Richards (9) recognized five species of Lecanium for Canada – namely L. coryli L., L. cerasifex Fitch, L. tiliae L., L. nigrofasciatum Pergande and L. caryae Fitch. L. coryli L. and L. cerasifex Fitch were distributed from British Columbia to Nova Scotia; L. tiliae L. occurred only in British Columbia.
Further, Richards (9) drew the following conclusions:
1.) L. coryli is the L. corni Bouché of Marchal (1908) and of most European workers but is not the L. corni of North American workers.
2.) L. corni Bouché of Sanders (1909) and subsequent North American workers is a mixture of two species, L. corni Bouché of Marchal and L. cerasifex Fitch of Richards.
3.) L. tiliae is L. coryli of Marchal (1908) and subsequent workers.