Sweetclover, Melilotus Miller, was planted in a field near Saskatoon, Saskatchewan, to determine the effects of species and cultivars on early season feeding by the sweetclover weevil, Sitona cylindricollis. The wild annual species M. infesta Guss. was consumed less than were cultivars of M. alba (Desr.), which were generally consumed less than cultivars of M. officinalis (L.). The amount of feeding injury by the weevil among nine sweetclover entries was not significantly correlated with nitrate levels in cotyledons, unifoliolate, or first trifoliolate leaves. Weevils fed equally well on entries with high and low coumarin levels. Results from greenhouse cultivar trials generally paralleled those from the field. In an experiment in which different levels of ammonium nitrate fertilizer were broadcast prior to seeding of M. officinalis cultivar Norgold, levels of nitrate ion in the foliage were significantly correlated with fertilizer regime, but not with damage indices of the weevil. These experiments suggest that the nitrate ion in isolation is not the principal factor in the deterrence to sweetclover weevil feeding in M. infesta, and that elevating nitrate levels in sweetclover leaves would not confer resistance to this insect.

Egg-laying data are available for laboratory colonies of Lygus lineolaris (Palisot de Beauvois) (Bariola 1969; Khattat and Stewart 1977; Fleischer and Gaylor 1988), but there is no information on egg-laying for females from field populations in Canada. This paper presents egg-laying data for field-collected, overwintered and first-generation females of L. lineolaris from southern Manitoba in 1990 through 1992.

Forest ants in Connecticut, especially Formica neogagates Emery and F. subsericea Say (Hymenoptera: Formicidae), feed on first- to third-instar larvae of gypsy moths, Lymantria dispar L. (Lepidoptera: Lymantriidae), but mainly forage on the ground while most young caterpillars are in trees. It would be helpful to obtain information about the individual ants that do climb trees. Thus, numbers of ants climbing up and down different species of forest trees were determined. Numbers varied with both tree species and trunk diameter. Some oaks, plus hickories, tended to have the most ant traffic. These trees were also the most likely to have trunk diameters positively correlated with ant activity. Ants appeared to obtain honeydew or perhaps nectar from the trees, as the crop contents of some ants tested positive for sugar. A possible way to induce more ants to climb trees, and thus to attack caterpillars in trees more frequently, would be to increase numbers of honeydew-producing insects in trees. It should also be possible to encourage ants by spraying trees with sugar solutions or other materials.

Trichogramma minutum Riley entered diapause, in the prepupal stage, in eggs of Lambdina fiscellaria fiscellaria Guenée held at 15°C, 12L:12D, but failed to do so in eggs of Ephestia kuehniella (Zeller), Sitotroga cerealella (Olivier), or Choristoneura fumiferana (Clemens) held under these conditions. The parasitoids emerged without diapause from eggs of all host species held at 25°C, 16L:8D, indicating a role of temperature or photoperiod, or both, in the diapause of the parasitoids in eggs of L. fiscellaria held at 15°C, 12L:12D. Percentage emergence of parasitoids from eggs of L. fiscellaria was virtually the same (>80%) after passing the winter outdoors or after approximately 3 months at 2 °C in the laboratory as it was when reared indoors in this host at 25°C, 16L:8D. Emergence of T. minutum was very poor (<20%) after long-term, low-temperature storage in eggs of C. fumiferana, E. kuehniella, or S. cerealella. Apparently, T. minutum must parasitize diapause host eggs in order to enter diapause, and good survival after long-term low-temperature storage is possible only when T. minutum is in diapause. Trichogramma minutum will enter diapause in L. fiscellaria after 14 days at 15°C, 12L:12D, but the parasitoids need a period of storage at 2°C, 0L:24D for a high percentage of emergence to happen. Over 50% emergence was recorded for T. minutum, held for 300 days in eggs of L. fiscellaria.

The daily pattern of oviposition, the rank order of oviposition preference for three potential hosts, and the effect of experience on oviposition preference were investigated under natural abiotic conditions in the obliquebanded leafroller, Choristoneura rosaceana. Females from the two adult cohorts occurring seasonally oviposited between 0400 and 2400 hours, with peak oviposition around 2000 hours. Both non-choice and choice oviposition trials revealed that the apple and snowberry hosts were preferred over wild rose. Oviposition preference resulted in delays in laying on the less preferred host, but seemed to have no effect on clutch size. Females caged with exclusive access to one of the three hosts appeared to have similar lifetime fecundity or longevity. A first oviposition on wild rose resulted in a delay in laying a second clutch on that host, which suggests the presence of aversive learning that could function to reduce the liklihood of laying successive clutches on a less preferred host. A first oviposition on the apple host, however, seemed to have no effect on further oviposition preference. Hence, it appears that learning would not function specifically to concentrate foraging of the females within apple orchards.

