Field experiments demonstrated that the western balsam bark beetle, Dryocoetes confusus, responded best to multiple-funnel traps baited with mixtures of (+)- and (−)-exo-brevicomin. (±)-exo-Brevicomin released at 0.8 mg per 24 h performed as well as or better than release rates of from 0.2 to 1.0 mg per 24 h in terms of the number of baited trees which were mass attacked (80%), average attack density, and average number of trees attacked within a 10-m radius of baited trees. Baiting more than one tree in a spot resulted in an intensification of attack on baited trees and increased the number of trees attacked within 10 m of each spot.

The Diptera occurring in various kinds of bird nests were investigated in the Japanese island of Hokkaido from 1985 to 1989. A total of 4623 Diptera, consisting of 23 species of eight families (Anthomyiidae, Fannidae, Muscidae, Calliphoridae, Heleomyzidae, Sphaeroceridae, Sepsidae, and Stratiomyiidae), was reared from 69 natural nests of 13 bird species of eight families (Strigidae, Picidae, Paridae, Sittidae, Sturnidae, Ploceidae, Laniidae, and Columbidae). Of 23 species of flies reared, 12 were new records from bird nests. An ectoparasite of birds, Protocalliphora maruyamensis Shinonaga and Kano, frequently emerged from the nests of hole-nesting birds of Paridae, Sturnidae, and Ploceidae, but it did not emerge from the nests of the hole-nesting birds Picoides major and P. minor of Picidae. The nests of Streptopelia orientalis yielded the most species of flies (12). Myospila meditabunda (Fabricius) and Mydaea urbana (Meigen), whose larvae are predacious, proved able to live in the bird nests. Among the scavengers, Potamia littoralis (R.-D.) was the most dominant and occurred in the nests of nine of 10 hole-nesting bird species. Sphaerocerid, sepsid, and stratiomid flies occurred in the nests of S. orientalis in which large quantities of bird feces had accumulated. The factors concerning the occurrence of flies in the nests are discussed.

We describe a method for identifying conifer-feeding species and lineages of Choristoneura Lederer in Canada and Alaska. The method relies on amplification of mitochondrial (mt) DNA by the polymerase chain reaction (PCR); amplified DNA is then digested with restriction enzymes to give characteristic DNA fragment patterns. We used the cytochrome oxidase I and II genes of mtDNA, which were previously shown to contain numerous nucleotide differences at the level of species. Ten restriction enzymes were surveyed and a combination of two of these (EcoR V + Hinf I) was sufficient to distinguish the major mtDNA lineages. Choristoneura fumiferana (Clemens), C. pinus Freeman, and C. rosaceana (Harris) were readily distinguished from each other and from an assemblage of three putative western species (C. occidentalis Freeman. C. orae Freeman, and C. biennis Freeman). The three western species have the same mtDNA marker pattern in most individuals and, although ecologically differentiated, their populations may actually be conspecific. At one locality in Alaska, pheromone traps bailed with lures for C. fumiferana attract moths with C. fumiferana mtDNA, and lures for C. orae attract moths with mtDNA that is characteristic of the western assemblage. This demonstrates geographic overlap of genetically distinct species in Alaska. The same two separate mtDNA lineages co-occur at two localities in Alberta, but pheromone attraction is unknown. In British Columbia, populations identified as C. biennis and C. occidentalis contain a few individuals with divergent mtDNA genotypes, the significance of which remains unclear. Amplified mtDNA thus provides a convenient, reliable marker for surveying genetic variation within species and for studying interactions among species of the C. fumiferana group.

Female southern pine beetles, Dendroctonus frontalis Zimmermann, may propagate two species of symbiotic fungi in a prothoracic mycangium. Females can carry either Ceratocystiopsis ranaculosus Bridges and Perry or an unnamed basidiomycete or both; some carry no fungi. Thus, females can be categorized into one of four groups based on mycangial content. We examined size and lipid content of emerging brood adult females based on these mycangial fungal classes. Female beetles carrying the basidiomycete, either alone or in combination with C. ranaculosus, were larger, heavier, and contained more lipid than did females carrying only C. ranaculosus. Size and lipid content also varied by season, as did the number of females carrying different fungal combinations. Regression analysis showed that variation in the occurrence of the basidiomycete was significantly related to variation in averages of beetle size and lipid content measurements.

