Agrilus bilineatus (Weber) is univoltine in Wisconsin. Adults were present from early June through mid-September; however, peak flight and oviposition occurred during the second half of June. Adults consumed significantly more oak foliage than foliage of hardwoods other than oak. Stressed oaks attracted significantly more adults than did uninjured controls, as measured by density of captured adults on sticky traps. Four larval instars were determined; instar IV was the overwintering stage. Fourth instar larvae generally overwintered in pupal cells in the outer bark or in sapwood if the bark was thin. Larvae, especially third and fourth instars, damaged oaks by girdling the conducting xylem and phloem. Attacked oaks had low root starch content relative to those unattacked. Tree death normally resulted after 2 or 3 years of borer infestation, yet tree death may occur in a single season. Initial attack usually began in the live crown and proceeded downward in succeeding years with no apparent reinfestation of previously killed areas. Mean adult longevity in days for adults fed red oak foliage was 28.1 at 20°, 37.8 at 24°, and 8.3 at 30 °C. Mean duration of the pupal stage in days was 11.7 at 24 °and 8.5 at 30 °C.

Pheromone traps were more efficient than blacklight traps for detecting and monitoring adult populations of fall armyworm, Spodoptera frugiperda (J.E. Smith), in southwestern Ontario. Several dispenser–chemical combinations were strongly attractive but best results were obtained with sticky traps baited with rubber septa impregnated with combinations of (Z)-9-dodecenyl acetate and (Z)-9-tetradecenyl acetate.

A new species, Oeneis excubitor, is described. This species has male valvae similar to those of Oeneis melissa and Oeneis jutta but the wing pattern is roughly similar to that of Oeneis chryxus.

Female mountain pine beetles, Dendroctonus ponderosae Hopkins, were exposed to papers soaked in outer bark extracts of lodgepole pine, Pinus contorta Douglas var. latifolia Engelmann. Both benzene and methanol–water extracts elicited greater feeding activity than did controls. Non-polar host compounds exhibited greater incitant (initiation of feeding) properties, while polar compounds were more powerful stimulants (continuation of feeding). No differences were detected in feeding on extracts from resistant or susceptible trees. Repellency appears to be associated with beetle responses to active host metabolism.

Tests of intertrap variability in catches of moths of the darksided and redbacked cutworms, Euxoa messoria (Harris) and E. ochrogaster (Guenée), were conducted by placing two traps for each species baited with synthetic sex attractants at 1.6 km (1 mi) intervals to form a grid covering 64 km2 (25 mi2) near Domain, Manitoba. These sex attractants were 93 and 99.6% species specific for E. messoria and E. ochrogaster respectively. Moth catches varied between traps and flights, but the ranking of the traps by catch for each species was consistent during any given flight period. Variability in intertrap catches of E. messoria indicated the moths were not evenly distributed throughout the test area and consequently a sex-attractant trap system with 1.6 km trap spacing is not suitable for monitoring population levels. For E. ochrogaster four traps within an area of 64 km2 would be required to give a population estimate within 20% of the true mean. The flights of E. messoria are not related to degree days and started abruptly and at the same time each year suggesting that development may be synchronized by the summer diapause of the prepupae. The flights of E. ochrogaster were related to degree day accumulations above a threshold temperature of 12.5 °C. Crops had no apparent influence on the distribution of moth catches for either species.

The biogeography of 171 North American species of Euxoa (Lepidoptera: Noctuidae) is reviewed. For biogeographical analysis, species are arranged in groups according to habitat; these are 62 aridland species, 69 forest species, 19 widespread species, and 21 species with special or unknown habitat requirements. Aridland species are distributed primarily in grassland areas in the Great Plains and in sagebrush areas or piñon–juniper woodland in the intermontane region. Ranges in these two regions are connected in arid corridors through the Rocky Mountain region. Forest species in western North America are arranged in two groups: those that occur in both conifer forests and piñon–juniper woodland (17 species), and those that occur only in conifer forests (40 species). Species in the former category occur throughout the mountain ranges of the west including those of the Great Basin wherever suitable habitat occurs. Those of the latter category occur in conifer forests on mountain ranges around the Great Basin but do not occur in the Great Basin, even in mountain ranges that support suitable habitat. Most forest species that occur in the Rocky Mountain region also occur in disjunct woodland areas in the Great Plains.