De Clercq and Degheele (1990, 1992) described the morphology and bionomics of a predatory stink bug under the name of Podisus sagitta (Fabricius). The studies were based on a culture started from specimens originating from Surinam. Workers from the Agricultural University of Wageningen, The Netherlands, who provided us with the specimens, referred to the species by the name “Podisus sagittus (L.)”(Adidharma 1986), which we corrected to P. sagitta (Fabricius), the name mentioned by Van Duzee (1916). Subsequent to our studies, Thomas (1992) published an illustrated key to the New World species belonging to the pentatomid subfamily Asopinae, which, for the first time, enabled accurate identification of species.

During the 1977–1986 outbreak of mountain pine beetle (Dendroctonus ponderosae) in southwestern Alberta and Saskatchewan, populations of this beetle developed in lodgepole pine and limber pine stands, and threatened to spread northeasterly to the extensive jack pine forests in the central parts of the two provinces. To assess jack pine as a potential new breeding host, I compare egg galleries, brood production, and adult characteristics of D. ponderosae reared in lodgepole, limber, and jack pine logs. Brood productivity, beetle size, sex ratios, and egg gallery characteristics are described for beetle populations reared from naturally infested limber pine logs from southwestern Alberta, and from artificially infested jack pine logs from east-central Alberta and central Saskatchewan. In a field experiment where logs of the three hosts were placed together, adult beetles and their gallery characteristics are described and compared on the three hosts. The results confirm that jack pine is a viable host, that D. ponderosae’s attack characteristics, survival, and progeny on jack pine all appear comparable to those characters observed for beetles reared on lodgepole pine, and that limber pine is highly productive of beetle brood.

The herbivore-resistant synthetic maize BS9 (C4) was grown in three environments, namely, greenhouse with reduced UV light, greenhouse with supplemental UV light, and outside, and leaves at the three-, five-, seven-, nine-, and 10-leaf stages of development were fed to the European corn borer, Ostrinia nubilalis (Hübner). Larvae preferred younger leaves, and leaves grown under reduced UV light, in spite of the high levels of the defence compound 2,4-dihydroxy-7-methoxy-2H-1,4 benzoxazin-3 (4H)-one (DIMBOA). The low level of feeding on leaves from plants grown outside was associated with increased toughness and increased photochemically derived phenolic dimers that cross-link hemicellulose. Tender young maize plants have a low level of cell wall phenolics and depend on a toxin (DIMBOA) for defence. In older plants, DIMBOA levels are low, leaves are tough, and resistance is largely structure-based.

Trachycrusus, gen.nov., and two included species, lescheni sp.nov. and striatulus sp.nov., are described and figured from eastern Peru. Morphologically the genus bridges the gap between the highly modified ceratocanthine genera such as Scarabatermes Howden and the more typical genera such as Astaenomoechus Martínez and Pereira.

Sequential decision plans based on aphid counts and binomial counts of infested plants (presence or absence of aphids) were developed to guide chemical control decisions for die potato aphid, Macrosiphum euphorbiae, on two growth stages of oilseed flax in western Canada. The plans were derived from studies of aphid dispersion among plants in field plots at two locations over 4 years, and verified in samples from 51 commercial fields, in Manitoba. The relationship between variance (s2) and mean aphid density () perplant was loges2 = 0.790 ± 0.050 + (1.649 ± 0.031) loge (n = 69, r2 = 0.98), for both crop growth stages. Neither sweep samples nor pan samples produced reliable estimates of the number of aphids per plant and, therefore, these sampling tools could not replace aphid counts on individual plants. Aphid counts and the binomial method gave similar control decisions with similar amounts of effort, but the aphid counting method required fewer plants to reach a decision. The same decisions were reached in 85–95% of fields by counting aphids on a minimum sample of 25 plants when the crop was in full bloom, or 20 plants at the green boll stage, as with samples of 50–100 plants.

We studied the effects of agricultural practice on ground beetles, using pitfall traps in field plots and in an uncultivated meadow near Edmonton, Alberta. Ground beetle abundance and species richness were higher in plots operated under an organic farming regime than in those under a chemical regime, but neither crop type [barley (Hordeum vulgare L.), faba bean (Vicia faba L.), barley-pea (Pisum sativum L.) intercrop] nor crop rotation had an effect. Reduced tillage did not significantly change overall carabid activity or species richness but species differed in their response to tillage treatments. The carabid assemblage from an uncultivated field differed conspicuously from assemblages in the crops and fescue. Carabid abundance was highest in the meadow and the fauna was dominated by the exotic species Pterostichus melanarius Illiger. Effects of agronomic practice on carabid assemblages are complex, reflecting the interaction of biological traits of particular species and the combination of agronomic treatments applied.

