In laboratory colonies, 8 temperate Bombus Latreille species and the tropical montane species, B. ephippiatus Say, had significantly more first-brood workers, more rapid worker development time, and faster rates of worker production than the tropical lowland species, B. atratus Franklin. Bombus ephippiatus did not differ from most temperate species in any of the 3 characters. Differences in these bionomic characters among arctic, temperate, and tropical Bombus are assessed in terms of latitudinal trends.

Xylosandrus germanus (Blandford) (Coleoptera: Scolytidae) is an ambrosia beetle that occurs in Japan, Korea, the Kuril Islands, Vietnam, Taiwan, China, Central Europe, and the United States (Nobuchi 1981). Unlike most ambrosia beetles, it will attack apparently healthy trees and those that are dying or recently dead (Weber 1982). It has been associated with plants infected with pathogenic fungi, including black walnut (Juglans nigra L.) infected with species of Fusarium (Anderson and Hoffard 1978; Kessler 1974); reported symptoms include cankers, wilting and dieback, and sprouts. We found black walnut with wilting and dieback symptoms in southern Illinois in spring 1978 and central Tennessee in spring 1980. Subsequent examinations showed that X. germanus was present and apparently closely associated with the disease symptoms because of the number of diseased trees that also contained X. germanus pinholes. Therefore, we decided to study the relation between X. germanus attack and disease symptoms in black walnut.

The fir coneworm, Dioryctria abietivorella (Groté), is a transcontinental pest of coniferous seed cones. Recently, the attractive pheromone components and lure blend for the fir coneworm in western Canada were identified as a 200 µg : 2000 µg ratio of (9Z,11E)-tetradecadienyl acetate (9Z,11E-14:Ac) and a polyunsaturated hydrocarbon, (3Z,6Z,9Z,12Z,15Z)-pentacosapentaene (C25 pentaene). A potential third component, (Z)-9-tetradecenyl acetate (9Z-14:Ac), which was detected in pheromone gland extracts, had no effect on males of the western population when added to the binary blend. In contrast, in eastern Canada (Quebec) we found that the 200 µg : 2000 µg binary blend was unattractive to male fir coneworms until 9Z-14:Ac was added. By means of several field experiments we established that a 67 µg : 200 µg : 2000 µg ratio of 9Z-14:Ac, 9Z,11E-14:Ac, and the C25 pentaene was attractive to fir coneworms in Quebec. Gas chromatography - mass spectrometry analysis of pheromone gland extracts of fir coneworm from Quebec confirmed the presence of the three components in extracts in an approximately 1 µg : 4 µg : 10 µg ratio of 9Z-14:Ac, 9Z,11E-14:Ac, and the C25 pentaene. Our results provide evidence that the eastern and western populations of D. abietivorella are distinct geographic pheromone races, with 9Z-14:Ac being required for attracting males of the eastern population but not males of the western population.

The study of populations and population trends of a forest insect embraces a wide field of activity. By implication, it includes a consideration of all mortality and survival factors. Therefore, in developing this portion of the symposium, it will be necessary to refer briefly to other related topics to be covered later. In addition, to obtain a proper understanding of the subject under discussion, the mode of operation of some population influences that will not be introduced by other members of the symposium will have to be described.

The Nearctic Idiocerini exclusive of the fauna of the Sonoran subregion are reviewed. The 68 recognized species are assigned to three genera: Idiocerus Lewis, Rhytidodus Fieber, and Balcanocerus Maldonado-Capriles. Three subgenera of Idiocerus are recognized, including I. (Liocratus) Dub. and I. (Populicerus) Dlab. (n. stat). Sahlbergotettix Zvk., 1953, Viridicerus Dlab., 1974, Tremulicerus Dlab., 1974, and Acericerus Dlab., 1974 are synonymized with Idiocerus Lewis, 1834.

