The effects of Panonychus ulmi (Koch) density on several yield components of Red Delicious apples in a Nova Scotia orchard were examined from 1967 to 1970. The same 96 trees were sampled in each of the 4 years, and from a peripheral sampling zone within each tree the number of dormant and blossom clusters and the eventual number of apples produced was determined. The other yield components — bloom, set, and crop — were computed from these counts. Applications of ryania, carbaryl, and animert on 6 June 1967 followed by supplementary applications of animert on 7 July (carbaryl plots) and 1 August (ryania plots) were used to induce varying densities of P. ulmi. Mites were sampled twice weekly from June to August and fortnightly in September. Chemical treatments in 1967 had significant effects on mite-days/leaf in each year from 1967 to 1970. Cumulative mite-days/leaf had a significant negative influence on the number of harvested apples/sampling zone in 1967 and 1969, the years of higher apple production and higher mean bloom, but not in 1968 and 1970. Mites in 1969 also had a significant negative effect on return bloom in 1970. These findings agree with other studies that suggest an interaction between fruit load and yield losses induced by mites.

The preference of the nabid, Reduviolus americoferus (L.), for potato leafhopper nymphs, Empoasca fabae (Harris), and pea aphids, Acyrthosiphon pisum (Harris), was examined using functional response models. The nabid exhibited a type-II functional response to each prey. Handling time was much higher for the aphid than for the leafhopper (3.623 vs. 0.211 h). Instantaneous search rates were also higher for the aphid (0.096 vs. 0.020 h−1). A preference index was calculated using the ratio of the instantaneous search rates. The nabid exhibited strong preference for the aphid; when both prey were present in equal numbers, the nabid consumed 3 times as many aphids. The predator did not switch to leafhopper nymphs as the proportion of leafhoppers was increased.

Embryogenesis, embryo survival, and hatching were studied in eggs of the red turnip beetle, Entomoscelis americana Brown, incubated at 9 constant temperatures (5–35 °C) for 5–50 days before cold storage at −5 °C for 200 days during winter. Embryogenesis occurred at all temperatures tested, but the threshold and upper limit for embryogenesis were near 5 and 35 °C, respectively, and the optimum-temperature range was about 12.5–20 °C. Embryo survival was about 12–65% lower in eggs incubated at 5 °C for 50 days and at 7.5 and 10 °C for 30–50 days than in those incubated at these temperatures for shorter times, indicating that prolonged exposure to temperatures near the threshold during embryogenesis adversely affects the embryos. Embryo survival declined to low levels in eggs incubated at 25 and 30 °C for more than 30 and 5 days, respectively, and only a small number of embryos survived in those incubated at 35 °C for 5 days. The times to 50% hatch in eggs that contained late-stage embryos before cold storage and had been incubated at 25, 30, and 35 °C were 1.6, 2.6, and 6.5 times longer, respectively, than in those at 12.5–20 °C. These results indicate that embryos incubated at 25–35 °C during embryogenesis before diapause require a recovery period before initiating the normal postdiapause events, and that these events can be adversely affected by unfavorably high temperatures before diapause. The physiological and ecological significance of the data is discussed.

The development and survival of mountain pine beetles axenically reared on standardized diet at 8 constant temperatures (10°–35 °C) were observed. At 32 °and 35 °C, 22 and 18% of the eggs hatched and all larvae died within 10 d of hatching. At the lower temperatures, 60–70% of the eggs hatched. The highest survival for all developmental stages was at 24 °C. At 10° and 15 °C development of all beetles reared in bolts of lodgepole pine or on axenic diet stopped when larvae were fully developed, whereas at 24 °and 27 °C all of the beetles developed normally to the adult stage. Larvae that had stopped developing during rearing at 15 °C resumed development after being transferred to 24 °C, indicating that pupation was limited by temperature. Although mean development times to the larval, pupal, and adult stages all decreased with increasing incubation temperature, heat-unit requirements above a base temperature of 5.6 °C were lowest for individuals reared at 27 °and 24 °C for all developmental stages. At these temperatures, an estimated average of 673 and 674 degree-days above 5.6 °C were required for development from egg to the tanned (dark) adult stage, respectively. The average widths of the prothorax and the sex ratios of axenic beetles were within published ranges. Mean development times and heat-unit requirements at constant temperatures for development to various life stages agreed well with published field and laboratory studies from western Canada.

Coincident populations of spruce budworm, Choristoneura fumiferana (Clem.) and spruce coneworm, Dioryctria reniculelloides (Mutuura and Munroe) were studied to compare spatial distribution, temporal abundance, relative abundance on spruce species, and the relative efficacy of aerial insecticide treatments.Most individuals of both species were found overwintering on the mid-crown branches of red spruce, and a whole branch is a suitable unit for simultaneous sampling of overwintering budworm/coneworm populations on red spruce. Survey records since 1949 show similar geographical and temporal population trends for these 2 insects in Maine. A correlation analysis (r = 0.87) indicates that the size of their coincident populations is related spatially. Both species were found overwintering in nearly equal proportions on red and white spruce sampled from the same stands. But twice as many budworm and coneworm were found overwintering on red spruce when red and black spruce were sampled on the same stands. Due to behavioral or physiological traits the coneworm appeared resistant to aerial spray treatments that significantly reduced budworm populations.

