Concentration:response regressions were established for male and female Panonychus ulmi from dicofol resistant and susceptible laboratory colonies using a rapid assay technique which utilizes pesticide residues in enclosed Petri dishes. Modification of the technique, which was developed for females, allowed reproducible results with males. Males and females from the resistant population showed similar levels of resistance compared with the susceptible population (ca. 4-fold). Within populations, males were approximately 3-fold more sensitive than females. Implications of these differences for field populations and the usefulness of males in inheritance studies are discussed.

Leaves were collected between 28 July and 10 September from 36 (1986) and 85 (1987) apple orchards, and examined for mites. Twelve species of Phytoseiidae were found: Amblyseius fallacis (Garman), Typhlodromus longipilus Nesbitt, A. andersoni (Chant), T. caudiglans Schuster, T. pyri Scheuten, T. pomi (Parrott), Phytoseius macropilis (Banks), T. herbertae Chant, A. driggeri Specht, A. finlandicus (Oudemans), T. conspicuus (Garman), and A. pusillus (Kennett), in order of frequency. The stigmaeid mites Zetzellia mali (Ewing) and Agistemus fleschneri Summers, a complex of erythraeid mites of Balaustium spp. and Hauptmannia spp., and tydeid mites, primarily Tydeus spp., were other common predatory species. Species of Tetranychidae, Bdellidae, Eriophyidae, Winterschmidtiidae, and Tarsonemidae, also were collected.

Predatory mites were present each season in all abandoned orchards and in 43–74% of the commercial orchards. Their abundance in commercial orchards was compared with the use of insecticides applied only for control of the spotted tentiform leafminer, Phyllonorycter blancardella (Fabr.). Fewer (P < 0.05) phytoseiids occurred where pyrethroids were employed than in sites without pyrethroids, but differences were not found for similar use of the carbamoyl oxime, methomyl. Fewer (P < 0.05) stigmaeids occurred in sites treated with methomyl than in sites without methomyl, whereas such differences were not found for pyrethroid use.

The toxicity of the insecticides permethrin, azinphosmethyl, and methomyl to adult Pholetesor ornigis (Weed) and P. pedias Nixon was evaluated in laboratory bioassays. Older P. pedias (2 and 3 days old) were more susceptible than younger parasites (1 day old) to permethrin. Azinphosmethyl was slightly more toxic to female P. ornigis than to male P. ornigis or to P. pedias. There was no consistent difference in the response of adult P. ornigis compared with P. pedias exposed to permethrin or methomyl on treated paper disks. Methomyl was twice as toxic as either azinphosmethyl or permethrin. Male P. ornigis were less susceptible than female P. ornigis to permethrin, but the difference was significant in only one of four populations tested. Male P. ornigis were less susceptible than females to azinphosmethyl. In 1986, populations of P. ornigis which had been exposed previously to pyrethroid insecticides were less susceptible to permethrin than P. ornigis from orchards where pyrethroids had never been applied. The response of both Pholetesor spp. to permethrin varied significantly from 1986 to 1987.

Developmental rates of post-diapause eggs of Diabrotica virgifera virgifera LeConte were compared in the laboratory at six constant temperatures, 12, 16, 20, 24, 28, and 32°C. Linear and nonlinear models were fitted to temperature versus developmental data and were used to predict egg hatch in the field. A four-parameter model fitted to median developmental rates (r2 = 0.99) indicated that development was linear between 16 and 28°C, optimal at 28°C, and decreased at 32°C. The lower development threshold (± SE) (10.5 ± 0.1°C) was determined by linear regression and the x-intercept method. Completion of post-diapause egg development required 258 ± 3 degree-days (± SE) above the base temperature. This compared well with the mean degree-days accumulated to 50% hatch (± SE) of 265 ± 24 which we observed in the field at several locations over 3 years using a degree-day model incorporating an 11°C developmental threshold and soil temperatures at 5- and 10-cm depths. A stochastic simulation model, incorporating a nonlinear developmental function dependant on soil temperatures taken every 2 h also predicted 50% hatch within 2 days. This model was validated in the field with 19 independent records of soil temperatures for several locations at two depths in the soil over 3 years. The simulation model accurately predicted time of 5 and 95% hatch, which indicates that this model has broad application in predicting the pattern of egg hatch for pest management.

