Culex pipiens entered diapause in early July with more than 90% in diapause by mid-August. Onset of diapause in Culex restuans was in early July with greater than 80% in diapause by late July. The incidence of diapause in C. pipiens increased when larvae were reared at low temperatures or high densities under similar photoperiod conditions. Diapausing adult females of C. pipiens and C. restuans had ratios of follicle:germarium length of less than 2.00:1.00. Ovarioles of recently emerged diapausing C. pipiens developed to the nondiapause stage in 3–4 weeks when held at 25 °C and a photoperiod of 16L:8D. Ovarioles of diapausing C. pipiens in the field did not develop to the nondiapause state before females left their overwintering sites in the spring.

The seven known species including two new species of Protearomyia are described and keyed: obscura (Walker) and mallochi n. sp., from southern Chile; cordillerensis McAlpine, martinia McAlpine and tricopleura n. sp., from temperate North America, and nigra (Meigen) and greciana McAlpine from Europe. Lectotypes are designated for cordillerensis and greciana. Male and female terminalia are figured where possible; female of martinia and male of trichopleura are unknown.

A comparison of the seasonal biology of Thymelicus lineola at Normandin and Joliette, Quebec from 1974 to 1976 showed marked differences between regions for the same year, and within regions for consecutive years. These data together with constant temperature development information were used to develop a predictive phenological model for this insect, which was then validated using independent data sets collected between 1976 and 1981. Good agreement between observed and predicted values were obtained. The usefulness of the model in predicting optimal spraying dates was tested at Amqui and Normandin, Quebec in 1982. Accurate predictions were obtained at least 2 weeks in advance, sufficient for use in a management programme.

Larvae of Nudomideopsis magnacetabula (Smith) are described. New distributional and host association data for this species are presented, along with remarks on the phylogenetic affinities and taxonomic status of Nudomideopsis. It is proposed that Nudomideopsis be removed from the genus Mideopsis and elevated to generic rank.

Along the Continental Divide in Alberta, British Columbia, and Montana three species of Capniidae were common at some lakes (Capnia confusa Claassen, Isocapnia integra Hanson, and Utacapnia trava (Nebeker and Gaufin)). Females of all three species had substantial reduction in wing length at least at one lake, while most lentic populations had slightly shorter wings than a macropterous river population of the same species. For females of all three species there was a weak positive relationship between functional wing length and lake elevation. Furthermore, there was also a significant negative relationship between functional wing length and the approximate year of Wisconsin deglaciation for C. confusa and U. trava. Suitable data were not available to test the significance of this relationship for I. integra. However, the relationships between wing length and elevation, and between wing length and Wisconsin deglaciation, suggest that wing length of these three capniid species is related to lake age. Present day wing length might be explained by selection for brachypterism over recent millennia.

Biological studies were conducted on Ceutorhynchus trimaculatus Fabricius, a weevil imported under quarantine from Italy into the U.S.A. for evaluation of host specificity and potential for control of Carduus thistles. Females reared under day–night temperatures of 21°–10 °C and 9 h photophase oviposited an average of 211.7 eggs over 23.6 wk; the preoviposition period was 19.9 wk. Two oviposition peaks were observed each calendar year, the first from February to April and the second in November. Eggs hatched in 12.4 days with mean viability of 64.2%. There were three larval instars; the mean larval developmental period was 42 days, and the pupal stage averaged 15.5 days. Adult longevity for males was 43.9 wk and for females 43.5 wk.

Allocosa Banks, 1904, with type-species Lycosa funerea Hentz, 1844, is diagnosed on the presence of apomorphic characters in the external genitalia, and is hypothesized to represent the sister-group of the remaining North American lycosine genera. Eighteen species are found in North and Central America, namely, A. funerea (Hentz), A. mulaiki (Gertsch), comb, n., A. sublata (Montgomery), A. chamberlini (Gertsch), A. pylora Chamberlin, A. furtiva (Gertsch), comb, n., A. absoluta (Gertsch), comb, n., A. floridiana (Chamberlin), A. apora (Gertsch), A. noctuabunda (Montgomery), A. panamena Chamberlin, A. chamberlini (Gertsch), A. mokiensis (Gertsch), A. subparva sp. n., A. parva (Banks), A. veracruzana (Gertsch and Davis), A. utahana sp. n., and A. mexicana (Banks), comb. n.

Hollow fibers containing synthetic pheromone (Z-6-heneicosen-11-one) were applied by helicopter to six plots of about 8 ha each. Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough), had reached such high population levels on the plots that trees in some areas were completely defoliated. Reproduction of the moths was reduced 71 and 81%, respectively, at dosages of 8 and 25 g of pheromone/ha relative to untreated control plots.

This study provides information on species of Pnigalio Schrank found in America north of Mexico: Pnigalio longulus (Zetterstedt), a Palearctic species, is recorded from the Nearctic for the first time; the previously unplaced species of Pnigalio of Miller (1970) are discussed. Seventeen species are recognized, of which the following eight are described as new: Pnigalio levis, P. brachysellus, P. elongatus, P. glaber, P. rugatus, P. neolongulus, P. boharti, and P. albiformis. A key to species, illustrations, distribution data, and host records are included.

The effectiveness of Thuricide 16B®, a water-based commercial formulation of Bacillus thuringiensis var. torstaki (B.t.), Dipel 88®, an oil-based formulation, and the Dipel® vehicle (Dipel 88 without B.t.) were compared by aerial applications against the spruce budworm, Choristoneura fumiferana (Clem.) in balsam fir, Abies balsamea (L.) stands. The two B.t. products applied at similar dosage rates were similar in effectiveness and the Dipel vehicle was not toxic for budworm larvae at rates applied Comparisons of populations of parasites made between pre- and post-spray sampling periods and between treated and untreated plots indicated no direct effect of Dipel 88 on the rate of larval and pupal parasitism.

