Features Agronomy
A weapon in the ongoing fight against the emerald ash borer

As the emerald ash borer continues to wreak havoc on targeted trees in its march through Ontario, arborists seeking to stop the pest in its tracks have sought any tool they can to fend off the devastation.

Lawn care professionals were told of an effective measure in March at the fourth annual Nutrite Professional Seminar in Guelph, Ont. Bryan Wolfe of Creative Sales Inc. spoke of the efficacy, application and long-term effects of ACECAP, a pesticide contained in a capsule which is injected into the whitewood of targeted trees.

The ash borer has been under study since 2000. At Michigan State University, it was believed in 2003 the insect’s movement would be limited to about half a mile a year, but, within only a few years, it was discovered the borer was moving six or seven miles a year.

“It’s moved a lot quicker than federal officials thought it be,” Wolfe said.

Most recently, the emerald ash borer has made its way to Welland, Ont.

ACECAP, which contains 99 per cent Orthene “is the strongest available, concentration-wise, pesticide in the industry,” Wolfe said.

It not only targets the emerald ash borer, but aphids, bagworms, tent caterpillars and several other destructive insect pests which feed on trees.

ACECAP 97, as the product is marketed in Canada, is a systemic insecticide which is safer to use than airborne-type pesticides because it is contained with a cartridge. A cordless drill is used to create a small hole into the whitewood of targeted trees. The insecticide-filled cartridge is then inserted into the created cavity and tapped flush with a flathead punch to prevent breakage of the capsule.

Once the cartridge is securely inserted into the tree, sap will dissolve the capsule and the pesticide will flow with the sap to the top of the tree within a few days. As long as the cartridge is securely inserted into the tree’s whitewood in the spring, the drilled out holes will naturally callous shut.

“In some of these trees, you couldn’t even see where the prior treatments were made,” Wolfe said.

The prescribed method for injecting ACECAP into trees is to drill in a spiral fashion from the tree’s base. The spiral method prevents compromising the tree’s structural integrity. As long as the treated trees are healthy, they will heal fine.

Some tree species will heal slower than others. Thin-barked trees, such as birch, will show scarring over the years. With such trees, it is recommended a silicone caulking be used to help seal the drilled holes.

There is no mixing or measuring required for the product, and exposure is targeted only to the tree. Even though the label recommends applicators wear protective gloves and long-sleeved shirts, none of the pesticide will ever come into contact with the body.

Injecting trees is simple to do and is fast with no waiting around, Wolfe said.

“The advantage is that most trees take only 10 minutes to treat.”

ACECAP is meant only for ornamental trees and not fruit-bearing species. It’s been used effectively in the fight against pine beetles in Western Canada, Wolfe said. One treatment was good for two seasons.

For emerald ash borer control, it is recommended trees be treated every season for a period of five or six years.

More than a dozen years ago, in St. John’s, Nfld., a spanworm problem existed in which several ornamental trees had become defoliated.

“They would come through the area and strip every tree, practically.”

ACECAP was tested to address the issue, and it was found to be the only thing studied to stop the insect from causing any further damage.

Wolfe said there was some concern expressed about five years ago among environmentalists in Alaska who wondered if the product was responsible for the deaths of several birds claimed to have been found at the base of treated trees. In response, the U.S. Forest Service initiated a study in which ACECAP was used to combat aphids. Five years after the test’s conclusion, a treated tree was cut up into sections where it was determined the insecticide had travelled the height of the tree and wasn’t responsible for any bird deaths.
Many of the trees in the study were in excess of 100 feet and all aphids were killed, but there was never a problem with birds, he said.

Trees large and small can be treated with the insecticide cartridges. Trees measuring a little more than an inch in diameter are treated with smaller-sized cartridges which deliver a smaller dose of the insecticide.
Only licensed pesticide applicators are legally able to treat trees with ACECAP.

In addition to the insecticide cartridge, the company also produces a tree fertilizer called MEDICAP MD which is administered in the same fashion as ACECAP, yet requiring no licence to apply.

Described as “a multi-vitamin for a tree,” its 12-4-4 (nitrogen-phosphorus-potassium) formulation also includes four per cent iron, four per cent manganese and four per cent zinc.

Wolfe said customers find an unhealthy tree will become green, full and healthy in less than four weeks.
“This is good for up to three seasons with a single application.”

Wolfe said it is best to use the fertilizer treatment when the tree is dormant. The manganese and zinc content demand the product be used before the tree has the chance to leaf out.

“Otherwise, you won’t move any of the nutrients into the plant once they’ve already fully leafed.”

Unlike ACECAP, MEDICAP MD is safe to use in fruit trees and will help to produce big, healthy fruit, Wolfe said.

After about two to three days, the cartridge’s gel cap breaks down, allowing the material to work its way into the foliage within about seven days.

“These are designed to stay in the tree. The tree will absorb the contents of the chemical, and it will be transported throughout.”

The cartridges are available in three sizes: quarter-inch, a standard three-eighths-inch, and a “super” half-inch.