An improved method for rearing horn flies, Haematobia irritans irritans (L.), on bovine hosts is reported in which adult flies were confined in cages fastened to the backs of stanchioned cattle. Survival of females was 75% per day and longevity averaged 3.5 days. Oviposition began when females were 2 days old. The number of eggs produced per female entering the population averaged 20.1, and a single female could produce up to 112 eggs in her lifetime. Immature survival averaged 48.9%. The generation growth rate was 4.91 females per female. Generation time was 20 days at 25°C. Approximately 1–3.8 g of manure per egg is recommended for larval rearing. Pupae can be stored at 10°C for up to 18 days with little loss in viability. Methods for using the life history information for optimizing rearing are discussed.

Moths of the genus Pseudexentera are early-season fliers that include three species of economic importance: P. spoliana (Clemens) on oak (Quercus), P. oregonana (Walsingham) on aspen (Populus), and P. mali Freeman on apple (Malus). GC and GC/MS analysis, EAG and behavioral bioassays, and field tests confirmed that Z10-16:Ac is an attractive sex pheromone component of female P. spoliana. Capillary GC analysis supported by GC/MS also indicated the presence of 16:Ac, Z10-16:OH, and 16:OH in pheromone extracts and there was tentative GC evidence for Z12-16:Ac. However, addition of these compounds to Z10-16:Ac in various blends did not enhance male attraction. The major sex pheromone component of female P. oregonana is Z8-14:Ac. There was also GC and GC/MS evidence for Z8-14:OH and tentative GC evidence for 14:Ac in the pheromone of this species. Their addition to Z8-14:Ac failed to increase moth catches in baited traps. Pseudexentera mali males were attracted by Z,Z-8,10-16:Ac, a previously reported sex pheromone of this species. Pheromone lures targeted for each species were not cross-attractive.

The within-cone distribution of Megastigmus spermotrophus Wachtl (Hymenoptera: Torymidae), the Douglas-fir seed chalcid, infesting Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] cones from north-central France was compared with that in samples from California. Results indicate that the mid-region of cones was more intensively utilized by seed chalcids in France than in California, whereas in the northwestern United States the mid-region is characteristically occupied by dipteran and lepidopteran species. This difference in distribution may explain the large discrepancy in infestation rates on the two continents. The potential impact of this finding on pest management strategies is discussed.

Cones were measured and dissected or X-rayed to determine seed chalcid infestation levels. Analysis of covariance performed on data from cones that were collected in 1986 and dissected showed cone diameter at maturity to be a highly significant factor in attack rate, although slopes were different among clones. Between-tree variation was also significant, but clonal source was not. Cone diameter, clonal source, and between-tree variation constituted 87.1% of the variation in rate of attack by the seed chalcid. Although clone was not a significant factor in data from dissected cones, X-rayed cones showed significant differences in attack rates for some clones.

Conspecific host discrimination and larval competition in two aphid parasitoid species were studied in the laboratory using the pea aphid, Acyrthosiphon pisum (Harris) (Homoptera: Aphididae), as a host. Aphidius ervi Haliday (Hymenoptera: Aphidiidae) used internal host cues to discriminate between unparasitized and conspecific parasitized hosts. When only parasitized hosts were available, females oviposited into recently parasitized ones where their progeny had a good chance to survive, but rejected those parasitized ≥24 h earlier where their offspring normally died. Competitions occurred only after both eggs had hatched. Larvae eliminated supernumeraries by means of physical combat and physiological suppression. In Aphelinus asychis Walker (Hymenoptera: Aphelinidae), factors, or changes in host internal condition, associated with hatching of the first egg resulted in suppression of conspecific competitors which could be in either larval or egg stage. The older larvae always won competitions through physiological means. A wasp’s oviposition decision is shown to be influenced by the probability of its progeny’s survival. Species that have different reproductive strategies may respond differently to identical host conditions.

