Podmosta macdunnoughi (Ricker) was partially described by Ricker (1947) and Harper & Hynes (1971). Details of the cercal intercalaries are difficult to see at 50X with a dissecting light microscope, and therefore require SEM.
1 Distribution east of 90 th meridian … macdunnoughi
1’ Distribution west of 100 th meridian …..……….. 2
2 Head with distinct, light interocellar spot (Fig. 2) ………………………………………....… delicatula
2’ Head without interocellar spot (Fig.1) ……….. 3
3 Whorl bristles of middle and anteapical cercal segments short, at most, ca. 0.20X the length of their segment, and bearing 2- 3 intercalary hairs as seen laterally (Fig. 44); widespread, Alaska south to Colorado ……………………………….. decepta
3’ Whorl bristles of middle and anteapical cercal segments long, 0.35-0.80X the length of their segment, and bearing variable number of intercalaries up to 7 (Figs. 48, 50); Alaska-Yukon and south to Oregon ……………..………………. 4
4 Whorl bristles of proximal 10 cercal segments short, ca. 0.25X length of their segment (Fig. 49); middle and apical cercal segments bearing 2- 4 intercalary bristles and/or fine hairs (Fig. 50); Alaska and Yukon ………………………..…. weberi
4’ Whorl bristles of proximal 10 cercal segments long, about 0.67X the length of their segment (Fig. 47); middle and apical cercal segments bearing 3-7 fine intercalary hairs (Fig. 48); Oregon and Washington ………………………………… obscura