We describe a model which estimates grasshopper body temperature (Tb) by linking energy-flow equations with empirical descriptions of aboveground gradients of air temperature (Ta) and wind speed. The model was tested using restrained grasshopper nymphs; estimated and observed Tb agreed well (r2 > 0.81). At a rangeland site near Lethbridge, Alberta, Canada (49 °42′N, 112 °48′W), we observed 315 free-living grasshoppers. We recorded the shadow each cast on a horizontal surface, then reconstructed their orientation to the sun by geometric analysis. We used the model to estimate their Tb and the range and frequency of possible Tb within their environment. Modelled Tb exceeded Ta, and was generally lower than the modelled maximum possible Tb, but was well correlated with Tb of insects on top of the dense layer of vegetation which pervaded the site. This observation suggests that behaviours which elevate Tb are constrained by environmental barriers. Tb exceeded the value expected if insects were located and oriented randomly within their environment (mean difference = 3.95 °C, SE = 0.115); this is unequivocal evidence for behavioural thermoregulation. Heuristic simulations using temperature-dependent developmental- and feeding-rate equations for Melanoplus sanguinipes (Fabricius) suggest that thermoregulatory behaviour increased these rates by 30–40% compared with those for insects located and oriented randomly within their environment. During this study, population processes were never inhibited by excess heat; therefore any climatic warming at the experimental site will probably accelerate the phenology of these grasshopper species. Effects at other sites may differ; the model can be applied to test this possibility.

The seasonal life history and mortality of the lodgepole terminal weevil, Pissodes terminalis Hopping (Coleoptera: Curculionidae), were investigated in young lodgepole pine, Pinus contorta Douglas var. latifolia Engelmann (Pinaceae), at three sites in west-central Alberta. Flight was monitored with traps. Development and mortality of all stages were investigated by dissecting infested leaders biweekly from late spring to early fall. Two years were required for P. terminalis to complete its life cycle, and generations overlapped. Overwintered adults emerged from the duff and commenced flight in late May, with a peak in mid-June. Eggs were present from mid-June to late July. There were four larval instars. The first two instars fed only in the phloem. Third and fourth larval instars eventually entered the pith to continue feeding, overwinter, and complete development the following spring. The new generation of adults emerged between mid-July and early August, fed on new shoots for several weeks, and overwintered in the duff. Adults have an obligatory diapause and did not reproduce until after winter. Fourth larval instars suffered the highest mortality. The major attributable cause of mortality was resinosis among eggs and young larvae and cold temperatures during the winter among mature larvae. Pathogens caused little mortality. Six species of parasitoids were collected.

The cabbage root maggot, Delia radicum (L.), was introduced to North America in the mid-1800s, likely from northwestern Europe, and probably reached Quebec and British Columbia before 1885 and Manitoba by 1922. The mean temperature of crystallization (Tc) for overwintering pupae was −22.8 ± 1.2 °C for the St-Jean-sur-Richelieu, Quebec, population and −23.8 ± 0.7 °C for the Vancouver, British Columbia, population. The mean Tc for these two populations and for Winnipeg, Manitoba (−24.4 °C), Ascot, England (−22.8 °C), Tallinn, Estonia (−25.2 °C), and St. Petersburg, Russia (ca. −20 °C), did not show any relation to mean January temperatures. These locations represent both temperate oceanic and temperate continental climates and a range of mean January temperatures from +4.6 to −17.7 °C. Survival of puparia from St-Jean-sur-Richelieu exposed to nonfreezing temperatures decreased as temperature decreased and exposure time lengthened. The parameters for the regression equations describing this relationship were similar to those describing the Winnipeg population, and both were more coldhardy than the Ascot population. The upper limit of the cold injury zone (ULCIZ) for the St-Jean-sur-Richelieu population was −12.7 °C and the lower limit of this zone (LLCIZ) was −27.6 °C. Coldhardy populations from temperate continental climates (St-Jean-sur-Richelieu, Winnipeg) showed a rate of decrease in survival with increased cold stress (lower temperature, longer exposure) within the cold injury zone which was much slower than in the less coldhardy population (Ascot). Thus, some individuals from the coldhardy populations would be physiologically capable of surviving exposure to temperatures below Tc, whereas in the Ascot population nonfreezing injury would kill all the overwintering puparia at a temperature (−19.6 °C) well above Tc (−22.8 °C). The observed survival of puparia from Vancouver, following various nonfreezing exposures, resembled more closely the calculated survival for these exposures when the equations describing the Ascot population were used than when the equations for Winnipeg or St-Jean-sur-Richelieu were used. The Ascot and Vancouver populations, both from temperate oceanic climates, are less coldhardy than the populations from St-Jean-sur-Richelieu and Winnipeg (temperate continental climates). The founder populations of D. radicum in North America, which probably originated in the temperate oceanic climates of northwestern Europe, have adapted to the colder temperate continental climates by increasing their ability to survive longer exposures to all temperatures within the cold injury zone and not by lowering Tc. Therefore, selection for coldhardiness in D. radicum must have operated on structures, processes, or physiological-biochemical mechanisms that help the organism to avoid or repair nonfreezing cold injury but not on those that determine Tc.