In field and cage experiments in a Costa Rican oil palm plantation, the largest, most fecund female bagworms, Oiketicus kirbyi, had the greatest mating success. Differential mating success of small and large females may be attributed to mate choice by males or to competition between protogynous females for access to males.

Greenhouse trials were conducted to evaluate the effect of treating adult and egg stages of the eastern spruce budworm, Choristoneura fumiferana (Clemens), with Insegar, a water-based commercial formulation of the juvenile hormone analog fenoxycarb, or with water (controls) at droplet sizes and densities comparable to what would be achieved through aerial spraying of field populations. When adult moths were sprayed with the juvenoid at dosages equivalent to 15.5, 155.4, and 310.8 g AI/ha, approximately 90% of the eggs that were subsequently oviposited failed to hatch. The efficacy of the compound (60% suppression of egg hatch) was not as high when the egg stages were sprayed directly at 15.5 and 155.4 g AI/ha. Insegar did not affect the egg productivity of the moths.

The Douglas-fir beetle (Dendroctonus pseudotsugae) antiaggregation pheromone, 3-methylcyclohex-2-en-1-one (MCH), was applied to stands at high risk for infestation. The MCH was applied in a bubble capsule formulation to plots ranging from 2.1 to 2.6 ha in size at rates of 45–76 g/ha. Catches of Douglas-fir beetles in attractant-baited Lindgren funnel traps located at the plot centers were significantly lower on MCH-treated plots compared with untreated plots. In contrast, catches of the most abundant predator, Thanasimus undatulus (Say), were unaffected by the MCH treatment. The percentage of Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] trees ≥20 cm dbh that were mass attacked was significantly lower on treated plots (0.2%) compared with untreated plots (8.5%). MCH alone was effective in reducing the probability of Douglas-fir beetle infestations occurring in high risk stands.

The aphid fauna of “Las Cañadas del Teide” (Tenerife Island) at present is made up of 11 species including the only species endemic to Macaronesia. This new species of the genus Acyrthosiphon is described and compared with other species of this genus; A. supranubius sp.nov. lives on the endemic Spartocytisus supranubius (Leguminosae).

A sampling plan for the estimation of the number of achenes damaged by the red sunflower seed weevil, Smicronyx fulvus LeConte, is useful in evaluating the efficiency of weevil management strategies. The objective of this study was to determine the distribution pattern of the damaged achenes that would allow the development of a fixed-sample-size plan for estimation of the damaged achenes. Taylor’s power law and Iwao’s patchiness regression were used to analyze the distribution pattern of the damaged achenes. Slopes from both models were >1, indicating an aggregated spatial pattern. The intercepts and slopes from both models were used to calculate the minimal mean number of damaged achenes per sunflower head that can be estimated for a given sample size and precision level. If the mean number of damaged achenes per head is low (<20), the plan developed using the parameters of Taylor’s power law requires significantly more samples than the plan using the parameters of Iwao’s patchiness regression to estimate the same density of damaged achenes. If the mean number of damaged achenes per head is high (>30), the two plans give similar results. If both low and high damage situations are considered, Taylor’s plan is preferred to Iwao’s plan. At the 0.10 precision level, Taylor’s plan requires approximately 40 samples (heads) to estimate a mean of about 200 damaged achenes per head (≈ current economic injury level).

The seasonal occurrence of four species of egg parasitoids of the tarnished plant bug (Lygus lineolaris) was determined in three different habitais: fields of mixed weeds. alfalfa (Medicago sativa L.). and crown vetch (Coronilla varia L.) in southwestern Quebec in 1991 and 1992. Parasitoids studied were the mymarids Anaphes iole Girault, Polynema pratensiphagum (Walley), and Erythmelus miridiphagus Dozier and a scelionid, Telenomus sp. Adult populations of these parasitoids showed three or four population peaks in all habitats throughout the season. Adult parasitoid activity started during the first egg-laying period of L. lineolaris at a temperature accumulation of 73 degree-days (DD). The overwintering period began in mid-October at 1277 and 1058 DD for 1991 and 1992, respectively. All the parasitoids had a strong synchrony with L. lineolaris populations; specifically, marked peaks in the adult population of all species were in synchrony with the egg-laying periods of L. lineolaris.

