Scolytus schevyrewi Semenov, the banded elm bark beetle, and S. multistriatus Marsham, the smaller European elm bark beetle, are morphologically similar. Reliance on adult external morphological characters for identification can be problematic because of wide within-species variability and the need for good-quality specimens. The inability to identify developmental stages can also hamper early-detection programs. Using two character identification systems, genitalic (aedeagus) morphology, and DNA markers (random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR)) to distinguish S. schevyrewi from S. multistriatus, we examined specimens from geographically distinct populations of both species collected from infested host trees or semiochemical-baited funnel traps. We found that aedeagus morphology can be used to identify the two species. The use of two oligonucleotide primers in the RAPD-PCR analysis yielded distinct DNA banding patterns for the two species. Species identification using RAPD-PCR analysis was validated by a blind test and used to make species identifications of larval specimens. These tools improve the ability to differentiate between S. schevyrewi and S. multistriatus at immature and adult stages, and could be developed and used for other scolytines as well.

We present the systematics and ecology of a new species of arboreal oribatid mite in the family Achipteriidae, Anachipteria geminussp. nov., a dominant arthropod in canopy lichens associated with western hemlock (Tsuga heterophylla (Raf.) Sarg. (Pinaceae)) and Pacific silver fir (Abies amabilis (Dougl. ex Loud.) Dougl. ex Forbes (Pinaceae)) in the coniferous temperate and montane forests of the Pacific Northwest of North America. The species is described on the basis of the morphology of all active instars plus molecular sequence data for the D3 region of the 28s rRNA (D3-28s) and mitochondrial cytochrome oxidase 1 (CO1) genes. Anachipteria geminus is the dominant oribatid mite in foliose lichens in the upper canopies of Pacific montane conifer trees. Specimens were found in 100% of canopy lichens sampled, and abundances can reach 1450 individuals / 100 g dry mass of lichen. Analysis of the population structure indicates that A. geminus has seasonally stable populations consistent with overlapping generations. Anachipteria geminus expresses morphological character states that require expanding the diagnoses of the genus Anachipteria and the family Achipteriidae. A revised diagnosis and morphological key to species of Anachipteria in Canada are given.

Cerodontha (Icteromyza) pilosan. sp. is described from the Yukon Territory. The Palaearctic species C. (I.) lineella (Zetterstedt) is recorded for the first time in North America, based on specimens from northern Canada and Alaska, and C. (I.) pollinosa (Melander) is synonymized with C. lineella. Cerodontha pilosa is most similar to C. (I.) longipennis (Loew) and C. (I.) lineella. Distinguishing characters and a modification of Spencer’s key to Canadian species of Cerodontha are given to separate these species.

It is well known that noctuid moths respond to ultrasound frequencies produced by insectivorous bats performing a series of evasive maneuvers such as loops, dives, rolls, and turns. Certain ultrasound frequencies may be considered an environmental stress factor for these moths, causing physiological and behavioral effects. We investigated changes in acetylcholinesterase activity of Helicoverpa armigera (Hübner) exposed to ultrasound produced from a commercial device (LHC20). Our results indicated that stress effects on acetylcholinesterase activity resulting from exposure to ultrasound do not differ according to sex, but effects on different developmental stages of H. armigera differ significantly depending on duration of exposure. Enzyme activity increased in adults after 20 min exposure to ultrasound and decreased in pupae after 30 and 50 min exposure. Enzyme activity in larvae was reduced after 20 min and increased after 40 and 60 min. The results of this study also indicate that stress caused by exposure to ultrasound could modulate the cholinergic system in H. armigera.

We examined whether collection time (pre-winter vs. post-winter) influenced adult and female emergence success and body mass of wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), from four Montana populations in 2005-2006. Adult emergence was generally higher from post-harvest material in post-winter collections but varied widely among populations. No significant effect of collection time on male-biased adult emergence from post-harvest residue collected near Conrad (37% vs. 31%) was detected, although adult emergence was greater for post-winter collection than for pre-winter collections from sites near Havre (90% vs. 81%), near Amsterdam (88% vs. 41%), and near Loring (67% vs. 0%); these three populations had a bias towards adult females that exceeded 2:1. Adult body mass was greater for post-winter-collected males (30% higher) and females (15%) only from near Amsterdam. Diapausing C. cinctus larvae overwintering under field conditions had better adult emergence, and spring collection is recommended in order to minimize time allocated to acquiring C. cinctus populations for research.

The forest tent caterpillar, Malacosoma disstria Hübner (Lepidoptera: Lasiocampidae), and large aspen tortrix, Choristoneura conflictana (Walker) (Lepidoptera: Tortricidae), are important pests of trembling aspen, Populus tremuloides Michx. (Salicaceae), in western Canada. Populations of both species can be monitored with sex pheromone-baited traps as part of an integrated pest management program. Moths captured in pheromone traps can also be used for ecological studies. Captured males of each species were examined to test the effect of population density, geographic region, and collection date on moth quality. Moth quality was assessed on the basis of wing area and level of infection with microsporidian parasites. The level of microsporidian infection of M. disstria was strongly dependent on geographic region but not on population density. Male M. disstria from high-density populations had smaller wings than males from endemic populations. Wing area of male M. disstria decreased throughout the flight period. Neither collection date nor microsporidian infection level affected wing area of male C. conflictana. Collection date also did not affect the level of microsporidian infection of C. conflictana. These data support pheromone trapping as a tool to detect microsporidian infections and examine their temporal and density-dependent effects on wing size in M. disstria and C. conflictana populations.