After about 20 years of wide usage in integrated pest management (IPM) programs on peach in the Niagara Peninsula of Ontario, populations of Oriental fruit moth, Grapholita molesta (Busck), resistant to azinphosmethyl and phosmet have been selected. Resistance, as expressed in first-instar larvae, was only two- to four-fold to azinphosmethyl or phosmet, but up to 45% fruit infestations have been documented in commercial blocks. Resistance to azinphosmethyl was not well expressed in adult Oriental fruit moths. In tests with larvae, cross-resistance occurred to most other organophosphorus insecticides except acephate and chlorpyrifos. Acephate was more toxic to resistant than to susceptible larvae. Resistance was higher (> 100-fold) to the methyl carbamates carbaryl and carbofuran but was approximately fivefold to the carbamoyl oxime methomyl. Cross-resistance to pyrethroids was not observed. Tests with field-collected material, either from crosses on mating trays in the field or from pupae collected in cardboard bands attached to trees, indicated that resistance was widespread across the Niagara production area but that the resistance was not uniformly expressed at all locations. Resistance was expressed in F1 larvae from crosses of susceptible females with field-collected males, indicating that the genetic change in resistant larvae was unlikely the effect of a single recessive gene. Field tests in replicated two-tree plots and in larger (0.25–0.6 ha) plots treated with up to five applications as a season-long control program indicated that neither chlorpyrifos nor acephate were as effective as a pyrethroid (deltamethrin). The sustainability of these IPM programs and potential resistance management strategies are discussed.

Copulations of Pseudoxychila tarsalis Bates and Pseudoxychila bipustulata Latreille consisted of 1–20 intromissions. The male performed four different genitalic movements: prying, thrusts, small thrusts, and pulls. The male also courted the female during copulation by rubbing her with his middle legs. The observed male behavior does not fit previous hypotheses concerning the phases of copulation in tiger beetles. The female sometimes ejected 1 or 2 spermatophores during or after copulation. There were geographic differences in quantitative aspects of P. tarsalis male copulatory behavior, and more pronounced differences between P. tarsalis and P. bipustulata. This variation could result from sexual selection by cryptic female choice on male copulatory behavior.

A 5-year survey of Saskatchewan alfalfa (Medicago sativa L. sensu lato) seed fields was undertaken to determine the level of infestation by the alfalfa seed chalcid, Bruchophagus roddi (Gussakovsky). Seed samples were taken from commercial seed fields, hay fields, and roadsides just before pod maturity. From sample lots of 250 pods, the numbers of healthy, chalcid-damaged, and frozen or immature seed were determined. Later, producers were questioned about the attributes of and management practices employed in their fields. Seed yields and infestation levels were correlated with temperature, precipitation, and degree-day data from the year of and the year preceding seed collection. Alfalfa seed chalcid infestation level was correlated most closely with the temperature and rainfall in July and August of both years. The proportion of damaged seed was highest the year following warm, dry summers. Alfalfa cultivar also influenced infestation levels; winter-hardy cultivars that became dormant early in the autumn had lower levels of chalcid-damaged seeds than less hardy cultivars which maintained growth later in the season. Management practices such as the use of insecticides (for plant bug and aphid control), fertilizers, and herbicides, size or age of field, soil type, and application of irrigation water did not affect the proportion of seeds injured by chalcids.

