The species of plant on which larvae of Mamestra configurata (Wlk.) fed had significant effects on the rate of larval development, larval and pupal survival, pupal weight, the percentage of females that mated, and the number of fertile eggs/mated female. Among the four plant species tested, using living plants, the canola cultivars (Brassica napus cv. Regent and B. campestris cv. Candle) were approximately equal in suitability, lamb's-quarters (Chenopodium album) was less suitable, and lentils (Lens culinaris cv. Chilean) was unsuitable as food for M. configurata. The parameters recorded for larval survival, pupal weight, and the number of eggs/female on the most suitable food plants were higher than those recorded previously for larvae reared on excised leaves of suitable hosts.

This study was undertaken as part of an investigation of the physical and biological requirements of the white pine weevil Pissodes strobi Peck. The broad aspects of the main problem will be given in a later paper and it need only be mentioned here that the immediate objective was to define the requirements of the weevil in terms of measurable factors of the environment. During the field studies, observed variations in behaviour between individual weevils within the limits of a single habitat indicated the need for additional studies that would permit analysis of behaviour in relation to previous conditioning. The responses of the adult weevils to diffuse and discrete light sources, and the effect of temperature on these responses, were investigated in conjunction with field studies of behavioural changes during relatively stable and variable weather conditions, in an attempt to explain observed weevil movements.

The species of the genus Entomacis Foerster in North America north of Mexico are revised. Nineteen species (12 new), including 8 species of the Holarctic-wide perplexa species group, are keyed, described, and figured. These taxa are E. ambigua (Brues), E. apopkaensissp. nov., E. arcticasp. nov., E. cellariasp. nov., E. cepasp. nov., E. eorariasp. nov., E. floridana (Ashmead), E. grandiclavasp. nov., E. longii (Ashmead), E. mellipetiola (Ashmead), E. parambiguasp. nov., and perplexa group members E. californica (Ashmead), E. microbipunctatasp. nov., E. notioxerasp. nov., E. oulasp. nov., E. parvasp. nov., E. perplexa (Haliday), E. sapratasp. nov., and E. subemarginata (Ashmead). Hemilexodes canadensis (Harrington) is synonymized under Entomacis mellipetiola (Ashmead) (syn. nov.). The status of Entomacis latipennis (Ashmead), E. filiformis (Ashmead), and Hemilexis jessei Mann is reviewed. New character complexes, particularly chaetotaxy, are emphasized for Diapriidae species taxonomy.

Capric acid added to a food – whole wheat flour and dried brewers’ yeast – to constitute 2.5% or more of the foodstuff killed all Tribolium confusum Jacquelin du Val within 8 weeks. Lesser amounts of capric acid resulted in different degrees of mortality. By the end of 4 weeks similar results were inevitable when varied levels of capric acid were added to two representative dehydrated foods, tapioca pudding and macaroni and cheese. This uncustomary use of a long-recognized insecticidal fatty acid has some merit: for immixed with foodstuff it can control insect pests, and yet it, as a natural constituent of milk etc., is no stranger to metabolic systems of higher animals, so probably is not too hazardous to humans.

Diapause induction in Hyphantria cunea is under the joint control of photo-period, temperature, humidity, food quality, and possibly other variables, but insufficient data are available to permit a precise evaluation of their actions and interactions. Short daylength and low temperature induce diapause and the critical thresholds for New Brunswick – Nova Scotia populations are in the vicinity of 14.3 hours and 72°F, respectively. Low humidity increases the incidence of diapause, as does also the change in the nutritional quality of foliage late in the season. Both field data and the extrapolation of laboratory data to field conditions indicate that the occurrence of a partial second generation is unlikely in this area, even in warm seasons.

The significance of the housefly, Musca domestica Linnaeus, as a probably introduced species in the Western Hemisphere is pertinent to a search for more exotic natural enemies in the Eastern Hemisphere. Avenues of entry into this hemisphere are discussed. A list is provided of the principal larval and pupal parasites found by the authors attacking M. domestica in North, Central, and South America and this is compared to species from the Eastern Hemisphere.

Evidence is provided that an obligatory pupal diapause is controlled by photoperiod. Diapause in H. cecropia is induced and maintained by a 12-hour photoperiod, and prevented or terminated by a 17-hour photoperiod; in either case, the incidence of diapause is graded according to the developmental stage at which the light regime is imposed. The validity of the distinction between "facultative" and "obligatory" diapause is discussed in the light of these results.

The aggregation pheromone of the ambrosia beetle, Trypodendron lineatum (Olivier), was isolated by MacConnell et al. (1977), identified as one of two isomeric, tricyclic acetals, and given the trivial name, lineatin. One of the isomers, 3,3,7-trimethyl-2,9-dioxatricyclo [3.3.1.0 4,7] nonane (4,6,6-lineatin), was synthesized in µg quantities by three different syntheses, assessed to be structurally identical to the isolated pheromone, and demonstrated to be highly attractive in field tests (Borden et al. 1979; Vité and Bakke 1979). The other structural isomer, 3,3,7- trimethyl-2,9-dioxatricyclo [4.2.1.0 4,7] nonane (4,5,6-lineatin), was not tested for biological activity. The enantiomeric composition of natural lineatin was not determined by MacConnell et al. (1977).

