This paper is a tribute to Dr. R.A. Ring upon his retirement. During the past 12 years (1993–2005), an emerging canopy research program has established a wealth of baseline information on the structure and functioning of temperate rain forest canopy arthropod communities. Studies from research sites on Vancouver Island, British Columbia, have shown that ancient temperate rain forest canopy ecosystems contain a largely undescribed fauna that is specific to habitat features found only in these canopies. In particular, diverse assemblages of free-living mites have been shown to dominate conifer species and canopy microhabitats. For example, oribatid mites are the dominant arthropod fauna on branches, branches with attached lichens, and suspended soil accumulations. Species composition differs significantly between the ground and the canopy at both the family and the species level. Arboreal specificity may be due to intrinsic variation in habitat quality, habitat architecture, patchiness, and (or) resource availability. The prevalent patterns of habitat specialization, low vagility, and restricted distribution displayed by a large percentage of the resident canopy microarthropods are features often associated with forest ecoregions that have enjoyed relatively stable conditions for long periods of time, as have the ancient forests on Vancouver Island. Investigators in the “one-Ring lab” continue to document the diversity and abundance of canopy arthropods of temperate forests in British Columbia. In particular, studies are concerned with defining the organizing principles that elicit community patterns associated with the various levels of complexity in arboreal communities. Our long-term goal is to provide a greater degree of predictability when addressing temperate forest diversity issues. To meet the stated goals of sustainable forest management and retention of biodiversity, an extensive plan of ecological research that features arthropods is needed. This plan, fostered by Dr. Ring, should have as a priority the inventory and cataloguing of species assemblages and should address dynamic processes such as organismal dispersal and the effects of habitat loss and fragmentation on arthropods in ancient forests.

The effect of certain monounsaturated dodecene and tetradecene acetates and alcohols on electroantennogram (EAG) response and pheromone-mediated trap catch was examined in male obliquebanded leafroller moths, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae). The stimulation of antennae with 0.1 ng of (Z)-11-tetradecenyl acetate (Z11-14:Ac), the major pheromone compound of this species, elicited an EAG response. The use of 1 ng of (Z)-9-tetradecenyl acetate (Z9-14:Ac) or (E)-9-tetradecenyl acetate (E9-14:Ac) or 10 ng of (Z)-9-dodecenyl acetate (Z9-12:Ac) or (E)-9-dodecenyl acetate (E9-12:Ac) was required to elicit a response. One hundred nanograms of (E)-9-tetradecenol (E9-14:OH) were required to elicit a response from antennae. The stimulation of antennae with up to 100 ng of (Z)-9-tetradecenol (Z9-14:OH) did not elicit a response. The addition of 0.1 mg of Z9-12:Ac to 1 mg of synthetic C. rosaceana pheromone consisting of a 100:2:1.5:1 blend of Z11-14:Ac, (E)-11-tetradecenyl acetate, (Z)-11-tetradecenol, and (Z)-11-tetradecenal reduced the capture of moths in pheromone-baited traps by more than 72%. Trap catch was reduced by more than 90% by the addition of 0.01 mg of Z9-14:Ac or E9-14:Ac to 1 mg of C. rosaceana pheromone. There was no detectable reduction in trap catch when 1 mg of E9-12:Ac, Z9-14:OH, or E9-14:OH was added to 1 mg of C. rosaceana pheromone. There was a greater than 95% reduction in trap catch when sources of Z9- or E9-12:Ac were mounted at the entrances to traps, 10 cm from the pheromone source. Trap catch was not affected by placing sources of Z9- or E9-14:Ac at trap entrances. Four 1 or 10 mg sources of E9-14:Ac placed 1 m from a trap did not affect the number of male C. rosaceana captured. The study demonstrates that although a compound may have profound attraction inhibiting activity when mixed directly with C. rosaceana pheromone, this activity may be lost if the inhibitor is emitted a short distance from the pheromone. The study also demonstrates that a potent attraction inhibitor such as E9-14:Ac does not repel C. rosaceana males and must be present along with pheromone to affect the behavior of this species.

