Four new species of the Neotropical scarabaeid genus Bdelyrus Harold are described: Bdelyrus asheisp.nov., Bdelyrus cochabambaesp.nov., Bdelyrus iquitosensissp.nov., and Bdelyrus ecuadoraesp.nov. This brings the total to 27 species of Bdelyrus. Bdelyrus lagopus Harold is redescribed and illustrated. A key to all known species of Bdelyrus is provided. Illustrations, a range map, and a revised phylogenetic tree are included. Inclusion of these new species in the revised phylogenetic analysis did not alter significantly the relationships among the 23 species included in the original analysis.

Liparocephalus litoralis Kirschenblatt is redescribed from specimens recently collected and illustrated. Additional data on its geographical distribution (Kuril Islands, Russia, and Hokkaido, Japan) are added. A modified key is provided to differentiate L. litoralis from the other recognized species of the genus Liparocephalus Mäklin.

A droplet-imbibing assay was used to assess the susceptibility of third-instar larvae of the spruce budworm, Choristoneura fumiferana Clemens, to Foray 48B, a commercial formulation of Bacillus thuringiensis subsp. kurstaki containing 12.7 billion international units (IU) per litre. We observed an LD50 of 1.17 IU/larva for third instars, as compared with 3.96 IU/larva for fifth instars. Comparison with previously published data on susceptibility of later instars revealed that third instars were two-to three-fold more susceptible to Foray 48B than fourth and fifth instars and about eightfold more susceptible than sixth instars. Vulnerability of third instars to simulated aerial spray deposits was investigated by using potted balsam firs, Abies balsamea L. Potted trees were infested in the greenhouse when the buds were starting to swell, using a density of about one newly emerged second-instar larva per bud. When 90% of the larvae had reached the third instar and 52% of the buds were breaking (4 d after infesting), infested twigs were harvested and sprayed with undiluted Foray 48B in a spray chamber. Spray droplets on the buds measured between 25 and 125 μm in diameter, with 80% having a diameter of 80 μm or less. A density of 4.2 ± 1.0 droplets per bud resulted in spruce budworm mortality of 83.4 ± 4.0% and a corresponding reduction in larval density of 86.5 ± 3.9% (means ± SD, n = 6) after 5 d at 25 °C. Results of the spray chamber test suggest that third-instar spruce budworms were able to acquire a lethal dose, despite their concealed feeding habits.

Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae) multiple nucleopolyhedrovirus (CfMNPV) expressing green fluorescent protein was used to study aspects of nucleopolyhedrovirus infection in the spruce budworm. The temporal and spatial distribution of fluorescence indicated that the virus infected the midgut, entered the tracheal system, and traveled to the epidermis, fat body, and muscles. In contrast to Autographa californica (Speyer) (Lepidoptera: Noctuidae) multiple nucleopolyhedrovirus (AcMNPV) infection, hemocytes from infected C. fumiferana did not exhibit fluorescence until after CfMNPV had passed from the midgut into the tracheae. Therefore the role of hemocytes may be limited during CfMNPV infection. Also the fluorescence pattern spread from the tracheolar cells to tracheal epithelial cells throughout the tracheal system. Our results indicate that the temporal and spatial events involved in CfMNPV infection of C. fumiferana larvae are consistent with those observed in other lepidopteran hosts infected with AcMNPV Minor deviations between these two systems may be attributed to differences in virulence, infection rate, and possibly host range of the virus.

Cultivars of winter wheat, Triticum aestivum L., previously identified as possible sources of resistance to wheat midge, Sitodiplosis mosellana (Géhin), were crossed with spring wheat to produce lines with a spring growth habit and assure synchrony between insect and plant. Many of the lines showed low levels of infestation by wheat midge in the field, and 21 of these were tested for resistance in the laboratory. All test lines exhibited resistance, ranging from 58 to 100% suppression of larvae and 70 to 100% suppression of seed damage, compared with a susceptible line. Larval development was delayed and survival was reduced on all lines. This antibiosis was associated with a hypersensitive reaction in the seed surface. The hypersensitive reaction, or feeding damage by young larvae before they died, reduced the biomass of some infested resistant seeds by 28% compared with over 60% for infested susceptible seeds. Some lines also reduced the level of infestation either through oviposition deterrence or a resistance which prevented newly hatched larvae from establishing on the seed surface. A few lines also reduced the hatching rate of wheat midge eggs. The resistance was equally effective in field trials during two consecutive summers in Manitoba and Saskatchewan, with at least a 20-times difference in the level of infestation between susceptible and resistant wheats. No larvae could develop to maturity on some resistant lines. Large plots of one resistant line produced less than 1% as many larvae as a typical susceptible wheat, and the larvae that did survive produced few, small adults. This resistance is the first documented case of a high level of true resistance to wheat midge in spring wheat, distinct from asynchrony between the insect and susceptible stage of the plant. The antibiosis component of the resistance is currently being incorporated in cultivars suitable for production in western Canada.

