This study confirms an earlier finding that the oystershell scale, Lepidosaphes ulmi (L.) is normally controlled in Nova Scotia apple orchards by the aphelinid Aphytis mytilaspidis Le B. and the predacious mite Hemisarcoptes malus (Shimer). The effectiveness of the former may be limited in colder areas by low winter temperatures, and both species are detrimentally affected by some spray chemicals. The evidence presented indicates that either A. mytilaspidis, or H. malus, or the two of them together, may operate as key-factors in regulating the density of oystershell scale populations.

On June 25th and 26th an old pasture supporting a thrifty growth of white spruce from 3 to 10 feet in height was inspected for spruce budworm injury. Very few budworm larvae were found but large numbers of Zeiraphera larvae were present. In the course of the study it developed that these were chiefly Z. ratzeburgiana with about 40% Z. fortunana. An older pasture adjoined and the growth was 15 to 25 feet in height. Here the relation was reversed. Z. fortunana formed over 75% and on the larger trees Z. ratzeburgiana was not found at all. No attempt was made to separate the larvae, and these figures are based on a study of the moths. In the case of old pastures where the small trees and reproduction were absent only Z. fortunana was found. Where the young growth was just taking possession and ranged from 3 to 8 feet, Z. ratzeburgiana was the dominant species.

For the last 50 years, populations of the Bruce spanworm, Operophtera bruceata Hulst, and other wingless geometrid species have been sampled using sticky bands placed around host-tree trunks to catch wingless females in search of oviposition sites. This method is tedious and, because of trap saturation by males, may underestimate female populations at moderate to high levels. A standard oviposition trap was developed to sample eggs of the Bruce spanworm and other wingless geometrid species. A small polyurethane foam band placed on a post covered by a Multi-Pher® plate detected low populations and was almost unsaturable during outbreaks. Sub-sampling can be easily done in such situations. Egg density on oviposition traps was higher than female density on sticky bands for both the Bruce spanworm and the fall cankerworm, Alsophila pometaria Harris. This suggests that the oviposition trap might be useful to sample other wingless geometrid species. Operating this system was easy and could involve woodlot owners and companies to reduce the traveling costs necessary to collect samples.

Adults of Sepedon fuscipennis Loew were sampled periodically throughout the summers of 1969 and 1970 in a backwater habitat. Several overlapping generations of this common marsh fly were present during both summers, and its population density reached a unimodal peak both years. Population estimates based on mean number per sweep agreed well with mark–release–recapture data. These estimates showed a reasonably good fit to the negative binomial distribution and indicated that aggregation of the flies probably is due to some heterogeneity in the environment. Flies lived more than 3 months in laboratory cages, and each female laid an average of 191 eggs.

Estimates were made of larval survival and net production for discrete cohorts followed in the field. The survival and production rates of larvae were greater when small snails were abundant in the habitat and much greater when the larvae were fed once before being released. Survival was not decreased perceptibly by the degree of larval crowding tested (50 larvae compared with 25 in an area of 254.34 cm2).

Wild codling moth, Cydia pomonella (L.), females were trapped from May through September in the upper (Yakima) and lower (White Swan) Yakima River Basin, WA, using 10 bait traps and 4 and 19 blacklight traps, respectively, for 2 and 5 years in abandoned apple orchards. The average spermatophore count per female at Yakima was 1.08; at White Swan it was 1.76. The spermatophore count was similar in both first (0.97 and 1.79) and second (1.00 and 1.70) generations at both locations. Regression analysis of field data and laboratory tests showed that cool temperatures reduced the number of spermatophores, which reflect reduced mating. There was a high correlation between the number of small spermatophores and females with multiple spermatophores. Usually females with a large spermatophore mated only once. Females usually mated on the 1st day following emergence. Once mated, even females with small spermatophores seldom mated again on subsequent days.

In unsprayed apple orchards in Ontario the sex ratio (female:male) of mature codling moth larvae was negatively correlated with total moth numbers, per cent fruit damage, and the fecundity of first generation females. Changes in both the larval and adult sex ratios were indicative of the tendency of moth populations to increase or decrease from one season to the next.

In many parts of the St. Lawrence drainage system, enormous numbers of Trichoptera, often mingled with Ephemerida, emerge during the summer and become a pest in a considerable zone bordering the water. The insects swarm in open areas, especially around trees and lights, invade houses, settle in large numbers on walls and other surfaces, ruining those that have been freshly painted, and pile in decaying and odoriferous drifts along the shore line. In addition, they give rise to a medical problem by evoking allergic reactions in hypersensitive individuals.