The lodgepole terminal weevil, Pissodes terminalis Hopping, is the only member of its genus that consistently oviposits in the expanding terminal shoots of its hosts (Stark and Wood 1964). The white pine weevil, Pissodes strobi (Peck), oviposits in the year old shoot of spruce and pine (Wallace and Sullivan 1985) and other Pissodes species have their oviposition sites on boles, root collars, and slash (Furniss and Carolin 1977). In southern British Columbia, P. terminalis is primarily univoltine although adults may live and oviposit for 2 or more years. Although its life cycle is closely synchronized with terminal phenology, its life history is extremely variable (Cameron and Stark 1989). Adults are active in late spring to early summer, when they can be found feeding on the tissues of the developing terminal shoot and foliage. Soon after this maturation feeding, mating occurs, and oviposition punctures are excavated in the bark of the new terminal. Usually a single egg is deposited into each puncture (Drouin et al. 1963; Stark and Wood 1964; Maclauchlan 1992).

In recent years, the obliquebanded leafroller, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae), has become a major pest of raspberries in the Fraser Valley, British Columbia (Anonymous 1994). Overwintering C. rosaceana larvae begin feeding on raspberry leaf buds in early April. Heavy infestation causes serious damage to raspberry plants. Larvae of the first generation hatch in late June to early July, and feed on growth terminals and berries. The occurrence of this generation usually coincides with berry harvesting time. Because the larvae are shaken from the plants by the harvesting machine, C. rosaceana can be a major contaminant of machine-harvested berries.

Araniella proxima (Kulczyński, 1885) occurs in northern Europe (Blanke 1982) and northern Asia (Marusik et al. 1992), but has not been previously reported from North America. Our attention was drawn to this species when we identified as A. proxima a male Araniella collected by Keith Roney at Peter Pond Lake, Saskatchewan (55°55'N 108°36'W) on 10 July 1989.

Field and laboratory studies were undertaken in southern Ontario to gain bionomical information on the adult strawberry root weevil (Otiorhynchus ovatus), a pest of ornamental conifer trees in nurseries. Emergence of overwintering adults began on 3 June 1991 and lasted 56 days, with 50% emerging within 18 days. Adults dispersed less than 5 m in 48 days from a single release point. About 50% of females were fecund. The laboratory temperatures at which adults were reared (15, 20, and 25°C) had no significant effect on fecundity (62.3 eggs per female) but influenced longevity; adults at 15°C lived longer than at 20 or 25°C. The mean preovipositional and ovipositional periods were 31.5 and 49.0 days, respectively. Less than 1% of adult weevils released in the field survived the winter; overwintering adults lived 10 months. Egg eclosion occurred 16 days after oviposition with 78% of the eggs viable. The significance of these biological observations in the development of management strategies for this pest is discussed.

In 1991, a whitefly infestation of unprecedented severity resulted in serious losses of a wide range of food and fiber crops across the southern United States (Perring et al. 1991). Initial indications were that the outbreak consisted of the “type B” or poinsettia strain of the sweetpotato whitefly, Bemisia tabaci (Gennadius). In Canada, B. tabaci was first collected from greenhouse poinsettias in 1988 (Broadbent et al. 1989) and was subsequently found in 18 of 3 1 Ontario greenhouses sampled.

Subsocial behaviour, defined as postovipositional parental behaviour that promotes the survival, growth, and development of offspring, has been reported in diverse orders in insects (Tallamy and Wood 1986). Especially in the order Coleoptera, more that 10 families include subsocial species (Hinton 1981; Brandmayr 1992). For chrysomelid beetles, with the exception of members belonging to the subfamily Cassidinae, such behaviour has been known previously in a few species (Windsor and Choe 1994).

Conophthorus Hopkins 1915 cone beetles are among the most damaging pests of pine (Pinus spp.) seed production in North America (Hedlin et al. 1980; Cibrián-Tovar et al. 1986). Current work on cone beetle molecular identification and semiochemicals requires a rapid and reliable method for sexing adult beetles. Head microsculpturation (Schwarz 1895; Wood 1982), overall beetle length, head width, and internal genital structures (or parts of them) visible when extruded through the genital opening (Lyons 1956) have been suggested as characters to sex adult Conophthorus. Herdy (1959) pointed out that abdominal tergite morphology could be used to distinguish males from females. The latter seems to be the most reliable, non-destructive way to sex Conophthorus specimens. Published illustrations (Kinzer and Ridgill 1972) have been found difficult to interpret by many researchers. To increase the reliability in sexing adult Conophthorus beetles, we prepared scanning electron micrographs (SEMs) of the terminal abdominal tergites of adult males and females, which we present here, clearly showing the diagnostic features of each sex.

Larvae of the leafminer Chromatomyia fuscula attack many wild and cultivated grass species, including cereals, in Europe (Spencer 1969, 1991; Griffiths 1980) and are considered a major pest in parts of Fennoscandia (Spencer 1973; Andersen 1989a). However, in North America this species has been reported only on non-cereal grasses (Spencer 1969, 1991; Griffiths 1980). Therefore in 1994 a survey was undertaken in the region around Quebec City to determine if C. fuscula was truly restricted to non-cereal grasses or if, as in Europe, it also attacked cereals.

In a study on the population dynamics of the predators of insect pests in apple orchards of Quebec, three specimens of the Asian coccinellid Harmonia axyridis were found. This is the first occurrence of this species in Canada