The effect of Wisconsinan glaciation on the biogeographic regions of western North America is reconstructed from a review of fossil pollen and plant macrofossil studies. From this synthesis it is suggested that during the Wisconsinan glacial maximum, forest species were widely distributed in the Great Plains south of the Laurentian ice sheet, and at low elevations in the Sierra Nevada and Rocky Mountain regions. Piñon–juniper woodland species were widespread in the Great Plains. Forest species that do not occur in piñon–juniper woodland were distributed around the Great Basin but were prevented from reaching suitable habitat in mountain ranges within the Basin by unsuitable habitat in the intervening lowlands. The ranges of aridland species were greatly reduced during Wisconsinan time, particularly in the Great Plains. Aridland corridors through the Rocky Mountains were eliminated during the Wisconsinan glacial maximum.

The possibility of speciation during Wisconsinan time is reviewed. Although the distribution of many sister-species are what would be expected from speciation during the Wisconsinan, the distributions may reflect allopatric distributions during Wisconsinan time and not speciation.

A stridulatory apparatus consisting of the juga of the forewings and specialized areas of the metanotum of both sexes of Merope tuber Newman (Mecoptera: Meropeidae) is described and illustrated. The sounds produced are discussed in light of their possible role in defence and intraspecific communication. This is the first verified instance of stridulation in the Mecoptera.

Spruce budworm egg deposition spanned 27 days during both 1979 and 1980. The egg deposition curve is essentially a normal bell-shaped distribution with a slight skew to the right. Spruce budworm eggs are most acceptable to T. minutum Riley for successful parasitism during the earlier stages of host–egg development. Parasitism rates at two different temperatures (21 °C and 27 °C) were significantly greater for 1- to 3-day-old eggs than for 6- to 8-day-old spruce budworm eggs. Major reduction in host–egg acceptability occurred after the fifth day at 21 °C and after the 4th day at 27 °C.

A total of 72 overwintering Anopheles earlei Vargas was collected from southern Manitoba during December 1980 and 1981. These mosquitoes were maintained at 15 °or 20 °C, and a photoperiod of 8L: 16D. Forty-two females were offered a blood meal and 25 of these fed. Extensive fat body development was seen in the blood-fed females collected in 1980; this was not seen in collections from 1981. Gonotrophic dissociation was observed in 24 of the blood-fed females.

Mortality of diapausing and non-diapausing pupae of Heliothis virescens (Fabricius) and H. zea (Boddie) at low temperatures was assessed in the laboratory. Comparison of the exposure time necessary to induce 50% mortality (LT50) indicated that survival of diapausing pupae was significantly higher than that of non-diapausing pupae. Similar comparisons showed no consistent significant differences in mortality of pupae from different geographic locations within Texas or in pupae preconditioned in several different ways. One exception was the response of pupae of H. virescens preconditioned to varying temperatures. This type of preconditioning appeared to increase the cold-hardiness of pupae at subfreezing temperatures. Contact moisture significantly decreased LT50 values of pupae of both species at sub-zero temperatures. Predictive models for low temperature mortality were developed for dry, diapausing pupae.

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.

The mean post-mating age of mated female moths of the European corn borer, Ostrinia nubilalis (Hübner), from light traps varied from 3.4 to 5.2 days during the June–September flight period at Harrow, Ontario, in a manner consistent with assignment of moths to 3 generations per year. At the beginning of the first generation the mean age was 3.66 days and rose to 5.21 before flights ceased. At the beginning of the second generation the mean age was 3.39 days and rose to 4.47 days. A third generation could be detected in early September by a significant drop in age and an increase in virgin females. The average age of mated females was negatively correlated with the proportion of virgin females in the same week (r = −0.648, P = 0.02), indicating that about 40% of the variance in age of mated females was associated with emergence of new recruits to the population. Females collected with a sweep net from their day time resting places in weeds were either the same age or older than those from the light trap. The mean age of moths from light traps was found to be not meaningful when it was tested as a factor in forecasting damage caused by their progeny in green peppers 3–5 weeks later.