The literature on Orthoptera (sens. lat.) includes a number of cursory notes describing laboratory drinking in various species, but an extended discussion of this behaviour is not available. The author has spent the past seven years studying the feeding behaviour of Michigan Orthoptera, during which time he has also made observations and conducted experiments on intake of water. Findings with respect to the latter, although of a preliminary nature, are given in the following paper.

The seed maggot complex, Hylemya (Delia) platura Meig. and H. (Delia) liturata Meig., is shown to be a primary pest of radish. In laboratory experiments larvae of this species complex attacked radishes and developed into pupae whether or not the plants were already damaged by the cabbage maggot, H. brassicae Bouché.

Entomophthora culicis (Braun) Fresenius was found parasitizing adults of Simulium venustum Say and Simulium vittatum Zett. in central Alberta. The first parasitized black fly adults were collected on 17 August 1973 from a moist log on the margin of Flat Creek (113°52′ W. long., 54°41′ N. lat.). In subsequent summers, parasitized black flies were found on various substrates at sites on three other creeks in the area. Parasitized black flies first appeared in late June and were present to mid-September with peak numbers occurring during August. The fungus kills young black fly adults. This is the first record of E. culicis on black flies in Canada.

Using 4 years of potato monitoring data containing insect counts, population development of the green peach aphid (Myzus persicae (Sulzer)) (Hemiptera: Aphididae), ladybird beetles (Harmonia axyridis (Pallas) and Coccinella septempunctata L.) (Coleoptera: Coccinellidae), and hymenopterous aphid parasitoids is described and used to consider revisions to current sampling plans. Depending on the year, field monitoring for aphids commenced between early May and early June. Aphid populations typically increased after 1 July and fluctuated until the end of the monitoring period (September). Winged M. persicae began to appear in sweep-net samples in late May, well in advance of the detection of aphids in visual samples. Aphid counts from field edge and interior sample sites were correlated and edge population levels were slightly and significantly greater than interior levels over the period 10 June – 14 July in 2 of the 4 years analyzed, suggesting a mild but inconsistent edge effect approaching mid season. Using an action threshold of 1 aphid/leaf to restrict the aphid-mediated spread of potato leaf roll virus (PLRV), the earliest whole-field action threshold was exceeded during 18–24 June in 1997. Using an action threshold of 10 aphids/leaf to address aphid-induced yield loss in fields not at risk to PLRV, the earliest whole-field action threshold was exceeded during 16–22 July in 1997. Therefore, monitoring for aphids can begin much later than the time it is currently commenced. A case is presented for monitoring only the edges of potato fields for an action threshold of 10 aphids/leaf, as interior samples rarely exceeded this action threshold when edge samples were below. This would further reduce the effort in sampling potato fields for aphids. Population development of ladybird beetle adults and larvae showed peaks occurring at different times during the growing season, depending on the year. Parasitism of aphids by hymenopterans occurred at low to moderate levels throughout the growing season (13% of total aphids in visual samples, on average), with peak parasitism appearing toward the end of the growing season in each year.

A revised key to the 94 species of Lasioglossum (Dialictus) currently known to occur in Canada is presented, incorporating new species and taxonomic updates since the publication of the first key in 2010. Two new species, Lasioglossum (Dialictus) immigrans and Lasioglossum (Dialictus) onuferkoi, are described from Canada. Lasioglossum (D.) ascheri, L. (D.) stictaspis, and L. (D.) tegulariforme are reported or confirmed from Canada for the first time. Lasioglossum (D.) gaudiale (Sandhouse, 1924) and L. (D.) helianthi (Cockerell, 1916) are resurrected from synonymy with L. (D.) tegulariforme (Crawford, 1907). The following five new synonymies are established: L. (D.) stictaspis (Sandhouse, 1923) (= L. (D.) albuquerquense (Michener, 1937)); L. (D.) ascheri Gibbs, 2011 (= L. (D.) curculum Gibbs, 2011); L. (D.) helianthi (Cockerell, 1916) (= L. (D.) imbrex Gibbs, 2010); L. (D.) megastictum (Cockerell, 1937) (= L. (D.) punctiferellum (Cockerell, 1937)); and L. (D.) obnubilum (Sandhouse, 1924) (= L. (D.) lilliputense Gibbs, 2010). Previously undescribed males of L. (D.) helianthi, L. (D.) reasbeckae, L. (D.) tegulariforme, and L. (D.) weemsi are diagnosed and figured.