Cast exuviae from final-instar larvae of four species of hymenopterous parasitoids of Dendroctonus rufipennis (Kirby, 1837) were examined for diagnostic characters. The head capsules of Bracon tenuis Muesebeck and Walkley, 1951, Coeloides rufovariegatus (Provancher, 1880), Roptrocerus xylophagorum (Ratzeburg, 1844), and Dinotiscus dendroctoni (Ashmead, 1894) each displayed unique combinations of characters allowing discrimination among species. Head capsules are illustrated, and a key to species is presented.

Morphological, biological, and distributional data are presented for the four Canadian species of Mantispidae. A key for the identification of these species is provided. Climaciella brunnea (Say) is the most frequently collected Canadian species, occurring in southern British Columbia, Alberta, Manitoba, Ontario, and Quebec. Dicromantispa interrupta (Say) comb. nov. is given as a new combination for Mantispa interrupta Say; it is recorded in southern Ontario and Quebec. Dicromantispa sayi (Banks) occurs only in extreme southwestern Ontario. Leptomantispa pulchella (Banks) inhabits the dry Okanagan Valley of British Columbia; it is also known from Ojibway Prairie, Windsor, Ontario. The presence of the latter two species in Canada is published for the first time.

Male and female adult wasps belonging to the atomus group of the genus Anagrus Haliday, classified according to morphological techniques, were analyzed for their cuticular hydrocarbons to detect any possible differences between species. Most female specimens that were identified as either A. atomus L. or A. ustulatus Haliday, using morphological and morphometrical characters, showed two distinct cuticular hydrocarbon profiles. These profiles seemed to be independent of the plants the insects were collected from, the potential leafhopper host species (Hemiptera: Cicadellidae), and the emergence period, and they were largely consistent with classification based on morphology. Both A. atomus and A. ustulatus females were shown to emerge from leafhopper eggs found on Vitis vinifera L. (Vitaceae). Males, for which conclusive diagnostic characters are not yet available, showed the same two cuticular hydrocarbon patterns observed in females; on average, specimens displaying one hydrocarbon profile differed from those showing the other profile in three characters used for morphometrical analysis.

Stem galls induced by the cynipid Diplolepis triforma Shorthouse and Ritchie are frequently inhabited by several species of parasitic chalcids and ichneumonids that consume inducers or other parasitoids. Two of these parasitoids, the eurytomid Eurytoma spongiosa Bugbee and the torymid Glyphomerus stigma (Fabr.), consume gall tissues after they have consumed their insect hosts and are considered entomophytophagous. Both are koinobiont ectoparasitoids. Eurytoma spongiosa oviposits within gall chambers and attacks larvae of the inducer throughout the summer season, from the early growth phase of the galls until the galls mature. If the inducer is killed by E. spongiosa in early summer, nutritive gall cells degenerate into vacuolate parenchyma and are consumed. If the inducer is killed later in the summer, when galls begin to mature, nutritive cells persist in the chambers for about 1 week before degenerating. Glyphomerus stigma kills and consumes inducer larvae when galls are maturing. New nutritive cells appear under the influence of G. stigma and are then consumed. The ability of entomophytophagous chalcids to promote the formation of gall cells provides insight into the derivation of the gall-inducing guild.

In British Columbia, native willows (Salix spp.) (Salicaceae) and, to a lesser extent, black cottonwood (Populus trichocarpa Torr. & Gray) (Salicaceae) are frequently attacked by the poplar and willow borer, Cryptorhynchus lapathi (L.) (Coleoptera: Curculionidae). Red alder (Alnus rubra Bong.) (Betulaceae), trembling aspen (Populus tremuloides Michx.), and bigleaf maple (Acer macrophyllum Pursh) (Aceraceae) are not attacked. We studied olfaction and feeding preferences in the laboratory and feeding, oviposition, and emergence in the field. Female C. lapathi preferred Scouler's willow (Salix scouleriana Barratt ex Hook.) over all other species by olfaction, but males did not discriminate between Scouler's willow and black cottonwood or trembling aspen. All species elicited at least some attraction in no-choice situations. Willow was generally preferred for feeding, but black cottonwood and red alder were also acceptable, unlike trembling aspen or bigleaf maple. In field caging experiments, adult weevils emerged from willow, black cottonwood, and red alder. We conclude that olfaction and feeding preferences are sufficiently powerful to mediate the frequent attack observed on native willows, the intermediate levels of attack on cottonwood, and the absence of attack on red alder. Successful development on red alder suggests that C. lapathi could expand its host range to include this species.

