple trees by borers. The species of primary concern is dogwood borer, but American plum borer can be prevalent in western New York apple orchards that are close to tart cherry and peach orchards. While we do not yet fully understand the effects these borers have on dwarf trees, we do know that they reduce vigor and can, in time, completely girdle and kill trees.

Over the last three growing seasons, we have tested a number of insecticides against these borers. Lorsban is very effective for this use and we would strongly urge growers to take advantage of it where needed. In 2001 and 2002 we compared some other materials, including white latex paint, endosulfan, Avaunt, Surround, Intrepid, and Danitol with Lorsban, with varying results. To make a long story short, only Avaunt and Danitol, applied two or three times, respectively, in midsummer, provided control comparable to one application of Lorsban.

Our tests so far have shown that borers can be controlled season-long by applying Lorsban at various times in the spring and summer. While postbloom trunk applications of Lorsban are still allowed, enabling growers to spray at the peak of the dogwood borer flight, applying this material prebloom as early as half-inch green works well, too, and may be more convenient. Fall also may be a good time to control dogwood borer. Results from 2002 indicated that Lorsban applied postharvest the previous year (sprays went on in October 2001) controlled both generations of dogwood borer. An October 2002 application of Lorsban similarly provided control of the first generation of dogwood borer this year. (Second generation control results will be in in late September or October.) Lorsban works when applied in the spring and fall because it infiltrates burrknot tissue and kills larvae concealed within. It is also very persistent in wood so it continues to work for a considerably long time after it is applied (apparently 9-12 months in our trials). Fall application may offer growers a more convenient alternative for applying borer control sprays.

In a survey we conducted recently, we observed some relationships between borer infestation and various orchard parameters such as the proportion of trees with burrknots, proximity to stone fruit orchards and presence of mouseguards. Conventional wisdom has held that borer problems are worse where mouseguards are in place. Mouseguards can contribute to increased expression of the burrknots borers invade and may shield borers from predators and insecticide sprays. This has led some growers to contemplate removing mouseguards under the premise that mice are easier to control than the borers. However, results of our survey indicate that dogwood borer larvae may be found as readily in trees without mouseguards as in those with them. (American plum borer may be a different story in orchards near tart cherry or peach trees.) The orchard in which we're conducting borer control trials has never had mouseguards and there is no shortage of dogwood borers. If mouseguards are deteriorated and no longer protect the tree, there may be some small advantage, in terms of borers, to removing them. But, in orchards where mouseguards still provide protection against rodents, removing them for the sake of borer control is probably not worth the risk. Instead, we would recommend the use of trunk sprays to control borers. Even with mouseguards on, insecticides will give adequate control if they are applied carefully (i.e., a coarse, low-pressure, soaking spray with a hangun). Bottom line: as we go into fall, consider using Lorsban after harvest to control borers, and reconsider removing mouseguards on trees where they still afford protection.

Upcoming Pest Events | Trap Catches | Insects | General Info

LAST CHANCE TO SALVAGE THE STEAK COOKOUT

So far, we have received an insufficient number of responses to justify proceeding with our steak cookout and end-of-season social gathering at the enchanting Geneva Country Club, which we had proposed to take place at 6:00 pm on Wednesday, Sept. 3. For $21, we are offering a sizzling steak, corn on the cob, salt potatoes, and tossed salad, with brownies and fruit for dessert, plus a cash bar, not to mention the scintillating company of your fellow fruit industry professionals. If we do not hear from enough interested participants by next Tuesday (i.e., immediately after Labor Day), we will regrettably have to cancel this event. Please contact Harvey Reissig (315-787-2336 or whr1@cornell.edu) to help rescue an otherwise unremarkable Wednesday evening.

Also, we presume the perceived lack of interest does not also extend to the Fruit Pest Control Field Day, which will begin the following morning at 8:30 in the foyer of Barton Lab in Geneva, continuing until noon and picking up again on Friday Sept. 5 at the Highland Lab.

Scaffolds is published weekly from March to September by Cornell University -- NYS Agricultural Experiment Station (Geneva), and Ithaca -- with the assistance of Cornell Cooperative Extension. New York field reports welcomed. Send submissions by 3 p.m. Monday to:

Scaffolds Fruit Journal
Editors: A. Agnello, D. Kain
Dept. of Entomology, NYSAES
P.O. Box 462
Geneva, NY 14456-0462
Phone: 315-787-2341 FAX: 315-787-2326
E-mail: ama4@cornell.edu

Online at <http://www.nysaes.cornell.edu/ent/scaffolds/>