Sixteen new species of Idiocerus are described: aureus, carolina, cedrus, freytagi, gillettei, immaculatus, inebrius, iodes, lucidae, midas, pericallis, taiga, unicolor, vanduzeei, venosus, and xanthiops. I. varions n. n. is created for varias DeLong & Hershberger, 1947 (nec Germar, 1818). I. lunaris Ball (n. stat.), I. obsoletus (Wlk.) (n. stat.), and I. raphus Freytag (n. stat.) are recognized as valid species for the first time. Twelve other species are removed from synonymy. I. verrucosus Ball is placed as a subspecies of I. musteus Ball (n. stat.). Five new synonymies are created: alnirubratus Bliven, 1955 = I. couleanus Ball & Pkr., 1946; nigrens DeL. & Cld., 1937 = I. distinctus Gill & Bak., 1895; duzeei Prov., 1890 and vagus Ball, 1902 = obsoletus Walker, 1851; and apertus DeL & Hbr., 1947 = I. verticis (Say), 1831.

Additional characters of the male antennae, male abdominal apodemes, and female ovipositor are described and illustrated. The phylogeny and hosts of the members of Idiocerus are discussed. Keys are provided to the genera of the Nearctic Idiocerini, and to the species of Idiocerus of the Nearctic region, exclusive of the Sonoran subregion, for both sexes.

In 1989 and 1990, the contamination rate of the European pine weevil Hylobius abietis (L.) by several pathogenic fungi for the Scots pine was measured [Leptographium procerum (Kendrick) Wingf. — 45% of the specimens; Pachnodium canum (Upadh. and Kendr.) — 14%; or Ophiostoma piliferum (Fries) H. and P. Syd — 3% (Piou 1993)]. To understand the processes of transportation, a detailed study was conducted by scanning electron microscopy. Several types of spores vectored are found mainly in the thoracic cuticular rounded wells located near the sensorial setae. These wells are connected with an epidermal glandular apparatus whose ultrastructural description is given. We question the origin and composition of these secretions which are believed to protect the spores and contribute to the infection process.

These studies show that Orgilus obscurator-purasitized Rhyacionia buoliana larvae initially gain weight in a manner similar to unparasitized larvae, but eventually attain a much smaller maximum size and then slowly decrease in weight with time. This decrease in weight is caused by the feeding of O. obscurator. The rate of increase in weight by O. obscurator increases with time during the second to fourth instars and decreases slightly during the fifth instar. During the fourth and fifth stages, the weight of O. obscurator changes from an initially minute proportion of the combined host–parasite weight to a significantly large proportion, eventually attaining ca. 80% of the combined weight. The feeding and activity of parasitized hosts remain high and continue for ca. 1 week longer than that of unparasitized hosts, resulting in a higher potential for damage to the host tree. Moulting of host larvae seems not to be affected by the presence of O. obscurator, although parasitized larvae remain in a "juvenile" state and do not develop testes. The implications of the size relationships of O. obscurator with its host on the activity of another parasite, Hyssopus thymus are discussed, and it is noted that parasitized hosts, on the average, needed fewer moults to complete their post-winter development than unparasitized hosts. This phenomenon is related to synchrony of the adult parasite with its host, and to host behaviour.

Aspects of cold hardiness of Phytoseiulus persimilis Athias-Henriot and Amblyseius cucumeris (Oudemans) were compared. Mean supercooling points (SCPs) ranged from −19.4 to −27.1°C and increased during development from egg to adult. Feeding status, diapause, and low temperature acclimation had little or no effect on supercooling capacity. Temperature/mortality curves confirmed that both species, including A. cucumeris in diapause, are freezing intolerant in the sense that the SCP represents the absolute limit to low temperature survival. However, the mites survived exposure to −12.5°C for less than 90 min. The results suggest that the SCP is directly related to body mass in these mites and that their ability to supercool is primarily a physical characteristic rather than an adaptation for survival of exposure to subzero temperatures.