Each of three insecticides—lindane, carbaryl, chlorpyrifos—was tested by topical application on the western pine beetle, Dendroctonus brevicomis LeConte, and two native coleopterous predators, Enoclerus lecontei (Wolc.) and Temnochila chlorodia (Mann.), to assess comparative toxicity. Lindane was more toxic to the predators than to western pine beetle, while carbaryl was relatively non-toxic to E. lecontei when compared with either T. chlorodia or western pine beetle. Chlorpyrifos was equally toxic to all three species. Results of topical application serve to estimate relative effects of insecticides on predacious associates in the western pine beetle community.

Twenty Nearctic species of Myllaena are recognized. All are redescribed or newly described and illustrated. A key for their identification, and maps of their distribution are provided. The species are arranged into four groups: the Cuneata, Insomnis, Potawatomi, and Seminole. Seven species are described as new: hopi (Arizona, Mexico), hopkinton (Massachusetts), kaskaskia (eastern U.S.A.), magnolia (Florida), potawatomi (transcontinental, also in Haiti and Jamaica), serrano (California, Baja California of Mexico), and seminole (southern U.S.A. and Illinois). Newly established synonymies are (the second name of each pair being valid): abdita Casey, 1911 = audax Casey, 1911; brevivestis Casey, 1911 = ludificans Casey, 1911; dissimulons Casey, 1911 = audax Casey, 1911; immunda Casey, 1911 = arcana Casey, 1911; molesta Casey, 1911 = audax Casey, 1911; obscurata Casey, 1911 = insipiens Casey, 1911; scobinella Casey, 1911 = decréta Casey, 1911; umbra Casey, 1911 = decreta Casey, 1911; and vegeta Casey, 1911 = audax Casey, 1911.

Fourteen lectotypes are designated. A checklist of Nearctic species is added. The systematics, phylogeny, and zoogeography of the genus and' species are discussed.

Aggregations of the ladybird beetle Hippodamia quinquesignata Kirby were found at several sites on the eastern edge of the Rocky Mountains in southern Alberta at altitudes of 1250–2439 m, and also in the Porcupine Hills (1780 m), just east of the Rockies. The beetles apparently migrate from the prairie region where they feed on pea and grain aphids to the aggregation sites in fall, and return to the prairie in spring.

H. quinquesignata can survive southern Alberta winters, but some protection is needed as high mortality sometimes occurs in localized areas of the aggregation sites. Supercooling data indicate that the greatest protection against cold occurs during mid-winter but a considerable amount of cold hardening occurs during the fall. The most critical period for survival appears to be April and May when the beetles have lost much of their cold resistance, and a late spring cold period could cause high mortality.

The spatial distribution of adult Ooencyrtus kuvanae (Howard) (Hymenoptera: Encyrtidae) was examined in central Pennsylvania during 1978–1980. Data were gathered over a wide range of gypsy moth (Lymantria dispar (L.) (Lepidoptera: Lymantriidae)) densities and from all phases of population growth. There was a linear relationship between the log variance and log mean, fitting Taylor's Power Law with a power of 1.27. The degree of aggregation in O. kuvanae populations, as measured by the variance-to-mean ratio, was correlated positively with the abundance of the parasite, and was independent of host density. Aggregation was believed to result from the habit of the female parasite ovipositing repeatedly on the same egg mass, and the resultant progeny emerging synchronously. Behavior and density of O. kuvanae populations were found to depend upon the gypsy moth population condition, i.e., low, rising, high stable, outbreak, or collapsed. The frequency distribution of O. kuvanae populations fit the Poisson at densities less than 0.2 parasite adult per egg mass, a condition which occurred early and late (July, November) in the season, and the negative binomial above this density; a few distributions fit the log normal. The data were also analyzed using analyses of variance (multivariate and univariate), correlation, and regression techniques. All main effects, i.e., study area, host egg mass volume, egg mass height from the ground (within the 0–2 m sampling universe), aspect of the egg mass on the tree, and tree species, were important in explaining the variance in parasite abundance; study area differences were the most important. The effects of aspect and tree species were explained on the basis of small sample sizes, and not studied further. There was a positive correlation between host egg mass volume (= size) and parasite abundance. There was also a positive correlation between the height of the egg mass and parasite abundance during the summer; however, this relationship became negative by late fall. This seasonal change in vertical distribution was attributed to the tendency of O. kuvanae to be closer to the ground where they overwinter. Variation in adult abundance was generally greater among gypsy moth egg masses on different trees than among egg masses on the same tree, except at low parasite densities. This was attributed to the parasites searching for egg masses on one tree before dispersing to another.