During a survey of frog-biting corethrellid midges in Costa Rica, we collected 79 female Uranotaenia lowii Theobald, mosquitoes known to bite frogs, from seven lowland localities using the recorded calls of a frog. The calls of male barking tree frogs, Hyla gratiosa LeConte, were repeated about once per second, lasted about 0.15 s, and had a fundamental frequency near 450 Hz. We suggest that this frequency is within the range of acoustic sensitivity of the female mosquito antennae. Males of several families of Nematocera use sound to detect flying females of their own species, but we believe ours is the first observation of female mosquitoes being attracted by the sound of a host.

We examined capture rates of honey bee workers (Apis mellifera L.) throughout the year and compared capture rates among four different vegetation communities. Capture rates varied throughout the year, with the largest number of bees collected from December through February, when nectar and pollen availability were low. Capture rates also varied among vegetation communities. Traps located in the woodland community contained fewer honey bees than those located in live oak in February and live oak and brushland in December, corresponding to lower estimates of nectar availability in the woodland. Few honey bees were collected during swarming periods, suggesting that most of the captured honey bees were searching for food sources. The number of honey bees collected in the traps provided a qualitative estimate of food resource availability. The traps also may be used to collect insects for genetic analysis or to examine the spatial and temporal distribution of other species.

In flight-tunnel assays in both clean and pheromone-permeated air, we compared attraction and behavioural responses of male Pandemis limitata (Robinson) to “calling” females, female pheromone gland extract (FGE), and synthetic sources of pheromone. In clean air, female-baited traps caught significantly more males than traps baited with rubber septa lures loaded with 10 or 100 µg of the known pheromone components ((Z)-11-tetradecenyl acetate (Z11-14:Ac) and (Z)-9-tetradecenyl acetate) blended in a 91:9 or 94:6 ratio. Traps baited with septa loaded with 500 µg of the 94:6 blend caught as many males as did female-baited traps. Proportions of males engaging in wing fanning, take-off flight, locking onto the plume, and upwind flight towards a rubber septum loaded with 100 or 500 µg of the 94:6 blend were not significantly different from proportions exhibiting these behaviours in response to calling females. Only 500 µg lures elicited as much source contact in the same time as did a calling female. In clean air, traps baited with FGE applied to filter paper at 5 or 10 female equivalents caught as many males as did calling females. In air treated with Z11-14:Ac applied as a pheromone disruptant, females attracted more males and did so sooner than did five equivalents of FGE on filter paper. Consequently, disruption of male orientation to calling females was significantly shorter (74 h) than disruption of orientation to FGE (146 h). However, FGE dispensed from a piezoelectric microsprayer at a rate equivalent to 50 pg of Z11-14:Ac·min–1 caught as many males as a calling female. At this delivery rate, two-choice microsprayer bioassays revealed that FGE containing the two known components at a 91:9 ratio was more attractive than a synthetic blend of these two pheromone components alone at the same ratio. In air permeated with Z11-14:Ac, disruption of orientation to this FGE lasted 74 h, equivalent to disruption of orientation to females. These results suggest the published two-component pheromone blend for P. limitata is likely incomplete, and in the absence of suitable synthetic attractants, we recommend use of calling females or FGE delivered using a microsprayer system for any laboratory examination of communication disruption in this species.