The density and efficiency of bumble bees, honey bees, and alfalfa leafcutter bees on sainfoin, Onobrychis viciaefolia Scop., grown in southern Alberta were studied. Six species of bees were identified as pollinators, with alfalfa leafcutter bees comprising 56% of the observations, honey bees 40%, and bumble bees 4%. The density of flowers over the season can be described as curvilinear. The mean number of flowers per raceme decreased significantly over the season. The rate of foraging by pollinator species from flower to flower varied and is described by multiple regression models. Julian date, hour of day, and flower density are the independent variables. More than 90% of the bees visited three or fewer flowers per raceme when 60% of the racemes had three or more flowers available for pollination. The bees foraged on sainfoin for about 12 h per day and average bee density increased significantly with the corresponding flower density. A theoretical approach used to predict the bee populations required to pollinate varying flower densities shows that the required population of bumble bees is about two-thirds that of honey bees or alfalfa leafcutter bees. The observed populations of pollinators did not correspond well with the derived values, probably because multiple visits per flower are required for fertilization.

The toxicity of a number of insecticides was tested against three species of springtails (Collembola), Folsomia candida (Willem), Onychiurus justi porteri (Denis), and Hypogastrura armata (Nicolet), which were cultured in the laboratory. Treatment was accomplished by incorporating the insecticide into moist Plainfield sand and exposing the springtails for 24 h on this substrate. Generally, the order of toxicity of the insecticides to all three species was: Counter® (phosphorodithioc acid S- (tertbutylthio) methyl O,O diethyl ester) > phorate > carbofuran > heptachlor > methomyl > chlorfenvinphos. Acephate, leptophos, p, p′-DDT, and chlordimeform were of low toxicity to all species. More significantly, however, there were large interspecific differences in susceptibility to insecticides; fensulfothion was virtually non-toxic to O. j. porteri (LD50 > 80 p.p.m.) but highly toxic to F. candida (LD50 = 0.1 p.p.m.). Results of these tests suggest that extrapolation of toxicity data from one species of springtail to other species would be unwarranted.

Pterostichus melanarius Ill. was the predominant ground beetle recovered in pitfall traps in three blocks of apple trees at Jordan Station, Ont. In one block, C, the number of mature fifth-instar larvae of Cydia pomonella (L.) seeking overwintering sites was related significantly (r2 = 0.5476, P < 0.05) to the number of P. melanarius caught, but was not related significantly (r2 = 0.1181, P > 0.10) to the proportion of beetles that were serologically positive. The proportion of larvae pupating also was not related significantly (r2 = 0.2014, P > 0.10) to the number of P. melanarius. The total number of all predators caught was related significantly (r2 = 0.4490, P < 0.05) to the number of larvae present, but the proportion of larvae that pupated was not related significantly (r2 = 0.3606, P > 0.05) to the total number of predators.

In block A, in 1983–1985, the number of mature larvae of C. pomonella seeking overwintering sites was not related significantly (r2 = 0.3763, 0.3619, and 0.5042, P > 0.05, respectively) to the number of P. melanarius taken in pitfall traps. In both blocks A and B, the number of serologically positive beetles was not related significantly (r2 = 0.3824 and 0.7921, P > 0.10, respectively) to the number of larvae seeking overwintering sites.

Amara aenea DeG., Anisodactylus sanctaecrucis F., Bembidion quadrimaculatum oppositum Say, Clivinia impressifrons LeC., Diplochaeila impressicolis (Dej.), Harpalus aeneus F., and Pterostichus chalcites Say also gave positive serological reactions to the antiserum against C. pomonella.

The occurrence of other species of Lepidoptera did not affect significantly the results obtained for C. pomonella.

Studies were carried out in the field and in the laboratory to determine if prolonged diapause of the Douglas-fir cone moth, Barbara coifaxiana (Kearfott), was correlated with the sizes of the cone crops maturing in the year of larval feeding (N) and in the year following larval feeding (N + 1), and to determine if weather during the period of larval feeding (year N) influenced the size of the maturing cone crop or the incidence of prolonged diapause the following year (N + 1). Field studies showed that prolonged diapause induction in B. coifaxiana was not rank correlated (but approached significance) with the size of the cone crop maturing in year N, but was negatively rank correlated with that in year N + 1. Two of seven weather parameters, mean maximum temperature and mean daily temperature, measured during the larval feeding period were positively rank correlated with cone crop size. No parameter was correlated with the incidence of prolonged diapause. In the laboratory, the incidence of prolonged diapause was negatively correlated with temperature. Photoperiod and parental diapause habit had no direct effect.