No sexual dimorphism in weight was observed at emergence of adult Aleochara bilineata Gyll. (Coleoptera: Staphylinidae). The weight of adults was strongly correlated with the size of the pupa in which the parasitoid developed. Newly emerged adults increased in weight after feeding, and this increase was greater in females than in males, reflecting the beginning of oogenesis. We showed that females invested simultaneously in reproduction and somatic functions the first day following mating. Although males and females showed no significant differences in weight at emergence, the females fed actively upon emergence and weighed significantly more than the males for 30 days after emergence. After that period, most of the eggs has been laid and both male and female weights were similar.

The Tachinidae of America north of Mexico have undergone extensive changes in nomenclature since the last catalogue was produced in 1965. Many of these changes were published in the Tachinidae chapter of Manual of Nearctic Diptera, but few of the changes in that work were explicitly stated and none was recorded in Zoological Record. These changes, which included a new genus, new records for America north of Mexico, new generic synonymies, and hundreds of new combinations (including extralimital species), are documented here. This paper also includes more than 30 nomenclatural changes proposed as new herein by the junior author (primarily for America north of Mexico), representing new generic and specific synonymies and new combinations. A new record for America north of Mexico is reported.

Using field and laboratory (stereoscope) observations, we investigated copulation and oviposition behaviours of Protopiophila litigata Bonduriansky, which mates and oviposits exclusively on discarded cervid antlers. Typically, a male leapt onto a female, briefly tapped the sides of her abdomen with his legs, then stimulated her abdominal tip with his tarsi, parameres, and gonopods until she extended her genitalia (~4 min), after which the pair established genital lock (~10 min). Meanwhile, the female emigrated to a part of the antler where density of single males was lower. Following sperm transfer (~87 min) and genital separation (~5 min), the female deposited and ingested two droplets containing spermatozoa (~6 min). Then she oviposited (~29 min) into cracks or pores in the antler’s surface while the male remained in tandem and pushed away single males with his wings. Males often wrestled for possession of females, but take-overs were rare. Whereas most aspects of the copulation-oviposition cycle of P. litigata are characteristic of other necrophagous or scatophagous flies, the manner in which P. litigata females expel and ingest ejaculate materials after copulation has not been reported in any other-species of Diptera.

Dung beetles (Scarabaeidae) were pitfall trapped at two sites in southern Alberta from 1993 to 1995. A 3-year total of 156 500 specimens representing 17 species was collected. Local assemblages were dominated, in descending order, by the exotic species Onthophagus nuchicornis (Linné), Aphodius prodromus (Brahm), Aphodius distinctus (O.F. Müller), and Aphodius fimetarius (Linné). Aphodius vittatus Say was the most common native species. Although adults were collected from mid-March to mid-November, the activity of individual species either peaked in the spring and again in the fall, or peaked once in spring to midsummer. Maps showing the Canadian distributions for 15 of these species were compiled from examination of collections and published records and identify 10 new provincial records. Most distributions are transcontinental, with the distribution of O. nuchicornis likely expanding only in the last 20–30 years to include Alberta and Saskatchewan. Aphodius erraticus (Linné) and Aphodius ruricola Melsheimer have not been previously reported from British Columbia. Aphodius pinguellus W.J. Brown, Canthon praticola LeConte, and Aphodius coloradensis Horn are restricted to western Canada.

Overwintering mortality in the spruce budworm, Choristoneura fumiferana (Clem.), was measured between 1983 and 1990 in several natural stands of balsam fir, Abies balsamea (L.), in Quebec and Ontario. Overwintering losses (disappearance of larvae) averaged 25.2%, occurred mostly in late summer and early fall, and were probably caused by, in large part, failure to spin a hibernaculum, diapause-free development, and invertebrate predation. An average of 24.1% of larvae were found dead in the hibernaculum. This mortality also occurred early in diapause and during post-diapause development, and overwintering mortality did not vary much from year to year. We conclude that overwintering mortality does not result from adverse winter weather conditions or from gradual loss of hibernacula. Overall overwintering mortality from the loss of hibernating larvae plus death within the hibernaculum averaged 43.2% and was not related to infection with the microsporidian Nosema fumiferanae (Thomson). We observed no influence of position in the tree crown on overwintering survival. There was a 40% decrease in overwintering survival among larvae from eggs laid very late in a female’s oviposition sequence. Survival within the hibernaculum on shoots of A. balsamea bearing different types of spinning substrates varied considerably, and was highly correlated with larval spinning preferences. Shoots bearing lichen mats, rough bark, male flower scars, or 1-year-old annular scales were most suitable, whereas shoots bearing annular scales older than 1 year or smooth bark were least suitable. The efficiency of the NaOH extraction technique to recover overwintering spruce budworm larvae was found to be highly variable, and to depend on population density, shoot type, and the proportion of live larvae on the branches.

