We describe four new species of feather mites of the family Gabuciniidae collected from Accipitridae and Falconidae (Falconiformes) from South and North America. Three of these belong to new genera, Metagabuciniagen. nov. with one new species and Proaposolenidiagen. nov. with two new species. We also describe one new species of the genus Aposolenidia Gaud and Atyeo. The new species and host records are Aposolenidia striatasp. nov. from the pearl kite, Gampsonyx swainsonii Vigors, Metagabucinia caracaraesp. nov. from the red-throated caracara, Ibycter americanus (Boddaert), Proaposolenidia accipitrissp. nov. from the Cooper’s hawk, Accipiter cooperii (Bonaparte), and Proaposolenidia elanoidessp. nov. from the swallow-tailed kite, Elanoides forficatus (Linnaeus). Aposolenidia, Metagabucinia, and Proaposolenidia constitute a morphologically distinct group within the Gabuciniidae. This “Aposolenidia genus group” is characterized by the following features: bases of epimerites of legs I and II inflated, ball-shaped, heavily sclerotized, and connected by sclerotized dorsolateral bridges; tarsi of legs I and II with dorsal walls strongly thickened and dorsobasal part of tarsus I inflated. Members of this group coexist on falconiforms with other gabuciniid taxa that exhibit longer and more extensively sclerotized bodies, such as the genera Aetacarus Gaud and Atyeo, Hieracolichus Gaud and Atyeo, and Ramogabucinia Gaud and Atyeo.

The Oriental clusiine genus Phylloclusia Hendel, 1913 is redefined and revised, with four new species (P. hendelisp. nov., P. darlingisp. nov., P. nigroscutellumsp. nov., and P. lanceolasp. nov.) described from Sri Lanka, Taiwan, Indonesia, Malaysia, and the Philippines. Phylloclusia is established as the sister genus to the Japanese, Afrotropical, and Australian Tetrameringia McAlpine, 1960 on the basis of newly recognized male and female genitalic synapomorphies. An identification key and illustrations for the six species of Phylloclusia are provided.

Rove beetle assemblages from forest dominated by yellow birch (Betula alleghaniensis Britt. (Betulaceae)) at two sites in southeastern Quebec were characterized in terms of composition, diversity, and relative abundance. In total, 143 species were collected over two seasons (June–August of 1999 and 2000). In the pretreatment year (1999), 88 species were found in uncut stands. In the post-treatment year, 116 species were found in treated (by patch harvesting and ground scarification) and control plots combined. Sixty-one species were common to the two sites, 27 species captured in the 1999 season were not recaptured in the 2000 season, and 55 additional species were captured in 2000. There are 23 new distribution records for Quebec, and one species, Atheta (Dimetrota) pseudomodesta Klimaszewski, sp. nov., is described. New bionomics data on relative abundance, seasonality, and the utility of different trapping methods are presented. Assemblage composition is compared with that of a red spruce (Picea rubens Sarg. (Pinaceae)) forest in New Brunswick.

The spruce budworm, Choristoneura fumiferana (Clem.), has an obligatory winter dormancy period that lasts up to 10 months in the field. In the Great Lakes Forestry Centre rearing facility, neonate larvae spin hibernacula in cheesecloth, which is then stored at 2 °C for between 20 and 30 weeks. Although dormancy survival and synchrony of postemergence development are highest when larvae are stored in the cold for 16–35 weeks, it is not known how cold-storage duration affects spruce budworm performance once diapause has been completed. We exposed approximately 9250 second-instar larvae (belonging to three rearing cohorts) to 2 °C for 16, 19, 22, 25, 28, 31, 34, or 37 weeks and monitored various postdiapause performance variables. Increasing cold storage from 16 to 25 weeks or more resulted in small (approximately 10%) increases in dormancy survival and larval development rates (from second instar to pupation), a larger (up to 23%) increase in pupal mass and realized fecundity (number of eggs laid per female), and an increase of at least 25% in late-instar survival (from fifth instar to pupation). The only variable that was negatively affected was the pupal survival, but the decrease was relatively small. Therefore, storing diapausing larvae for at least 25 weeks optimizes postdiapause performance variables that are important for mass-rearing efficiency.