We investigated the impact of different fluorescent marking powders on both survivorship and daily body condition, measured as mass/volume ratio, using adult mountain pine beetles, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae: Scolytinae), in a laboratory study. Initial condition of the marked beetle groups did not differ from that of an unmarked group. However, beetles in better initial condition survived longer, thus validating our condition index. The condition but not the survivorship of mountain pine beetles was affected by the marking treatment. Overall, the condition of beetles declined over time. The condition of marked beetles decreased at a higher rate than that of unmarked beetles while alive but at a lower rate after death. This pattern of decreasing condition suggests that marked beetles lost water faster than unmarked beetles while alive, so unmarked beetles had more water to lose after death. Because reduced condition may affect optimal dispersal behaviour, we suggest that these effects be routinely examined and minimized in mark-recapture studies.

Bees of the genus Osmia Panzer (Hymenoptera: Megachilidae) are among the contenders to replace honey bees, Apis mellifera L. (Apidae), for pollinating tree-fruit crops. One species, Osmia lignaria Say, has shown great potential in western North America and was recently introduced into Nova Scotia for evaluation as a pollinator of apple, Malus Mill. (Rosaceae). A major component of that study was to develop management options for O. lignaria, including methods of sustaining nesting females following crop flowering to maximize population recovery for pollination in subsequent seasons. The objective of this study was to evaluate bigleaf lupine, Lupinus polyphyllus Lindl. (Fabaceae), as a secondary food plant for nesting female O. lignaria by investigating nesting activity, pollen-use patterns, and fecundity. During 2002–2003, female O. lignaria collected high proportions of apple pollen (>70%) during mid and late flowering; after then, most pollen (>90%) was collected from bigleaf lupine. The flowering period of lupine in Nova Scotia (late May to early July) slightly overlapped that of apple, so there was no scarcity of pollen resources during the life-span of O. lignaria. Most nests typically showed high levels (≤200%) of population growth, but recorded levels varied among nest types and locations. In 2004, nests closer to lupine plots exhibited significantly greater population recovery than nests located farther away (i.e., approximately 600 m). Bigleaf lupine is a suitable plant species for meeting the pollen requirements of nesting populations of O. lignaria following apple flowering, thus promoting the recovery of populations to meet apple pollination requirements in subsequent seasons.

The specific impact of the aphid Macrosiphum euphorbiae (Thomas) on seedlings of common flax, Linum usitatissimum L., is 3.317 mg/mg, quantified as the dry mass of plant tissue required to produce a unit of herbivore tissue. This measure of the efficiency of biomass conversion between trophic levels for the aphid–flax interaction is similar to that previously reported for seven species of aphid on monocotyledonous cereals (Poaceae), but lower than that for two species of aphid on a species of Brassicaceae, a dicotyledonous plant. Therefore, the interaction between M. euphorbiae and the dicot, flax, does not support the hypothesis that aphids have less impact on monocots than on dicots.

Egg masses of the horse fly, Hybomitra nitidifrons nuda (McDunnough), and the deer fly, Chrysops aestuans Wulp (Diptera: Tabanidae), were collected during the summers of 1996–2000 from five different locations in southern Manitoba. On average, hymenopterous egg parasitoids were reared from more than 90% of collected egg masses. Telenomus hybomitrae Iranpour and Galloway and (or) Telenomus utilis Iranpour and Galloway (Hymenoptera: Platygastridae: Telenominae) emerged from multilayered egg masses of H. n. nuda. However, Trichogramma semblidis (Aurivillius) (Hymenoptera: Trichogrammatidae) and (or) Telenomus chrysopsis Iranpour and Galloway were reared from single-layered egg masses of C. aestuans. In H. n. nuda egg masses, more than 33% of individual eggs were parasitized and more than an additional 35% were apparently damaged by the two telenomine parasitoids. In C. aestuans egg masses, approximately 40% of individual eggs were parasitized and 18% produced neither parasitoids nor larvae.

Past studies of gall-maker-host interactions have been hampered by an inability to conduct experimental transplants of individuals between host plants. We describe a method for transplanting gall-maker larvae between galls on different individual host plants. Our method involves removing and inserting larvae through slits cut in young galls, and allows for healing and continuing growth of the gall. We developed and tested our method with larvae of the gall-making moth Gnorimoschema gallaesolidaginis Riley (Lepidoptera: Gelechiidae) on its two host plants, Solidago altissima L. and S. gigantea Ait. (Asteraceae). For three of four host × year combinations, unparasitized larvae survived at similar rates in transplants and controls. On one host in one year, transplant survival was low, possibly as a result of severe drought stress. Interestingly, survival of parasitized gall-maker larvae was lower in transplants for three of four host × year combinations, suggesting that gall-makers stressed by parasitoid attack are less able to tolerate transplant stress. Our technique may be applicable to many other gall-maker species, especially those making relatively thin-walled galls, and should represent a valuable new tool for the study of gall-maker-host interactions.

Two non-destructive sexing techniques suitable for use in the field and laboratory are described, and tested with the Warren root collar weevil, Hylobius warreni Wood (Coleoptera: Curculionidae). On the second visible abdominal sternite of males is a longitudinal depression that is absent on females. In addition, setae on the last visible abdominal sternite of females are arranged longitudinally; setae on males are arranged radially. For the first character, accuracy was 90% and sex could be determined without the aid of magnification. The latter character was slightly more reliable, at 95% accuracy, but required at least 12× magnification.