The objective of this study was to assess the similarities and differences between selected bioindicator groups within tallgrass prairie and adjacent aspen forest. Based on pitfall trapping from 1998 to 2000, species richness and abundance of ground beetles and spiders were examined across a tallgrass prairie – aspen forest ecotone located near Winnipeg, Manitoba. The abundance of spiders and ground beetles was higher in the forested portion of the transect than in the prairie section. There were 639 specimens of ground beetles collected, representing 53 species; 19 species were found only on the prairie, 19 species were found only in the forest, and 15 species were found in both habitats, although the abundance of most species was too low to confidently assign them to either habitat type. Excluding single records in any sampling year yielded 9 prairie species, 5 forest species, and 10 species found in both aspen forest and tallgrass prairie. The five most abundant species of ground beetles were Agonum placidum (Say), Pterostichus caudicalis (Say), P. femoralis (Kirby), P. melanarius (Illiger), and Synuchus impunctatus (Say). There were 4499 specimens of spiders collected, representing 92 species; 25 species were found only in the prairie, 15 species were unique to the aspen forest, and 52 species were found in both habitats. Excluding single records in any sampling year yielded 26 prairie species, 15 forest species, and 22 species found in both habitats. The five most abundant species of spiders were Pardosa moesta Banks, P. distincta (Blackwall), Agroeca ornata Banks, Centromerus sylvaticus (Blackwall), and Alopecosa aculeata (Clerck). Our study concurs with other studies in demonstrating that there are distinct assemblages of both groups of predators in each of the two habitat types.

We found larvae of Chylizasplendida Iwasa (Diptera: Psilidae) feeding on galls induced by Asphondyliabaca Monzen (Diptera: Cecidomyiidae) on the buds of Weigelafloribunda (Sieb. & Zucc.) K. Koch (Caprifoliaceae) in Japan. This is the first confirmed report of cecidophagy in the Psilidae.

Protein-rich pea flour is an antifeedant and a repellent and is toxic to the rice weevil, Sitophilus oryzae (L.), but its mode of action is not known. Results showed that protein-rich pea flour had no fumigant effect on adult survival or offspring production of S. oryzae. In a contact experiment, immobilized weevils were fed every other day and had their abdomens brushed with protein-rich pea flour or wheat flour on the alternate days. Insects treated with protein-rich pea flour had an average longevity of 9.6 days, which was significantly shorter than that for insects treated with wheat flour (11.3 days) or brushed controls (17.6 days). These results suggest that toxins from the protein-rich pea flour may be able to penetrate the insect cuticle. Midguts from weevils fed protein-rich pea flour, a pea flour extract, or a mixture of pea peptides contained numerous bubbles. Midgut tissues in these treated adults were injured, as shown by dual staining with the fluorescent dyes calcein AM and propidium iodide. The volume of the bubbles increased rapidly when insects were fed protein-rich pea flour or pea flour extract. There were no bubbles found in the midguts of S. oryzae that fed on wheat kernels or wheat flour.

Variation in leaf quality includes differences in both primary nutrients and secondary metabolites. Both of these factors can influence the feeding preference and resulting performance of herbivores in ways that are difficult to disentangle when comparing foliage from different sources. Our study was designed to assess the effects of the ratio of the primary nutrients in host-tree foliage, protein and sugar, on the performance and feeding behaviour of the forest tent caterpillar (Malacosoma disstria Hübner (Lepidoptera: Lasiocampidae)). Fourth-stadium larvae were fed trembling aspen leaves (Populus tremuloides Michx (Salicaceae)) supplemented with casein, sucrose, or buffer only (control). No differences in taste responses to the three leaf types were detected. In a cafeteria situation, feeding behaviour over the short term was largely determined by the use of pheromone trails and hence depended on which leaf was contacted first. Over the longer term, caterpillars fed most on the control leaf and the sugar-supplemented leaf and discriminated against the protein-supplemented leaf. Sugar supplementation increased survivorship relative to the control treatment but slowed development and did not affect growth; protein supplementation decreased growth. These findings are consistent with past research comparing forest tent caterpillar performance and feeding preference on different host plants.

