The use of Hoechst (33258) stain in quantifying spermatozoa contained in the spermatheca and spermatophore of the decorated cricket, Gryllodes supplicans (Walker) (Orthoptera: Gryllidae), is described. The technique was used to estimate the number of sperm remaining in spermatophores removed from females at various times after females had mated.

Significant variation in the morphology of late-instar nymphs of Stenonema tripunctatum (Banks) in Lake Huron could not be ascribed to their proximity to warm-water plumes originating from the Bruce Nuclear Power Development, by either multivariate or univariate analyses of size and shape. Major sources of variation in S. tripunctatum were developmental state and sex. Nymphs collected just prior to emergence had low values of transverse measurements in anterior regions (inter-orbital width, prothoracic width), whereas males and females were separated by these measurements and other components of head geometry.

No significant effects of thermal exposure were found in the reproductive development of S. tripunctatum, but this species is most commonly found below depths at which thermal-plume effects are expected. Based on a small but representative sample, ultimate-instar nymphs of Stenonema vicarium (Walker) from a depth of 3 m contained significantly fewer eggs and allocated a significantly lower proportion of biomass (dry weight) to reproduction in locations with higher temperatures.

Parasitized cabbage aphids, Brevicoryne brassicae (Linnaeus), produced fewer offspring than unparasitized aphids. Aphids parasitized by Diaeretiella rapae (M'Intosh) during the first, second, or third instar died before producing any offspring; those parasitized during the fourth instar or the adult stage produced a variable number of offspring. The aphid's survival time was correlated with the rate of development, as measured by the length of the pre-reproductive period. A multiple-linear-regression equation is provided for predicting the mean total fecundity of parasitized cabbage aphids from the host age at the beginning of parasitism and the pre-reproductive period.

The subgenus Steropus Dejean of the genus Pterostichus Bonelli (Coleoptera: Carabidae) is redefined. The subgenus includes 24 species occurring in the Palaearctic and Nearctic regions. Eight species previously included in Steropus, P. catalonicus K. Daniel, P. ferreri (Español andMateu), P. galaecianus Lauffer, P. ghilianii (Putzeys), P. globosus (Fabricius), P. insidiatrix (Piochard de la Brûlerie), P. madidus (Fabricius), and P. riffensis (Antoine), are transferred to the subgenus Corax Putzeys (formerly considered as a junior synonym of Steropus) which is recognized as a valid taxon. Refonia Casey, with two North American species, Eosteropus Tschitschérine (type-species: Platysma creperum Tschitschérine, present designation), with four Asiatic species, and Steropinus Lutshnik, with one Asiatic species, are placed in synonymy with Steropus. Adult and larval character states of the subgenus Steropus are described. Larvae of Steropus are synapomorphic with those of P. (Corax) madidus and P. (Feronidius) melas Creutzer in having the mandible strongly curved with wide retinaculum in the first instar and a membranous area on antennomere I.

Diplolepis triforma n. sp. is described and distinguished from other members of the genus. Diagnoses are given for closely related species: D. ashmeadi (Beut.), D. inconspicuis Dailey and Campbell, D. nodulosa (Beut.), and D. verna (O.S.). Lectotypes are designated for D. ashmeadi, D. nodulosa, and D. verna. The genus Diplolepis Fourcroy is briefly reviewed. The biology and ecology of D. triforma and its gall are described. Diplolepis triforma induces a multichambered, polymorphic stem gall on Rosa acicularis and is distributed throughout central and western Canada. The form of the gall depends on the developmental condition of the host plant at the time of oviposition.

Two new species of Neoathyreus, lyriferus and apiculatus, both from Costa Rica, are described and illustrated. New records for Mexico and Central America are listed for eight other species of Neoathyreus.

A new species, Chironomus (Camptochironomus) vockerothi, is described in the adult male and female from Alberta and is compared with other species in the subgenus.

The true armyworm, Pseudaletia unipuncta (Haw.), has no evident diapausing stage, is not freeze tolerant, shows no consistent seasonal changes in either supercooling-point values or longevity at 0 °C for different developmental stages, and did not survive when held in overwintering cages in the field. These facts support the hypothesis that this species cannot overwinter in Quebec and that the adult populations observed each spring must therefore be the result of a northerly migration from sites, such as Tennessee, where overwintering is known to occur.

Cyanobacterial mats of Oscillatoria spp., found in the habitat of Bembidion obtusidens, a halophilic carabid beetle, emit metabolites that act as allelochemic attractants to these insects. In a wind tunnel designed for use with small, fast-running carabid beetles, B. obtusidens adults responded to a homogeneously dispersed wind-borne mixture of these allelochemics by walking upwind. These results suggest that wind-borne metabolites of Oscillatoria spp. could act as distant chemical cues that invoke positive, odor-mediated anemotaxis in migrant B. obtusidens, enabling them to locate their habitat.

The distribution and adult flight activity of obliquebanded leafroller, Choristoneura rosaceana (Harris) and threelined leafroller, Pandemis limitata (Rob.) were studied in the Okanagan and Similkameen valleys of British Columbia using traps baited with the sex pheromone of each species. Adult activity began in early June and continued through September and the two species were distributed throughout the apple-growing region of the Okanagan and Similkameen valleys. In the northern Okanagan and in uncultivated areas at higher elevation, the trap captures indicated that both species are univoltine. In the southern Okanagan and the Similkameen Valley, large numbers of both species were captured throughout the season which may indicate more than one generation. Traps captured similar numbers of adults in orchards with known infestations and in orchards lacking infestations, suggesting that males are attracted to traps in orchards from native hosts in uncultivated sites.

In 1981 and 1982, the following ant species and numbers were detected preying on pupae of the western spruce budworm, Choristoneura occidentalis Freeman, in eastern Oregon and western Montana: Formica obscuripes Forel, 174; Camponotus modoc Wheeler, 160; C. laevigatus Smith, 53; C. vicinus Mayr, 48; F. podzolica Francoeur, 43; F. accreta Francoeur, 32; F. neorufibarbis Emery, 12; F. lasioides Emery, 1; and Formica sp. (microgyna group). The Camponotus species and F. obscuripes were detected preying on budworm on one-third or more of the trees they foraged.

Peanuts, Arachis hypogaea L., have been grown experimentally in Ontario since 1970, with the ultimate objective of commercial production. The pests of this new Canadian crop have been surveyed and the most important one has been identified as the potato leafhopper, Empoasca fabae (Harris) (Ellis and Roy 1979). This pest is native to North America and disperses into Ontario from the south in early June; it attacks a number of crops including potatoes, alfalfa, beans, and peanuts. Feeding by E. fabae interferes with translocation and results in yellowing of the tips of peanut leaves, followed by necrosis, a condition called hopper bum. Reported here are experiments on the injury of this pest to peanuts in 0ntarioT

Invertebrate predation of egg masses of the gypsy moth has been little studied in North America despite its reported impact on populations of this pest in Eurasia and North Africa (Nonveiller 1959; Stefanov and Keremidchiev 1961; Hérard 1979). There, on occasion, this feeding guild has regulated local gypsy moth outbreaks (DeLépiney 1933). The most important predators were dermestids of the genera Anthrenus, Dermestes, Megatoma, and Trogoderma.

Dans la toundra forestière, zone correspondant non seulement à la limite des forêts et des arbres (Payette 1983), mais aussi à celle de la plupart des espèces de tabanides (Chvála et al. 1972; Baribeau et Maire 1983), les tourbières constituent le principal type de milieux humides propice au développement des larves de tabanides (Miller 1951; Teskey 1969).