The birch skeletonizer Bucculatrix canadensisella Chambers was univoltine in central Alberta in 1992 and 1993. Adults occurred from early June until the end of July, and larvae were present from early July on, co-occurring with larvae of the ambermarked birch leafminer, Profenusa thomsoni (Konow). Larval B. canadensisella densities were higher in 1992 than in 1993, and were higher on rural trees at George Lake than on urban ones in Edmonton.

The gregarine, Leidyana canadensis Clopton and Lucarotti was found infecting the guts of larvae in a declining population of the hemlock looper, Lambdina fiscellaria fiscellaria (Guenée), in Charlotte County, New Brunswick. Total mortality, in rearing, of field-collected larvae and pupae was 75.5% in 1993 and 89.2% in 1994. Leidyana canadensis infections were present in 60.1 and 80.5% of these dead insects in the two respective years. The incidence of L. canadensis in larvae that died in rearing was greater than 50% for all instars except those collected in the fifth instar, where the incidence was below 30%. Gregarine infections were present in first-instar larvae on the first days of collection for both years and, in 1994, 74% of all first-instar larvae collected were infected with L. canadensis. Of 678 larvae collected in 1994, 73 survived to adults and, of these, 44 had harbored L. canadensis as larvae. The incidence of other microbes and parasitoids in dead larvae and pupae is also reported.

Nine species of the subfamily Typhlocybinae (Auchenorrhyncha: Cicadellidae) were collected from Corylus avellana L., Solatium tuberosum L., and Vitis vinifera L. Seven species were parasitized by Dryinidae, among which Alebra coryli Le Quesne 1977 and Edwardsiana staminata (Ribaut, 1931) were recognized for the first time. Clearly parasitized and apparently unparasitized leafhoppers and dissected dryinid larvae were assayed by polyacrylamide gel electrophoresis. The α-glycerophosphate dehydrogenase (α-GPD) enzyme system proved to be a reliable tool for indicating the presence of dryinids in all sampled species: the parasitized adults always showed a fast band, which was absent in unparasitized adults. The α-GPD was a reliable enzyme system to detect dryinids at an early stage of their development but not to discriminate among dryinid species. The occurrence of dryinids in the males of A. coryli and Zygina rhamni Ferrari, 1882 was also pointed out by the change of their colouration.

A specially constructed fence was developed to exclude cabbage flies, Delia radicum (L.), from plantings of rutabaga. The number of first-flight female D. radicum caught on traps inside fenced enclosures declined linearly with fence height from 0 to 90 cm. Females caught in plots surrounded by a 90 cm high fence were 80.6 and 82.8% fewer than in open check plots in 1991 and 1992, respectively. The percentage of transplanted rutabagas killed by cabbage maggot in the 90 cm high enclosures was 1.4% in 1991 and 25.5% in 1992, compared with 11.8 and 84.5% in the open check plots, respectively. The mean damage index rating for rutabagas was severe in the open check plots but slight in the 90 cm high enclosures in 1991. Only 1.2% of rutabagas in the open check plots would have been of marketable grade in 1991, compared with 54% in the 90-cm enclosures. The mean damage rating was highest in the open check plots in 1992, but damage was also severe in all fenced plots due to the heavy infestation levels that year. The potential of exclusion fences for use in pest-management programs for rutabagas and other brassica crops is discussed.

In two laboratory experiments, adult western conifer seed bugs, Leptoglossus occidentalis Heidemann, did not feed on seed infested by the Douglas-fir seed chalcid, Megastigmus spermotrophus Wachtl. When presented with seed lots containing 0, 20, 40, 60, 80, or 100% chalcid-infested seed, seed bugs fed on uninfested seed only when the percent chalcid infestation was ≤ 40% (Exp. 1), ≤ 20% (Exp. 2, females), or ≤ 60% (Exp. 2, males). In a third experiment, nymphs exposed to similar seed lots did not feed on M. spermotrophus when sound seeds were present. However, when exposed to 100% chalcid-infested seed, nymphs in two of 10 replicates fed on M. spermotrophus. Feeding by seed bugs caused seeds to lose 51% of their weight on average, but 18% of 43 test seeds on which seed bugs had fed germinated. In three Douglas-fir orchards surveyed, both species exhibited a clonal preference, but the ranking of clones preferred by each species was not the same. These results suggest that the impacts of L. occidentalis and M. spermotrophus are segregated and additive.

