First-stage forest tent caterpillar larvae were tested for the presence of active and sluggish behavior types such as Wellington found in Malacosoma californicum pluviale (Dyar). Larvae capable of directed movement towards a 30 w light source were classified as active. Larvae were tested on 3 consecutive days, and only a small percentage responded on all 3 days. A much larger percentage remained sluggish throughout the period. Chi-square tests confirmed that the differences in response were not random. There was a tendency for some larvae to respond to light during the test and for others not to respond. The reduced consistency in the response of "active" larvae in M. disstria Hübner compared with that reported for M.c. pluviale may be partly due to real behavioral differences, but it also may be partly due to some procedural differences between our tests and Wellington’s.

The receptivity of sexually mature Plodia interpunctella females during courtship was quantitatively analyzed. When males approached from the rear, two thirds of the females moved away from them on the first courtship encounter so that only 22% of these encounters led to copulation. In second encounters from the rear, however, 86% of the females turned and accepted the males, and 40% of them copulated. When the males approached head-on there was no observable difference in female receptiveness between first and second encounters; in each case over 90% of the females accepted the males and at least 55% of them copulated. Since the acceptance of the male by the female is dependent on her perception of a male sex pheromone released by scent glands on his forewings, she can probably identify the male immediately in head-on encounters but requires additional time or stimulation to do so in rear encounters.

In 1965, strains of the predaceous phytoseiid mite, Typhlodromus occidentalis Nesbitt, had developed resistance to azinphosmethyl, one of the organophosphate insecticides used to control the codling moth, Laspeyresia pomonella (L.). From 1966 to 1968, trials with integrated mite control in growers’ orchards were carried out successfully preserving the predator T. occidentalis. In most cases, an application of oil at the half-inch green bud stage was applied. The integrated concept of orchard mite control was recommended to the British Columbia fruit industry in 1969 and gained wide acceptance. In 1974, a survey of eight of the original integrated control orchards revealed that none of them had been treated with a summer acaricide since 1968. In six orchards, application of oil at the half-inch green bud stage had been used annually but two had not even received the oil spray. In all the orchards there was a good biological balance of a few predators and a few prey.

Population models for the Egyptian alfalfa weevil and alfalfa are reported, which compared favorably with field data. A mechanism for coupling the plant–herbivore trophic levels is suggested.

Tetracanthella pacifica sp. n. from Coastal British Columbia is described and illustrated. A key to the Nearctic Tetracanthella species is given.

Larvae of the mountain pine beetle, Dendroctonus ponderosae Hopk., were reared to adults in naturally infested bolts of lodgepole pine, Pinus conforta Dougl. var. latifolia Engelm., at 21 ± 3 °C. The mean pronotal width of the emerging beetles of both sexes decreased, and the male:female ratio increased, during the emergence period. On the average, larger individuals of both sexes survived longer when adult beetles were stored at 1 ± 2 °C. Also, the male:female ratio of the surviving beetles decreased with increased storage duration. These and related results in the literature suggest that in natural populations of the mountain pine beetle average adult size increases, and the male:female ratio decreases, following stress-induced mortality in the larval and(or) adult stages.

The birch casebearer, Coleophora fuscedinella Zeller, has five larval instars in northeastern North America, but commonly only four in insular Newfoundland. The occurrence of four larval instars in Newfoundland represents the omission of either the third or the fourth instar. Local Newfoundland populations may have five larval instars, but the late-developing larvae of these populations have only four larval instars. Head capsule width can be used to identify instars but case characteristics are recommended because the bimodality of third instar head widths can cause confusion.

The introduced parasite Lophyroplectus luteator Thunberg has spread 305 km in an easterly direction in the 13 years since its release and has dispersed faster in southern Ontario than its host, Neodiprion sertifer (Geoffroy). The prevailing westerly winds were probably an important factor. The limited dispersal from a second liberation is discussed.

Larvae and pupae of eight species of Tabanidae are described: Chrysops sequax Williston, Hybomitra cincta (Fabricius), H. longiglossa (Philip), H. microcephala (Osten Sacken), H. daeckei (Hine), Tabanus novaescotiae Macquart, T. colon Thunberg, and T. wiedemanni Osten Sacken. A key is provided for identification of nine of the 10 species of Tabanus currently known to possess a stigmatal spine.

Rapeseed flour fed to package honey bee colonies was preferred to soya flour, wheast, and pea protein concentrate. Rapeseed flour was equal to wheast and fresh mixed pollen for longevity when fed in small cages. Rapeseed flour was equal to wheast but both were inferior to fresh mixed pollen for brood rearing. Pea protein concentrate was the poorest diet in longevity and brood rearing tests.

