Lygus species were sampled from the flowering heads and developing racemes of three species of Brassica [B. campestris L., B. juncea (L.) Coss., and B. napus L.] and two species of Sinapis (S. alba L. and S. arvensis L.) from cultivated fields during a survey from Prawda, Manitoba, to Lethbridge, Alberta. Lygus elisus Van Duzee and L. borealis (Kelton) were the most prevalent and abundant in Alberta and Saskatchewan; L. lineolaris (Palisot) was the most prevalent and abundant in Manitoba. Lygus rubrosignatus Knight, L. solidaginis (Kelton), and L. shulli Knight, previously unreported on Brassica, occurred in low numbers at most sites in Alberta and Saskatchewan.

Preston and Westwood (1981) reported on the distribution of Thymelicus lineola (Ochsenheimer) in Manitoba. They suggested that the species arrived here about 1970 by way of northwestern Ontario. At that time the population in central Winnipeg was the most western known in the Prairie region and they suggested that the spread of the species might be impeded by the arid nature of the Great Plains to the west. Klassen et al. (1989) noted that specimens subsequently had been taken 70 km west of Winnipeg at Rathwell(49°39'N; 98°33'W) near the western edge of the Red River Valley soils on the eastern edge of the Prairie. In 1986 Preston and McKillop collected the European Skipper at Eriksdale (50°52'N; 98°06'W) 100 km to the northwest of Winnipeg in the marginal lands of the interlake region (Klassen et al. 1989).

The use of pyrethroids in southern pine seed orchards to control seed and cone insects has sometimes resulted in outbreaks of scale insects (Nord et al. 1985). Onset of these infestations has been related in part to the relatively low contact toxicities of pyrethroids (Clarke et al. 1988). Pyrethroids have lower contact toxicities than organophosphorous insecticides against crawlers of the striped pine scale, Tourneyella pini (King). Our objective was to determine if a similar relationship existed for the pine tortoise scale, Tourneyella parvicornis (Cockerell), another scale insect pest that infests southern pine seed orchards.

In the course of a systematic survey from 1979 to 1982 in southern Quebec and eastern Ontario, 11 genera of mites, representing five families and 15 species, were found associated with Phyllophaga anxia (LeConte). The rate of infestation in each growth stage of the host ranged from 0 (eggs and prepupae) to 54.6% (third-instar grubs). Although it was not possible to determine with certainty the ecological roles of the mite taxa, and thus to assess the real impact of the species involved, it is likely that the Macrochelidae, Parasitidae, and possibly Eviphididae were partially regulating local P. anxia populations. The Acaridae and Histiostomidae (Anoetidae) probably had a harmless phoretic or saprotrophic relation with their hosts. Most of the mite species reported here were found associated with Phyllophaga Harris in Canada for the first time.

Gross morphological changes in Ceratitis capitata (Wied.) during metamorphosis within the puparium are described and temporally correlated with the appearance of main differentiation markers. A table that allows determination of physiological age of pupal and pharate adult stages is presented.

During 1984 and 1985 macrolepidopterous larvae were collected by pole pruning of foliage of black birch, mixed oaks, black cherry, and red maple at Cooper’s Rock State Forest in northern West Virginia. A total of 3027 larvae representing 100 species in 14 families was collected. The most abundant species were the noctuids Polia latex (Gn.) and Morrisonia confusa (Hbn.), and the geometrids Probole amicaria (H.-S.), Itame pustularia (Gn.), and Melanolophia canadaria (Gn.). Of the 100 total species of larvae, 43 were recorded from birch, 61 from mixed oaks, 63 from black cherry, and 57 from red maple.

Hypogastrura (Mucrella) arborea sp.nov. is described from a mature sitka spruce forest on Vancouver Island. Specimens occurred both in ground litter and in epiphytic moss in the canopy. The new species differs from the four other species of the subgenus by the absence of anal spines and the presence of 2-3-2 clavate tibiotarsal hairs.