Fungus-growing ants (Hymenoptera: Formicidae: tribe Attini) engage in mutually beneficial symbioses with fungi (Basidiomycota) that serve as their main food source. The leaf-cutters (genera Acromyrmex Mayr and Atta Fabricius), the most derived attine ants, employ elaborate nest-hygiene behaviours, including substrate preparation. By preparing substrate prior to its incorporation into the fungus garden, workers facilitate the physical breakdown of leaf material while reducing the abundance of potentially harmful microbes that contact their fungal mutualist. Despite its importance in ant fungiculture, substrate preparation has not been investigated in other genera of fungus-growing ants. We examined substrate-preparation procedures used by five genera of fungus-growing ants (Apterostigma Mayr, Cyphomyrmex Mayr, Trachymyrmex Forel, Acromyrmex, and Atta) representing most of the phylogenetic range of the Attini. Behavioural observations revealed that all five genera engage in substrate-preparation behaviours. Furthermore, these behaviours vary by genus, with Trachymyrmex, Acromyrmex, and Atta engaging in more elaborate preparation behaviours than the other genera. Additionally, we found that during substrate preparation, leaf-cutting ants inoculate leaf fragments with actinomycetous bacteria. These filamentous bacteria are known to produce antibiotics that suppress fungal pathogens, which suggests that inoculation with the bacterial mutualist during substrate preparation helps protect the fungus gardens of leaf-cutter ants from these parasites. Our finding that substrate-preparation behaviours occur across the phylogenetic range of attine ants suggests that these behaviours are a critical component of successful fungiculture by ants.

The susceptibilities of genetically diverse Canadian spring wheats, Triticum aestivum L. and Triticum durum Desf., to three aphid species, Rhopalosiphum padi (L.), Sitobion avenae (Fabricius), and Schizaphis graminum (Rondani), were investigated. Trophic interactions measured as changes in biomass of aphids and wheat plants were used to quantify levels of resistance, components of resistance, and impact of aphids on yield. Plants in field cages were infested with small numbers of aphids for 21 days at heading. These plants were usually more suitable for the development of S. avenae and S. graminum than of R. padi. Partial resistance, measured as seed production by infested plants as a proportion of that by a control, varied from 11% to 59% for different aphid species and wheat classes when all wheat plants were infested at the same stage. Cultivars within wheat classes responded similarly to each of the aphid species. None of the wheat cultivars showed agriculturally effective levels of antibiosis. The specific impact of each aphid species and wheat class varied from 5 to 15 mg of plant biomass lost for each milligram of biomass gained by the aphids. Canadian Western Red Spring wheat had a lower specific impact and therefore was more tolerant to aphids than the other two classes, but not tolerant enough to avoid economic damage at the aphid densities observed. Plants did not compensate for feeding damage after aphid feeding ceased, based on the higher specific impacts observed for mature plants than for plants that were heading. The interactions between aphids and plants show that current economic thresholds probably underestimate the damage caused by cereal aphids to Canadian spring wheat.

The fungus Fusarium circinatum Nirenberg and O’Donnell (Hypocreaceae) causes pitch canker, a disease affecting pines worldwide. In California, many native insect species have been implicated in transmission of F. circinatum. This study showed that two twig beetle species, Pityophthorus setosus Blackman and Pityophthorus carmeli Swaine (Coleoptera: Curculionidae: Corthylini), can make wounds on healthy Monterey pine (Pinus radiata D. Don (Pinaceae)) branches that are suitable for infection by the pitch canker pathogen. Because these two species are not known to engage in maturation feeding and the observed wounds were not associated with tunneling, we hypothesize that the wounds reflect “exploratory tasting” to assess the suitability of the substrate for colonization. This behavior would help to explain how twig beetles can serve as wounding agents on healthy host branches, which are not amenable to colonization by these insects. We tested two specific hypotheses: (1) two native species of Pityophthorus can create wounds on F. circinatum-contaminated trees that are sufficient for development of disease; and (2) the efficiency with which F. circinatum infects beetle wounds is affected by relative humidity. Under growth-chamber conditions, both Pityophthorus species indulged in exploratory behavior that caused wounds suitable for development of pitch canker. Field experiments did not confirm a significant effect of beetle activity on infection frequency, perhaps because of an overall low infection rate due to low temperatures. Experiments conducted under controlled conditions documented a significant effect of relative humidity on the success rate of twig beetle-initiated infections.

