Under favourable conditions some species of insects and mites complete development very quickly. This paper considers species with a mean minimum generation time of 15 days or less and tabulates developmental data for many sample species. Such species belong chiefly to a limited number of taxa of small size, notably aphids and several families of mites and parasitoid Hymenoptera. Characteristics of these taxa are reviewed. Even in families containing many species with rapid life cycles, normally many other species lack such rapid development. Very short life cycles depend on phylogeny, strain, rapid development in all stages, small size, rich food, and other habitat features including high temperatures. Within this framework, life cycles are accelerated by reducing elements requiring the investment of resources (size, fecundity, longevity, structural complexity), eliminating instars and even life stages, accelerating development (through lower requirements especially of heat, heat gain by adaptations such as basking, and rapid reproduction), and choosing the most suitable habitats and microhabitats from those available. Mean minimum generation times in insects and mites with coincident adaptations of this sort can be as short as 4 days. Notwithstanding the advantages of rapid development in maximizing the intrinsic rate of natural increase (and hence fitness), most species cannot achieve the highest rates of development. They are constrained not only by resources and intrinsic physiological or phylogenetic patterns but also by variability of conditions and seasonality that can be survived only by interpolating delays or resistant stages.

Scudderopsisgen. nov. is described from New Guinea (type species: Scudderopsis baiyerensissp. nov.). This monobasic genus is placed in the tribe Oedemopsini. A diagnosis and key are provided to distinguish Scudderopsis from the other 11 genera in the tribe.

Ontogeny, interspecific homogeneity, and intraspecific variability of female genitalic and other characters of North American Cybaeus L. Koch spiders are described and used to resolve taxonomic problems in the genus. Ontogenetic changes in spermathecal duct morphology occur as females mature and age. Three distinct ontogenetic stages are described: pre-epigynum/pre-vulva, subadult / teneral adult, and mature adult. Concordant with aspects of sexual selection theory, closely related females may be morphologically indistinguishable. Many Cybaeus species exhibit a wide range of body size. Within single species, ontogenetic stages and outlier size classes have been described as separate species. Species with similar females have been lumped under one name. Based on this, 10 new synonyms are proposed for North American Cybaeus: C. adenoides Schenkel = C. grizzlyi Schenkel; C. chaudius Exline and C. hatchi Exline = C. shoshoneus Chamberlin and Ivie; C. exlineae Chamberlin and Ivie = C. bulbosus Exline; C. hystrix Chamberlin and Ivie = C. cribelloides Chamberlin and Ivie; C. janus Chamberlin and Ivie = C. eutypus Chamberlin and Ivie; C. marinensis Chamberlin and Ivie and C. angelus Chamberlin and Ivie = C. consocius Chamberlin and Ivie; and C. olympiae Exline and C. tius Chamberlin and Ivie = C. reticulatus Simon. In addition, four old synonyms are rejected: C. grizzlyi Schenkel and C. adenoides Schenkel ≠ C. adenes Chamberlin and Ivie; C. patritus Bishop and Crosby and C. silicis Barrows ≠ C. giganteus Banks.

The Canadian species of Stenocranus Fieber are keyed by external characters correlated with species concepts defined by known genitalic characters. Stenocranus is differentiated from Terauchiana Matsumura (Asian; here reported from the New World for the first time) and Embolophora Stål (from Africa) by the remarkable development of the female pygofers, which completely conceal the ovipositor. Based on both head and genitalic characters, the genus is divided into two subgenera: typical Stenocranus with many Old World species and two Canadian species, and subgenus Codexnov. for other New World species. The type of Delphax dorsalis Fitch, 1851 is a specimen of Stenocranus pallidus Beamer, 1946 syn. nov., and "S. dorsalis" sensu Beamer is S. unipunctatus (Provancher, 1872). A lectotype of Delphax vittata Stål, 1862 is designated for the taxon S. unipunctatus (sensu Beamer, nec Provancher); its paralectotypes are specimens of S. acutus Beamer. The apparent evolutionary relationships of this fauna to other species of the world Stenocranini and within the superficially similar Saccharosydnini reveal numerous homoplasies and dramatic autapomorphies, contrasted with only a few reliable synapomorphies. A hierarchical classification of Delphacidae, based on the most distinctive synapomorphies, defines subfamily Delphacinae as encompassing at least four tribes: Vizcayini, Stenocranini, Tropidocephalini, and Delphacini, with "Kelisiinae" reduced to subtribe of Stenocranini and "Saccharosydnini" placed within Tropidocephalini.

Five new species of the Neotropical geocorid genus Epipolops are recognized, raising to 14 the number of known species. The new species E. angelaesp. nov., E. kathrynaesp. nov., E. scudderisp. nov., E. slaterisp. nov., and E. thomasisp. nov. are described, the identity of E. mucronatus Distant is clarified, and the nine previously known species are diagnosed and redescribed. Photographs, scanning electron photomicrographs, outline illustrations of all pronota and hemelytra, and an identification key are provided to help distinguish species.

Morphological, biological, and distributional data are presented for the four Canadian species of Mantispidae. A key for the identification of these species is provided. Climaciella brunnea (Say) is the most frequently collected Canadian species, occurring in southern British Columbia, Alberta, Manitoba, Ontario, and Quebec. Dicromantispa interrupta (Say) comb. nov. is given as a new combination for Mantispa interrupta Say; it is recorded in southern Ontario and Quebec. Dicromantispa sayi (Banks) occurs only in extreme southwestern Ontario. Leptomantispa pulchella (Banks) inhabits the dry Okanagan Valley of British Columbia; it is also known from Ojibway Prairie, Windsor, Ontario. The presence of the latter two species in Canada is published for the first time.