Lodgepole pines, Pinus contorta var. latifolia Engelm., treated with the herbicide glyphosate applied by axe frill or drill hole into the sapwood around the root collar, were readily infested by mountain pine beetles, Dendroctonus ponderosae Hopk. On trees treated with 360 mg of glyphosate per centimetre of circumference, foraging woodpeckers, Picoides spp., debarked 15% of the bole surface within 10 weeks and > 30% after 1 year, compared with < 5% for controls. Foraging efficiency on mountain pine beetle at 4 m exceeded 90% after applications by axe frill of glyphosate at doses of 360, 36, and 3.6 mg per centimetre of circumference, compared with < 50% for controls. Glyphosate-treated trees rapidly became suitable for cavity excavation by woodpeckers.

We investigated the effects of synthetic honey bee (Apis mellifera L.) queen mandibular gland pheromone on colony foraging and brood rearing. Colonies newly established in the spring showed a significant, dose-dependent increase in the number of foragers gathering pollen, and individual pollen foragers returned to the nest with larger pollen loads. These two effects combined resulted in a doubling of the amount of pollen brought into colonies by foraging bees. Brood rearing also increased, but not significantly. In contrast, large, established colonies showed no effects at their summer population peak. We conclude that queen mandibular pheromone can significantly affect foraging, but its effects depend on colony conditions and environmental factors.

Several insect species have life cycles that last more than 1 year, because of very slow growth, repeated or prolonged dormancies, or very long lived adults. These long life cycles are correlated with environmental adversities, such as cold or unpredictable temperatures, patchy, unreliable or low quality food supplies, and natural enemies, as well as with some other properties such as large size. Long life cycles are most prevalent when several of these factors are present simultaneously. Adversities tend to prolong the life cycle of all individuals in the population, whereas unpredictability tends to extend the life cycle of only some individuals. Extreme extensions, such as diapause for more than 10 years, usually affect only a very small fraction of the population. Modest extensions, such as development over 2 years, prolonged dormancy for one additional adverse season, cohort-splitting between 1- and 2-year life cycles, and oviposition over two seasons, are relatively common. Insects with long life cycles provide insights into the nature of adaptations to adverse and unpredictable conditions, and also provide useful material for the analysis of questions related to population and community structure.

Survival and development of Ips paraconfusus Lanier larvae reared individually in intact Pinus ponderosa Laws. phloem without associated fungi and dietary supplements was demonstrated. Survival was reduced.in intact ponderosa pine phloem previously occupied by other larvae or by bluestaining fungi [i.e. Ophiostoma ips (Rumb.) vectored by I. paraconfusus, O. minus (Hedge.) H. & P. Syd. vectored by Dendroctonus brevicomis LeConte, O. clavigerum (Robins.-Jeff. & Davids.) vectored by D. ponderosae Hopkins, and Leptographium terebrantis Barras & Perry vectored by D. valens LeConte] compared with those reared without fungi or symbiotic yeasts. The highest proportion of larvae initiating tunnels and surviving to adult was observed for untreated eggs, and the lowest proportion occurred in the L. terebrantis treatment. Size was reduced and developmental rate was slower for larvae reared without fungi compared with larvae reared with associated fungi.

Tunnels excavated by first- and second-instar larvae reared without associated fungi were longer than those excavated by larvae reared with associated fungi. The most frequent larval turnabouts occurred with larvae reared axenically and reared with Ips yeast and O. ips. The fewest occurred with larvae reared with Ips egg niche plugs and from untreated eggs. Females reared free of any fungi or with Penicillium or Aspergillus did not oviposit in surface-sterilized ponderosa pine logs. Naturally eclosed females from ponderosa pine logs in which they developed, laid eggs in these sterilized logs. Potential for a new association among bark beetles and fungi is discussed.

