Two viruses, one a nuclear polyhedrosis virus and the other a granulosis virus, were applied in an attempt to initiate epizootics in populations of western spruce budworm, Choristoneura occidentalis Freeman, on Douglas-fir trees, Pseudotsuga menziesii (Mirb.) Franco, in southeastern British Columbia. Two 172-ha plots were aerially treated in 1982 with 9.0 kg of lyophilized, virus-infected larval powder that was formulated in an emulsifiable oil tank mix and applied at 9.4 L per hectare. Each plot was treated when larval populations were at the peak of the fourth instar. The nuclear polyhedrosis virus was applied at 5.4 × 1011 polyhedral inclusion bodies per hectare and the granulosis virus at 1.7 × 1014 capsules per hectare. Results showed that the granulosis virus treatment caused 34.6% population reduction (Abbott’s formula) and the nuclear polyhedrosis virus 51.8%. Larvae from treated and check plots were reared individually in the laboratory and the incidence of viruses, parasitoids, and successful adult emergence was recorded. Studies m these plots continued in 1983 and 1984. Although vertical transmission of both viruses was evident, their impact on budworm mortality was less than in 1982. Consequently, the epizootics were not sufficiently intense to control the target insect population.

Adult pear psylla, Psylla pyricola Foerster, from commercial pear orchards near Wenatchee, WA, were tested using a slide-dip technique for susceptibility to fenvalerate over a 5-year period from 1984 to 1988. Results were compared with those from similar tests using psyllids from an unexposed population near Corvallis, OR. During 5 years, resistance of adults to fenvalerate increased by 16- to 32-fold at Wenatchee while that of the Corvallis population did not change. In 1988, tests with five pyrethroids and pyrethroid – piperonyl butoxide combinations indicated that pear psylla adults also were resistant to permethrin and flucythrinate but not to fenpropathrin or cyfluthrin which contain a cyano group that reduces their susceptibility to oxidase metabolism. Piperonyl butoxide synergism was proportional to the level of resistance, indicating that resistance is probably due to increased mixed function oxidase activity. Implications of this study to control of post-diapause winter form adults in commercial pear orchards is discussed.

Numerical analyses were performed on three nominal species of the family Tristiridae. The synonymy existing between Philippiacris Liebermann and Elasmoderus Saussure is corroborated. Philippiacris rabiosus Liebermann is placed in synonymy under Elasmoderus lutescens (Blanchard) as a morphotype. The new combination Elasmoderus wagenknechti (Liebermann) is proposed, and a new species from Chile, Elasmoderus minutus, is erected.

Male native elm bark beetles, Hylurgopinus rufipes (Eichhoff), had distinctive simple multipulse stress and rivalry chirps, and a bimodally patterned premating stridulation at the gallery site. Males were strongly arrested at attractive female galleries. Not all female galleries were attractive to males. For a short period after the arrival of the first (resident) male, conspecific males often contested the resident male. Stridulation by females was not detected.

Patterns of seasonal abundance of Colorado potato beetle, Leptinotarsa decemlineata (Say), potato flea beetle, Epitrix cucumeris (Harris), potato leafhopper, Empoasca fabae (Harris), and aphids on potato cv. Norland are reported for the 1983–1985 growing seasons in southern Manitoba. Each year, Colorado potato beetles and potato flea beetles underwent one generation on the crop. There were two peaks of leafhopper abundance in 1983 and 1984, but only one was evident in 1985. Aphid populations rose to a single peak in August of each year.

In experimental plots in the absence of insecticides, Colorado potato beetles completely defoliated plants in two seasons out of the three. In commercial fields, insecticide sprays applied in July and early August greatly reduced populations of Colorado potato beetles for the rest of the season, and there was no defoliation at harvest. Insecticides had less effect on potato flea beetle populations. Leafhopper and aphid populations were small at the time of spraying.

The 45-cm mid-crown branch tip from balsam fir and white spruce is described in terms of surface area, fresh weight, and bud density. Fresh weight is suggested as the most appropriate unit to express density of all stages of the spruce budworm’s, Choristoneura fumiferana (Clem.), life cycle, particularly for the purposes of comparisons between host species and locations with different foliage conditions.

Changes in distribution of the spruce budworm in the crown of balsam fir are documented for all stages of the insect’s life cycle. Correction factors to account for these changes when estimating density on the basis of the 45-cm branch tip sampling unit are given for balsam fir and white spruce.

The amount of error in detection of spruce budworm larvae on foliage of both host trees by sampling personnel varied systematically and consistently as a function of insect development. A method to compensate for this type of error is also suggested.

Adults of Arrenurus (?Micruracarus) kitchingi sp.nov. are described. This is the first species of Arrenurus to be reported from a tree-hole habitat. Problems with the currently used subgeneric classification of Arrenurus are discussed.

Stage survival is typically calculated from estimates of numbers entering two successive life stages. We present a method that estimates stage survival by reference to the difference between directly measured recruitment to the stage and the estimate of recruitment obtained from Southwood and Jepson’s graphical technique. The method assumes mortality is constant within the stage. The method is applied to two generations (at two sites) of the egg stage of the Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), and the predicted stage survivals are compared, for two generations, with direct field measurements of egg mortality.

Two new species of Brachypauropodidae are described, Aletopauropus tanakai and Deltopauropus reticulatus. They represent the first records of the family from Japan.