LIFE HISTORY, HABITS, AND DAMAGE OF CHRYSOBOTHRIS ORONO (COLEOPTERA: BUPRESTIDAE) ON RED PINE IN MICHIGAN

Abstract

Chrysobothris orono Frost, a buprestid which attacks living red pine (Pinus resinosa Ait.) and jack pine (P. banksiana Lamb.), has a 2-year life cycle and two separate broods in Michigan. Adults emerge from May to July. The eggs are laid singly, usually on the southwest side of a tree; the fifth and sixth whorls from the top are the preferred oviposition sites. Larval eclosion usually occurs in early June. Each larva excavates a cell in the bark and causes the flowing pitch to coagulate into a large pitch mass. The first three instars feed in the bark and the last two instars feed in the xylem. Advanced larvae may reach the fourth instar by fall of the first year; overwintering occurs in the third and fourth instars. The fifth instar, which appears in the spring of the second year, bores a short L-shaped gallery in the xylem and plugs it with frass and wood chips to form a pupal cell. It pupates in the spring of the third year. Adults emerge by chewing through the plug and pitch mass. The bark cell and xylem gallery seldom injure the tree directly, but they remain as defects in the bole after the wounds have healed. Because damage is slight and the insect population low, C. orono is not likely to become an important forest pest.