Characteristics of cephalic structures and spiracles of final-instar larvae of three species of the genus Toxophoroides (Hymenoptera: Ichneumonidae: Lycorininae) are described and illustrated, and a key for their separation is given. As this is the first known information on larvae of the subfamily Lycorininae, characteristics of the group are defined, based only on the single genus studied.

The males of four very similar species of Macrocera are keyed and briefly described. They are grandis Lundström (Finland, U.S.S.R.), nobilis Johnson (Nearctic, widespread), summatis n. sp. (Sweden), insignis n. sp. (New Hampshire). The group of species is characterized as the nobilis group.

Over 95% of feeding balsam woolly aphids occur in crevices on balsam fir branches and the highest density occurs within the 3-year tip of branches. The crevices occur under the bud scales at nodes, the base of each season’s growth, and among staminate flower buds or among and within flower bracts. The abundance and survival of aphids as well as mortality factors vary with the location of the nodes in a branch, the type of branch, and aphid generation. The significant differences show that there are 9 to 13 strata within the 3-year tip of a branch. For ecological studies and measuring population levels, the cluster of aphids within a defined crevice, for example under the bud scale at the base of a cluster of shoots, can be selected as a sample unit.

Mated females of the aphid parasite Aphidius smithi produced only unfertilized eggs (i.e. sons) for the first 2–3 h after copulation and a variable proportion of fertilized eggs (i.e. daughters) thereafter. As a result, the mean proportion of daughters among the offspring of single females was always less than unity, even in a highly favourable environment; the limiting value of the sex ratio was estimated at approximately 85% females. An argument is presented that in haplodiploid species with a variable and environmentally controlled sex ratio a male-producing mechanism is required to ensure the production of a sufficient number of males for the fertilization of all females.

The characters of Omomyia are compared with those of the tephritoid complex of families (Lonchaeidae, Otitidae, Platystomatidae, Pyrgotidae, Tephritidae, Tachiniscidae, Richardiidae, Pallopteridae, Neotteophilidae, Piophilidae, and Thyreophoridae). The possession of a peculiar piercing-type ovipositor by all females of this assemblage, including Omomyia, is considered a strong synapomorphic feature of the complex. Omomyia is found to be a sister-group of two aberrant richardiid genera, Automola Loew and Epiplatea Loew. Consequently, Omomyia is transferred from the Thyreophoridae to the Richardiidae with a suggestion that Automola, Epiplatea, Omomyia, and several other genera represent a separate subfamily of Richardiidae. The paper contains one table and three figures.

Mating studies with M. sanguinipes (Fabr.) indicated that egg hatchability and percentage of males among the hatchlings decreased as copulatory period decreased; this was probably caused by depletion of viable sperm in the female resulting from inadequate sexual contact with the male.

The majority (about 94%) of birch casebearer larvae, Coleophora fuscedinella Zeller, abandon the leaves in the fall and attach their case to the bark surface at spurs, at the base of buds, and at twig crotches. Casebearer populations were studied in six white birch, Betula papyrifera Marsh., stands of 3 m to 6 m in height. An average of 50% of overwintering population of the birch casebearer occurred within 50 cm of the crown periphery of the middle half of the crown. This proportion was the same at the three population densities studied: 2,000, 10,000, and 20,000 cases per tree. Intra-tree distribution differed significantly between stands and between years and was modified when there were more than 3,000 larvae in a tree. However, the relation between log10 (cases + 1) at midcrown and the whole tree was consistent and usually explained more than 85% of the variance. For all population densities, the number of casebearers in the tree could be estimated from a sample of the crown. To preserve the form and aesthetic value of trees, the sample should comprise spurs or crotches and not a crown sector as used in this study.

Dispersal from earwig nests includes an inter-brood dispersal by female parents and two nymphal dispersals. One nymphal dispersal occurred in nature, but was not evident in the laboratory. The two other types were associated with heightened activity and a rejection of the nest in the laboratory. This locomotory behavior, which is probably adapted for dispersal, is termed “dispersive behaviour.”

A pour-on formulation of ronnel and 1% coumaphos dust were tested for control of cattle lice under southern Ontario feedlot conditions. Moderate to heavy populations of the cattle biting louse Bovicola bovis and light populations of the sucking lice Linognathus vituli and Haematopinus eurysternus were present on the treated cattle. The ronnel and coumaphos dust gave excellent reduction of lice populations for 43 and 35 days, respectively.

Carbofuran at 2 oz AI/acre caused a 94% reduction in 3rd- and 4th-instar larvae of alfalfa weevil. There was a 67% reduction in 1st- and 2nd-instar larvae which were protected within the buds. Carbofuran did not reduce the percentage parasitism by Bathyplectes curculionis (Thomson) although the total parasitoids that developed per unit area was less.