Three buprestid species, Actenodes acornis (Say, 1836), Dicerca asperata (Laporte et Gory, 1837), and Dicerca lepida LeConte, 1857, are newly recorded from Canada on the basis of a collection of 57 buprestid specimens taken from females of the crabronid wasp Cerceris fumipennis Say, 1837 in Rondeau Provincial Park, Chatham-Kent region, Ontario, in July 2004. Nine additional buprestid species were taken from wasps that were intercepted as they approached their nests, demonstrating the effectiveness of C. fumipennis nest sites as sampling stations for buprestid beetles. We suggest that this sampling method could be applied to efficiently monitor the spread of the emerald ash borer (Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae) in eastern North America.

Seventy-three species of the acalyptrate family Sphaeroceridae are recorded from Canadian peatlands, largely on the basis of pan trap samples from peatlands in southern Ontario, the Yukon, and Alberta. Spelobia nana (Rondani), Spelobia ibrida (Roháček), and Trachyopella atomus (Rondani) are newly recorded from North America. Fifteen species are identified as characteristic of peatlands, and their distributions and relationships are discussed. Southern peatland populations of several of these species are interpreted as relict populations in peatlands serving as post-Pleistocene refugia. Some species are known so far only from peatlands along the postglacial fringe.

The 75 Nearctic species of Platycheirus Lepeletier and Serville found north of Mexico are revised, including five species new to North America: Platycheirus alpigenus Barkalov and Nielsen, Platycheirus brunnifrons Nielsen, Platycheirus clausseni Nielsen, Platycheirus speighti Doczkal, Stuke & Goeldlin, and Platycheirus splendidus Rotheray. Platycheirus rufimaculatus Vockeroth, Melanostoma willistoni Goot, and Melanostoma concinnus Snow are recognized as junior synonyms of Platycheirus pictipes (Bigot). Melanostoma carinata Curran is recognized as a junior synonym of Platycheirus chilosia (Curran). Melanostoma atra Curran is recognized as a junior synonym of Platycheirus luteipennis (Curran). Platycheirus holarcticus Vockeroth is recognized as a junior synonym of Syrphus naso Walker. Platycheirus trichopus (Thomson) is resurrected and represents what was previously considered the western population of Platycheirus obscurus (Say). One new species, Platycheirus neoperpallidus Young sp. nov., is described. Females of 26 species are described for the first time, and an illustrated key to Nearctic Platycheirus is presented. DNA barcode data are presented for 60 Nearctic species and a COI gene tree of all available world Platycheirus species, as well as morphological and combined morphological/COI phylogenetic analyses of the Platycheirus albimanus species group are presented and discussed.

Recent phylogenetic analyses of Ocyptamus Macquart, 1834 (Diptera, Syrphidae) confirmed the paraphyly of this genus and provided evidence to divide it into several monophyletic subgroups, of which the largest is the clade traditionally treated as the Ocyptamus tristis species group. This group is here redefined, divided into the genera Pelecinobaccha Shannon, 1927 and Relictanum gen. nov., and revised along with the closely related and newly resurrected genus Atylobaccha Hull, 1949. Twenty-four new species (22 in Pelecinobaccha and two in Relictanum) are described and 35 species (27 in Pelecinobaccha, seven in Relictanum and Atylobaccha flukiella Curran, 1941) are redescribed. Pelecinobaccha is divided into four species groups (P. adspersa species group, P. brevipennis species group, P. peruviana species group and P. susio species group). An identification key, illustrations and distribution maps for all species from this study are also presented.

The New World species of Coproica Rondani, 1861 (Diptera: Sphaeroceridae) are reviewed on the basis of over 17,000 examined specimens. The genus is divided into three major clades: the C. acutangula, C. vagans, and C. urbana species groups. Eight new species (C. bifurcata, C. bispatha, C. brachystyla, C. diabolica, C. emarginata, C. galapagosensis, C. novacula, and C. testudinea) are described, and redescriptions are provided for eleven additional species. Included are two keys (one for the twenty New World species only and one for all described species), updated New World distribution records, and illustrations of male and female genitalic structures.

The family Nothybidae (Diptera: Schizophora) is revised. The family consists of 11 species in the single genus Nothybus Rondani, which occurs in Papua New Guinea, Nepal and much of the Oriental Region. Three species are described as new: N. absens spec. nov. (China), N. cataractus spec. nov. (Laos, Thailand) and N. procerus spec. nov. (India). Nothybus longithorax Rondani, 1875 is treated as a junior synonym of N. longicollis (Walker, 1856). Nothybus decorus Meijere, 1924 syn. nov. is included as a junior synonym of N. lineifer Enderlein, 1922.