The activity of native and domestic insect pollinators was studied for 3 consecutive years, during the blossom period in a semi-dwarf apple orchard of the Niagara Peninsula. Insect numbers and activity were correlated with apple cultivars (Empire, McIntosh, Golden Delicious, Red Delicious) located on the east and west slopes of the orchard and with temperature, humidity, and light intensity fluctuations. The physical factors, especially temperature, were mainly responsible for the variation in the numbers of honeybees. Factors such as cultivar, east and west slopes, and year were more significant for native pollinators. Native pollinators less affected by adverse conditions seem to compensate for reduced honeybee activity during unfavorable years.

Using a slide-dip bioassay, Psylla pyricola Forester from intensively sprayed, minimally sprayed (IPM), recently abandoned, and long-abandoned pear orchards in the Hood River, Rogue River, and Willamette valleys of Oregon were surveyed for resistances to azinphosmethyl, endosulfan, Perthane®, and fenvalerate. Lethal-concentration (LC50) values showed resistance levels from 12- to 41-fold to azinphosmethyl and 5- to 12-fold for endosulfan in selected populations. Resistance patterns did not correlate with orchard-treatment histories in the Hood River and Rogue River valleys, where even long-abandoned orchards harbored resistance psylla. There was better association between treatment histories and resistance levels in populations from the more widely scattered orchards in the Willamette Valley. A regional analysis of mean LC50 values indicated that psylla resistance was significantly higher to azinphosmethyl in the Rogue River Valley and to endosulfan in the Hood River Valley. Regional resistance levels for these compounds reflect differences in intensity of past use. A regional hypothesis is proposed to explain the patterns of resistance developed in the Hood River and Rogue River Valleys, where pear production is intensive as opposed to the more localized patterns of resistance in the Willamette Valley. Applications of results to the management of resistance are discussed.

In laboratory colonies, 8 temperate Bombus Latreille species and the tropical montane species, B. ephippiatus Say, had significantly more first-brood workers, more rapid worker development time, and faster rates of worker production than the tropical lowland species, B. atratus Franklin. Bombus ephippiatus did not differ from most temperate species in any of the 3 characters. Differences in these bionomic characters among arctic, temperate, and tropical Bombus are assessed in terms of latitudinal trends.

Unlike some tortricids that are refractory to diflubenzuron, the oak-leaf shredder, Croesia semipurpurana (Kearfott), is susceptible to this molt-inhibiting insect growth regulator. Aerial application of 140 g in 4.7 L/ha provides good control of this insect and affords foliage protection. The success of diflubenzuron was evaluated by sampling larvae and pupae. Monitoring male moths with pheromone traps provided corroborative evidence of a significant decrease in the post-treatment population. The successful assessment by pheromone monitoring here merits its consideration for other control operations in forestry.

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.

The Cypress Hills consist of a hilly elongate plateau straddling the Alberta–Saskatchewan border. They are mostly covered in a foothills-type vegetation but are surrounded by short-grass prairie and lie about 250 km east of the Rocky Mountain foothills. The upper 95 m remained unglaciated as a nunatak during the Wisconsinan glaciation. Dragonflies were collected at various times during May–August in 1982–1984 at 24 localities in Cypress Hills Provincial Park, Alberta. Thirty-one species were obtained, 3 of which (Aeshna multicolor, Gomphus graslinellus, and Libellula pulchella) are new records for Alberta. The dragonfly fauna of the Cypress Hills consists of species with the following Canadian distributions: 22 transcontinental (13 boreal, 7 southern, and 2 widespread), 4 southwestern, 2 western boreal–northwestern, 2 cordilleran, and 1 primarily prairie. An analysis of this fauna indicates that, following northward retreat of the glaciers, 22% of the present species came from cordilleran regions and 42% were derived from the boreal fauna. This corroborates the boreo–montane forest connection that is considered to have extended along the retreating ice front before the climate became too warm and resulted in the forest being replaced by grassland.

Kissinger (1982) published the first program for producing labels on a microcomputer. This program was limited in that it allowed only 3 lines of labels, worked only on a printer connected to LPTI: (parallel port), had no print options, and restricted the number of characters per label. The program described here is written in BASIC for the IBM-PC microcomputer. It has none of the above restrictions and is more versatile. The program is self-activating with AUTOEXEC to an opening menu with 12 options. Each option is called by number and the user follows a series of explicit, on-screen prompts.

The pheromones lineatum and (+)-sulcatol were used in traps in a sawmill to survey the ambrosia beetles Trypodendron lineatum (Olivier) and Gnathotrichus retusus (LeConte) respectively. Spatial and temporal distribution patterns for both species were identified. This information can be used for the establishment of a pheromone-based mass-trapping program for ambrosia beetles. The addition of ethanol and α-pinene to traps baited with (+)-sulcatol significantly increased the catches of G. retusus.

