First-generation mullein bug, Campylomma verbasci (Meyer), nymphs damaged four major cultivars of apple in commercial and research orchards from 1982 to 1984. In commercial orchards, C. verbasci was ranked among the top three pests in 22 of 40 samples collected at harvest, and its damage exceeded the economic injury level of 1% culled apples in 17 of the samples. Injury was greatest in "Delicious" cultivars, for which a linear relationship was derived between population density and damage at harvest. Economic injury levels of one and four nymphs per tap are proposed for cvs. Golden and Red Delicious, respectively, in British Columbia.

Agrypon flaveolatum (Gravenhorst), introduced from Europe to control the winter moth, Operophtera brumata (L.), on apple and oak in Nova Scotia and British Columbia, was distinguished from the closely related native species, A. provancheri (Dalla Torre) and A. alaskensis (Ashmead). A detailed study of the three species revealed that they could be distinguished by specific morphological characters and by results of morphometric analyses of intra- and inter-specific variation of number of annuli of the antennal flagellum. The history of introductions of both the host and parasite is reviewed, including an account of host–parasite interactions. All of the characters defining species entities were found to be correlated with differences in host insect, host plant, and distribution.

The larvae of Pterostichus (Bothriopterus) ohionis Csiki and P. (Gastrellarius) blanchardi Horn are described and compared respectively with the other known larvae of Bothriopterus Chaudoir and Gastrellarius Casey. A key to larvae of 38 species of Pterostichini occurring in eastern North America is presented.

Females of Heliothis zea (Boddie) were stimulated to produce pheromone by injection of brain – subesophageal ganglion homogenates. Females injected with this homogenate during the photophase produced the same amount of pheromone and same ratio of components as neck-ligated females injected during the peak of pheromone production. Decapitated females and isolated abdomens also produced pheromone when injected with the brain – subesophageal ganglion homogenate during the photophase. These data show that the neurohormone which stimulates pheromone production is not degraded by enzymes during the photophase and that pheromone is not metabolized at a greater rate during periods when the insect is not producing pheromones.

In 1986 a greenhouse population of Liriomyza trifolii (Burgess) was shown to be highly resistant (155-fold at LC50) to the organophosphorus compound pyrazophos. However in 1987, the same population had only 35–40% resistant individuals remaining. A survey in 1986 of five other greenhouses reporting leafminer control failures indicated three other resistant populations in southern Ontario. Resistance was not affected by the addition of the synergists diethyl maleate or triphenyl phosphate to pyrazophos. Cross-resistance to the phosphorothioate insecticides demeton, chlorpyrifos, and triazophos was indicated.

Oil-based formulations of Bacillus thuringiensis Berliner var. kurstaki, Dipel 132, Dipel 176, and Dipel 264, were aerially applied at rates of 1.18–2.36 L/ha over five 30-ha plots in a balsam fir, Abies balsamea (L.) Mill., forest in efficacy tests against the eastern hemlock looper, Lambdina fiscellaria fiscellaria (Guen.), in Newfoundland. Double applications of 30 Billion International Units (BIU) per hectare of each formulation and single applications of 40 BIU per hectare of Dipel 176 and Dipel 264 were tested. Larval population reductions of more than 95% and no defoliation of old or new foliage were observed in the plots receiving double applications and in the plot treated with a single application of Dipel 264. Larval numbers were reduced by 85% and defoliation was 4% in the plot treated once with Dipel 176.

These treatments were applied against low to moderate larval populations, and their success was attributed to excellent spray coverage and early application when 50% or more of the larvae were still in their first instar.

