In the 20th century, five species of birch-leafmining sawflies were inadvertently introduced from Europe to North America: Heterarthrus nemoratus (Fallén), Fenusa pumila Leach, Profenusa thomsoni (Konow), Fenusella nana (Klug), and Scolioneura vicina Konow. All have been recorded at outbreak levels in North America, and three (F. pumila, P. thomsoni, and H. nemoratus) have been the targets of successful biological control programs. The most recently detected species, F. nana and S. vicina, are good candidates for future biological control in Canada. We review the biology of all five of these birch-leafmining sawflies in North America and present keys to adults, larvae, and mines to aid correct identification.

The European oak borer, Agrilus sulcicollis Lacordaire, a newly detected alien species in Canada, is reported from southern Ontario. This species is illustrated and diagnosed to facilitate its recognition among other North American species of Agrilus Curtis. Data are provided on its phylogenetic affinities, host plants, native distribution, and all North American records known to date. The other eight non-native Agrilus species known in North America (A. cuprescens (Ménétriés), A. cyanescens Ratzeburg, A. derasofasciatus Lacordaire, A. hyperici (Creutzer), A. pilosovittatus Saunders, A. planipennis Fairmaire, A. sinuatus (Olivier), and A. subrobustus Saunders) are briefly discussed.

The oribatid mite genus Ceratozetes Berlese is represented in America north of Mexico by 21 previously described species known from forest, grassland, subarctic and arctic soils and litter, and canopy habitats. The closely related genus Ceratozetoides Shaldybina is represented in America north of Mexico only by C. cisalpinus (Berlese). Three new species of Ceratozetes from North America are described: C. biporosus sp. nov. from forest habitats of southeastern North America, C. cyclopea sp. nov. from montane habitats in western North America, and C. pseudomediocris sp. nov. from forest habitats of western North America. A detailed revised diagnosis is given for Ceratozetes, Ceratozetoides, all previously described species of Ceratozetes (C. angustus (Banks), C. borealis Behan-Pelletier, C. cuspidatus Jacot, C. enodis (Ewing), C. fjellbergi Behan-Pelletier, C. gracilis Michael, C. kutchin Behan-Pelletier, C. longispinus Jacot, C. mediocris (Berlese), C. oresbios Behan-Pelletier, C. pacificus Behan-Pelletier, C. parvulus Sellnick, C. spitsbergensis Thor, C. subaquila (Ewing), C. subinconspicuus (Berlese), C. thienemanni Willmann, C. virginicus (Banks), and C. watertonensis Behan-Pelletier), and Ceratozetoides cisalpinus. Ceratozetes figuratus (Ewing) and C. zeteki (Ewing) are considered junior subjective synonyms of C. enodis (Ewing) syn. nov., and C. inupiaq Behan-Pelletier is transferred to Mycobatidae as Cyrtozetes inupiaq (Behan-Pelletier) comb. nov. New distribution records are given for Ceratozetoides cisalpinus and Ceratozetes angustus, C. borealis, C. cuspidatus, C. gracilis, C. mediocris, C. longispinus, C. oresbios, C. pacificus, C. parvulus, C. thienemanni, C. virginicus, and C. watertonensis. A diagnostic key is provided to adults of the Ceratozetes and Ceratozetoides species now known for America north of Mexico. An analysis of the systematic relationships of 23 of these species based on adult characters indicates that Ceratozetes, excluding Ceratozetoides, is paraphyletic. The clade that includes Ceratozetoides cisalpinus and 15 species of Ceratozetes includes most species for which immatures are known. One sister clade includes Ceratozetes cyclopea, C. enodis, and C. fjellbergi and another includes C. kutchin, C. parvulus, and C. thienemanni. The decision whether or not these 6 species should be retained in Ceratozetes sensu stricto awaits discovery of their immatures and molecular analysis.

The hemlock looper, Lambdina fiscellaria, is one of the most economically damaging defoliators of North American coniferous forests. Basic information on its reproductive biology is an essential prerequisite for understanding its population dynamics. Realized fecundity for the two major hemlock looper ecotypes varies along a latitudinal gradient in eastern Canada, but their daily oviposition patterns are similar. Mated females lay eggs after a short pre-oviposition period, with daily oviposition peaking in the first 3 days. Mated females lay significantly more eggs than unmated ones, the latter laying their eggs more evenly throughout their life. Eggs deposited early in the oviposition period are larger than those deposited near the end. This may influence over-winter survival of hemlock loopers and should be considered in studies to better understand the population dynamics and improve management of this defoliator.