Sexual conflict may drive the evolutionary elaboration of sexually antagonistic traits that function in mating interactions. One of the most striking cases of elaboration of male morphology occurs in the water strider genus Rheumatobates Bergroth (Hemiptera: Gerridae). The functional significance of the bizarre modifications of appendages in this group is not known. Here we focus on one of the more elaborate of the species, R. rileyi Bergroth. We conduct observational and experimental studies aimed at determining the general sequence of mating behaviour, the role of females in the outcome of sexual interactions, and the functional significance of the highly modified appendages of males. We also map these traits on a known phylogeny of the genus to determine their pattern of evolution. Males repeatedly harass females and females respond with evasive skating or, if the male successfully grasps her, with a premating struggle. The dynamics of the struggle determine the success of mating attempts. Short struggles typically lead to mating, and long struggles typically result in disengagement of the pair. Following a short period of copulation, males withdraw their genitalia and dismount. Females that have been isolated from males for a period of time become less reluctant to mate. During the premating struggle, the antennae of males are used to grasp the females around the head, and the rear legs are used to lift the females' rear legs off the water surface. Neither antennae nor rear legs are used during copulation, thus they are not used for copulatory courtship. Mapping of these traits on the phylogeny indicates multiple independent origins and a pattern of escalation (16 origins, 7 losses). We conclude that these bizarre traits of males are sexually antagonistic and have evolved repeatedly in the genus.

Fungus gnats (FG) (Diptera: Sciaridae: Bradysia spp.) are economically important pests of greenhouse flowers. Larvae feed on root tissue and transmit a variety of phytopathogens. Atheta coriaria (Kraatz) (Coleoptera: Staphylinidae) is a new biological control agent (BCA) for FG. To support its successful use by the greenhouse industry, its compatibility with current integrated pest management (IPM) programs used in floriculture was assessed. This included investigations of prey preference, possible detrimental interactions with other soil-dwelling BCAs, and the toxicity to A. coriaria of registered and novel insecticides. Atheta coriaria showed little preference among eggs of different pest species or between pest eggs and eggs of the intraguild predator Hypoaspis aculeifer (Canestrini) (Acari: Mesostigmata: Laelapidae). It preferred FG 1st-instar larvae to larvae and pupae of other soil-dwelling pests. The entomopathogenic nematode Steinernema feltiae (Filipjev) (Rhabditida: Steinernematidae) was compatible with A. coriaria, but H. aculeifer mites fed on A. coriaria larvae. Insect growth regulators with limited contact activity (e.g., diflubenzuron) were compatible with adult A. coriaria and had minimal effects on larvae compared with other insecticides. Atheta coriaria can be incorporated into an IPM program for FG if harsh insecticides are avoided, but interactions with predatory mites, as well as its effectiveness against other greenhouse pests when FG are present, require further investigation.

Field studies were conducted to determine the attractiveness of monoterpenes and pheromones to the white pine cone beetle, Conophthorus coniperda (Schwarz), the most destructive cone and seed pest of eastern white pine, Pinus strobus L. (Pinaceae). Limonene was identified as a new attractant that acts synergistically when added to the female-produced sex pheromone, pityol. Trap catches were higher with increasing release rates of S-(–)-limonene. The enantiomers of limonene showed equivalent efficacy on mean trap catch. (–)-β-Pinene was not attractive and may be repellent to both sexes, and (–)-α-pinene was shown to have no effect on female response when added to pityol or pityol + S-(–)-limonene. The pheromones trans-verbenol, trans-pinocarveol, and myrtenol were not attractive to C. coniperda.

