Weight gain during the penultimate and ultimate stadia of the pale western cutworm, Agrotis orthogonia Morr., comprises about 37% and 39%, respectively, of the maximum larval weight. For the army cutworm, Euxoa auxiliaris (Grt.), the corresponding values are 20% and 69%. The proportion of final larval weight that is gained by the ultimate-instar larva of the army cutworm is similar to that reported for other noctuids, whereas the proportion gained by the ultimate-instar larva of the pale western cutworm is much lower and is likely related to the prepupal aestivation that occurs in this species. Because of the growth pattern of pale western cutworm, a substantial proportion of total food consumption, and consequently, crop damage, occurs during the penultimate stadium of this species.

The effects of photoperiod and temperature on the diapause of Aphelinus varipes (Focrster) from Kazakhstan and Apheiinus near varipes from Alberta, which both attack Russian wheat aphid, were studied in the laboratory. At 20 °C, 50% of A. varipes entered diapause when the photoperiod was between 12.5L:11.5D and 13L:11D whereas 50% of A. nr. varipes entered diapause when the photoperiod was around 14L:10D. Diapause induction was close to 100% at 11.5L:12.5D for both species. Maximum sensitivity to photoperiod occurred 2 days alter parasitization for A. varipes and 3 days after parasitization for A. nr. varipes. At 30 °C, the proportion of wasps entering diapause was reduced to 40 and 72% for A. varipes and A. nr. varipes, respectively. Exposing diapausing mummies to temperatures from 10 to −10 °C for 4–20 weeks shortened the postdiapause developmental time. Survival was lowered by exposing mummies to −10 °C for over 8 weeks. Postdiapause developmental rate was directly temperature dependent. The lower threshold and thermal constant for postdiapause development were estimated to be 10.3 °C and 189 degree-days (DD) for A. varipes and 7.41 °C and 204 DD for A. nr. varipes.

A gynandromorph of Rachispoda subpiligera (Malloch) is described. The specimen exhibits both bilateral and anterior/posterior division of male and female genitalic components. Abdominal segment 5 is male, segments 6 and 7 are bilaterally divided into male (right) and female (left) halves, and segments 8–11 are female. Comparison of male and female components supports the view that the large, asymmetrical sclerite posterior to sternite 5 in male Sphaeroceridae is synsternite 6 + 7. Circumversion of the genitalia, normally seen in male segments 8–11, is absent, although male components of segments 6 and 7 exhibit asymmetry normally associated with circumversion. This suggests that asymmetry of sternites 6 and 7 is a developmental process independent of circumversion, not a direct consequence of circumversion.

Crude tall oil and two of its derivatives were assessed for antifeedant and growth inhibitory effects, via incorporation into an artificial diet, in the variegated cutworm (Peridroma saucia Hübner). The substances tested are both toxic to neonate P. saucia and inhibitory to larval growth. The dietary LC50 (lethal concentration for 50% mortality) values are 4.3, 4.7, and 5.3% fresh weight for depitched tall oil (DTO), crude tall oil (CTO), and tall oil pitch (TOP), respectively. These materials significantly reduced growth, feeding, and dietary utilization by first-, second-, third-, and fourth-instar larvae in chronic larval growth bioassays, choice and no-choice feeding tests, and nutritional experiments. The EC50s (effective concentration to inhibit growth by 50% relative to controls) of DTO, CTO, and TOP were 1.4, 2.0, and ≥2.4%, respectively, when first-instar larvae fed on treated diets for 10 days. DTO significantly reduced both growth and consumption rates with corresponding reduction in the efficiency of conversion of food (i.e. nutritional efficiency), suggesting that both antifeedant and toxic effects are involved in larval growth inhibition. DTO and CTO are consistently more biologically active than TOP. Our results suggest that an environmentally sound, low cost natural pest control agent may be developed based on tall oil.

Descriptions of Procloeon rubropictum (McD.), P. quaesitum (McD.), and P. rufostrigatum (McD.) are expanded to include features not previously published. A description of the nymph of P. quaesitum is given for the first time. Procloeon irrubrum sp.nov. is described from nymphs and female imagoes. From our interpretation of preliminary data, it is possible that P. rufostrigatum and P. rubropictum form one species group; P. quaesitum is included with P. pennulatum (Eaton) in another. Procloeon irrubrum does not fit either species group but shows some affinities to the P. rufostrigatum group. Some characters for separating the nymphs of Procloeon and Centroptilum are given.