The extent of allozyme variation and the amount of genetic divergence were assessed among populations of the aphid Rhopalosiphum maidis in Ontario. Allozyme analysis of individuals from 12 sites revealed no polymorphism for 32 loci. In addition, the extent of karyotypic, allozyme, and mitochondrial DNA (mtDNA) variation was examined for clones from North America, Europe, and North Africa. As previously noted, chromosome number varied in relation to the host-plant on which aphids were collected, but neither allozyme nor mtDNA patterns allowed discrimination among clones. Further work is needed to determine whether the lack of genetic diversity in R. maidis is linked with its recent introduction to North America or with its loss of a sexual phase.

Cultural practices (tillage, planting date) were examined for their effect on flea beetle, Phyllotreta cruciferae (Goeze), populations in three species of oilseed crucifers—Brassica napus L., B. rapa L., and Crambe abyssinica Hochst. No-till appeared to reduce flea beetle densities when compared with conventional tillage. The greater structural diversity of the no-till plots might be interfering with host plant location. Earlier plantings had significantly more flea beetles per plant than later plantings. The Brassica crops yielded higher densities of beetles compared with crambe, supporting earlier reports of crambe resistance.

Because microbial insecticides based on Bacillus thuringiensis subsp. kurstaki cause temporary cessation of larval feeding at sublethal doses, we hypothesized that the delivery of a given dose in a single droplet is more efficacious than delivery of the same dose in multiple smaller droplets. We tested this hypothesis by exposing larvae of the spruce budworm, Choristoneura fumiferana (Clem.), to an LD50 of a commercial product (Dipel 8L) in combinations of droplet sizes and densities that are commonly observed on coniferous foliage after aerial application. A nominal dose of 5.2 International Units (IU) was presented to fifth-instar larvae on one, two, or four balsam fir, Abies balsamea L., needles in the form of one, two, or four droplets with diameters of 84, 66, or 52 μm, respectively. The combinations of droplet size and density were chosen to represent an increasing degree of dose dispersion. Overall mortality after a 24-h exposure was significantly reduced with increasing dose dispersion from an average of 66% when the dose was presented in one 84-μm droplet on one needle to 40% when presented in multiple droplets on several needles. Increased dose dispersion reduced the proportion of larvae that were able to ingest the full dose, presumably because of feeding inhibition caused by ingestion of sublethal droplets. In addition, mortality of fully dosed larvae declined significantly with increasing dispersion, implying a reduction in the effectiveness of the ingested dose. When compared with operational spray deposits, our results suggest that efficacy of spruce budworm sprays may be improved by increasing the proportion of needles receiving a lethal spray deposit by increasing product potency and possibly the active ingredient application rate.

Male moths of Choristoneura occidentalis Freeman, C. biennis Freeman, C. fumiferana (Clemens), and C. orae Freeman were caught in pheromone-baited traps. Ten traps were placed at each site, five baited with an aldehyde lure and five with an acetate lure. This procedure permitted separation of species based on the specific chemical lure and also provided specimens for further study of morphological and isozyme differences. The color of the forewings, presence or absence of spicules on the aedeagus, and a specific allozyme frequency were determined on selected specimens where these characteristics were useful in separating species at a particular site. Distributions of all species were more extensive than previously known, sometimes adding hundreds of kilometres to the recorded range. Areas of sympatry were identified and the fidelity and usefulness of characteristics for separating species in areas of overlap were discussed.

