They are based on the premise that large, low-vigor, and exposed trees are most likely to generate borers.
(They; are based; on the premise that large, low-vigor, and exposed trees are most likely to generate borers) (large, low-vigor, and exposed trees; are; most likely to generate borers) (large, low-vigor, and exposed trees; to generate; borers)
They large, low-vigor, and exposed trees large, low-vigor, and exposed trees
are based are to generate
on the premise that large, low-vigor, and exposed trees are most likely to generate borers
most likely to generate borers
borers