The currently recognized Ephemerella species are included in 13 subgenera. New subgenera are Cincticostella and Acerella. Ephemerella levanidovi Tshernova is transferred to Cincticostella n. subg., thus it contains six species, E. nigra Ueno n. comb., E. castanea n. sp., E. delicata n. sp., E. imanishii n. sp., E. insolta n. sp., and E. levanidovae Tshernova n. comb. The subgenus Acerella n. subg. includes four species, E. longicaudata Ueno n. comb., E. commodema n. sp., E. perculta n. sp., and E. undatella n. sp., Ephemerella yoshinoensis Gose is transferred to the subgenus Drunella and four undescribed and unnamed species, E. kohnoi n. sp., E. aculea n. sp., E. hifurcata n. sp., and E. borakensis n. sp., are placed in Drunella. Three undescribed species, E. denticula n. sp., E. keijoensis n. sp., and E. maxima n. sp., are included in the subgenus Ephemerella s. s.

This project arose out of studies of the European spruce sawfly, Gilpinia hercyniae (Htg.), in connection with the Canadian Forest Insect Survey at the Dominion Entomological Laboratories, Fredericton, N.B. Bessa selecta (Mg.) had been observed as a parasite of the larch sawfly, Pristiphora erichsoni (Htg.), but particular interest was aroused in it as a parasite occurring on the European spruce sawfly. The latter host was frequently found to bear the eggs and integumental funnels of B. selecta. The object was to study its biology and effectivness as a possible control factor of the spruce sawfly. However, great difficulty was experienced in rearing the host due to high mortality caused by disease. Hence the original aims were not attained to the entire satisfaction of the author.

The efficacy of mating disruption for controlling the grape berry moth, Endopiza viteana (Clemens) (Lepidoptera: Tortricidae), was evaluated from 1987 to 1989 in the Niagara peninsula, Ont. Mating disruption was tested in commercial vineyards with high-, moderate-, and low-density grape berry moth populations using the Biocontrol Ltd. tape-type and wire-type pheromone dispensers. Pheromone-baited trap catches were reduced by 92% or more in plots treated with pheromone. Treatment with pheromone significantly reduced damage (percentage infested clusters) compared with an untreated control in each of two tests, and provided control as good as or better than an insecticide control programme in two of four tests. Damage increased from 1.3- to 12.8-fold between successive generations in plots treated with pheromone, and was greater on the borders of some plots treated with pheromone or insecticide. It is concluded that mating disruption may have potential as a control method for use in the integrated management of E. viteana.

Grasshopper assemblages inhabiting eight pastures of shortgrass prairie rangeland in northeast Colorado were studied for 4–6 years during a general increase and decrease in grasshopper abundance. Average densities increased 10-fold during a 3- to 4-year increase phase, with individual species and populations in separate pastures exhibiting greater or lesser changes. Asynchrony in grasshopper population characteristics was noted. The co-dominant species, Opeia obscura (Thomas) and Melanoplus gladstoni Scudder, exhibited similar trends in density, but M. gladstoni dominance, expressed as its proportion of the population, declined steadily relative to O. obscura. Subdominant species similarly were asynchronous. Species richness did not change during this cycle. Grasshopper densities and assemblage structure were not affected by rangeland management practices of fertilizer (nitrogen) and herbicide (atrazine) application.

Typhlodromus pyri Scheuten (= T. tiliae Oudms.) is the predominant species of predacious mite on apples in Nova Scotia. It feeds on a wide range of prey species (Herbert, 1959). Chant (1960) investigated the life-history and habits of this species in southeastern England and Herbert (1956) studied its life-history under controlled laboratory conditions. A knowledge of the life-histories of various components of the fauna is basic to an evaluation of predation; therefore, a study of the life-history and habits of T. pyri in the field was undertaken. This was supplemented by a laboratory study in which an attempt was made to duplicate field temperarures. The results of these studies are presented here.

Two techniques for sexing adults of the white pine weevil Pissodes strobi Peck are described. Both techniques are based on the external anatomy of the terminal segments of the abdomen as viewed with a dissecting microscope.

A seasonal light-trapping study of Culicoides species, in particular C. obsoletus Meigen, was conducted in the Fraser Valley of British Columbia to determine seasonal peaks and first and last appearance of these insects. Culicoides obsoletus is the causal agent of Culicoides Hypersensitivity (CH), an allergic dermatitis in horses, in British Columbia. Trapping at two sites in 1987 showed that C. obsoletus was first trapped in late March, and peaked in early May and again in late June. Small numbers were collected into mid-November. This coincided with the appearance and regression of clinical signs associated with CH in horses in the area. Stabling horses during the peak activity of Culicoides spp. has been recommended to prevent the development of CH. Light-trapping Culicoides both inside and outside stables showed that although fewer insects were caught inside, some (6%) were trapped indoors. A horse kept in an unscreened stable will not be protected from being bitten.

