A revision of the genus Hoplandria of America north of Mexico is presented. Four subgenera are recognized, of which two (Genosema Notman and Lophomucter Notman) previously were given generic status and one (Arrhenandria) is here newly described. Twelve species are defined, of which eight are described as new: H. alternans, H. isabellae, H. kisatchie, H. klimaszewskii, H. oconee, H. okaloosa, H. sanbornei, and H. smetanai. The species are arranged according to their relationships into species groups within the subgenus Lophomucter, where seven species are assigned. For the remaining subgenera species grouping was not possible due to the smaller number of species. The following synonymies are confirmed (the first specific name is valid): Subg. Hoplandria, H. lateralis (Melsheimer) = H. ochracea Kraatz = H. texana Casey = H. arizonica Casey = H. carinata Casey; Subg. Arrhenandria, H. laeviventris Casey = H. acudentata Dury. The species Genosema sexualis Notman is here synonymized with H. pulchra Kraatz. Hoplandria brittoni Casey was previously regarded as a synonym of H. lateralis (Melsheimer); it is now considered as a junior synonym of Platandria carolinae Casey. Lectotypes are designated for Gyrophaena lateralis Melsheimer, Hoplandria arizonica Casey, H. carinata Casey, H. laeviventris Casey, H. ochracea Kraatz, H. pulchra Kraatz, and H. texana Casey. Keys to subgenera and species are provided. All species are described, diagnostic characteristics of each are illustrated with line drawings and scanning electron microscope photomicrographs, and all available bionomic and distributional data are given. The morphology, systematics, and phylogeny of the subgenera and certain species are discussed, and a checklist of Nearctic species is added.

Three subfamilies are classified in Eupelmidae: Calosotinae Bouček, Eupelminae Walker, and Metapelmatinae Bouček. Diagnoses of these three subfamilies and of Tanaostigmatidae are given, together with a key to distinguish members from each other and from other Chalcidoidea. Genera of Calosotinae and Metapelmatinae are revised for the world, with a key to genera given for both subfamilies. For each genus the following is provided: synonymy, description of structural features of males and females, notes on distribution and hosts, available keys to species listed by biogeographic region, and a catalog of species. New generic combinations are made in the catalogs of species based on examination of type specimens of the species. Eight genera are included in Calosotinae [type species in brackets]: Archaeopelma gen.nov. [A. tropeotergum sp.nov.], Licrooides gen.nov. [L. umbilicatus sp.nov.], Paraeusandalum gen.nov. [P. chilense sp.nov.], Eusandalum Ratzeburg, Chirolophus Haliday, Calosota Curtis, Balcha Walker, and Tanythorax gen.nov. [T. spinosus sp.nov.]. Four genera are included in Metapelmatinae: Metapelma Westwood, Neanastatus Girault, Eopelma gen.nov. [E. mystax sp.nov.], and Lambdobregma gen.nov. [L. schwarzii (Ashmead) comb.nov.]. The following are proposed as new synonymies: Notosandalum De Santis and Exosandalum Bouček = Eusandalum Ratzeburg, and Metacalosoter Masi = Calosota Curtis. Eighteen structural features of adults of the three eupelmid subfamilies, and of other Chalcidoidea including Tanaostigmatidae, Encyrtidae, Aphelinidae, and Pteromalidae, are studied to delimit character states and determine their distribution among the higher taxa. Twenty-two additional features of adults of Calosotinae and Metapelmatinae are studied for supplemental evidence of relationships among the genera in these two subfamilies. Observed character-state distributions are used to postulate character polarity and homoplastic states, and hypotheses of monophyly and relationships among taxa are based on proposed synapomorphic states. Aphelinidae sensu lato (including the subfamily Eriaporinae) are indicated as either a paraphyletic or polyphyletic taxon if the Eriaporinae are included but the Signiphoridae are excluded. Tanaostigmatidae sensu lato (including the genus Cynipencyrtus Ishii) are indicated as the sister group of Encyrtidae based on a relatively long mesoscutal process for the muscle pl2–t2c, and structure of the articulation between the mesoscutum and scutellar-axillar complex. The genus Cynipencyrtus Ishii is indicated to be most closely related to Encyrtidae based on common possession of transverse axillae and mesotibial apical pegs. Possible relationships among Calosotinae, Metapelmatinae, and Eupelminae, and among these and Tanaostigmatidae + Encyrtidae remain unresolved. There are no derived character states unique to either Eupelmidae, or Eupelmidae + (Tanaostigmatidae + Encyrtidae), so that these taxa and relationships are not definitively supported as monophyletic. Eupelmidae may represent a grade-level taxon with membership determined by similar suites of apomorphic states that function to enhance jumping ability. Cladograms are used to illustrate alternate hypotheses of character-state evolution and relationships among the genera of Calosotinae and Metapelmatinae. Distribution of character states for the higher taxa and for each genus of Calosotinae and Metapelmatinae is summarized in two tables. Scanning electron photomicrographs are used to illustrate structural features.