The 6 LC50 for nymphs of Hexagenia rigida exposed to permethrin-contaminated water without sediment was estimated to lie between 0.58 and 2.06 μg/L. No nymphs survived a 6 h exposure to 7.63 μg/L. Laboratory simulated application of 7.3 g/ha permethrin to H. rigida nymphs in culture resulted in a final mortality of 88.0 ± 15.2% after a 1-day exposure, and 100.0% after a 7 day exposure; initial permethrin concentrations in water were estimated to be 7.63 μg/L and maximum mean concentrations in sediment, measured 1 and 7 days after application, were estimated to be approximately 50 μg/kg dry weight. Exposure of nymphs to sediment contaminated 8 days previously resulted in 100.0% mortality. An application of 0.6 g/ha resulted in final mortality of up to 45.0 ± 4.1%. Lethal effects occurred in some cases between 1 and 4 and possibly up to 10 weeks after application.

The age at which Pseudaletia unipuncta females initiated calling varied with temperatures experienced during pupal and adult stages. Entrainment was induced by temperatures during pupal development if similar to or lower than temperatures during adult life. However, adult temperatures were of major importance if lower than those experienced during pupal development. These observations were generally supported by data from field experiments repeated at different periods of the summer. The possibility that entrainment occurs at a specific period of development is proposed to explain certain field observations.

Changes in mean onset time of calling and the time spent calling also varied, although generally not in the same manner as reported for other species. Differences in the life cycles, particularly the site of pupation, are proposed to explain these discrepancies.

A 3-year faunal survey of insecticide-free potato fields revealed that Carabidae were the most abundant ground arthropods followed by Arachnida and Staphylinidae. Generic and species composition of Carabidae did not vary substantially from year to year but abundance did. The arthropods were distributed along a gradient decreasing with distance from the edge of the field closest to the woodland. Results of yellow pan trappings indicated that all types of Carabidae present in the pitfalls could fly but that flight activity was variable among genera. More than 50% of Staphylinidae and 85% of the Carabidae were trapped in the yellow pans at the time of field colonization in June. The significance of these findings in relation to the potential of the arthropods for natural biological control of potato pests is discussed.

The effect of interplanting collards with a mixture of herbs on oviposition of the imported cabbageworm, Pieris rapae (L.), was investigated at Chesterfield Co., Virginia during 1981 and 1982. Analysis of the dispersion indices of the insect using Taylor's power law and Iwao's model revealed that P. rapae eggs were significantly — m (P < 0.001) clumped (b > 1) on collards interplanted with herbs. However, insect counts on control collards conformed to the Poisson distribution (b = 1, P > 0.05). Pieris rapae laid significantly (P < 0.01) more eggs on collards hidden between sage than on collards hidden between other companion plants. Also, P. rapae laid significantly (P < 0.005) more eggs on collards bordered by companion plants than on non-bordered control. These data suggest that companion herbs did not repel P. rapae but instead significantly encouraged colonization of the insect and produced an aggregated distribution.

The critical photoperiod for diapause induction in pupae of Mamestra configurata Walker in Manitoba was 16 h 06 min at Glenlea (49°38′ N), 16 h 20 min at Grandview (51°10′ N), and 16 h 42 min at Birch River (52°24′ N). The differences in cirtical photoperiods observed at Glenlea and Grandview were not significant. At least two different photoperiods exist, one in the Glenlea and Grandview areas and the other in the Birch River area. In the laboratory, the critical photoperiod was 13.5 h when larvae were exposed to a daily fluctuating temperature regime of 12 h at 25 °C and 12 h at 10 °C. Longer critical photoperiods found for the field populations may be related to the relatively low ambient temperatures to which the larvae were exposed in field cages.

In laboratory studies, ovipositing northern corn rootworm beetles significantly preferred Ste. Rosalie clay soil with particles 1 mm – 1.4 cm in diameter. In the field, unaltered local farm soil with natural cracks was preferred for oviposition to mechanically-disturbed soil. Surface condition, surface cover, and soil moisture all combined to influence the choice of oviposition site in field soils.

In the palearctic region Noctua pronuba (Linnaeus), the Large Yellow Underwing Moth, ranges from North Africa through Western Europe to Finland and Iceland. In Britain the flight period extends from April to October with peak emergence in August. The larva feeds in winter on grasses and low plants and is often a pest in gardens. This species is occasionally bivoltine when eggs laid early in the year develop to adults in the fall. The moth comes readily to bait (fermented fruit and molasses) applied to tree trunks at dusk, and is also attracted to light. The moth is polymorphic and sexually dimorphic. All of the usual forms are present in Nova Scotia.

Since its description by Canning (1953) from cultures of the African migratory locust, Locusta migratoria migratorioides (R. & F.), in England, Nosema locustae has been found in grasshoppers in southern Ontario, Canada (Smith 1965), and in most of the western United States (Henry 1969; Henry and Oma 1981). It probably was the unnamed organism noted earlier by Goodwin (1949) in locusts from Africa (Canning 1962). Thus, the known geographic range is England, central Canada, the western United States, and probably Africa. However, as Henry and Oma (1981) speculated, its known range undoubtedly will be extended as grasshoppers are examined from other locations. This report extends the geographic range of N. locustae to several locations in southern and central Saskatchewan.

The northern corn rootworm, Diabrotica longicornis (Say), is a recent pest of corn in southern Québec (Guibord 1976). Little is known of local quantitative temperature relationships, although such information could have important practical applications in developing a pest management program.

The object of this study was to determine the threshold temperature and thermal constant for egg development and eclosion, and to relate soil and air temperatures to the phenology of egg hatch in the field under Qutbec corn-growing conditions.