Attempts to develop artificial diets for the Colorado potato beetle, Leptinotarsa decemlineata (Say), have had limited success (Hsiao 1972; Krzymanska and Zwolinska-Sniatalowa 1980). Consequently, all available rearing methods require the use of fresh potato foliage (e.g., de Wilde 1957) and large greenhouse space over an extended period of time. We needed a rearing method that could produce batches of beetles < 1 week old and with synchronized emergence (± 3 days) from a small laboratory colony of < 100 pairs of adults. One method might have been to induce adult diapause and break it whenever sufficient numbers had accumulated for testing. Unfortunately, this method requires mature adults that have fed for 1–2 weeks. not her procedure used in rearing a number of insect species uses a period of low temperature storage. For example, 2nd instar Choristoneura fumiferana (Clem.) can be stored at 1°C for 4–8 months (Grisdale 1970). Wegorek (1959) suggested that the hatching of eggs of L. decemlineata could similarly be delayed by placing them at relatively low temperatures. Wegorek observed that the incubation period of the eggs in Poland could take < 8 days in warm weather but last as long as 19 days in periods of cool weather when the temperature fell below 15°C. The feasibility of using this temperature dependence for incubation in our rearing program was investigated.

Aggressive behavior of the western cherry fruit fly studied both under laboratory and field conditions indicates that males are extremely territorial, especially in the field, where they do not tolerate the presence of another fly on a cherry unless the invader is a mating partner. Under confined laboratory conditions, the sense of territoriality was markedly reduced. Aggressive behavior in this insect included a wing jerking display, head-on collision, and "boxing" (fight involving prothoracic legs).

Six species of Apanteles (Hymenoptera: Braconidae) that attack microlepidopterous larvae in growing tips of spruce and fir are described, figured, and keyed. They are: A. fumiferanae Vier., A. petrovae Walley, A. absonus Mues., A. renaulti n. sp., A. milleri n. sp., and A. morisi n. sp.

Detailed generic descriptions are given for all stages of Brillia Kieffer. Keys are presented to separate them from those of allied genera, Eurycnemus Wulp, Euryhapsis Oliver, and Xylotopus Oliver. The known stages of five Nearctic species, including one new species Brillia laculata, are described. Two species-groups, the flavifrons group and the modesta group, are defined.

Seventy-seven species of weevils are newly reported in New Brunswick, increasing the known provincial fauna to 206 species. Trichapion nigrum (Herbst), Ceutorhynchus semirufus LeConte, and Listronotus laramiensis (Angell) are recorded for the first time in Canada. Three species, Bagous planatus LeConte, Plocamus hispidulus LeConte, and Dryocoetes granicollis (LeConte), are removed from the province's faunal list. Components of the fauna are discussed with a particular focus on the introduced species found in the province. Monitoring to detect changes of both native and introduced species is emphasized.

The spatial distribution of the Egyptian alfalfa weevil larvae using Iwao’s index of dispersion was examined in a California alfalfa field. The changing dispersion patterns with time were found to be influenced by both density induced competition for food and varying spatial distribution of host plants. values characteristic for both years quickly stabilized. This made possible a method for estimating leaf consumption rates by larval populations with an aggregated distribution, k being derived from . Field sampling decision rules were also determined.

