Host Adaptation, Sex Ratio, and Flight Activity in Male Black Pineleaf Scale1

Abstract
Field studies of male black pineleaf scale, Nuculaspis californica (Coleman), revealed a biased sex ratio which varied from tree to tree. Male frequency correlated with insect density and adaptation to a single individual ponderosa pine, Pinus ponderosa (Lawson). Sticky-trap capture data showed a diurnal pattern of male flight activity.