Larvae of the wheat midge, Sitodiplosis mosellana (Géhin), feed on developing seeds of common and durum wheats, Triticum aestivum L. and Triticum durum L. (Graminae). The trophic relationships between insect and plant were quantified as biomass gains or losses using plants infested artificially in the laboratory and naturally in plots and commercial fields. The biomass of seeds from different parts of a wheat spike varied, but seeds in all parts of a spike were infested, independently of their potential biomass. Most infested seeds had 1–3 larvae, but at least 11 larvae could mature on a single seed without reducing larval biomass. When larvae finished feeding and seeds attained about one third of their biomass, specific impact varied from 4.1 to 8.5 mg of seed biomass lost for each milligram of biomass gained by a larva, with the impact declining as the number of larvae per seed increased. Specific impact rose to 100 mg/mg as seeds of T. aestivum and a primitive wheat, Triticum monococcum L., matured, and higher still for T. durum. Wheat plants did not compensate for wheat midge damage, and no indirect damage to uninfested seeds was detected. The distribution of biomass for infested seeds was bimodal, with over 40% less than 8 mg when hand harvested, whereas infested seeds harvested mechanically had a unimodal distribution, with nearly all of the most severely damaged seeds removed during harvest. A visual rating system of six damage categories was related to the biomass of the seeds. The germination and early growth rate of infested seeds were reduced compared with those of uninfested seeds. Based on the biomass relationships for the insect–plant interaction and the visual rating of damage, high-protein number 1 grade common and durum wheat and number 1 grade durum wheat can tolerate up to 6% of the seeds being infested by larvae, before downgrading is likely. For other grades, the economic threshold is 10% of the seeds infested, based on yield loss. Seed growers can adopt the threshold for number 1 wheat (6% infestation) to prevent downgrading, which would also reduce the effects of infestation on seed germination to an acceptable level.

We used pitfall trapping to measure the species richness and relative abundance of ground beetles (Coleoptera: Carabidae) in four forest habitats on Kent Island, a 80-ha island in the Bay of Fundy, New Brunswick, Canada. Sixteen species of ground beetles representing 11 genera were identified in the forested habitats on Kent Island; the relative paucity of ground beetle species may be a result of the island’s harsh climate, dense colonies of breeding seabirds, and isolation from the mainland. Estimates of ground beetle population densities on Kent Island ranged from 50 000 to 250 000/ha. Most ground beetle species were trapped in all habitats and appeared to be habitat generalists. In a series of experiments in which we removed all ground beetles trapped daily over a 3-week period in two experimental plots, ground beetle densities remained as high as in a control plot; other ground beetles quickly moved into the experimental plots to replace beetles that had been removed. The density of ground beetles was highest in intact forest and large forest patches; in contrast, the density of invertebrates other than ground beetles (i.e., possible prey or competitors of ground beetles) was highest in open habitats and isolated forest patches, where ground beetles were less common. Removing ground beetles from experimental plots did not result in an increase in the density of other invertebrates.

Concentrations of organic N and minerals Ca, Fe, K, Mg, Na, P, and S in tissues of galls induced by Diplolepis spinosa (Ashmead) and Diplolepis triforma Shorthouse and Ritchie in growth and maturation phases were compared with those in ungalled tissues of host roses and tissues distal to galls to increase our understanding of nutritional relationships between gall wasps and their host plants (Rosa blanda Aiton and Rosa acicularis Lindley, respectively). Concentrations of N and most mineral nutrients were lower in galls than in ungalled tissues, and tissues distal to galls, suggesting that cynipids regulate rather than concentrate nutrients within their galls. Concentrations of mineral nutrients within the larvae of both species of inducers, and their parasitoids, were determined for galls in the maturation phase. Absolute amounts of most minerals in gall tissues were positively correlated with the number of inhabitants, indicating that control of translocation of nutrients to galls occurs on a per inducer basis. Concentrations of nutrients in mature larvae of parasitoids were the same as concentrations in mature larvae of inducers, which explains why parasitism of gall inducers had no influence on the concentrations or amounts of nutrients in galls. Galls of D. triforma had greater concentrations of N and most mineral nutrients than did galls of D. spinosa. Likewise, larvae of D. triforma, and the parasitoids feeding on D. triforma, had greater concentrations of N and mineral nutrients than did larvae of D. spinosa and its parasitoids. Galls of both species had different concentrations of nutrients compared with ungalled tissues and tissues distal to the galls. Galls of both species also had seasonal decreases in concentrations of nutrients. Parasitoids of each species of inducer were generally similar in mineral composition to their hosts.

The angiosperm bark volatile, conophthorin, was tested at release rates of 3.0 and 0.3 mg/24 h against the Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, the spruce beetle, Dendroctonus rufipennis (Kirby), the pine engraver, Ips pint (Say), and the western balsam bark beetle, Dryocoetes confusus Swaine (all Coleoptera: Scolytidae). The responses of D. pseudotsugae, I. pini, and (in one of two experiments) female D. confusus to attractant-baited traps were disrupted by conophthorin in a dose-dependent manner. Dendroctonus rufipennis was not disrupted by conophthorin. Our results extend the repellent bioactivity of conophthorin to Ips DeGeer spp. and confirm earlier experiments with D. pseudotsugae. Conophthorin may have some utility in protecting susceptible timber from bark beetle attack.

