Palaeoleptochromus schaufussi (gen.nov., sp.nov.) is the first antlike stone beetle (Coleoptera: Scydmaenidae) to be described from Cretaceous amber. The piece of amber containing this specimen was collected in an area near Grassy Lake, Alberta, Canada, and is dated 79 million years old. This new genus is placed within the Mastiginae and is most likely the sister taxon to the recent Neotropical genus Leptochromus Motschulsky.

Eudorylas alternatus (Cresson) is recorded as a parasitoid of Cuerna striata (Walker) (Homoptera: Cicadellidae, Cicadellinae), providing the first known example of a big-headed fly parasitizing a cicadelline. Rearing methods and parasitism rates are discussed, and a summary of known Nearctic pipunculid–host associations is presented along with an overview of big-headed fly natural history.

The larval morphology of the dytiscid genus Oreodytes Seidlitz was investigated through a detailed analysis of 16 Nearctic and two Palearctic species. Many structural features, especially those of chaetotaxy and porotaxy of head capsule, head appendages, legs, last abdominal segment, and urogomphi, were found to be useful for taxonomic and phylogenetic comparisons. Within the tribe Hydroporini, it is proposed that Oreodytes shares a monophyletic origin with the genera Deronectes Sharp, Scarodytes Gozis, Nebrioporus Régimbart, and Stictotarsus Zimmermann. A tentative phylogenetic reconstruction of the genus Oreodytes, based on 29 larval characteristics, is provided. The classification of members of Oreodytes indicated by larvae is shown to be only partly reconcilable with the one indicated by adults. Once subdivided into three species-groups, Oreodytes now comprises four species-groups: the O. picturatus, O. obesus, O. scitulus, and O. quadrimaculatus species-groups. Oreodytes quadrimaculatus was found to share a monophyletic origin with the members of the O. picturatus and O. scitulus species-groups. The taxonomic status of the genus-name Neonectes J. Balfour-Browne is reconsidered as the larvae of N. natrix (Sharp) and N. babai Satô are revealed to be most similar morphologically to members of the O. scitulus species-group.

The Collembola of commercial balsam fir [Abies balsamea (L.)] forests of western Newfoundland were surveyed through Berlese funnel extraction of samples taken from soil and various forest microhabitats and through pit-fall trapping. A total of 64 species representing 30 genera was collected. Twenty-three genera and 47 species are new records for the Island of Newfoundland; eight additional species were identified to genus level only. For each species, the abundance in soil samples and distribution among microhabitats are described. The fauna of Newfoundland is about equivalent in species richness to that of Quebec and almost twice as rich as the recorded fauna of the Maritime Provinces. Few species are common to the three areas. However, this probably reflects the general paucity of knowledge of Canadian Collembola rather than indicating strong regional patterns in faunal composition.

Laboratory studies of seven North American Choristoneura species and two subspecies from widely distributed locations demonstrate the low level of genetic separation among them. No differences were found in numbers (n = 30) or morphology of chromosomes among members of the group or in any of the hybrids examined. High levels of mating success were obtained in all inter se matings as well as in crosses and back-crosses. However, mating success was greater for crosses within host type and within pheromone type than for crosses between types. Viability and fertility were similar in all the hybrids and close to those of the inter se progenies. Mean weights of initial eggs varied by a factor of 2 from the lowest (C. pinus Freeman) to the highest (C. lambertiana ponderosana Obraztsov). Mean weights of initial eggs produced by hybrids were generally close to those of the parental species. However, when one parent was C. fumiferana (Clem.), mean weights of initial eggs were either much larger (male C. fumiferana) or much smaller (female C. fumiferana) than either parental type. These differences could affect survival of some progeny under harsh conditions. This evidence supports other studies in indicating that C. fumiferana is genetically distinct from other species in this group.

Species of the oribatid mite genus Tegeocranellus from North and Central America are discussed, and immatures are described for the first time. Six new species are described and keyed: Tegeocranellus alas from Costa Rica, T. barbarae from Alabama, Mississippi, and Florida, T. kethleyi from Alabama and Mississippi, T. mississippii from Louisiana and Texas, T. muscorum known from Ontario to Florida, and T. mediolamellatus from Guatemala. Descriptions of T. alas, T. barbarae, T. mediolamellatus, and T. muscorum are based on adults and immatures, and those of the other two species on adults only. I expand the generic diagnosis to include information on the apheredermous, plicate immatures, and present a character analysis hypothesizing that the monogeneric family Tegeocranellidae is a member of the Ameronothroidea, closely related to Selenoribatidae and Fortuyniidae.

Thanasimus formicarius (L.), a main predator of bark beetles in Eurasia, was studied at constant temperatures of 15, 21, and 25 °C. Morphological data and duration of development are indicated for the egg (2.4 by 0.8 mm; 28–7 days at temperatures from 15 to 25 °C), three larval instars (9–14 days depending on instar and temperatures of 21 and 25 °C), pupa (15 and 33.5 days over the range of temperatures), and adult. Information is also given on head capsule size, sex ratio, fecundity, and length of adult life.

The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is a major worldwide pest of cruciferous vegetables (Talekar and Shelton 1993). Male and female adults of this species can be accurately identified by visible differences in their external genitalia. According to Robertson (1939), the sex of pupae can also be identified, but, in our experience, this approach is more difficult. For some types of research, determination of larval sex would be useful. For example, one could determine sex-specific responses of larvae to a treatment by observing mortality, development rate, or behavior of male and female larvae separately. In studies requiring hybrid mating between different strains of diamondback moth (Tabashnik et al. 1992), one could isolate groups of male larvae separately from female larvae to avoid mating within a strain. Some lepidopteran larvae can be sexed by the gonads being visible through the cuticle of the fifth abdominal segment or by the position of external pits marking the location of the genital discs in the eighth and ninth abdominal segments (Stehr 1987). But, because of their small size, it is not practical to sex diamondback moth larvae by external pits and we have found no studies in which male and female larvae were identified by gonadal form. Herein we report that third- and fourth-instar larvae of diamondback moth can be sexed efficiently and reliably.