Angerilli, N.P.D., & Logan, D.M. 1985 Early season apple pest management: control of two species of scales (Homo.: Diaspididae) and Bruce Spanworm (Lep.: Geometridae) with methidathion.. Journal of the Entomological Society of British Columbia 82: 31-35.

Notes: Abstract: Chemical control of Quadraspidiotus perniciosus & Q. ostraeformis; methidathion more effective than dormant oil when applied at tight cluster stage of bud development.