Tetracyclos boreios Kryger is redescribed and illustrated, and its placement within the family Encyrtidae (Chalcidoidea) confirmed. The peculiar mechanism of movement of thoracic sclerites is described; this is compared with that of other Encyrtidae and Eupelmidae (Chalcidoidea), and its possible biological significance is discussed.

Four species of each of the genera Chrysops, Hybomitra, and Tabanus were collected while feeding on cattle in southwestern Quebec; T. quinquevittatus accounted for 75% of the tabanids. The more abundant species had a flight period of at least 5 weeks. Nearly 90% of the specimens were positive for fructose as determined by the cold anthrone test.

Venom of the hyperparasitoid Asaphes lucens (Provancher) immediately paralyzed and stopped development of the larva of the aphid parasitoid Aphidius smithi Sharma and Subba Rao, which did not void a meconium and deteriorated into a soft, blackened mass. On the other hand, venom of a second hyperparasitoid, Dendrocerus carpenteri (Curtis), did not immediately paralyze the larva of A. smithi, which developed up to the prepupal stage, voided a meconium, and remained bright yellow for up to 4–6 weeks before decaying.

Studies were conducted under controlled laboratory conditions to determine the effect of temperature on development and oviposition of the variegated cutworm, Peridroma saucia (Hübner). Developmental thresholds and Celsius degree days necessary for completion of a given stage are: egg (threshold 5.6°C) = 89 DD; larvae (threshold 6.2°C) = 387 DD; pupa (threshold 8.5°C) = 210 DD; and total development (threshold 7.2°C) = 676 DD. The threshold for oviposition was 3.5°C with 128 DD necessary for oviposition to occur.

Light trap catches of variegated cutworm moths from 1965 to 1979 were plotted as a function of accumulated heat units based on laboratory data. For the 15-year period, peaks of activity occur at 500 and 1200 DD based on 7.2°C threshold. The data generated in this study would be utilized best in an alert network for determining when scouting should occur, based on peak capture of variegated cutworm moths.

Cypermethrin was more toxic to adults of the braconid parasite Apanteles ornigis Weed than fenvalerate, permethrin, azinphosmethyl, or methomyl. Endosulfan was the least toxic insecticide. Permethrin, however, was 19 × more toxic to the leafminer host Phyllonorycter blancardella (Fabr.) than to A. ornigis and could be most useful in an integrated pest management program. Several chalcids, Sympiesis spp., showed less sensitivity to azinphosmethyl than did A. ornigis.

Nine species are recognized, of which six are new to science: Teleas crassifemur ♂, T. neptuni ♀ ♂, T. niger ♂, T. punctifrons ♀ ♂, T. terricola ♀, and T. villus ♂. The three previously described species which are retained in the genus Teleas, viz. T. lineaticeps Ashmead, T. pallidipes Ashmead and T. sibiricus Kieffer, are redescribed. Females of T. lineaticeps and T. pallidipes are described for the first time. All other Nearctic species listed by Muesebeck (1979) under Teleas are presently transferred to the genus Trimorus Foerster (subfam. Teleasinae) (all new combinations): Trimorus americanus (Ashmead), T. coxalis (Ashmead), T. harringtoni nom. nov. (= Teleas canadensis Harrington nec Acolus canadensis Ashmead), and T. mandibularis (Ashmead). T. sibiricus Kieffer is the only member of the genus known to have Holarctic distribution.

A key to the females and males of Nearctic Teleas and a key to Nearctic genera of Teleasinae are presented.

The multiporous plate sensillum occurs on the antennae of Hymenoptera. The internal and external cuticular surfaces of these sensilla, as well as the cellular ultrastructure, were examined in the Braconidae by electron microscopy. The sensillum has an elongated, external, porous plate and an inner, cuticular septum in which there is an aperture. It is innervated by numerous neurons, the dendrites of which pass through the aperture, branch and traverse the longitudinal axis of the sensillum. The ratio of aperture length to sensillar length was measured on the internal cuticular surface in 32 species. This ratio increased from the ancestral to the derived species. This sensillar character may be useful in elucidating braconid systematics. It also has potential use in the systematics of other hymenopterous parasitoids.

When 95% ethanol was sprayed at the rate of approximately 46 ml/m2 of bark surface on the lower 1 or 2 m of standing living spruce trees, Picea engelmannii Parry – P. glauca (Moench) Voss hybrid population, 23 of 47 and 18 of 19 treated trees in two areas received one to many spruce beetle, Dendroctonus rufipennis (Kirby), attacks, whereas only 2 of 63 and 2 of 64 untreated trees, respectively, were attacked. Some of the treated trees were killed by mass attacks of the beetles, but most trees pitched out the attacks. Thus beetle attacks on essentially resistant trees were induced by the ethanol treatment. However, spruce beetles were not attracted by the ethanol treatment.

Responses were recorded of male spruce budworm (Choristoneura fumiferana (Clem.)) exposed to natural pheromone and a wide range of concentrations of synthetic pheromone in an all-glass wind tunnel equipped with a moving, patterned ceiling. The numbers of males wing-fanning and plume-following decreased with decreasing concentration of the pheromone plume. Speed of upwind flight with the ceiling stationary increased with decreasing concentration, but the durations of flight sustained by moving the ceiling were not significantly different under the different concentrations.

Males exposed to pheromone produced by calling females showed a higher incidence of plume-following, and flew significantly faster, than males exposed to a similar concentration of synthetic pheromone.

White spruce, Picea glauca (Moench) Voss, is a major commercial tree species used in reforestation programs throughout Canada, and seed requirements cannot be met in some years because of insect damage and the periodic nature of cone crops. The spruce budworm, Choristoneura fumiferana (Clem.), feeds on buds and cones of its hosts, causing a pronounced decrease in cone production (Schooley 1978). A current outbreak in northeastern Ontario poses a serious threat to white spruce seed supply from high value, managed seed production areas. Therefore, in 1979, we began an experiment to determine whether carbofuran, a systemic insecticide, could be used to protect buds and cones when applied to soil. We chose carbofuran because it has proved successful for control of some insects in seed orchards in the southeastern United States (DeBarr 1978)