Amber coloration, called saffroning, extends from 1 to 15 mm across the hind-wing base in females of Sympetrum internum Montgomery from the prairie provinces but extends only from 2 to 3 mm in males. There are no substantial differences in hind-wing length between the sexes. A significant correlation was found between hind-wing length and the extent of saffroning for both males and females. Regressions of these characters against latitude and longitude revealed that (1) there is a significant decrease in hind-wing length northward for both sexes; (2) there is a significant decrease in saffroning northward that is more significant for females; (3) there is no significant effect of longitude on hind-wing length; and (4) saffroning in females significantly increases westward but there is no similar effect in males, and the trend in females is much less significant than the latitudinal trend. Within the prairie provinces, extensive saffroning is confined to the Prairie Ecozone and moderate saffroning occurs around the edges of this ecozone. The surrounding Boreal Plains Ecozone is characterized by females with very limited saffroning. There is generally extensive variation in the extent of saffroning within some Prairie Ecozone locations, ranging from limited to moderate or extensive, but limited and moderate saffroning were more frequent at most locations in the Prairie Ecozone. Various explanations for saffroning are considered. Since limited, moderate, and extensive saffroning occur together throughout an extensive area, and occur within many populations and within a group emerging at the same time, formal taxonomic recognition of individuals with moderate or extensive saffroning seems unwarranted.

This study examined the effects of indoor fumigation with formic acid on survival of honey bee, Apis mellifera L. (Hymenoptera: Apidae), queens and varroa mites (Varroa destructor Anderson and Trueman (Acari: Varroidae)). A relationship between cumulative formic acid concentration and varroa mite mortality was established for colonies subjected to high-concentration fumigation while held indoors at 2–4 °C during winter. We also examined the effects of the formic acid release pattern and room ventilation rate on queen loss and treatment efficacy during fumigation. Two experiments were conducted in a wintering building. In both experiments, room air had higher formic acid concentrations than hive air. In experiment 1, 50% and 95% of mites were killed when exposed to in-hive concentration × time combinations of 49 ppm × days (CT50 product) and 111 ppm × days (CT95 product), respectively. No queen loss was observed under either the increasing-concentration or constant high concentration fumigation pattern. In experiment 2, 33% of queens were lost when minimum ventilation was used with room air concentrations of 57 ± 8 ppm (mean ± SE), whereas no queens were lost in controls or colonies exposed to room air concentrations of 27 ± 8 ppm with variable ventilation. Queen loss was associated with peak in-hive formic acid concentrations >20 ppm, but not with CT product, suggesting that queens are affected by acute rather than chronic exposure to formic acid. Formic acid fumigation significantly reduced the mean abundance of mites under both minimum- and variable-ventilation treatments.

Megaplatypus mutatus (= Platypus mutatus) (Chapuis), an ambrosia beetle (Coleoptera: Platypodidae) native to South America, is a forest pest that attacks live standing trees, affecting commercial poplar and other broadleaf plantations. Traditionally, single-chambered emergence traps have been used to collect live beetles for field and laboratory studies. However, the lack of separation in these chambers results in antagonistic interactions between individuals. Wounded M. mutatus are incapable of successful reproduction and are of little value in physiological and behavioral experiments. We introduce a new, multiple-chambered trap that isolates individual insects until collection, thus increasing the number of uninjured and fully functional insects available for physiological and behavioral experiments.