The Agabus semivittatus-group is revised. The group, which is restricted to temperate North America, contains six species: Agabus semivittatus LeConte, which is almost transcontinental; Agabus johannis Fall in peninsular Florida; Agabus astrictovittatus new species along the Atlantic coast from New York to northern Florida and Alabama; Agabus stagninus (Say) along the Atlantic coast from New York to Florida and along the Gulf of Mexico coast to Louisiana; Agabus flavovittatus new species with a wide distribution east of the Great Plains, from southern Ontario to Mississippi and eastern Texas but not along the Atlantic coast; and Agabus texovittatus new species in Texas. Agabus stagninus and A. flavovittatus hybridize in southeastern Pennsylvania. The placement of Agabus texanus Sharp as a junior synonym of A. semivittatus is confirmed. A lectotype is designated for Agabus spilotus LeConte (= A. semivittatus). A neotype is designated for A. stagninus. A key to species is presented and, for each species, the following information is provided: description; illustrations of taxonomically important characters; morphological measurements on selected population samples; notes on relationships, variation, and ecology; and a map of collection localities. A cladistic analysis of the relationships of the group within Agabus indicated that the americanus-, spinipes-, and confusus-groups belong to the same clade as the semivittatus-group and that the seriatus-group is sister to this clade. Within the semivittatus-group, there are three well-defined subgroups as follows: A. semivittatus; A. johannis and A. astrictovittatus; and A. stagninus, A. flavovittatus, and A. texovittatus.

The first North American records for Deraeocoris punctulatus (Fallén), Labopidea artemisiae (Sahlberg), and Labopidea bermani Kerzhner indicate that the species are naturally Holarctic. Lygus rugulipennis Poppius is now considered naturally Holarctic after specimens of Lygus perplexus Stanger from Alaska, Yukon Territory, and Northwest Territories are correctly identified as L. rugulipennis. Additional North American localities for Labopidea discolor (Sahlberg) support the contention that the species is naturally Holarctic. Collections of Orthotylus ochrotrichus Fieber from Royal Oak, British Columbia, and Malacocoris chlorizans Panzer from British Columbia and Washington state suggest that these species are adventive to North America. Diagnoses are provided to distinguish all the taxa from other North American congeners. A key to the northern Nearctic species of Labopidea is given.

The influence of diet on oviposition and survival of Forficula senegalensis Serville was studied in laboratory conditions using four different regimens: millet leaves and stems, lepidopteran eggs and larvae, millet pollen, and no food at all. Four parameters were monitored: female weight, survival time, time to oviposition, and number of eggs produced. Starving females and females fed millet leaves and stems lost weight and survived for an average of 30–40 days without any of them laying eggs. Females fed millet pollen or lepidopteran eggs and larvae gained weight and survived for more than 60 days. Forty percent of the females fed pollen laid an average of 49 eggs the first time, and 50% of those fed lepidopteran eggs and larvae produced an average of 67.5 eggs. In both cases, less than 2% of the females oviposited a second time (average of 30 eggs). Earwigs fed lepidopteran eggs and larvae oviposited sooner. A diet of millet leaves is insufficient for oviposition in F. senegalensis; females need a richer diet based on pollen or animal preys in order to lay eggs.

The purpose of this study was to explain a peculiarity of resource use by two sympatric bumble bee species. In one study area, pronounced resource partitioning was observed: Bombus terricola Kirby was confined to Asclepias syriaca L. and Bombus ternarius Say to Apocynum androsaemifolium L., and yet in another area both species frequented Apocynum. Measurements of floral characteristics and forager behaviour on Apocynum led to an hypothesis regarding floral use by two bumble bee species: B. terricola is relatively inefficient at flying between flowers, and so tends to visit Apocynum only in areas where the plants are closely spaced. Half of the patch of Apocynum was clipped so as to decrease flower density, with the expectation that, as a result, the frequency of B. terricola relative to B. ternarius would be reduced. The prediction was confirmed. The results underscore the role of context in floral use by bees.