Tuberculatus (Pacificallis) passalus sp.nov. and T. (P.) chrysolepidis sp.nov. are described and their relationship with other species of the subgenus Pacificallis is discussed. The status of T. (P.) quercifolii (Davidson) is elucidated. A key for the identification of the species of the subgenus is presented.

In the laboratory, the longevity and fecundity of female Zeiraphera canadensis Mut. & Free. (Lepidoptera: Tortricidae) given access to a 10% sucrose solution and water was greater than that of females provided only water. The presence or absence of sucrose did not affect oviposition rate during the first 10 days post-emergence, after which most females denied sucrose died. The enhanced fecundity of sucrose-fed females was due to their increased longevity and, hence, longer oviposition period. Greater longevity, combined with a decrease in oviposition rate and egg viability with age, resulted in a lower average lifetime oviposition rate and percentage viable egg production for females provided sucrose. Although carbohydrate ingestion resulted in increased fecundity and longevity in the laboratory, its effect in nature may be minimal because Z. canadensis usually does not live more than 10 days under field conditions.

Carabid beetles were collected with grids of pitfall traps during two seasons in five habitats in the ecotone between aspen parkland and boreal mixedwood forest in central Alberta. The 23 abundant species (54 species in total) were divided into the following four distributional types: (1) Pterostichus adstrictus Eschz. was numerous in all five habitats (habitat generalist); (2) Platynus decentis Say, Calathus ingratus Dej., and Scaphinotus marginatus Fisch. were abundant in all four forest habitats (forest generalists); (3) another 10 species were common in one or two forest habitats (forest specialists); (4) nine species, representing mainly Agonum, Amara, and Bembidion, were restricted to a recently cleared timothy–clover grassland (meadow species). Soil moisture seemed to be important in determining habitat associations of the species among the forest types. Captures of most species were aggregated also within habitats, and the consistency of aggregation among particular traps suggests that it is mainly a response to subtle microhabitat differences. All abundant species, except S. marginatus, showed a peak of capture in May–June. Number of species, corrected for sample size by rarefaction, was highest in the meadow (27.5) and lowest in the dry upland aspen forest (11.9). Species diversity was highest in meadow and the lakeside forest habitats, but carabid assemblages of the four forest habitats were more similar to each other than to the meadow assemblage.

For most species, the male accessory glands are mesodermal derivatives. Their form is as varied as are the functions of the secretion they produce. The post-embryonic development and differentiation of the glands, like those of other tissues, appear to be regulated by the interaction of juvenile hormone (JH) and ecdysteroid, the former inhibiting and the latter promoting these processes. Post-eclosion accessory gland activity (i.e. production of secretion), for most species examined, is regulated by JH. However, the precise mechanism of control and the site of action are not at all clear. A limited amount of in vitro work indicates a direct action of JH on the accessory glands though only for Drosophila melanogaster Meigen has a JH-receptor protein been identified. The JH promotes the synthesis of specific proteins in the accessory gland secretion, and two proposals have been made for the site and mode of action of the hormone. In the first it is suggested that the hormone affects membrane permeability, thereby influencing the supply of protein precursors; in the second a more direct action of JH at the gene level is proposed, namely, the promotion of translation.

The involvement of ecdysteroids in accessory gland activity is virtually unexplored though there have been a few demonstrations that these hormones can stimulate protein synthesis. An hypothesis worth further consideration suggests that ecdysteroids may have a role in those species that eclose in a sexually mature condition, i.e. where the accessory glands have both differentiated and produced their secretion in the pupal or pharate adult stage, presumably in the absence of JH.

The palearctic cutworm, Apamea ophiogramma (Esper), is reported from North America for the first time. Four specimens were collected at a light trap in Langley, British Columbia, in 1989, 19 in 1990, and 38 in 1991. Descriptions of wing markings and genitalic characters that distinguish A. ophiogramma from the nearctic Oligia fractilinea (Grt.) are provided.