North American species of Agabus Leach of the elongatus-, zetterstedti-, and confinis-groups, as defined by Larson (1989), are revised. Study of character state distribution indicates that the elongatus- and zetterstedti-groups are clades within the confinis-group but the names are retained in this paper to maintain consistency. Twenty species belonging to this complex occur in North America, namely: elongatus-group with A. elongatus Gyllenhal and A. inexspectatus Nilsson; zetterstedti-group with A. zetterstedti Thomson; and the confinis-group with A. thomsoni (J. Sahlberg), A. moestus (Curtis), A. clypealis (Thomson), A. phaeopterus (Kirby), A. immaturus sp.nov. (Great Lakes and Maritime Provinces regions), A. canadensis Fall, A. audeni Wallis, A. mackenziensis sp.nov. (northwestern Canada), A. bicolor (Kirby), A. subfuscatus Sharp, A. discolor (Harris), A. approximate Fall, A. kootenai sp.nov. (southwestern Canada and northwestern United States), A. inscriptus (Crotch), A. smithi Brown, A. sasquatch sp.nov. (alpine areas of California and Nevada), and A. confinis (Gyllenhal). For each species the following information is provided: synonymy; description and illustration of taxonomically useful characters; notes on relationships, variation, distribution, and ecology; and a map of North American collection localities. A key to the North American species of the confinis-group is presented. Lectotypes are designated for A. subfuscatus Sharp, Gaurodytes inscriptus Crotch, G. ovoideus Crotch, and G. longulus LeConte.

Mistblower applications of permethrin at 70 g AI per hectare to individual white spruce trees near the onset of the hatching period reduced spruce budmoth, Zeiraphera canadensis Mut. and Free., larval populations by 90% and damage to leaders to a very acceptable index of 0.49. A dosage of 35 g AI per hectare was less effective but did provide acceptable leader protection (damage index: 0.93). Further mistblower trials, designed to determine the optimum time to spray with permethrin, demonstrated that at 70 g AI per hectare, effective control (87–94%) and acceptable protection (damage indices: 0.87–1.13) were obtained during a 9-day period before the onset of hatch. An earlier treatment. 11 days before hatch, did not provide as effective control (58%) or acceptable protection (damage index: 1.60). Two later treatments, 3 and 4 days after the onset of hatch, gave less effective control (75–79%) but did provide acceptable leader protection (indices: 0.83–1.17).

Comparisons of selected biological attributes were made to establish a phylogenetic basis for the classification of the Cicindela splendida Hentz group taxa. Recognized members of the group, C. splendida, C. limbalis Klug, and C. denverensis Casey, are spring-fall species, and northern populations emerge later during spring than southern populations. Despite differences in time of peak abundance, the three species overlap in time and space. The absence of large numbers of hybrids of these three species suggests that although closely related, their adults can distinguish from each other, and thus their rank as species should be retained.

Comparison of geographical distribution of these species with that of dominant soil types revealed that they had similar soil preferences. The geographical distribution of all three species was smaller than the range of their preferred soil types, probably because of the same factors that influence their local distributions.

Morphometric analyses of these species revealed a closer similarity between C. splendida and C. limbalis. In both sexes elytral pattern, percentage maculation, elytral colour, and non-sensory setae number collectively distinguish these species from each other, whereas body measurements, body ratios, sensory setae, and labral setae collectively fail to distinguish them.

Based on plesiomorph/apomorph character polarization, and the C. purpurea Olivier group as outgroup, it was determined that C. denverensis represents an early lineage of the C. splendida group, whereas C. splendida and C. limbalis are more recent sister species.

The ancestor of the C. splendida group probably evolved during late stages of the Tertiary Period as a North American resident and was a continental, riparian, cool-temperate form that ranged across Canada and northeastern and central United States. Extant forms speciated during the late Pleistocene as a result of spatial fragmentation of populations, isolation, and adaptation during glacial and interglacial periods.

