Larvae of the driedfruit moth, Vitula edmandsae serratilineella Ragonot, enter uncapped tunnels in hives of the alfalfa leafcutter bee, Megachile rotundata F., and eat the pollen and nectar provisions of incomplete cells. Significantly more cocoons are destroyed in hives made of pine nesting material than in those made of polystyrene nesting material. However, significantly more tunnel walls are chewed into and through in the polystyrene than in the wood material. A significant positive relationship exists between the number of moth larvae per hive and the number of bee cells produced in that hive. After hives are removed from the field and placed in storage for the winter, most mature larvae leave the tunnels upon completion of feeding and aggregate in spaces between hives.

The rate at which adult house flies, Musca domestica L. developed resistance to permethrin and dichlorvos, in response to two spray regimes, was studied on eight farms near Guelph, Ontario during 1980 and on four of these farms during 1981. These regimes were: continuous reliance on permethrin or permethrin alternated with dichlorvos throughout the spray season. Where sanitation was comparable, resistance to permethrin developed more rapidly in fly populations from the farms on the continuous permethrin regime than on the farm in which permethrin and dichlorvos had been alternated. Resistance to dichlorvos did not decline under the continuous regime while in the alternately selected flies resistance ratios dropped from 11 to 6 after 2 years. Frequent sanitation delayed the development of resistance in a population continuously selected with permethrin. Alternation of dissimilar insecticides appeared to be a viable means of delaying resistance in the field.

Emerging Trichoptera were collected from the littoral zone of a newly-created reservoir, Southern Indian Lake, Manitoba, from 1977 to 1981. The relationship between caddisfly emergence and lake shoreline type, depth of sampling, and shoreline erosion rate was studied. Twenty-five species of Trichoptera were collected; six species of Polycentropodidae comprised almost 75% of the total number of individuals. Abundance and richness of Trichoptera were correlated with shoreline stability, with higher abundance and richness being found at more stable (i.e. lower erosion) shorelines. Highest numbers of Trichoptera emerged in 1981, 5 years after impoundment. Maximum abundance and richness of Trichoptera was found at 3.5 m depth, which is also the depth at which maximum deposition of organic matter occurred. Agrypnia straminea Hagen, a case-maker, dominated the trichopteran fauna at the marsh shoreline; species of net-spinning Polycentropodidae dominated at the clay shorelines. Patterns of species composition and abundance in 1982 artificial substrate collections were similar to those found in 1977–1981 emergence trap collections. Interspecific differences in Neureclipsis capture nets may explain the greater abundance of N. validus (Walker) than N. bimaculatus (L.) at a high erosion shoreline.

Intertrap variability in catches of moths of the cutworms Leucania commoides Guenée and Peridroma saucia (Hübner) was tested by placing two traps for each species baited with artificial sex attractants at 1.6 km (1 mi) intervals to form a grid covering 64 km2 (25 mi2) near Domain, Manitoba. During the flight periods of the test species the attractants were 86.5 and 93.6% species-specific for L. commoides and P. saucia respectively. Moth catches varied between traps and flights, but the ranking of the traps by catch for each species was consistent during any given flight of L. commoides and during the first flight of P. saucia. The low intertrap variability in numbers captured of both species indicated the moths were uniformly distributed in the area. For L. commoides 10 traps within an area of 64 km2 would be required to give a population estimate within 20% of the true mean and for P. saucia three traps would be needed. The flights of L. commoides started abruptly each year and appeared to be triggered by rainfall. Flights of P. saucia did not occur below 10 °C but otherwise weather had no apparent influence on the flights. It was concluded that the moths of this species are blown in from the south each spring. Neither species showed a consistent distributional relationship with crops.

Coloration of larval, pupal, and adult progeny of Choristoneura spp. collected from Pseudotsuga menziesii (Mirb.) Franco and Abies concolor (Gord. & Glend.) Lindl. in south-central Oregon depended on the temperature at which the insects were reared. Sex and genetic background were also major sources of variation in coloration. Many of the characters which varied with temperature were thought to be of value in distinguishing C. occidentalis Freeman from C. retiniana (Walsingham). The association between a combination of larval characters and a combination of adult forewing maculations, though weak, allows a calculation of the probability that an adult belongs to a certain lineage defined by larval features. Individuals from mixed families were particularly difficult to categorize because of the variation encountered and the sensitivity of their appearance to rearing temperature. The biological significance of this variation and its implications to pest management are discussed.

The genus Stomis Clairville is redefined. It includes two subgenera: Neostomis subg. nov. (type-species: Pterostichus termitiformis Van Dyke) with one Nearctic species and Stomis s. str. with 15 Palaearctic species. Eustomis Semenov, previously considered as a distinct genus, is synonymized with Stomis s. str. Description of the genus Stomis and of the two subgenera, as well as a diagnosis and comments on ranking and relationships of the genus, are provided.

The effectiveness of the phytoseiid predator Neoseiulus fallacis in controlling population growth of the spruce spider mite, Oligonychus ununguis was examined in the laboratory. Development and fecundity of N. fallacis under various relative humidity levels were also studied. Under controlled conditions, N. fallacis significantly limited population growth of O. ununguis on Fraser fir seedlings. Survival, development, and fecundity of N. fallacis were similar for all relative humidity ranges tested, except at the lowest range (60–65%), in which none of the individuals survived to maturity.

