Lecanium tiliae (L.) is now attacked in British Columbia by three species of parasites, about 18 predators, and a fungus. Parasites are the most important natural enemies but parasitize an average of only 30% of the scales. Reasons for low parasite effectiveness include: hyper-parasitism by one species, Coccophagus lycimnia, which is apparently a recent arrival in the district, on itself and on the chief parasite, Blastothrix longipennis; a tendency for C. lycimnia to be relatively abundant in low scale populations; differences in sex ratio of B. longipennis between low and high host populations; and parasite mortality in the scales. It was confirmed that the parasites pass the summer as diapausing adults rather than in alternate hosts. It is concluded that the biological control attempt of 1928 and 1929 that has been widely regarded as a success was in fact probably a failure, as the introduced parasite, B. sericea, did not apparently become established. An attempt in 1969 and 1970 with an introduced fungus also failed.

The cabbage maggot, Hylemya brassicae (Bouché), had three generations per year from 1970 to 1973 inclusive, a partial fourth was noted in most years. A small proportion of first generation pupae entered aestivation in 1971.

Thermal units required for fly emergence from overwintered pupae fell within a narrow range (174 to 199), but there was little correlation between thermal units and fly emergence in subsequent generations. Lack of adequate moisture delayed establishment of larvae in roots in some generations. Lack of adequate soil moisture delayed establishment of larvae in roots in some generations, and this appeared to be the chief reason for the lack of correlation between thermal units and fly peaks.

Throughout this investigation the over-all population remained remarkably constant. Parasitism by a staphylinid, Aleochara bilineata Gyll., and a fungus, Strongwellsea castrans Batko and Weiser, and soil moisture were the most important biological and climatic factors affecting survival. Parasitism of the adult by a nematode, Heterotylenchus sp., was recorded for the first time.

Although large numbers of seed maggot adults, Hylemya florilega (Zett.) and H. platura (Meig.), were recorded, few infested rutabaga. Other species trapped included Euxesta notata (Weid.) and Muscina spp.

A sex pheromone, detected in female moths of the bertha armyworm, Mamestra configurata Wlk., was extracted from females that were more than 3 days old. Males responded to the pheromone from 2 days of age until they died; younger males were not tested. Chemical and bioassay analyses indicated that the pheromone was an acetate.

The stimulatory effect of several chemicals was determined with males in a laboratory bioassay. Sexual responses were induced by Z7-, Z9-, Z10-, Z11-, and Z13-hexadecen-1-ol acetates. The maximum response in the laboratory was from the Z10-isomer, but this compound was only weakly attractive to males in the field.

A potent sex pheromone produced by female bertha army worm moths was isolated. A 16 carbon, unsaturated, alkenol acetate was indicated from chemical degradative and GLC retention data. The location and configuration of the double bond was determined from the antennal responses (EAG) of male moths to a series of cis and trans mono-unsaturated alken-1-ol acetates; cis-11-hexadecen-1-ol acetate elicited the greatest EAG response. GLC retention times of the purified insect sex pheromone corresponded exactly with those of authentic cis-11-hexadecen-1-ol acetate on several analytical columns. Maximum biological response in laboratory bioassays of synthetic materials was obtained from a mixture of approximately 85% cis- and 15% trans-11-hexadecen-1-ol acetates.

The San Jose scale, Quadraspidiotus perniciosus (Comstock), was killed on harvested apples by fumigation with 32 g/m3 of methyl bromide for 2 hours followed by standard cold storage for about a month. Fumigation, without storage, did not kill all the scale.

The spider genus-group names Horodromoides Gertsch 1933, Rhysodromus Schick 1965, and Locupletus Schick 1965 are synonymized with Philodromus Walckenaer 1826. Horodromoides validus Gertsch 1933 is the sole North American member of the fuscomarginatus group of Philodromus, other representatives of the group occurring in Eurasia. Rhysodromus histrio (Latreille) 1819, Philodromus mysticus sp. n., Rhysodromus (Locupletus) alascensis (Keyserling) 1884, and one European species constitute the histrio group of Philodromus. P. lentiginosus Keyserling 1882 is synonymized with P. histrio, and Rhysodromus (Locupletus) alascensis dondalei Schick 1965 is synonymized with P. alascensis.

Insect infestations in farm-stored grain, country elevators, and grain residues or spillages were detected by probes, traps, and scoops. Of 68 storages examined at 50 Saskatchewan farms in 1970, 25 were infested with the rusty grain beetle, Cryptolestes ferrugineus (Stephens). Of 52 storages examined in Saskatchewan in 1971 none of the permanent buildings was infested, but 27%, 30%, and 45% of temporary cribs, open piles, and grain residues, respectively, were infested with rusty grain beetles, fungus beetles, or both. The fungus beetles found most frequently in the traps were Lathridius minutus L. Cryptophagus varus Woodroffe and Coombs, and Cartodere constricta (Gyllenhal). A survey of different grain storages in Manitoba in 1972 showed that 44%, 45%, and 69% of country elevalors, farm granaries, and open piles of grain, respectively, were infested with fungus beetles. None of the storages contained the rusty grain beetle alone but 5% of farm granaries and 31% of open piles examined were infested with both kinds of insects. The least infestation occurred in country elevators and the highest in open piles. In general, the lowest insect infestations were in grain stored in weather-proof buildings, and the highest in exposed grain. Grain in open piles or temporary cribs suffered considerable spoilage. The traps were useful in determining insect distribution and behavior in stored grain.