A 3-year survey of apple and cherry orchards in the interior of British Columbia revealed that speckled green fruitworm, Orthosia hibisci, is the dominant fruitworm species in the south of the Okanagan Valley. Larvae of speckled green fruitworm collected from orchards that used no or minimal insecticides experienced 22.5–29.0% parasitism in 1988–1990. Earinus limitarus was responsible for 98.9% of the parasitism in the 3 years. Parasitoids of minor significance included a Meteorus sp. (Hymenoptera: Braconidae) and Compsilura concinnata (Mg.) (Diptera: Tachinidae). Data from laboratory trials indicated that feeding by O. hibisci in the fifth and sixth instars was significantly (P < 0.05) reduced when larvae were parasitized by E. limitarus. Orthosia hibisci in the second through sixth instars in sleeve cages damaged developing apples in the field. Earinus limitarus appears able to reduce O. hibisci numbers for the following year as well as immediate host feeding damage in at least the last two instars.

Eight species and seven subspecies of costate Altica are described and illustrated. Lectotypes are designated for Altica alni Harris, A. ambiens LeConte, A. prasina LeConte, A. subplicata LeConte, and Graptodera plicipennis Mannerheim. A neotype is designated for Altica bimarginata Say. Two subspecies are recognized for A. ambiens, three for A. bimarginata, and two for A. prasina. Graptodera plicipennis is removed from synonymy and given a new subspecific status under Altica bimarginata, and A. populi Brown is given a new subspecific status under A. prasina. Altica latiplicata Blake is placed in synonymy with A. ambiens LeConte. Altica bimarginata labradorensis LeSage is described as a new subspecies of A. bimarginata. Keys are given for males and females, and data are provided on distribution, host plants, biology, parasites, predators, and economic importance of these species.

Adults of Choristoneura fumiferana, C. biennis, and an unidentified species reared from larvae or caught in pheromone traps from British Columbia were used for isozyme analysis to confirm the species identity, and for morphological study to determine the percentage of individuals with spiculate aedeagi. About 82% of C. fumiferana and less than 3% of both C. biennis and C. unidentified species (CPG) have spicules on the left side of their aedeagi. The number of moths that need to be sampled to determine a species is presented, based on the presence or absence of spicules.

The effect of conservation and conventional tillage on carabid communities was compared using pitfall trapping in two commercial barley (Hordeum vulgare L.) fields located 4 km apart on similar soils. Carabid abundance was significantly higher under conventional tillage but abundances of individual species varied between the two fields. Agonum placidum Say and two Amara Bonelli species were more abundant at the conventional tillage farm whereas Pterostichus adstrictus Eschscholtz and three Bembidion Latreille species were significantly more abundant at the reduced tillage farm. Slightly more carabid species were collected in this latter field and species diversity and evenness were significantly higher.

A large population of Peponapis pruinosa, a solitary, oligolectic, ground-nesting bee and important pollinator of cucurbits in the United States and Mexico, was studied foraging on pumpkin (Cucurbita pepo) at a site in Cambridge, Ontario, from 23 July to 30 August 1990. We measured the diurnal and seasonal foraging trends for P. pruinosa and compared our findings with those for P. pruinosa elsewhere. The females are active on flowers in the mornings from dawn on. The males are active later in the mornings and spend afternoons and nights in closed flowers. The seasonal emergence of the bees closely parallels that of the plants’ anthesis. Diurnal activity is related to the availability of pollen resources on the flowers of C. pepo. Almost all pollen is removed from the synandria within 2 h of the start of foraging by female bees. Ambient temperature threshold for foraging by both sexes is about 10 °C.

Volatile compounds were isolated and identified from a crude extract of garry oak, Quercus garryana, foliage which was known to be attractive to the tachinid fly Cyzenis albicans. Candidate compounds were identified by the combined use of gas chromatography–mass spectrometry, and infra-red spectroscopy. Specific oak-leaf volatiles were field-tested in 2 different years in an apple orchard. Compounds were applied singly or in combination to individual apple trees; the number of C. albicans entering the canopy of each tree was observed and the number of eggs they oviposited on foliage was estimated. Borneol was the only compound that attracted flies when compared with the other treatments, but this did not result in more fly eggs being oviposited on borneol-treated trees. None of the compounds tested resulted in a greater number of Cyzenis eggs being oviposited. A greater abundance of borneol in oak foliage than in apple foliage, and its attractiveness to C. albicans, may explain the aggregation of flies in response to feeding-damage among oak trees and the absence of this pattern among apple trees.