Monitoring of adult flight patterns of the blueberry maggot fly, Rhagoletis mendax Curran, in New Jersey, indicated that the adults are active over a much longer period than previously reported. Captures on Pherocon AM traps over two seasons in wild sites and commercial fields of highbush blueberry, Vaccinium corymbosum L. (Ericaceae), showed that adult flies are present for most of the period from early July to early November. Trap captures in wild sites peaked during July–August, whereas in some commercial fields, peak captures were recorded in September. Emergence patterns were determined by collecting pupae from a wild site and a commercial field at the time of peak fruit infestation. The following year, the wild-site and commercial-field populations showed distinct emergence periods that were in broad agreement with trap captures at these locations. Comparison of an allozyme locus, using individuals collected in commercial blueberry fields, both on Pherocon AM traps and from infested fruit, confirmed that these populations were R. mendax and not any of the sibling species with a similar flight period. These data show that there are considerable phenological differences between some R. mendax populations. Given this plasticity, current debates on evolutionary mechanisms in flies of the genus Rhagoletis Loew should consider that the flight period of R. mendax is probably neither a major limiting factor in the use of hosts with different fruiting schedules nor an effective premating isolation mechanism with respect to other sibling species.

Field testing of a large number of synthetic compounds and several combinations of them revealed that male moths of the darksided cutworm, Euxoa messoria (Harris), were attracted to combinations of Z-7-hexadecen-1-yl acetate and Z-11-hexadecen-1-yl acetate. The most satisfactory attractants were combinations of these two compounds in ratios of 1:20 or 1:40. The presence of small amounts of the corresponding E-isomers did not interfere with the attractant. The diene, Z-7, Z-11-hexadecadien-1-yl acetate, in combination with Z-11-hexadecen-1-yl acetate also attracted the males, but there was no advantage in using the diene in place of Z-7-hexadecen-1-yl acetate.

Wheat midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), was first detected as early as 1901 in Western Canada. The first major outbreak in Saskatchewan was recorded in 1983. In 1984, Saskatchewan wheat midge populations were found to be parasitized by the egg parasitoid Macroglenes penetrans (Kirby). Parasitism levels vary from year to year but, on average, 33% of wheat midge populations are parasitized by M. penetrans. In 1993 and 1994, Agriculture Canada and the International Institute of Biological Control in Delémont, Switzerland, collaborated to release Platygaster tuberosula Kieffer into Saskatchewan to augment biological control of wheat midge. Platygaster tuberosula individuals were recovered at low numbers in follow-up monitoring programs in each of the last 5 years. In 2001, the parasitoid population density increased fivefold at the release site and showed signs of migrating into the surrounding area.

Damage to apple (cv. McIntosh) by five species of phytophagous mind bugs was characterized by confining numbers of them in sleeve-cages placed on apple-bearing branches. Overwintering adults of Lygus lineolaris (P. de B.) pierced apple buds and flowers early in the spring but did little damage after fruit-set. The damage caused to apples by young nymphs of Lygocoris communis (Knight) and Lygidea mendax Reuter was mostly either deep circular depressions or long sinuous scars. Campylomma verbasci (Meyer) and Heterocordylus malinus Reuter were of little importance in the orchard studied. All species did cause circular depressions (“pits”) in fruit and some damage to leaves.

The functional response of the predacious mite Phytoseiulus persimilis Athias-Henriot to increases in the prey density of adult female Tetranychus urticae Koch was examined. Previous studies on artificial substrates have described the functional response curve of P. persimilis to adult female prey as dome-shaped, because as prey density increased the predator was disturbed by prey activity.

An experiment to determine the effect of artificial and natural substrates on the activity level of T. urticae was conducted. T. urticae showed a significant increase in activity on artificial substrates of plastic and waterproof paper compared with a substrate of excised bean leaf (Phaseolus vulgaris L.). Since prey activity was significantly influenced by substrate, the functional response of P. persimilis to adult female T. urticae was re-examined. P. persimilis exposed to various densities of T. urticae on excised bean leaf disks (5 cm2) showed a functional response curve having a curvilinear rise to a plateau as prey densities increased from 0.2 to 10.0 prey/cm2.

The functional response curve predicted by Holling’s disk equation did not differ significantly from the observed functional response curve.

The rate of successful search and the handling time predicted by the disk equation were 0.194 and 10.34 h respectively.

Experiments were conducted on Fraser fir, Abies fraseri (Pursh) Poir, seedlings or cut terminals. Results indicate that Oligonychus ununguis (Jacobi) responds most favorably to temperatures approximating 26 °C and to relative humidity levels approaching 50 to 60%. Developmental time, time to 50% mortality, net reproductive rate, mean generation time, intrinsic rate of natural increase, finite rate of increase, and days for populations to double were computed for each temperature and relative humidity regime. Simulated rainfall severely limits population density on Fraser fir seedlings.

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.

Russian wheat aphid, Diuraphis noxia, was first detected in Canada in late July 1988 when a few were found on late-maturing spring cereals in southern Alberta near the International Boundary between Coutts and Aden. By the end of September, after dispersal or further immigration influx, it was widespread in Alberta south of Highway #3 and in southwestern Saskatchewan as far east as Swift Current. By mid-October more than 30% of the plants in many fields of winter wheat and fall rye in southern Alberta and up to 20% of plants in some fields of fall rye in southwestern Saskatchewan were infested. In November, Russian wheat aphid was also found on winter wheat in the Creston Valley of British Columbia.