Characteristics of cephalic structures, spiracles, and skins of final-instar larvae of 42 species of 24 genera of the subfamily Ichneumoninae (Hymenoptera: Ichneumonidae) are described and illustrated and keys are given for the separation of tribes, genera, and species. An additional two species that were previously described and illustrated are included in the keys for a total of 44.Larval characteristics support most of the tribal, generic, and specific entities defined on the basis of adult characteristics. They place species of the tribe Phaeogenini as the most primitive and suggest a close relationship between them and species of the tribe Gyrodontini. There is no obvious close relationship between larvae of the tribe Platylabini and other tribes of the subfamily. The tribe Ichneumonini appears to be a relatively distinct group, although the inclusion of the genus Syspasis is questioned. The two subtribes, Trogusina and Callajoppina, of the tribe Trogusini are quite distinct from each other and from other groups of the Ichneumoninae; they appear to possibly have different origins, and perhaps each deserves tribal rank. There is a high degree of taxonomic congruence between the adult and larval classifications.

Presented, with comments, are 131 plates of illustrations of geometrid eggs representing five subfamilies of the Geometridae: one species of Oenochrominae, 72 species of Ennominae, four species of Geometrinae, nine species of Sterrhinae, and 45 species of Larentiinae. The illustrations are useful as identification aids, in demonstrating relationships between species, and in assessing the validity of species groupings based on taxonomic criteria from other life stages.

The Neopsini encompasses two genera, both exclusively Neotropical: Neopsis Oman (5 species) and Nollia n. gen. (2 species). Neopsis amazonica n. sp., Neopsis tumidifrons n. sp., Neopsis magna n. sp. (Brazil), and Nollia rustica n. sp. (Chile) are described, and the genera and species of the Neopsini are keyed.The New-World Macropsini encompasses five genera: Pediopsis Burmeister (1 species), Pediopsoides Matsumura (2 species), Reticopsis Hamilton (2 species), Macropsis Lewis (55 species), and Oncopsis Burmeister (36 species). Biological and morphological data are used to define the species in this taxonomically difficult tribe, with the result that 45 new species are described: Macropsis acapulco, M. dimorpha, M. igniscutellata, M. mexicana, M. oncopsimilis, and M. zebra from Mexico; Macropsis aureocephala, M. californiensis, M. ferrax, M. inversalis, M. palustris, M. pulchra, Oncopsis arizona, O. aureostria, and Reticopsis udrobates from southern California and Arizona; Oncopsis insignifica, O. mica, and O. tangenta from Utah; Macropsis borealis, M. rufescens, Oncopsis albicollis, O. incidens, O. interior, O. juno, O. marilynae, O. monticola, and O. tenuifoliae from northwestern North America; Macropsis dixiensis and O. infumata from southeastern North America; Macropsis decisa, M. jocosa, M. microceps, M. tunicata, M. xena, Oncopsis citrella, O. concurrens, O. dentata, O. deluda, O. prolixa, O. quebecensis, and O. vartyi from northeastern North America; and Macropsis deviridis, Oncopsis citra, O. crispae, and O. prairiana from Canada. Five new subspecies are described: O. cinctifrons kootenensis, O. prairiana ferrosus, and O. prairiana occidentalis, all from southern British Columbia; Oncopsis nigrinasi florida from Florida; and Macropsis deviridis alberta from western Canada. Five new synonymies are created. Keys to all taxa, host associations, and distribution maps are provided and the colour phases of the various polymorphic species are analyzed.The morphology and significance of intersex individuals of Oncopsis spp. are discussed.

This memoir is the fourth of a series dealing with the fauna of the Trichoptera of Canada and the adjacent States. It deals with the families Hyalopsychidae, Psychomyiidae, Goeridae, Brachycentridae, Sericostomatidae, Helicopsychidae, Beraeidae, Odontoceridae, Calamoceratidae and Molannidae. These families have been arbitrarily gathered here because of their small size and in spite of the fact that they are not all taxonomically related. In the following pages, one will find familial, subfamilial, generic and specific diagnosis of all the taxa constituting these families. Dichotomic keys are included and distributional records for each species are mapped. Ecological characters are given when possible.