Embryonic development in the mosquito Aedes (O.) sticticus (Meigen) was studied on moist surfaces at five constant temperatures between 5° and 34 °C. Time for complete embryogenesis was 608, 272, 192, 152, and 120 h at 10°, 15°, 20°, 25°, and 30 °C, respectively. Upper and lower temperature thresholds were 33 °C and from 6° to 8 °C, respectively. Embryonic development proceeded normally when eggs were submerged in water at 25° and 30 °C, and no difference in developmental rate was observed between eggs on moist filter paper and those submerged in water.

Bioenergetic studies on populations of the two-striped grasshopper, Melanoplus bivittatus (Say), and the red-legged grasshopper, M. femurrubrum (De Geer), at a natural grassland site in Ottawa in 1971 and 1972 indicated that the former species ingested 0.42% and the latter 0.44% of the green shoot primary production (3057 kcal/m2). An additional 1.22 and 1.30% of this production were cut and dropped by the grasshoppers, so that a total of 1.64 and 1.74% of the green vegetation was removed by M. bivittatus and M. femurrubrum, respectively. These two species assimilated 41 and 35% of the ingested food, the remainder being voided as faeces. Respiration accounted for 62% of the energy assimilated by M. bivittatus and for 63% of that assimilated by M. femurrubrum. Approximately 0.06% of the energy of primary production was converted by each species into body and was available to higher trophic levels. However, 94% of the potential energy of the green vegetation removed by the grasshoppers was returned to the "decomposer compartment" of the ecosystem, with only 6% removed or lost from the system.

Chant (1956) has shown that spiders are common predators in apple orchards in southeast England. Dondale (1956) listed the species of spiders found in Nova Scotia orchards. This is a note on population densities in the latter orchards from 1953 to 1956.

The sampling device used in this study was a cloth-covered, yard-square tray (Lord, 1956), supplemented in a minor way by a collecting umbrella. Each tray or umbrella collection represented the spiders jarred from the lower branches of a single tree, or from the lower branches of half of each of two trees.

Ten alfalfa clones, Medicago sativa L., were tested at 60°, 70° and 80° F. in Kansas and Quebec for resistance to pea aphid biotypes, Acyrthosiphon pisum (Harris), originating in the respective areas.

The resistance of the clones at the three temperatures varied differentially at the two locations. One clone was resistant at all temperatures to aphids of both locations. Results indicated that biotype C61-86 of the pea aphid at St. Jean, Quebec, is biologically different from the population of the same species in Kansas. Results also suggest the possibility of finding or combining clones so that varieties of alfalfa resistant to pea aphids over broad geographic areas and environmental conditions can be secured.

Species of Ceratozetes Berlese (Ceratozetidae) of Canada and Alaska are revised. Four new species, Ceratozetes watertonensis, C. borealis, C. oresbios and C. pacificus are proposed, C. gracilis cuspidatus Jacot is elevated to specific status and redescribed, and C. gracilis (Michael), C. peritus Grandjean, C. kananaskis Mitchell, C. virginicus (Banks), C. mediocris Berlese, and C. thienemanni Willmann are redescribed. Immatures of C. borealis and C. pacificus are described and those of C. peritus, C. kananaskis, C. mediocris, C. gracilis, C. virginicus and C. thienemanni are redescribed. Ceratozetes jeweli Rockett and Woodring is synonymized with C. virginicus. A key to species from Canada and Alaska is given.

Male moths of Choristoneura occidentalis Freeman, C. biennis Freeman, C. fumiferana (Clemens), and C. orae Freeman were caught in pheromone-baited traps. Ten traps were placed at each site, five baited with an aldehyde lure and five with an acetate lure. This procedure permitted separation of species based on the specific chemical lure and also provided specimens for further study of morphological and isozyme differences. The color of the forewings, presence or absence of spicules on the aedeagus, and a specific allozyme frequency were determined on selected specimens where these characteristics were useful in separating species at a particular site. Distributions of all species were more extensive than previously known, sometimes adding hundreds of kilometres to the recorded range. Areas of sympatry were identified and the fidelity and usefulness of characteristics for separating species in areas of overlap were discussed.

