The American plum borer (APB) is a cambium-feeding moth pest of fruit and ornamental trees. It is unusual because it belongs to the pyralid, rather than the sesiid (clearwing) family, which is more commonly associated with this kind of damage. It is the major borer pest of stone fruits in Michigan, causing up to a 33% decline in the life span of tart cherry trees there. Recent studies indicate that it is the most abundant borer in commercial tart cherry orchards in New York. Significant numbers are also found in peach trees infected by canker diseases. Widely distributed throughout most of North America and parts of South America, it has an extensive range of hosts including at least 15 families of fruit, nut, ornamental, and forest trees, and a few woody annuals. Its rise to major pest status in tart cherry can be traced to bark damaged by mechanical harvesters, which provides larvae an entryway to the cambium.