We used three sampling methods to identify the arthropod predators most abundant and active in fields of cabbage, Brassica oleracea L. var. capitata, and determined those most likely to be important predators of the imported cabbageworm, Pieris rapae L., by testing the predators’ abilities to forage on cabbage plants and to feed on Pieris rapae in small arenas in the laboratory. Abundance and activity in the field were monitored with pitfall traps, sticky traps applied directly to leaves, and plant samples. Four criteria were used to assess the species’ potential value as a predator of Pieris rapae in cabbage: relatively high overall abundance in trap catches and plant samples, occurrence on plant foliage in the field, a high propensity to feed on Pieris rapae eggs and first instars, and the ability to search for larval Pieris rapae on cabbage plants. Four species, the wolf spider Pardosa milvina (Hentz) (Araneae: Lycosidae), the harvestman Phalangium opilio L. (Opiliones: Phalangiidae), and the lady beetles Coleomegilla maculata lengi Timberlake and Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae), demonstrated these attributes, although all four species appeared unable to search for prey on some parts of the cabbage plants, owing to unsure footing on the plants’ slippery cuticular wax. Linyphiids (Araneae) and syrphids (Diptera), the most abundant taxa in the plant samples, may prove better at thoroughly searching cabbage plants, but remain to be tested in future laboratory trials. Our results show that only a small portion of the predatory arthropod species that occur in cabbage fields is likely to prey on Pieris rapae on the plants, although important questions remain about the roles of some taxa. Future efforts to enhance biological control of Pieris rapae by naturally occurring predators can now focus on further elucidating and finding ways to enhance the roles of those predators that are effective.

Significant outbreaks of saddled prominent, Heterocampa guttivitta (Walker), have been recorded in northern hardwood stands throughout the northeastern United States since 1907 and were first noted in Ontario in 1938 (Martinat and Allen 1988). The insect overwinters as a pupa beneath litter, adult emergence begins in late May and peaks in mid-June, and oviposition activity ends in early July. Consequently, the major impact of defoliation usually occurs in late summer feeding. Principal hosts are sugar maple, Acer saccharum Marsh. (Aceraceae), American beech, Fagus grandifolia (Ehrh.) (Fagaceae), and yellow birch, Betula alleghaniensis Britton (Betulaceae) (Rush and Allen 1987). Two successive years of severe (>75%) defoliation of sugar maple result in significant growth loss (Bauce and Allen 1991), and heavy mortality may occur to understory sugar maple (Grimble and Newel1 1973). The quantity and sugar content of sugar maple sap are dramatically reduced the spring following heavy (>50%) defoliation (Magasi 1981; Handy 1968). Heavy to severe defoliation may cause crown dieback and defoliation and, in concert with other stresses, may initiate maple decline (Giese et al. 1964). Currently, monitoring and evaluation of saddled prominent populations must rely on egg sampling (Grimble and Kasile 1974), a time-consuming process that is inconvenient for survey personnel and landowners. A sex pheromone has not been identified for this species (nor for any other North American Notodontidae) and would be a potentially useful tool for detecting incipient outbreaks, predicting population levels, and evaluating population trends.

The apple ermine moth, Yponomeuta malinellus Zeller, is a univoltine pest species that defoliates apple, Malus domestics (Borkh) (Rosaceae), in the temperate region of the Palaearctic. First instars overwinter within a communal hibernaculum beneath the covering of the egg batch (Kock 1998). In spring, larvae emerge to initially mine apple leaves and subsequently feed externally within a communal tent (Menken et al. 1992). During heavy infestations, the communal tents may envelop the entire apple tree, resulting in total defoliation (Parker and Schmidt 1985). There have been several accidental introductions and subsequent eradications of the apple ermine moth in eastern North America (Hewitt 1917; Parker and Schmidt 1985) but, by 1989, the pest was found in the Fraser River Valley in British Columbia, in Whatcom county, Washington, and in northwestern Oregon (Antonelli 1991; Unruh et al. 1993).

The recent paper by Poinar et al. (1999), entitled “New amber deposit provides evidence of early paleogene extinctions, paleoclimates, and past distributions,” reports a new deposit of fossiliferous amber from the Eocene of British Columbia. This report of a significant discovery by one of the co-authors (Bruce Archibald) is compromised by unexplained statements that ants in this amber are the “earliest unequivocal ants.” They cited unpublished cladograms by Cesare Baroni Urbani as the source of information that showed that previous reports of ants in Cretaceous amber were not really ants.

Our study of the Hat Creek amber (Poinar et al. 1999) was undertaken to determine the range of the biota in the resin, to identify the plant that produced the resin, and to assess the future implications of these significant deposits. The study was in no way “compromised” by providing an alternative interpretation of the systematic position of the genus Sphecomyrma Wilson and Brown.