This is the third volume by Wright and Gilligan treating the geometrid moth genus Eucosmia of North America. The authors review a total of 83 species representing four genera in the tribe Eucosmini that occur in the contiguous United States and Canada. Diagnostic morphological features useful in species identification are emphasized. Included are 51 species of Epiblema Hübner, fifteen species of Sonia Heinrich, eleven species of Suleima Heinrich, and six species of Notocelia Hübner. Twenty new species are described.
This volume is in the same format as the past two volumes in this series on Eucosma and Pelochrista (Wright and Gilligan 2015, 2017). Species are numbered sequentially as they appear in the book and these numbers are also used to refer to the adult and genitalia plates. Several numbers are assigned to morphospecies or complexes that are not described. Each species account includes information on the taxonomy/synonymy, type information and discussion, morphological description, distribution, adult flight period, and biology (if known).
The plates include 540 images of adults in full colour and 612 genitalia drawings.