Du, J.W., Ding, D.C., Tang, X.H., Xu, S.F., & Wu, H. 1991 Preliminary studies on sex pheromone of pine needles Hemiberlesian scale, Hemiberlesia pitysophila (Coccoidea: Diaspididae) I. Activity of crude extract and its separation methods.. Contributions of the Shanghai Institute of Entomology 45-50.

Notes: Releasing time of sex pheromone by pine needle hemiberlesia females has been established at 6-9 a.m.; methods include capillary GC analysis and bioassays of GC fractions.