Southern pine beetles, Dendroctonus frontalis Zimmerman, often carry mites as they emerge from host trees. At least 14 species of mites are phoretic (Moser and Roton 1971). But for D. frontalis, it is not clearly known where in the host tree and at what stage of the beetle's development the mites attach themselves. After the beetle larvae construct oval feeding cells, they develop in three stages: pupa, callow adults, and brood adults (Fig. 1). In trees with thick bark, the larvae bore into the outer bark from within, construct pupal cells, and pupate. But in trees with thin bark, the larvae pupate directly in the larval cells next to the xylem. Thus, the larval galleries in either case are in the living phloem adjacent to the sapwood.