The objective of this study was to assess the similarities and differences between selected bioindicator groups within tallgrass prairie and adjacent aspen forest. Based on pitfall trapping from 1998 to 2000, species richness and abundance of ground beetles and spiders were examined across a tallgrass prairie – aspen forest ecotone located near Winnipeg, Manitoba. The abundance of spiders and ground beetles was higher in the forested portion of the transect than in the prairie section. There were 639 specimens of ground beetles collected, representing 53 species; 19 species were found only on the prairie, 19 species were found only in the forest, and 15 species were found in both habitats, although the abundance of most species was too low to confidently assign them to either habitat type. Excluding single records in any sampling year yielded 9 prairie species, 5 forest species, and 10 species found in both aspen forest and tallgrass prairie. The five most abundant species of ground beetles were Agonum placidum (Say), Pterostichus caudicalis (Say), P. femoralis (Kirby), P. melanarius (Illiger), and Synuchus impunctatus (Say). There were 4499 specimens of spiders collected, representing 92 species; 25 species were found only in the prairie, 15 species were unique to the aspen forest, and 52 species were found in both habitats. Excluding single records in any sampling year yielded 26 prairie species, 15 forest species, and 22 species found in both habitats. The five most abundant species of spiders were Pardosa moesta Banks, P. distincta (Blackwall), Agroeca ornata Banks, Centromerus sylvaticus (Blackwall), and Alopecosa aculeata (Clerck). Our study concurs with other studies in demonstrating that there are distinct assemblages of both groups of predators in each of the two habitat types.

Sexual conflict may drive the evolutionary elaboration of sexually antagonistic traits that function in mating interactions. One of the most striking cases of elaboration of male morphology occurs in the water strider genus Rheumatobates Bergroth (Hemiptera: Gerridae). The functional significance of the bizarre modifications of appendages in this group is not known. Here we focus on one of the more elaborate of the species, R. rileyi Bergroth. We conduct observational and experimental studies aimed at determining the general sequence of mating behaviour, the role of females in the outcome of sexual interactions, and the functional significance of the highly modified appendages of males. We also map these traits on a known phylogeny of the genus to determine their pattern of evolution. Males repeatedly harass females and females respond with evasive skating or, if the male successfully grasps her, with a premating struggle. The dynamics of the struggle determine the success of mating attempts. Short struggles typically lead to mating, and long struggles typically result in disengagement of the pair. Following a short period of copulation, males withdraw their genitalia and dismount. Females that have been isolated from males for a period of time become less reluctant to mate. During the premating struggle, the antennae of males are used to grasp the females around the head, and the rear legs are used to lift the females' rear legs off the water surface. Neither antennae nor rear legs are used during copulation, thus they are not used for copulatory courtship. Mapping of these traits on the phylogeny indicates multiple independent origins and a pattern of escalation (16 origins, 7 losses). We conclude that these bizarre traits of males are sexually antagonistic and have evolved repeatedly in the genus.

The present study was undertaken to determine the influence of some major constituents of plant essential oils on the toxicity and fate of thymol, a phenolic monoterpene from garden thyme (Thymus vulgaris L.) (Lamiaceae), following topical administration to the cabbage looper, Trichoplusia ni (Hubner) (Lepidoptera: Noctuidae). Tested individually, trans-anethole (LD50 = 71.2 µg/larva) and methyl salicylate (93.6 µg/larva) were the most toxic, whereas phenylethyl propionate (555.8 µg/larva) and mineral oil (2279.3 µg/larva) were the least toxic. However, when coadministered, mineral oil was the most synergistic (synergy ratio, SR = 25). A proprietary blend of essential oils (A4 Blend) was strongly synergistic (SR = 9), as was trans-anethole (SR = 5), while the majority of the other compounds tested yielded SRs of 2–3. Based on experiments using tritiated thymol as a radiotracer, the fate of this plant toxin within 60 min of topical administration varied widely with the essential oil carrier. Some carriers facilitated rapid disappearance of thymol from the insects' integument and rapid appearance internally, whereas others prolonged the tenure of thymol on the integument and delayed entry into the insect. The highest internal levels of radioactivity were observed when phenylethyl propionate was the carrier (47% of the topical dose), the lowest when rosemary oil was the carrier (9%). The highest proportion of the dose was excreted when eugenol was the carrier (20% of the topical dose), the lowest when mineral oil was the carrier (4%). Overall, there are no apparent trends linking the fate of thymol in the different carrier oils to the synergies observed or to the relative polarities of the carriers.

Populations of Orius spp. were surveyed in the lower Fraser Valley, British Columbia, to determine whether O. insidiosus Say, a non-indigenous species, had established in the region as a result of being released inside greenhouses for biological control of pests. Field collections over 8 years revealed a low incidence of O. insidiosus (10 specimens, <1% of total Orius spp. collected). Numbers in collections did not increase, and collection localities did not become more widespread over the 8 years of survey. Competitive exclusion and temperature and diapause thresholds are discussed as possible mechanisms limiting the establishment of this otherwise widespread North American species.