The genus Symmorphus Wesmael is distributed throughout the Oriental, Palearctic, and Nearctic regions, as well as the northernmost Neotropical region, and appears to occupy a relatively isolated phylogenetic position within the Eumeninae. Females of Symmorphus, for those species in which nesting behavior is known, mass-provision cells in pre-existing cavities with chrysomelid, curculionid, or microlepidopterous larvae.Thirty-six species are recognized, including three new species and two new subspecies. Keys are provided for the identification of adult specimens, all species are described, and their geographical distributions mapped.Two subgenera, S. (Parasymmorphus) Cumming and Vecht and S. (Symmorphus) Wesmael, are recognized. Symmorphus (Parasymmorphus) includes S. parvilineatus (Cameron), S. momunganensis (Schulthess), and S. negrosensis Cumming and Vecht. Within S. (Symmorphus) three informal species groups are recognized, with the following included species and subspecies: (1) S. hoozanensis group — S. hoozanensis (Schulthess), S. alkimus alkimus Cumming and Vecht, S. alkimus dialeukus ssp.nov. (type-locality Sibolangit, N. Sumatra), S. ambotretus sp.nov. (type-locality Mt. Omei, Sichuan Province, China), and S. canlaonicus sp.nov. (type-locality Mt. Canlaon, Negros Oriental, Philippines); (2) S. declivis group — S. declivis Harttig; (3) S. murarius group — S. murarius (Linnaeus), S. foveolatus Gussakovskij, S. glasunowi Morawitz, S. sichuanensis Lee, S. crassicornis (Panzer), S. captivus (Smith), S. angustatus (Zetterstedt), S. albomarginatus albomarginatus (Saussure), S. albomarginatus midas ssp.nov. (type-locality Bentsen Rio Grande Valley State Park, Texas, USA), S. decens (Kostylev), S. violaceipennis Soika, S. mizuhonis Tsuneki, S. bifasciatus (Linnaeus), S. debilitatus (Saussure), S. cliens Soika, S. connexus (Curtis), S. lucens (Kostylev), S. sublaevis (Kostylev), S. canadensis (Saussure), S. projectus Bohart, S. tukvarensis (Meade-Waldo), S. nipteroides sp.nov. (type-locality N. Yourdou, India), S. fuscipes (Herrich-Schaeffer), S. apiciornatus (Cameron), S. aurantiopictus Soika, S. allobrogus (Saussure), S. cristatus (Saussure), S. gracilis (Brullé), and S. paralleliventris Soika.The following new synonymy is proposed: S. calciatii (Zavattari) = S. glasunowi Morawitz; S. nursei (Bingham), S. hospes (Nurse), and S. hospitans (Dalla Torre) = S. crassicornis (Panzer); S. hakutozanus Tsuneki and S. nansetsurei Tsuneki = S. angustatus (Zetterstedt); S. walshianus (Saussure) and S. meridionalis Viereck = S. albomarginatus albomarginatus (Saussure); S. kurentzovi Kurzenko, S. iiyamai Tsuneki, S. shiroyamai Tsuneki, S. piceanus Tsuneki, and S. sassai Tsuneki = S. mizuhonis Tsuneki; S. sinuatus (Fabricius), S. sinuatus mutinensis (Baldini), S. sparsus Morawitz, S. sinuatissimus Richards, S. mutinensis auster Soika, and S. mutinensis yezoanus Tsuneki = S. bifasciatus (Linnaeus); S. ishikawai Soika = S. lucens (Kostylev); S. seoulensis Tsuneki = S. apiciornatus (Cameron); S. pumilus (Saussure) and S. trisulcatus Cameron = S. cristatus (Saussure); S. elegans libanicus Soika = S. gracilis (Brullé); and S. allobrogus (Saussure) is removed from synonymy with S. bifasciatus (Linnaeus). Odynerus latipennis Smith and Odynerus cilicius Cameron, previously considered to belong within Symmorphus, are excluded from the genus, and S. sounkionis Tsuneki is transferred as Ancistrocerus sounkionis (Tsuneki) comb.nov. Neotypes are designated for S. crassicornis (Panzer) and S. fuscipes (Herrich-Schaeffer), and lectotypes are designated for S. foveolatus Gussakovskij, S. glasunowi Morawitz, S. nursei (Bingham), S. laeviventris (Thomson), S. albomarginatus (Saussure), S. decens (Kostylev), S. sinuatus (Fabricius), S. sinuatus mutinensis (Baldini), S. debilitatus (Saussure), S. lucens (Kostylev), S. sublaevis (Kostylev), S. debilis (Saussure), S. apiciornatus (Cameron), S. philadelphiae (Saussure), and S. elegans (Wesmael).A cladistic analysis of Symmorphus, based on 26 characters, is presented, including a discussion of the relationships of the genus to the remainder of the Eumeninae. Hypotheses outlining the historical zoogeography of Symmorphus are presented in light of current paleogeographic and paleoclimatic reconstructions, by comparing these cladistic relationships with the chorological patterns observed within the genus and other Vespidae.

