The North American species of Dicladocerus are revised. Twelve new species from North America and one from Japan are described and illustrated: alaskensis, australis, prealatus, occidentalis, exoteliae, epinotiae, betulae, vulgaris, nearcticus, pacificus, japonicus, and terraenovae. The species attacking larch casebearer are nearcticus, pacificus, terraenovae, all Nearctic, and japonicus and westwoodii, Palaearctic. Relationships of species-groups in North America are discussed. A key to species, and host records are included.

Life cycles of Peristenus pallipes (Curtis) and P. pseudopallipes (Loan), parasitoids of the tarnished plant bug, Lygus lineolaris (P. de B.), were investigated in an alfalfa field and in uncut weeds in the Ste. Anne de Bellevue area. In 1972, P. pallipes adults emerged in mid-May and P. pseudopallipes adults emerged in late July. The incidence of parasitism in nymphal and adult stages of the tarnished plant bug, L. lineolaris, was measured. The population of the tarnished plant bug in the weeds was more heavily parasitized than the one in the alfalfa field. The ichneumonid hyperparasite Mesochorus curvulus Thomson was also found in this area.

Adult males of the Indian meal moth, Plodia interpunctella (Hübner), were irradiated with doses of 25 or 35 krad or various equal fractions thereof spaced over a period of 1 to 3 days. Longevity of males was not decreased by any of the irradiation treatments, but it was significantly increased by fractionation when the second fraction was administered the second day. The mating ability of males with single females, was not significantly affected by irradiation or fractionation of irradiation doses. The percentage of sterile pairs was dependent both on the dose and on the pattern of fractionation. The lowest percentages of sterility at both doses occurred in the treatments that had three equal fractions. The numbers of progeny produced by fertile pairs were also correlated with both dose and pattern of fractionation. Significantly more progeny were produced by males treated with some of the fractionated doses than by males treated with a single dose of 25 krad. No differences in number of progeny occurred at 35 krad.

Hemlock sawfly infestations occur most commonly in the warm southern half of southeast Alaska. Biotic factors that limit sawfly populations are a fungus, Entomophthora sphaerosperma, which kills disproportionately large numbers of female larvae; food quality as affected by host site and defoliation; and three ichneumonid parasitoid species, Delomerista japonica diprionis, Oresbius tsugae tsugae, and Itoplectis quadricingulatus, which attack prepupal larvae in cocoons. E. sphaerosperma was the most effective natural control in recent years, especially during wetter than normal summers. Parasites which attack after the fungus has decimated larval populations were most abundant during two dry summers. Parasitization and sawfly emergence were directly related, and both were highly inversely correlated with percentage fungus killed sawflies. Sawflies reared on lightly defoliated trees produced significantly more eggs than those reared on heavily defoliated trees, and fecundity was directly related to cumulative heat units during the summer. Between 1952 and 1974, most negative sawfly population trends south of Frederick Sound occurred when two wet summers occurred consecutively. Apparent widespread collapse of sawfly populations in 1974 was associated with low temperatures in 1973 which delayed sawfly development and reduced opportunities for successful oviposition.

A rearing method, based upon an artificial diet, has proved successful in establishing laboratory colonies of 36 species of the genus Euxoa. The diet is described, along with methods for controlling disease, particularly by the use of antimicrobial agents.

Many of the 36 species of Euxoa have not been reared before and their habits and life histories are little known. The data derived from their development under laboratory conditions and which can be related to seasonal distribution are recorded. Particular emphasis is given to the overwintering stage and to the occurrence of an aestivating stage.

Annual population estimates of spruce budworm, Choristoneura fumiferana (Clem.), larvae and the incidence of larval parasitism were monitored in northern New Brunswick following the collapse of the 1949–1959 epidemic in the region. The most common parasitoid among the very sparse hosts was Synetaeris tenuifemur, although it had been rarely found during the epidemic. Larval parasitism sometimes exceeded 50% but it could not be shown as a key factor associated with changing host abundance.

The biology of Cassida hemisphaerica Hbst. (Coleoptera: Chrysomelidae) is given and its suitability as a biological control agent of bladder campion, Silene cucubalus Wibel, is evaluated. Because its host range includes a number of ornamental plants in the genus Dianthus and the adults will feed on economic plants in the family Chenopodiaceae, introduction of C. hemisphaerica is not at this time justified.

Continuous trapping on the bark surface of Dendroctonus brevicomis LeConte infested trees in the central Sierra Nevada mountains was undertaken with the objective of determining the spatial and temporal arrival patterns of the natural enemies and other insect associates of the western pine beetle. Over 100 species of D. brevicomis associates were collected and patterns of arrival were described for many of these. The main bark beetle predators were trapped during D. brevicomis mass arrival and shortly thereafter. Enoclerus lecontei, Temnochila chlorodia, and Aulonium longum, all predaceous beetles on D. brevicomis adults and larvae, were among the first species to arrive, as was Medetera aldrichii (Diptera), a larval predator. The bark beetle parasites Roptrocerus xylophagorum and Dinotiscus (=Cecidostiba) burkei (Hymenoptera) were well synchronized with the beetles’ life cycle as they arrived late in the beetles’ larval stages when suitable hosts were available.