The present study was undertaken to determine the influence of some major constituents of plant essential oils on the toxicity and fate of thymol, a phenolic monoterpene from garden thyme (Thymus vulgaris L.) (Lamiaceae), following topical administration to the cabbage looper, Trichoplusia ni (Hubner) (Lepidoptera: Noctuidae). Tested individually, trans-anethole (LD50 = 71.2 µg/larva) and methyl salicylate (93.6 µg/larva) were the most toxic, whereas phenylethyl propionate (555.8 µg/larva) and mineral oil (2279.3 µg/larva) were the least toxic. However, when coadministered, mineral oil was the most synergistic (synergy ratio, SR = 25). A proprietary blend of essential oils (A4 Blend) was strongly synergistic (SR = 9), as was trans-anethole (SR = 5), while the majority of the other compounds tested yielded SRs of 2–3. Based on experiments using tritiated thymol as a radiotracer, the fate of this plant toxin within 60 min of topical administration varied widely with the essential oil carrier. Some carriers facilitated rapid disappearance of thymol from the insects' integument and rapid appearance internally, whereas others prolonged the tenure of thymol on the integument and delayed entry into the insect. The highest internal levels of radioactivity were observed when phenylethyl propionate was the carrier (47% of the topical dose), the lowest when rosemary oil was the carrier (9%). The highest proportion of the dose was excreted when eugenol was the carrier (20% of the topical dose), the lowest when mineral oil was the carrier (4%). Overall, there are no apparent trends linking the fate of thymol in the different carrier oils to the synergies observed or to the relative polarities of the carriers.

This study consisted of two field experiments designed to assess the effects of acaricide treatment timing on the mean abundance of the mite Varroa destructor Anderson and Trueman and its impact on honey production and colony survival in honey bees, Apis mellifera L. (Hymenoptera: Apidae). In the first experiment, replicated colonies with different levels of infestation by V. destructor were given one of six treatments: untreated, with a low level of infestation by V. destructor; untreated, with a moderate level of infestation by V. destructor; exposed to fluvalinate for 42 days; exposed to two applications of Perizin®; or exposed to four applications of a pour-on formulation of formic acid at 4- or 10-day intervals. The six treatments were applied in either spring or fall. In experiment two, replicated colonies with a high level of infestation by V. destructor were left untreated, exposed to fluvalinate for 42 days, exposed to five applications of formic acid at 7-day intervals, or exposed to an equivalent amount of formic acid applied as a slow-release formulation. For each experiment, V. destructor densities, measured by alcohol wash, and colony survival were monitored for 1 year, and honey production was assessed in the year in which the spring treatment was applied. The results showed that all of the acaricide treatments were effective in reducing the mean abundance of V. destructor. However, efficacy varied with season. Fluvalinate was effective in controlling varroa under either spring or fall treatment conditions. Fall applications of Perizin® provided better control than spring applications. Formic acid provided consistent control of V. destructor in spring applications, regardless of the interval between treatments or whether pour-on or slow-release formulations were used, but was ineffective in the fall. Honey production was improved by spring acaricide treatments in both years. When the mean abundance of V. destructor was 0.02 ± 0.005 mites per bee (2 mites per 100 bees) in mid-April, honey production increased from 66 ± 17 kg per colony in untreated colonies to up to 116 ± 23 kg per colony in colonies treated with acaricide. When V. destructor levels were 0.21 ± 0.02 mites per bee (21 mites per 100 bees) in mid-May, spring acaricide treatments increased honey production from 1.3 ± 2.3 kg per untreated colony to up to 48 ± 17 kg per acaricide-treated colony. For the prairie region of Canada, producers will need to assess colonies in both spring and fall and treat when the mean abundance of V. destructor is more than 0.02 mites per bee (2 mites per 100 bees) in spring to prevent losses in honey production. Producers should treat when the mite level is greater than 0.04 mites per bee (4 mites per 100 bees) in late August to early September to prevent fall or winter colony loss. In this study, tracheal mite (Acarapis woodi (Rennie)) (Acari: Tarsonemidae) levels were very low, so interactions between mites were not studied. If both tracheal and varroa mites are present, lower fall thresholds might be required. In the absence of tracheal mites, colonies with varroa mite levels of more than 0.17 mites per bee (17 mites per 100 bees) in late fall experienced significant winter loss.