Until mid- or late July, most larvae of the wheat stem sawfly generally move into the upper internodes of the host stems. Then, as the stems mature, the larvae migrate down to the basal internodes and cut the stems at about ground level.

The migration is initiated in response to the visible and infrared light transmitted through the ripening stems. The direction of the migration, toward the basal internodes, results from the orientation of the larvae to the vertical axis of the stems reinforced by a positive larval response to gravity.

The larvae cut the stems at ground level because they are shielded there by the soil from visible and infrared radiation. The location of cutting is also influenced by the preference of the larvae for drier sites in which to cut.

The date of cutting is directly related to the loss of moisture from the stems, but not to a precise level of stem moisture. The larvae may form their cocoons in response to desiccation.

By beating foliage with a stick, insects inhabiting the foliage can be dislodged onto a sheet held beneath it. In an attempt to develop this as a quantitative method for sampling lepidopterous defoliators feeding on exotic conifers in New Zealand, the size of the sheet and method of beating were standardized. Analysis of samples made over a period of 2 years revealed that differences between individual collectors were minimal, and that although very similar proportions of larvae were captured on the three areas of sheet used, the middle size gave the optimum balance between precision and cost of sampling. It also showed that as the number of larvae captured increased, the number of samples could be decreased in a semi-sequential manner.

Methoprene, when incorporated into the food of laying hens at concentrations of 0.005 and 0.01%, produced 70.9 and 99.3% larval mortality, respectively, among house flies (Musca domestica L.) reared in the resultant poultry droppings. Exposure to the treated diet did not produce any weight loss in the chickens. However, it was not effective when the poultry droppings were treated topically under field conditions. In laboratory studies, when incorporated with moistened droppings, concentrations of 0.001 and 0.0001% produced complete larval mortality throughout a 7-day exposure period, though only 98% mortality was achieved on the first day at the higher concentration. Concentrations of 0.5 and 1.08 of the compound in fly food produced only a low order of sterility. Topical applications produced a low order of sterility except in the insecticide-susceptible females.

The relationship between the temperature and the speed of development is described for the Kamloops ‘biotype’ of the pea aphid, Acyrthosiphon pisum, and some of its associated hymenopterous parasites. The primary parasites are: Aphidius ervi ervi, A. ervi pulcher, A. smithi, and Praon pequodorum; and the secondary parasites are: Asaphes lucens and Dendrocerus niger. For each species the lower temperature threshold for development and the time-to-adult was determined under constant laboratory conditions using field-grown alfalfa as a host plant for the pea aphid and the first-generation offspring of field-collected aphids and parasites. The thermal constants enable the prediction of aphid and parasite population growth, as influenced by temperature, on a physiological time-scale.

The evolutionary success of the mites, which rivals that of the insects, is reviewed briefly. A remarkable secondary adaptive radiation apparently occurred in the mites, probably beginning in the late Mesozoic, in conjunction with the major evolution and radiation of the insects and to a lesser extent of the higher plants and the warm-blooded vertebrate animals.

The spectrum of forest floor microhabitats, in which mite–arthropod associations may occur, is discussed. The problems in elucidating the living relationships between mites and other arthropods, due to biological complexities and physical difficulties, are reviewed. Some of the elements of close mite–arthropod associations are discussed, including protected stable habitats provided by insects, shared habitat specificities, regularity of co-occurrence, host specificity, site constancy of mites on their arthropod hosts, and life cycle synchrony.

Examples are given of the apparently few morphological adaptations of insects for accommodating mites. The variety of morphological structures which are adaptations of mites to an association with other arthropods are discussed, particularly regressive modifications. Physiological and behavioral adaptations of mites to secretions or to other actions of their arthropod associates are mentioned. Cases are given showing the different ways in which mites have achieved synchrony of their life cycle with that of their hosts.

Some thoughts on the usefulness of research on the interrelationships between mites and other arthropods conclude the paper.

Population growth and dispersion of Tetranychus mcdanieli McGregor were studied in an experiment conducted on Red Delicious apple trees grown in a light and temperature controlled walk-in growth room. Lloyd’s index of mean crowding was calculated as a means of interpreting aggregation patterns; however, it was found that mean colony size was a more generally useful population parameter . The regression of on mean density (m) and the ratio of mean density to were used to determine and characterize the patterns of dispersion obtained under the experimental conditions of the study.

It was shown that the ratio of mean density to is the proportion of sampling units (i.e. individual leaves) that would have a colony size of individuals per unit, all other units being unoccupied. Characterization by the concomitant parameters and provides a more sensitive and meaningful method of describing populations than does the arithmetic mean.

The data indicated that adult female populations of T. mcdanieli tend to be distributed as clumped colonies on apple trees. A plant feeding mite damage scale was devised to evaluate the reliability and accuracy of gross observational estimates as indicators of spider mite levels.

A new species, Chironomus athalassicus, is described from saline lakes in south-central British Columbia.

Twelve species are recognized in the abietina group of Pristiphora. A key to species and illustrations of the lancets and penis valves are presented. Only P. erichsonii (Hartig) is holarctic in distribution. P. gerula (Konow) is re-established as a species since it is not a variety of P. saxesenii (Hartig). A new species P. thalenhorsti is described. The name P. takagii is proposed for laricivorus Takagi nee Brischke.