The broad-necked root borer, Prionus laticollis (Drury), causes economic damage to apple orchards in the eastern United States by boring in the roots of apple trees. The insect has a 3- to 4-year life cycle. Eggs are deposited in the soil or on the soil surface in mid-summer, and larvae tunnel through the bark and may excavate the interior wood of living, weakened, or dead apple tree roots. Larvae leave the roots to pupate in the soil and have been found up to a depth of 84 cm below the soil surface. Prepupae occur in the soil during May and June and pupae in June and July. Adults live approximately 1 week after emergence and mate several times. A tachinid fly, several potential pathogenic microorganisms, larvae biting one another, and freezing temperatures were observed to be mortality factors.

Field studies were conducted in the United States and Canada to determine the response of the white pine cone beetle, Conophthorus coniperda (Schwarz), and the red pine cone beetle, Conophthorus resinosae Hopkins, to two potential inhibitors, conophthorin and verbenone, of pheromone communication. Trap catches of male C. coniperda and C. resinosae were significantly reduced and generally declined with increasing concentrations of conophthorin in traps baited with the pityol, a female-produced pheromone. Verbenone did not significantly reduce trap catches of C. coniperda. Conophthorin, but not verbenone, significantly reduced cone attacks by C. coniperda when placed near cone clusters. The twig beetles, Pityophthorus cariniceps LeConte and Pityophthorus puberulus (LeConte), responded to traps with pityol and α-pinene baits alone or with conophthorin. Thanasimus dubius (F) (Coleoptera: Cleridae) was attracted to the pityol and α-pinene, but conophthorin had no effect on attraction of this generalist bark beetle predator. Verbenone significantly reduced trap catches of T. dubius in pityol-baited traps.

Two new species of the mite family Erythraeidae (Acari: Prostigmata: Parasitengona) found associated with the spruce budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae), in Maine are described. Larvae of Leptus treati sp.nov. parasitize spruce budworm adults; L. treati is the first member of the genus to have both larval and postlarval instars described. Adults of Balaustium kendalli sp.nov. prey on spruce budworm eggs; B. kendalli is only the second member of the genus to have both larval and postlarval instars described.

To characterise their functional diversity and seasonal activity, dung beetles (Coleoptera: Scarabaeoidea) were collected with baited pitfall traps at three sites for three years on a native grassland in southern Alberta, Canada. The total collection of 125 820 beetles comprised 12 species of which eight were of European origin. For each combination of site and year, assemblages were dominated by two or three core species of European origin that represented 70–95% of total beetles and more than 75% of total biomass, but only 10–30% of species richness. Core species consistently included Onthophagus nuchicornis (Linnaeus) and occasionally Chilothorax distinctus (Müller) and Colobopterus erraticus (Linnaeus). Coexistence of these core species appears to be facilitated by differences in their size, seasonal activity, and life history traits.

Adults of the anthomyiid Coenosia tigrina (Fab.), which are predators of flying insects including pest Diptera such as the onion maggot fly, feed on earthworms in the larval stage. The bionomics of C. tigrina females were studied in the laboratory at 15, 20, and 25°C, under different mating regimes. Adult female longevity slightly exceeded 1 month at 25°C and was close to 2 months at 15°C. Oviposition started 1–3 weeks after emergence, the delay tending to decrease with increased male presence. Females laid eggs at intervals of 1 to several days, in batches averaging 10–30 eggs depending on temperature. Fecundity reached an average of 230 eggs at 25°C with the sustained presence of males. Egg hatch decreased with the mother’s age, except when males were present for most of the female’s lifetime. Females exhibited maximal daily rate of predation at 25°C, but maximal lifetime predation was observed at 20°C. Male predation was less than females’, and female predation decreased with age. The time to eclosion decreased from 11 to 5 days as the temperature of egg incubation increased from 15 to 25°C. Larval weight at eclosion decreased with mother’s age. Postembryonic development and larval growth were studied at 15, 20, and 25°C, larvae being fed on four lumbricids. Development times decreased with increasing temperature between 15 and 25°C: from 35 to 15 days for larval development, and 28 to 12 days for pupal development. Males developed at a slower rate than females, but females weighed more at emergence. Larval survival was 30–60% on worm sections, and dropped to 17% on live mature Eisenia foetida (Sav.); but survival reached 90% on live, immature E. foetida 1–2 cm long. The larvae of C. tigrina penetrate the epidermis of earthworms, and feed internally with a preference for circulatory and chlorogogonous tissues.

Thelytokous reproduction was developed and fixed in arrhenotokous Muscidifurax raptor Girault and Sanders by mating hybrid females, of interhemispheric strains, with naturally occurring males of M. uniraptor Kogan and Legner. A change in ovipositional behavior was shown by these mated hybrid females which subsequently produced thelytokous Fx offspring for 10 generations. Sperm depletion and extranuclear factors are considered.