Eggs of the larch casebearer, Coleophora laricella (Hübner), were sampled for 6 years at 3 sites in Oregon to determine causes of mortality. Infertility was of minor importance. Predation by Deraeocoris diveni Knight, Phytocoris calli Knight (Heteroptera: Miridae), and perhaps other predators caused up to 28.4% mortality. Up to 58.5% of the remaining embryos died before or at the time of hatching, probably as a result of high temperatures.

The species of plant on which larvae of Mamestra configurata (Wlk.) fed had significant effects on the rate of larval development, larval and pupal survival, pupal weight, the percentage of females that mated, and the number of fertile eggs/mated female. Among the four plant species tested, using living plants, the canola cultivars (Brassica napus cv. Regent and B. campestris cv. Candle) were approximately equal in suitability, lamb's-quarters (Chenopodium album) was less suitable, and lentils (Lens culinaris cv. Chilean) was unsuitable as food for M. configurata. The parameters recorded for larval survival, pupal weight, and the number of eggs/female on the most suitable food plants were higher than those recorded previously for larvae reared on excised leaves of suitable hosts.

Mating behavior among many moth species is mediated by female-released pheromones that attract males over distance. Males of the western spruce budworm, Choristoneura occidentalis Freeman, are attracted by pheromone which has been identified and synthesized (Cory et al. 1982; Silk et al. 1982). In response to pheromone, males will fly upwind and thus approach a bait on a fir limb, then land and persistently search near the bait, often locating it (Sower and Shorb 1985). Male budworm moths moving upwind toward a pheromone source are seen to use a wandering, left-and-right and up-and-down flight pattern. This is the classic anemotactic response of male moths to female-released pheromone as described by Shorey (1976), David et al. (1983), and references therein.

The braconid Pholetesor (= Apanteles) ornigis (Weed) was the major parasite of the spotted tentiform leafminer, Phyllonorycter blancardella (Fabr.), at 21 sites, in 9 counties in southern Ontario. The eulophids Sympiesis sericeicornis (Nees) (12 sites, 6 counties), S. dolichogaster Ashmead (9 sites, 5 counties), S. marylandensis Girault (8 sites, 6 counties) and Pnigalio maculipes (Crawford) (6 sites, 5 counties) were the major chalcidoids recovered. Other species recovered were 10 eulophids, 2 pteromalids, and 2 ichneumonids. The major hyperparasite of P. ornigis was S. sericeicornis, but S. dolichogaster, Habrocytus sp., Catolaccus sp., Gelis sp., and Hypopteromalus sp. were also recovered.

During the summer of 1982, aerial experimental sprayings were carried out with a new formula of Bacillus thuringiensis named Futura®. This formula provided a treatment of the 20 × 109 IU of B. thuringiensis/ha required for suppression of spruce budworm (Choristoneura fumiferana), in a final volume of 2.5 L/ha. Results of spraying with Grumman AgCat and DC-4G aircraft are presented. These results were compared with those obtained with formulas of B. thuringiensis used in the past at 4.7 L/ha. Futura® caused 91.1 and 88.7% larval mortality and resulted in 86.6 and 75.1% foliage protection with the Grumman AgCat and DC-4G aircraft, respectively. Such results were equal to or better than those obtained with the formulas used earlier at 4.7 L/ha and confirm the feasibility of using B. thuringiensis operationally in an efficient and economical way.

A cattle-baited (C-B) trap and a Trueman–McIver (T-M) segregating CO2 trap provided information on seasonal abundance, host-seeking activity, and blood-feeding of biting-flies near St. John's, Newfoundland. A total of 19 682 biting-flies (26 species) were collected (C-B trap = 11 407; T-M trap = 8275) from 26 May to 16 September 1982. Black-flies (Simuliidae) comprised 94.1% of the total sample (C-B trap = 10 747; T-M trap = 7773). Mosquitoes (Culicidae), biting midges (Ceratopogonidae), and tabanids (Tabanidae) comprised the remainder. Blood-fed flies represented 54.7% of the total catch in the C-B trap, but the proportion varied considerably among species. Black-fly activity was concentrated in June and July, though flies were also collected in May, August, and September. Prosimulium mixtum was the predominant species in June and Simulium venustum/verecundum complex was the major pest in July. Prosimulium mixtum was most active from mid-morning to late-afternoon, with little evening activity. Simulium venustum/verecundum complex showed 2 peaks of activity, one in the morning and another in the early evening. A few P. mixtum and S. venustum/verecundum complex were active after dark. Captures from the T-M and C-B traps were compared to test the reliability of the T-M trap as an indicator of activity of biting-flies attracted to cattle. Significant correlations (P < 0.001) between the number of flies collected in the 2 traps were found for P. mixtum and S. venustum/verecundum complex. Remaining species were taken in numbers too low for analysis.