The Nearctic species of Lonchoptera Meigen are reviewed, including three new species: L. barberi Klymko sp. nov. from Manitoba, Newfoundland, Ontario, Quebec, Iowa, Michigan, Minnesota, and New Hampshire, L. megaloba Klymko sp. nov. from British Columbia and California, and L. longiphallus Klymko sp. nov. from British Columbia and the Northwest Territories. Lonchoptera borealis Curran is proposed as a new junior synonym of L. impicta Zetterstedt, and L. occidentalis Curran is proposed as a new junior synonym of L. uniseta Curran. Lonchoptera nigrociliata Duda, formerly known only from the Palaearctic Region, is recorded from the Yukon and Alaska. Descriptions, a key, and Nearctic distribution maps are presented. Phylogenetic relationships are briefly discussed and two sister species pairs are documented.

The mountain pine beetle (Dendroctonus ponderosae Hopkins) (Coleoptera: Curculionidae) is a significant destructive force in the pine forests of western Canada and has the capacity to spread east into a novel host tree species, jack pine (Pinaceae). New populations have been documented in central Alberta, Canada, but the source populations for these outbreaks have yet to be identified. In this study, we use genetic data to identify parent populations for recent outbreak sites near Slave Lake, Lac La Biche, and Hinton, Alberta. We found the northern population cluster that entered Alberta near Grande Prairie was the source of the most eastern established population near Lac La Biche, and the range expansion to this leading-edge population has been too rapid to establish evidence of population structure. However, some dispersal from a population in the Jasper and Hinton area has been detected as far north and east as Slave Lake, Alberta. We also identified two potential source populations for the current outbreak in Hinton: most beetles appear to be from Jasper National Park, Alberta, but some also originated from the northern population cluster. These findings demonstrate the dynamic dispersal capabilities of mountain pine beetle across the Alberta landscape and the potential hazard of increased dispersal to newly established leading-edge populations.

The wheat midge, Sitodiplosis mosellana Géhin (Diptera: Cecidomyiidae), is a serious pest of spring wheat in North America. Currently, most commercial cultivars in the state of Montana, United States of America are susceptible. A study was conducted to assess the variability of adapted spring wheat cultivars to wheat midge infestations. A secondary objective was to determine the relationship between wheat midge infestation levels and spring wheat agronomic traits, including yield, test weight, grain protein, plant height, and heading date. This relationship was determined by evaluating 16 hard red spring wheat cultivars over a six-year period at the Northwestern Agricultural Research Center, near Kalispell, Montana. Levels of infestation had a negative impact on grain yield and test weight. Overall, the average infestation level was 40 larvae/spike with the lowest being observed with “Reeder” and the highest for “Thatcher”. Concurrently, “Reeder” had the highest yield, whereas “Thatcher” had the lowest yield and the highest grain protein, demonstrating that wheat midge infestations were positively associated with grain protein. Heading date had a positive association with midge density with higher infestations associated with later maturing cultivars. The economic injury level was estimated at 12 and 20 midge larvae/spike for a market price of USD $0.27 and USD $0.16/kg, respectively.

Discovery of diapause in Barbara colfaxiana (Kft.) in the pharate-adult stage of development has allowed establishment of morphological characteristics to distinguish 1-year-diapause individuals from 2-year-diapause individuals at an earlier stage than previously possible. These morphological and some histological criteria are described. On the basis of morphological characteristics alone, 1- and 2-year-diapause individuals can be readily and reliably recognized by the unaided eye. The practical significance as well as the potential contribution of these findings to further research are pointed out.

Susceptibility of many insects to baculoviruses decreases with host development (Hochberg 1991), whereas the time required for infected hosts to die increases with larval age (Boucias et al. 1980; Bucher and Turnock 1983; Smits and Vlak 1988). The actual mechanism of this phenomenon, however, has not been established in many cases. The present study was undertaken to investigate the effect of larval age on the susceptibility of Spodoptera litura Fabricius to nuclear polyhedrosis virus (NPV) through oral and intrahaemocoelic routes of infection.

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.

Chemical studies utilizing colour tests, gas chromatographic and mass spectrometric analysis have shown that hydrogen cyanide and benzaldehyde are constituents of the defensive secretion of the polydesmoid millipede Apheloria coriacea (Koch).