Ips mexicanus (Hopkins) and I. paraconfusus Lanier can transmit a frugal pathogen that causes pitch canker [Fusarium subglutinans (Wollenw, and Reink.) Nelson, Toussoun, andMarasas], a disease recently identified in Monterey pines (Pirns radiata D. Don) in California. In Santa Cruz County, F. subglutinans was recovered from Ips spp. that emerged from pitch canker-in fee ted P. radiata and were captured in multiple-funnel traps baited with racemic Ips spp. pheromones. Ips paraconfusus adults experimentally contaminated with propagules of the fungus transmitted it to seedlings and mature pines. Field transmission was demonstrated when cankers were produced following pheromone-induced beetle attacks on pines. Ips spp. inoculated F. subglutinans into pine slash, thus creating reservoirs of this fungus. Larvae, pupae, and young adults acquired the fungus when their parents introduced it into logs. Ips spp. progeny production and development were not significantly altered by the fungus. In proximity to other bark beetle-associated fungi, growth of F. subglutinans was reduced and patchy. A new association may be developing among native Ips spp. and F. subglutinans.

Beginning 1 year after an intense forest fire in the Interlace region of Manitoba, carabid beetles were sampled by pitfall trapping in two burned sites and two unburned control sites. Before the tire, one burned site had been dominated by aspen, Populus tremuloides Michx,, and the other by conifers (mostly Picea spp.). During the 11-year study, burned sites became dominated by aspen saplings. Three carabid species were caught significantly more frequently in burned sites than in control sites. Two of these, Harpalus laticeps LeConte and H. egregius Casey, invaded soon after the fire and were caught in the burned sites for several years after the fire. Seventeen species were caught significantly less often in burned than in control sites; catches of another 13 common species were not significantly affected by burning of the site. Burning influenced the seasonal patterns of catches of Carabus taedatus F. and Pterostichus adstrictus Eschscholtz; this was attributed to higher litter and soil temperatures in burned sites. Seasonal patterns of other common species were not markedly affected by burning. In burned sites, the incidence of brachypterous species and the size of beetles increased with time after the fire. In control sites, the incidence of brachyptery was independent of time, but the percentage of brachypterous species was significantly higher in the conifer site than in the aspen site. Trends of brachyptery and size are those expected if early colonizers are super-tramp r-strategists and later invaders are K-strategists. Patterns of species occurrence during forest regeneration can be explained in terms of dispersal and competitive abilities, preference for physical attributes of the habitat, and responses to prey availability.

Z8-tetradecenyl acetate (Z8-14OAc andZ8-tetradecenyl alcohol (Z8-14OH) were identified as sex pheromone components of the eyespotted bud moth, Spilonota ocellana (Denis and Schiffermüller) (Lepidoptera: Olethreutidae). Compounds were identified by gas chrornatographic-eleclroantennographic (GC-EAD) and GC-mass spectroscopic analyses and field tested in apple orchards in the Okanagan Valley, B.C. Although Z8-14OAc alone was attractive to male S. ocellana, the addition of 1–5% Z8-14OH strongly synergized its attraction. Field tests comparing the attractiveness of virgin female S. ocellana with various doses of a 99:1 blend of Z8-14OAc and Z8-14OH indicated the natural sex pheromone has only two significant components. A 99:1 blend of Z8-14OAC and Z8-14OH is suggested for monitoring and control of S. ocellana populations in British Columbia.

Seventeen species of the genus Otiorhynchus are known to occur in North America (including Greenland) (O'Brien and Wibmer 1982; Wibmer and O'Brien 1989). Warner and Negley (1976) provide a key to 16 species (not including O. monticola Germar, since recorded from Greenland) and provide information on distribution and natural history. All species occurring on mainland North America are known to be introduced. Whereas some of the species have broad distributions in North America, for example O. ovatus (L.), others are known from only a few adjacent localities. Species such as O. singularis (L.) and O. sulcatus (F.) are found in both western and eastern North America but not in intervening areas. Such distributions likely represent separate introductions.