The subfamily Inostemmatinae is considered a symplesiomorphic assemblage and the genera currently classified here are reassigned either to the subfamily Platygastrinae or the Sceliotrachelinae. Forty-one genera are treated, of which 15 are classified in the Platygastrinae, viz. Acerotella Masner, Aceroteta Kozlov and Masner, Allostemma gen.nov., Almargella gen.nov., Annettella gen.nov., Inostemma Haliday, Iphitrachelus Walker, Isostasius Foerster, Magellanium gen.nov., Metaclisis Foerster, Orseta gen.nov., Proplatygaster Kieffer, Rao gen.nov., Sacespalus Kieffer, and Zelostemma gen.nov. Twenty-six genera are classified in the subfamily Sceliotrachelinae, viz. Afrisolia gen.nov., Aleyroctonus gen.nov., Alfredella gen.nov., Allotropa Foerster, Amitus Haldeman, Aphanomerella Dodd, Aphanomerus Perkins, Austromerus gen.nov., Calomerella gen.nov., Errolium gen.nov., Fidiobia Ashmead, Helava gen.nov., Isolia Foerster, Nanomerus gen.nov., Neobia gen.nov., Oligomerella gen.nov., Parabaeus Kieffer, Platygastoides Dodd, Platystasius Nixon, Plutomerus gen.nov., Pseudaphanomerus Szelényi, Pulchrisolia Szabo, Sceliotrachelus Brues, Tetrabaeus Kieffer, Zelamerus gen.nov., and Zelandonota gen.nov. The following extant taxa are described: Afrisolia obesa gen.nov., sp.nov. ♀ (South Africa), Aleyroctonus pilatus gen.nov., sp.nov. ♀ ♂ (Java), Alfredella tasmanica gen.nov., sp.nov. ♀ ♂ (Australia),Allostemma fuscum gen.nov., sp.nov. ♀ ♂ (Chile), Almargella cristata gen.nov., sp.nov. ♀ ♂ (Chile), Annettella gracilis gen.nov., sp.nov. ♀ ♂ (New Zealand), Austromerus grandis gen.nov., sp.nov. ♀ ♂ (Australia), Calomerella scutellata gen.nov., sp.nov. ♀ (USA, Canada), Errolium piceum gen.nov., sp.nov. ♀ (New Zealand), Helava alticola gen.nov., sp.nov. ♀ ♂ (Colombia, Venezuela, Peru), Magellanium furviceps gen.nov., sp.nov. ♂ (Chile), Nanomerus spinulus gen.nov., sp.nov. ♀ (Chile), Neobia badia gen.nov., sp.nov. ♀ (Venezuela, Colombia, Ecuador, Trinidad [W.I.]), Oligomerella donnae gen.nov., sp.nov. ♀ (Australia), Orseta ornate gen.nov., sp.nov. ♀ ♂ (Canada), Plutomerus gen.nov. for Platygastoides indicus Mukerjee ♀ (India, Nepal), Rao pselaphus gen.nov., sp.nov. ♀ ♂ (Australia), Zelamerus amicorum gen.nov., sp.nov. ♀ ♂ (New Zealand), Zelandonota kiwi gen.nov., sp.nov. ♀ ♂ (New Zealand), and Zelostemma gen.nov. for Eurytoma oleariae Maskell ♀ ♂ (New Zealand). Fahringeria Kieffer is considered junior synonym of Fidiobia Ashmead; Nasdia Nixon and Platytropa Kozlov are considered junior synonyms of Allotropa Foerster. The above 41 genera are keyed, with separate keys to world genera and genera of America north of Mexico; with generic diagnoses, taxonomic remarks, distribution, biology, bibliography, and list of species described since Kieffer (1926). Higher classification and relationships of the above genera are discussed. Eighty-one plates with 258 figures (line drawings and micrographs) are included.