Low temperature is a major factor regulating diapause development in Holcothorax testaceipes Ratzeburg. Diapausing pupae required a cold period of 0°C, 5°C, or outdoor (≤0°C) for ca. 15 weeks to terminate diapause. The pupae required a further 21–27 days at 21°C for 50% emergence. Longer periods and higher temperatures of storage often were associated with shorter times of morphogenesis and duration of emergence. Percentage emergence of H. testaceipes was constant after various periods of cold storage at low temperatures. After storage at 0°C, pupae held at 21°C and a 16-h photophase reached 50% emergence sooner than those held at the same temperature but at a 12-h photophase. Photoperiod did not affect percentage or duration of emergence of the parasitoid. The threshold temperature for development of pupal H. testaceipes was estimated to be 9°C regardless of sex or host species. The thermal constant did not vary with sex of the parasitoids but differed significantly for H. testaceipes reared on Phyllonorycter ringoniella Matsumura (237 DD) and on Phyllonorycter blancardella (F.) (202 DD). Temperatures from 11 to 29°C did not affect percentage and duration of emergence from overwintered pupae, which were 75.5% and 2.4 days respectively, when reared on P. ringoniella, and 86.2% and 1.7 days respectively, on P. blancardella. These results suggest that H. testaceipes accepts P. blancardella as a host and will be synchronized with its development in Ontario.

Four benzoylphenyl ureas (BPU’S) were tested on the four feeding larval instars of western spruce budworm, Choristoneura occidentalis Freeman, from a nondiapausing laboratory colony. BPU’s compared were chlorfluazuron, penfluron, triflumuron, and XRD-473 (N-(((3,5-dichloro-4-(1,1,2,2-tetrafluoroethoxy)phenyl-amino)carbonyl)-2, 6-difluorobenzymide). Although previous evidence suggested that BPU’S were generally most active on younger instars, last-instar western spruce budworm larvae were most susceptible to three of the four tested. Contour plots of estimated effectiveness during development of a western spruce budworm laboratory population indicated that the optimal time of application (lowest LC90) for XRD-473 would be ca. 16 days after the first group of larvae hatched, but the optimal time for the other three BPU’s would be between 40 and 50 days after hatch began. However, chronological age of insects in natural populations is difficult to estimate because of the influence of factors such as climatic conditions (e.g. temperature) and other ecological factors. The need to estimate optimal timing for application of BPU’s and other chemicals in terms of physiological time during population development is discussed.

Laboratory tests with selected carbamate, organophosphorus, and pyrethroid insecticides demonstrated that the pyrethroid permethrin has the best potential for controlling newly hatched larvae of Zeiraphera canadensis Mut. and Free. Permethrin possessed high crawling contact toxicity (toxicity of insecticide deposits on foliage when contacted by crawling larvae) and direct contact toxicity to first-instar larvae and exhibited long residual effectiveness on potted, white spruce trees. Chlorpyrifos, fenitrothion, mexacarbate, and methomyl had high crawling contact toxicity but short residual activity. Azinphos-methyl appeared to possess long residual effectiveness but relatively low crawling contact toxicity. Aminocarb and thiodicarb exhibited short residual effectiveness and relatively low toxicity. In field trials, an aerial application of permethrin (70 g/ha) at egg hatch resulted in an 81% population reduction and limited the destruction of tree leaders to 9%. Leader destruction was greater than 19% after treatments of permethrin at 35 g AI/ha or aminocarb at 180 g AI/ha or aminocarb twice at 90 g AI/ha. Leader destruction in an untreated plantation was 51%.

The balsam twig aphid, Mindarus abietinus Koch, infested nearly all trees in a range-wide provenance plantation of balsam fir, Abies balsamea (L.) Mill., in Michigan. Infestation levels were highest on eastern and lowest on western seed sources of fir. Large populations of the aphid were correlated with low survival and reduced developmental rates of the spruce budworm, Choristoneura fumiferana (Clemens). We propose that chronic, high susceptibility of trees to aphids could reduce concomitant susceptibility to budworm through direct (competition) and indirect (host and community-level) effects.

Woolly-bear caterpillars of Grammia blakei (Grt.) are sometimes abundant in early spring on overgrazed native range pastures in southern Alberta and southwestern Saskatchewan, occasionally reaching population densities exceeding 50 per square metre (Byers 1988). Grammia blakei has a wide distribution in the Great Plains and Intermountain regions of western North America. Although the brownish-black caterpillars are quite often abundant, the moths (Fig. l), which are not attracted to food baits or light traps, have been rarely collected and few field-caught specimens are present in collections (D.C. Ferguson, U.S. National Museum, Washington, DC; J.D. Lafontaine, Biosystematics Research Centre, Ottawa, personal communication).