Eggs of western tent caterpillars hatch just as leaves of their food plants are developing. To determine the impact of asynchrony between leaf development and egg hatch during a year of peak density and the initiation of decline, egg masses were introduced to four study areas after the time of normal egg hatching. Survival of caterpillars was not significantly influenced by delays of 3–6 weeks in hatching. Populations composed primarily of introduced insects and control populations declined following the summer of the experiment. Although hatching of deployed eggs was delayed, caterpillar development during warmer temperatures later in the spring was sufficiently rapid that caterpillars from all groups reached the fifth instar by mid-June, and parasitization of caterpillars from control and experimental areas was similar. Tent caterpillar survival was apparently resilient to substantial delays in egg hatch which suggests that cyclic population declines are not likely to be associated with minor variation in the synchrony of leaf development and egg hatch.

Field trials in northern Ontario in 1990 and 1991 confirmed that survival of spruce budworm larvae [Choristoneurafumiferana (Clemens)] (Lepidoptera: Tortricidae) parasitized by Apanteles fumiferanae Viereck (Hymenoptera: Braconidae) was greater than survival of nonparasitized budworm larvae following application of Bacillus thuringiensis var. kurstaki Berliner (Bt). Apparent parasitism by A. fumiferanae increased slightly when application of Bt was early (instar III or IV) but increased significantly when applications were later in the season (instars IV–VI). Delaying the timing of the spray conserved parasitoids while providing significant reductions in budworm densities and not compromising the primary objective of Bt application, i.e. the protection of current year foliage. The potential for long-term management of spruce budworm through the strategic integration of natural and imposed mortalities is discussed.

The fecundity of first-generation adult Pholetesor ornigis (Weed) increased when individuals were confined with flowers of creeping "Charlie" (Glechoma hederacea L.), dandelion (Taraxacum officinale Weber), and apple (Malus domesticus L.), but not with blossoms of chickweed [Stellaria media (L.) Cyrillo] or Shepherd’s purse [Capsella bursa-pastoris (L.) Medic]. Longevity of P. ornigis was little affected. The fecundity of second-generation P. ornigis increased when individuals were confined with terminal leaves of apple with honeydew of the aphid Aphis pomi DeGeer, but not when confined with terminal leaves without honeydew or with flowers of round-leaved mallow (Malva neglecta Wallr.) or red clover (Trifolium pratense L.). Longevity of P. ornigis adults also increased when they were provided with aphid honeydew. There were significant differences between the total number (oviposited and ovarian) of eggs produced by second-generation females given different food sources. Those given aphid honeydew oviposited a greater proportion of their eggs than those confined with apple leaves without honeydew or with flowers of M. neglecta or T. pratense, Adult P. ornigis fed an aqueous solution of honey (50:50, v/v) lived longest and produced more eggs than those provided with any other food source.

The phenology and reproductive status of adults of the redbacked cutworm, Euxoa ochrogaster (Guenée), were determined from blacklight (BLT) and sex-attractant (SAT) trap catches at four locations in southern Manitoba in 1987 through 1989. The flight period was of 9–12 weeks duration, extending from late June to early October. The first male and female moths were captured at about the same time in the BLT and SAT. The peak catches of the BLT occurred during the first 3 weeks of August (weeks 5 and 6 of the flight period) and those of the SAT about 1 week later. The SAT continued to capture male moths for 2–3 weeks after the last moths appeared in the BLT. Most females captured during the first 2–3 weeks of the flight period were virgins who had not yet initiated egg development. Most mating, egg development, and oviposition took place during a 3- to 4-week period that included the 2 weeks before, the same week as, and the week after the peak BLT catches (weeks 3–7 of the flight period); these activities occurred in the 3–4 weeks before the peak SAT catches. The data suggested that there was competition between SAT and females in attracting males and, consequently, the SAT catch data may not be providing accurate measurements of the sizes of breeding populations of males in the field. The BLT catches underestimated the length of the flight period by about 1.5–3 weeks.

Intra- and inter-plant spatial patterns were determined for adults and nymphs of Orius insidiosus (Say) and O. tristicolor (White) on greenhouse sweet pepper for three greenhouses using four sampling methods. The population density of the Orius was monitored biweekly for 4 months from May to August using plant tappings, blossoms, plant leaves, and whole plants. The intra-plant spatial patterns of adult and nymphal populations of Orius were aggregated with the majority of the Orius collected from the top one-third of the plant. The inter-plant spatial pattern for the nymphs also was aggregated. However, the adults exhibited a random inter-plant spatial pattern. The accuracy of plant tapping, blossom, and leaf samples was determined for monitoring the adult and nymphal population densities of Orius throughout the growing season. The blossom sampling method for adult Orius was the best sampling method for monitoring the population density of Orius on greenhouse sweet pepper throughout the growing season.