Wheat midge larvae, Sitodiplosis mosellana (Géhin), attack developing seeds and cause losses of common wheat, Triticum aestivum L., and durum wheat, Triticum durum Desf. (Olfert et al. 1985; Lamb et al. 1999). Insecticide applied as the crop flowers can reduce damage (Elliott 1988). The economic threshold varies from 4 to 7% of common wheat seeds infested by larvae, depending upon grade of wheat and cost of insecticidal control (Lamb et al. 2000). To make control decisions, farmers count adults at sunset during the period from heading to flowering (Elliott and Mann 1996), and apply insecticide if densities reach a nominal threshold of one adult per four or five wheat spikes (Anonymous 1993). Decisions must be made although no relationship has been detected between the number of adults in the crop and subsequent densities of damaging larvae (Oakley et al. 1998), and farmers have little confidence in their counts. The pest is difficult to sample because adults are small, short-lived, crepuscular, and are usually hidden in the crop canopy (Pivnick and Labbé 1993); eggs are microscopic (Mukerji et al. 1988); larvae feed inside florets (Lamb et al. 2000); and mature larvae and pupae are in the soil (Lamb et al. 1999). Sticky traps have been used to sample midges in sorghum (Merchant and Teetes 1992) and in wheat (Oakley et al. 1998), with mixed results. Our objective was to determine if catches of wheat midge adults on sticky traps can effectively guide farmers in making control decisions.

During a 2-year period, 47 species of spiders in 37 genera were taken in pitfall traps set within, or bordering a wheat field near Clavet, Saskatchewan. Species diversity and evenness were determined for the collections from both areas. Lycosids were predominant, both in the field and in the field borders. Seasonal distribution of captures of the two most common species, Arctosa emertoni Gertsch and Pardosa nebraska Chamberlin & Ivie, are given.

There are now two strains of the European corn borer, Ostrinia nubilalis (Hübner), in Quebec. The strain normally found produces one generation while the more recently introduced strain produces two generations per year. Both strains have been characterized and compared with corn borer strains from Ontario and New York State. The two attributes of the recently introduced strain that promote the development of a second generation are (1) early emergence in the spring with less intense diapause and (2) a lower critical photoperiod for diapause induction. The latter characteristic allows pupation of first generation larvae. Field and laboratory tests on the pheromone response of adult male moths demonstrated that the origin of this recent introduction was New York State.

Pheromone baited traps and trap trees attracted an aggregate of 29 scolytid species associated with white spruce in three localities in Alaska. Species diversity was higher in the Fairbanks (lat. 64°45′) area than in the Brooks Range (lat. 68°15′) or Kenai Peninsula (lat. 60°37′). Scolytids were found inhabiting all bark-producing areas of the tree from the roots to small branches with the highest density in the tree bole. The most abundant scolytids were Ips perturbatus (Eichhoff), Ips tridens tridens (Mannerheim), Polygraphus rufipennis (Kirby), Dryocoetes affaber (Mannerheim), Trypodendron lineatum (Olivier), and Scolytus piceae (Swaine).

Nymphs and adults of Gerris remigis Say were collected for 7 months from a stream with only this species of Gerridae. The colour markings of the nymphal stadia are described and illustrated. Measurements of antennal and hind limb segments are given and these can be used to distinguish successive instars.

Apple clearwing moth (ACM), Synanthedon myopaeformis (Borkhausen) (Lepidoptera: Sesiidae), is an invasive species and destructive pest of commercial apple trees in British Columbia (BC), Canada. Mass trapping with Concord grape juice and sex pheromone is being developed as an organic pest management tactic. We quantified the diversity and abundance of arthropod by-catch in these traps during the 2009 flight (13 June–31 July) of ACM. Paired traps were deployed in organic and conventionally managed apple orchards planted using different tree densities representing the extremes of the current BC apple industry. Using seasonal by-catch and community-level statistical analyses we determined that family communities of arthropods caught in juice-baited and pheromone-baited traps differed significantly. Yellow juice-baited traps caught a greater variety of arthropod families in greater abundance than pheromone-baited yellow Unitraps®. We show that for each trap type, family communities caught in organic versus conventional orchards were significantly different. Organic orchard management affected abundance of some beneficial taxa, but the sign of the difference depended on the taxon examined (e.g., ladybeetles increased versus lacewings declined). Tree density had no effect on by-catch. Managing ACM by mass trapping may be detrimental to ecosystem services because many nontarget beneficial species are caught. A balanced risk-to-benefit approach should be taken before this technology is widely implemented against ACM.