Cornicle length measuremetns of Acyrthosiphon pisum (Harris) nymphs reared in the laboratory were instar-specific and unaffected by rearing temperature. A multimodal analysis of cornicle lengths of field-collected aphids clearly detected four distribution peaks (i.e., instars) in five different field populations, and there was generaaly little overlap between successive instar distributions. However, third and fourth instars in the spring field sample could not be separated accurately due to the shorter cornicle length of nymphs that developed from overwintered eggs. Cornicle length proved to be a useful criterion for separating virginoparous A. pisum instars in samples collected in southern Wisconsin.

An equation is presented for the determination of sample sizes needed to estimate with a given precision the larval population density of spruce budworm on balsam fir and white spruce branch tips in Ontario. This equation is primarily applicable to low densities, but is valid to a density of 50 larvae/branch tip. The distribution of budworm larvae at densities below 0.1/branch tip is nearly random, and is aggregated at higher densities. Their distribution is the same on the two host species.

Pissodes strobi (Peck) and P. approximatus Hopkins are sibling species that can produce fertile hybrids in the laboratory, but in nature they are isolated by differences in their breeding habits. In a laboratory assay for feeding preference, these species exhibited similar patterns of acceptance of most conifer hosts in the fall, but differed distinctly in their preferences for certain conifers in the spring. Both species had high levels of feeding on white spruce in the fall and spring tests, hut these data apparently do not reflect host preference in nature. In field tests, P. strobi males and females confined on 1-year-old terminal leaders of eastern white pine (their usual breeding sites) produced abundant progeny, whereas P. approximatus pairs confined on leaders produced few progeny. Mixed species pairs were successful in killing and breeding in white pine leaders when the females were P. strobi, but not when the females were P. approximatus. Laboratory-reared hybrids were unsuccessful when forced to breed in leaders. When confined on red pine bolts (the usual breeding sites of P. approximatus), P. strobi and hybrids produced substantially fewer progeny than did P. approximatus. Breeding site separation provides compelling evidence of reproductive isolation between these sympatric species.

Field studies were conducted in which adult white pine weevils, Pissodes strobi (Peck), were confined on the leaders of six different conifer species and various parameters of weevil attack were recorded. Eastern white pine, Pinus strobus, the preferred native host, was the most susceptible to attack and the most suitable for brood production. All white pine leaders on which 3 or 6 male–female pairs of weevils were confined were killed, and mean numbers of emerging brood adults per leader were 26.0 and 37.3, respectively. Some leaders of the other species of pine and of spruce, Picea spp., were also killed, but brood production from them was very low. White spruce, P. glauca, leaders proved to be the least suitable for production of brood because no adult progeny emerged, even from leaders that had been killed.

Numerous spruce budworm, Choristoneura fumiferana (Clem.), moths were observed and trapped in western Newfoundland between 8 and 17 July 1982. At that time about 91% of the native Newfoundland budworm population was in the 5th and 6th instars and less than 1% had pupated. Spruce budworm moths probably emigrated with the aid of suitable weather from New Brunswick to Newfoundland.

Flower production, fruit set, and pollinator activity were measured in two 1-year postburn blueberry fields on the coastal barrens of the Avalon Peninsula, Newfoundland. Honey bees were stocked at a density of 1.7 colonies/ha in one field while the control field lacked honey bees. Bloom production was similar in the two fields but fruit set was 54% in the test compared with 39% in the control field. Native pollinator (bee) populations were similar between fields but total pollinator populations were much higher in the test field with the difference contributed by honey bees. On the coastal barrens, where native pollinator populations are low and bloom exists in abundance for a short period of time, under-pollination may limit fruit set under some conditions and thus honey bees may have value in increasing fruit yield.

Using the pea aphid, Acyrthosiphon pisum (Harris), as the host and Aphidius smithi Sharma and Subba Rao as the primary parasitoid, intraspecific tertiary parasitoidism was studied in the aphid hyperparasitoid, Asaphes lucens (Provancher). Laboratory experiments indicated that tertiary parasitoidism by a second A. lucens female on a first A. lucens is possible. Although the average success rate over 18 test-days was 16.9%, however, the day of attack by the second A. lucens female in reference to the age of the first A. lucens larva or pupa developing inside the dead aphid "mummy" was of major importance. Success by the second A. lucens in the early days averaged 27.2%, but was significantly reduced to an average of only 1% for the last 7 days. Comparisons are made with similar experiments on intraspecific tertiary parasitoidism using another aphid hyperparasitoid, Dendrocerus carpenteri (Curtis).

In laboratory studies with the codling moth, Cydia pomonella (L.), TH 6043 and TH 6044, new benzoylphenylurea chitin-synthesis inhibitors, were more effective than TH 6045 and diflubenzuron in reducing hatch of eggs from treated adults. With TH 6043 and TH 6044, egg hatch was reduced only when the female of each mating pair was treated. Topical application of diflubenzuron to adults moderately reduced egg hatch while TH 6045 had no effect. Diflubenzuron also reduced oviposition by females. None of these compounds adversely affected mortality, longevity, or mating propensity of adults.