In the boreal forest of northwestern Ontario, where carpenter ants (Camponotus spp.) construct extensive underground tunnels, few worker ants were seen on the aerial portions of trees containing colonies of the ants or on neighboring trees, even though the trees were infested by large numbers of spruce budworm [Choristoneura fumiferana (Clem.)] larvae. Immunochemical techniques detected less spruce budworm soluble protein in worker ants from this area than in a laboratory colony that had been fed budworm larvae, or in a colony located in a spruce tree that was surrounded by gravel where the ants were unable to build underground tunnels and instead foraged extensively in the tree crown. This suggests that, in contrast to evidence from western North America, carpenter ants in the boreal forests of northwestern Ontario, and perhaps elsewhere throughout the range of the spruce budworm, are of limited importance as predators of the spruce budworm.

The genus Parasimulium Malloch holds a position of special interest within the family Simuliidae. Not only is it the sister group to all remaining members of the family (Wood and Borkent 1982; Cume 1988), but the four described species of the genus are known only from northern California to Washington State. The genus was considered to be very rare until the rediscovery of a population of P. crosskeyi Peterson by Wood and Borkent (1982) in northern Oregon. Since then, the egg, first and second larval instars (Borkent and Wood 1986) of P. stonei and the nearly mature larva and pupa (Courtney 1986) of P. crosskeyi have been described. Larvae and pupae of P. crosskeyi have been collected from the hyporheic zone of a seep near a larger creek (Courtney 1986). The immatures were found among debris retained by a net held below the outlet while excavating the seep by hand. Finally, Currie and Walker (1992) have discovered fossil larval fragments of Parasimulium from Marion Lake, B.C., (50 km east of Vancouver) that were dated at 10 500 – 11 000 years before present and these represent the first records of the genus from Canada.

Individual larvae of western spruce budworm (Choristoneura occidentalis Freeman) were observed from overwintering emergence to pupation at six locations spread over a wide range of altitudes and thus climate. A weekly census of 100 lower-crown buds per plot indicated large differences in rates of bud development and larval survival among locations.

Emerging second-instar larvae attempted to mine swelling buds of Douglas-fir. If the buds were hard and tight, larvae mined 1-year-old needles until penetrable buds were available. Larvae dispersed over the crowns with only one larva becoming established in each bud; thus, many early-emerging and surplus larvae could not find suitable feeding sites and disappeared. Within the protective bud, survival was high. After buds flushed and larvae became exposed, densities dropped, probably due to increased predation and decreased food quality. Correlations indicated a close association between larval survival for the exposed period between bud flush and pupation, and overall larval survival.

Douglas-fir trees responded to initial bud removal, but not to needle removal, by inducing latent buds in the axils of needles to grow into active vegetative buds ready to develop and flush the next spring. The number of these new vegetative buds formed was greatest when the initial buds were removed early in the season before flush, and decreased thereafter. Trees with vigorous crowns had the greatest response to defoliation by inducing the largest number of latent buds into becoming active vegetative buds; these were found mainly on the 2- and 3-year-old internodes.

European corn borer males have hair pencils located ventrally on the 8th sternite and these are extruded when a male approaches a calling female. The fact that (i) antennectomized females mated significantly less than both intact controls and individuals subjected to other forms of surgery, and (ii) males with hair pencils removed had a significantly lower mating success than control males, suggests that a male pheromone is involved in the mating system of the European corn borer.

Blacklight traps (BLT) are commonly used in trapping and monitoring systems (Harding et al. 1966), employing either a 12-V battery or commercial alternating current as the power source. Both power systems have major disadvantages. Batteries need to be recharged frequently (every 2–3 days), and the commercial alternating current system often restricts the BLT to locations that are not well suited for trapping or monitoring. We describe here a portable, solar-powered charging system for 12-V batteries, which we developed to overcome the disadvantages of these power systems.