A Palearctic species, Cnephasia stephensiana (Doubleday), was first collected in Nova Scotia in 1954 and has since been found in Prince Edward Island, Quebec, and near Ottawa, Ontario. C. stephensiana is compared with the introduced C. interjectana (Haworth) which was found first in Newfoundland in 1915.

Bacillus thuringiensis var. israelensis (serotype H-14) and B. sphaericus strain 1593 were tested against Aedes stimulons larvae in the laboratory and in 38-cm-diam, open-ended cylinders embedded in the bottom detritus of a woodland pool. Estimates of LC50 were lower against fourth instars in the field at a mean temperature of 15.9 °C than in the laboratory at 21.1 °C. The greater efficacy in the field was attributed to high daytime water temperatures (mean 20.5 °C) following treatment and exposure of the larvae to substantially greater amounts of toxic material in a larger volume of water than in the laboratory. The regression of probit on log10 concentration was not linear over the entire range of mortality caused by B. sphaericus, increasing the difficulty of estimation of LC values. Bacillus sphaericus was significantly less active than B. thuringiensis.

The effects of the major factors on populations of the wheat stem sawfly, Cephus cinctus Norton, were studied in the field at Lethbridge, Alberta between 1970 and 1977. Fecundity of the females, which contain an average of 32.7 eggs, is influenced by the condition and variety of host plants in which they develop as larvae. Populations of the adults that emerge from infested crops cut 7–9% by the larvae in one year may infest 70–80% of the stems of adjacent crops in the following year. Increased adult densities, however, fail to increase markedly the percentage of stems infested because the adults concentrate at field margins when they reinfest the most preferred stems. Because only one larva can mature in each stem, competition within stems that receive more than one egg causes a major drop in the population but not in the percentage of infested stems cut. Another major drop is caused by host plant resistance, which is influenced in both susceptible and resistant wheats by the weather during the growing season. On an average, all of the larvae die in 28% of the infested stems of two susceptible wheats and in 67% of those of a resistant wheat. The mortality in resistant wheats, however, is generally not sufficient to prevent economic infestations in subsequent years. Parasitism, which was a major factor in only 7 of 36 years in southern Alberta, is increased by weather conditions that cause delayed ripening of the wheat crops. The mortality of mature larvae and pupae averaged 21.3%. It is affected by extremes of moisture and temperature and can be increased slightly by shallow tillage of infested stubble.

Laboratory and experimental studies of four of the five subspecies of Euxoa comosa (Morr.), i.e. annir, altera, lutulenta and Ontario, each formerly considered of specific rank, were undertaken to assess their taxonomic status. Morphologically the immature stages of the subspecies are similar although lutulenta has a 40–50% larger egg and the larvae of lutulenta and Ontario are darker than those of annir and altera. The subspecies show differentiation in larval growth rate, number of larval instars, duration of preimaginal development and length of the preoviposition period. The possible adaptive significance of these differences are discussed. Hybrid F1 were obtained from 11 of the 12 possible pairwise combinations. Eight of the F1 hybrids were inbred and six produced fertile eggs. Some of the F2 progenies exhibited a wide range of phenotypes encompassing all subspecies including those of the 5th subspecies, E. c. comosa. Although hybridization success was high there was some evidence of genetic incompatibility including dyssynchronous emergence of the sexes and the absence, shortage, or inviability of female moths in some crosses. Mating discrimination tests show a moderate level of mating bias between subspecies. Calling periods of females of the subspecies largely overlap although differences in the time at which calling begins might be responsible for some of the mating bias. Both laboratory and field tests of sex pheromone attraction indicate considerable sex pheromone specificity among the subspecies. The results are discussed with reference to a companion paper which on the basis of conventional taxonomic characters and biogeographic considerations concludes that Euxoa comosa is best regarded as a polytypic species encompassing five subspecies.