American Plum Borer Eggs of this moth are deposited on cherry and peach trees in cracks under loose bark and hatch in a few days. Larval tunnels are shallow with frequent openings to the outer bark, where red frass accumulates. The larvae can't bore into the cambium unless a wound of some sort is present. Because most of the tart cherries in New York are mechanically harvested, APB has become the major borer pest in some orchards in the Lake Ontario fruit growing region. Cocoon of American plum borer Directed trunk sprays are recommended in cherries at petal fall, when first generation adults are emerging.
Adults begin to emerge during bloom and the flight peaks around petal fall or shortly thereafter.
Lorsban 4E used for lesser peachtree borers at petal fall will provide control against any APB that may be present. Field trials indicate that if APB number just a few per tree on average, this single application at petal fall will probably be adequate, given the economic constraints of tart cherry production. Under more severe pressure, a second application around the beginning of August would be warranted against the second generation larvae. This would also correspond with the timing for the last of the season's peachtree borer sprays. Lesser Peachtree Borer You should be applying trunk and scaffold sprays on peaches and cherries during the first week of June if borers are a problem in your blocks.