Genetic divergence among populations of cone beetles, Conophthorus banksianae McPherson, C. coniperda (Schwarz), and C. resinosae Hopkins, was assessed by isozyme electrophoretic data. All but one of the eight loci examined were polymorphic, and one locus (Pgi) was sex-linked for C. coniperda. Genotype frequencies generally met Hardy-Weinberg expectations, and fixation index (FST) values indicated low-to-moderate genetic differences among conspecific populations. Fixed allele differences were detected at two loci, Pgi and Dia-2, which separated C. resinosae from C. coniperda, and thus confirmed their specific status established previously by morphological, karyological, and other biochemical characters. Electrophoretic data strongly suggested C. coniperda does not attack red pine cones, and C. resinosae does not attack white pine cones. No diagnostic loci were found to separate C. resinosae from C. banksianae. Phenetic clustering and pairwise comparisons of genetic distance coefficients indicated very little genetic divergence between C. resinosae and C. banksianae. These data were interpreted as failing to reject the null hypothesis that C. resinosae and C. banksianae are one species, an interpretation consistent with available taxonomic evidence from ecological, karyological, and other biochemical characters.

Metaltella simoni (Keyserling, 1878), an amaurobiid spider species precinctive to Argentina and Uruguay, and probably southern Brazil, is well established in the southeastern coastal regions of the United States (Leech 1972: 107). It was brought to North America by commercial and trade activities, hence the apparent distribution disjunction. The first Nearctic record is 23–30 July 1944, from Harahan, Louisiana (Leech 1972: 107).

Records of anomalies in trichobothrial pattern in pseudoscorpions are rare. Different abnormalities in the location of trichobothria in Xenochelifer davidi Chamberlin (Chamberlin 1949), Roncus pripegala Ćurčić (Ćurčić 1988), Neobisium carpaticum Beier, N. cephalonicum (Daday) (Ćurčić 1980), N. simoni (L. Koch), and N. bernardi Vachon (Ćurčić and Dimitrijević 1989) have been reported. In the Neobisiidae, anomalies in trichobothrial disposition are confined to adults and tritonymphs. The aberrations include the following: the irregular distribution of some trichobothria on both pedipalpal chelae, although normal setal count is still maintained, as in N. cephalonicum (Ćurčić 1980); the reduction in the number of trichobothria due to reduction in size or some other anomaly of one or both pedipalpal chelae, as in N. bernardi, N. simoni, and N. carpaticum (Ćurčić 1980; Ćurčić and Dimitrijević 1989); or the occurrence of a supernumerary trichobothrium when both pedipalpal chelae are of normal length, as in R. pripegala (Ćurčić 1988).

Members of the Holarctic genus Sperchon Kramer are among the most common and widespread water mites in lotic habitats. Approximately 225 species and subspecies of Sperchon have been described worldwide (Viets 1987), and about 25 of them have been reported from North America (Habeeb 1967). Smith and Cook (1991) estimate that over 100 species, mostly undescribed, occur in the Nearctic region. Adults and deutonymphs of this genus are free-living predators (Smith and Oliver 1986; Proctor and Pritchard 1989). Larval Sperchon are typically parasites of adult nematocerous Diptera, especially Chironomidae (Smith 1982; Smith and Oliver 1976, 1986) and Simuliidae (Davies 1959; Smith and Oliver 1986), but have also been reported to use certain Trichoptera as hosts (Smith and Oliver 1986). Larvae of Sperchon are initially aquatic, and actively crawl or swim to locate the prepupae or pupae of appropriate hosts. They transfer to host adults during ecdysis, embed their chelicerae in host tissue, and engorge rapidly, often within a few hours, on fluids before dropping off the host and into the water where the life cycle continues. Larvae preferentially select attachment sites on the thorax of hosts, but can utilize sites on the anterior segments of the abdomen when thoracic sites are already occupied. Most larval Sperchon are evidently specialized to parasitize hosts whose immature stages inhabit stenothermal, lotic habitats. We report here on the first records of larval Sperchon parasitic on mountain midges.