Approximately twice as many associates were trapped in the first (spring) beetle generation as in the second (fall). Differences between species with regard to height distribution were common, and these often varied with seasonal beetle generation.

Calculations of changes in species diversity through time, of the associate complex trapped at the bark surface, were made for both the first and second beetle generation. Linear correlation analysis indicated a highly significant increase in species diversity occurred from the time of the beetles’ mass arrival until brood emergence. This increase may correspond to an increase in diversity of the structure of the subcortical community, as more insect species arrived and progressively modified the habitat of the newly killed tree.

A strain of the alfalfa leafcutter bee, Megachile pacifica Panzer, that has produced less than 1% second-generation adults for 3 consecutive years was produced by selection against bivoltinism. The selection process also resulted in the production of bees that reproduced at a much higher rate than the unselected parent stock.

The activity of two insect growth disruptors PH 6038 and PH 6040 was assessed against larvae of the winter moth, Operophtera brumata (L.) in the laboratory and field. Larvae fed on foliage treated with PH 6038 and PH 6040 until death occurred at ecdysis owing to disruption in cuticle formation. Field tests with PH 6040 indicated that concentrations of 165 ppm were effective for control. As measured by bioassay, using winter moth larvae, PH 6040 was persistent for at least 28 days in the field.

Traps baited with the codling moth, Laspeyresia pomonella (L.), sex pheromone, trans-8, trans- 10-dodecadien-1-ol, were evaluated for their suitability in a pest management program in an area of high host abandonment. Modifications in trap design, trap condition, or pheromone cap type resulted in variation in male moth catch. In commercial orchards the necessity of both interior and perimeter traps is indicated. Reduction in pesticide sprays was obtained in two of the four orchards monitored, but utilization of traps in a pest management program is hampered by several factors including orchard design, grower attitude, and considerations of cultural practices.

A survey in southern Quebec from 1972 to 1974 at 178 sampling sites shown revealed the presence of 30 culicidian species. For 2 of these species (Aedes decticus and C. melanura), their presence represents a geographic extension. The breeding sites of these 2 species have been characterized by the type of vegetation.

Two forms of Hybomitra typhus (Whitney) flying together have been collected from Ontario bogs. The two forms have been clearly segregated by size and colour characters and also by differences in the appearance of esterase isozymes shown by electrophoresis. The combined data indicate that insects recorded as H. typhus comprise more than one species.

Two regions of esterase isozyme activity have been examined in Euxoa declarata (Walker) and E. campestris (Grote) and in their laboratory-reared hybrids. The two species could be distinguished in terms of one group of isozyme phenotypes although there was a small amount of overlap of phenotypes in one region. Two populations of E. campestris examined could not be distinguished clearly from each other. Canonical analysis was used to compare the two species and the populations within each species and the hybrids obtained by crossing various components of the two species. The generalized distance between the species appeared much larger than between populations; the hybrids appeared closer to the male parent.

Pseudodiamesa arctica (Mall.), Heterotrissocladius subpilosus (Kieff.), Orthocladius (s.s.) lapponicus Goetgh., Orthocladius (s.s.) sp., Paracladius quadrinodosus Hirv., Trissocladius tricornis n. sp., and Lauterbornia sedna n. sp. develop from egg to pharate adult in Char Lake. The occurrence of the larvae of 7 additional species is apparently adventitious, All stages of the two new species plus the larvae of P. arctica and P. quadrinodosus are described. The males of T. tricornis are dimorphic and L. sedna is parthenogenetic. New distribution records are given for most of the species. The chironomid fauna of Char Lake is compared with that of other arctic lakes.

A small colony of the striped flea beetle, Phyllotreta striolala (F.), has been maintained in a cage in the greenhouse for more than 21/2 years. Horseradish [Armoracia rusticana (Lam) Gaertn., Mey. & Scherb.] was found to be a suitable host plant, and the caged beetle colony has followed a similar life cycle to natural populations in the field.

The mass production of Nosema fumiferanae spores using second, third, and fourth instar larvae of Choristoneura fumiferana is described. In general, second instar larvae inoculated with 2 × 105 spores per millilitre of suspension resulted in a maximum spore yield of 1.3 × 108 spores per larva. A spore concentration of 2 × 107 reduced larval weights and increased larval mortality.

A new species of the genus Quedius Steph., Q. infernus spec, nov., is described from Oregon and Washington.

Additional data on taxonomy, bionomics, and geographical distribution of many species are presented.

New observations on parental behavior of the earwig, Forficula auricularia L., are reported and the literature on the parental behavior in the Dermaptera is summarized. The construction of the nest, care of the eggs and nymphs, and the duration of parental care are described. The control of parental behavior and the role of the male in nest establishment are also considered.

The feeding habits of Melanoplus bivittatus (Say) and M. femurrubrum (DeGeer) in an Ontario grassland were investigated by analyzing crop contents. The study revealed that both species are mixed feeders which prefer forbs over grasses. Both species ingested a wide range of host plants in the field, showing preferences for some species over others. Differential growth and mortality resulted when grasshoppers were reared on different host plants.