Adults of the two main rape-infesting flea beetle species in Manitoba, Phyllotreta cruciferae (Goeze) and Phyllotreta striolata (F.), that were parasitized by Microctonus vittatae Mues., emerged earlier from overwintering sites than unparasitized adults of the same species. Early emergence of parasitized beetles ensures early emergence of parasite adults and thereby probably increases the impact of the parasite on the host's population.

We monitored 12 colonies of the nomadic social caterpillar Malacosoma disstria Hübner (Lepidoptera: Lasiocampidae) on trembling aspen, Populus tremuloides Michx. (Salicaceae), under field conditions in spring 2007. We examined cohesion and synchronization of colonies and spatiotemporal activity patterns to compare foraging in the field with the results of laboratory studies and with foraging by central-place foragers. All colonies were highly cohesive; fragmentation was observed only three times. Activity was highly synchronous within colonies, with clear alternation between periods of activity and quiescence. Colonies performed 4.25 ± 0.12 (mean ± SE) activity bouts per day, and foraging was more likely to occur in the early morning than at midday. Colony activity was weakly correlated with temperature. In contrast to that of M. americanum (F.), the foraging schedule was flexible: foraging was observed at all recorded times and temperatures. Colonies searched for a new feeding site every 2.54 ± 0.37 days (mean ± SE) after a food source was depleted. Time spent at a food source decreased with colony size, and distance travelled between food sources increased with instar. Malacosoma disstria caterpillars on trembling aspen are not very selective; rather, they minimize movement, thus decreasing potential contacts with predators.

Pissodes terminalis Hopping attacks the terminal leaders of jack pine and at least two of the four geographic subspecies of lodgepole pine. The development on Pinus contorta murrayana in central California is described and compared with the development on jack pine in Canada. The oviposition period is synchronized with leader elongation, early spring to mid-summer. Feeding of the first three instars is in the phloem-cambial region and the fourth (last) instar is found in the pith. Part of the population completes development in late summer; adults emerge and presumably overwinter in the ground. The balance overwinter usually as mature larvae and occasionally as pupae, completing their development in the spring.

Mortality is high and is caused by feeding of associated insects, possibly resin flow, high parasitism and other unknown factors. Seven parasite species from five families were reared.

Diplolepis triforma n. sp. is described and distinguished from other members of the genus. Diagnoses are given for closely related species: D. ashmeadi (Beut.), D. inconspicuis Dailey and Campbell, D. nodulosa (Beut.), and D. verna (O.S.). Lectotypes are designated for D. ashmeadi, D. nodulosa, and D. verna. The genus Diplolepis Fourcroy is briefly reviewed. The biology and ecology of D. triforma and its gall are described. Diplolepis triforma induces a multichambered, polymorphic stem gall on Rosa acicularis and is distributed throughout central and western Canada. The form of the gall depends on the developmental condition of the host plant at the time of oviposition.

During a study on the population dynamics of the gypsy moth, Porthetria dispar (L.), conducted in the Town of Glenville, New York, some factors were found to affect the sexes differentially. The importance of this differential mortality is indicated by the fact that 78 per cent of the variation in the logarithm of an index of population trend (the ratio of population density from year to year) was associated with the logarithm of adult sex ratio.

Disease and desiccation during instars IV-VI and among pre-pupae were strongly selective against the female insects. This differential mortality caused a change in the pupal sex ratio from about 70 per cent females where no disease occurred to less than 25 per cent female pupae following an epizoötic. Ichneumonids, on the other hand, usually killed more male pupae than females, except when host size was reduced by excessive larval density and competition. The net result from this series of factors that distort the sex ratio has been to produce adult sex ratios varying from more than 80 per cent female moths to only 2 per cent females.

In this host species, as in most other animals, it seems that the population consequences of a mortality factor that kills the host sexes in different proportions should be evaluated in terms of the more critical (female) sex destroyed.

New-world leafhoppers with strongly flattened heads are here assigned to three tribes: Deltocephalini (six genera), Dorycephalini (two genera), and Hecalini (seven genera). Revised keys are presented to the new-world genera, and 44 new-world species of the Nearctic genera Attenuipyga Oman (Dorycephalini) and Neohecalus Linnavuori, the Holarctic genera Hecalus Stål and Memnonia Ball, and the widespread new-world genus Spangbergiella Signoret (Hecalini). In Dorycephalini, Attenuipyga (with subgenus Dorycara Emeljanov, stat.nov.) has nine species, including Attenuipyga (s.s.) joyceaesp.nov. from Manitoba and Dorycephalus sinuatus Beamer, 1942b = Dorycephalus minor Osborn, 1920, syn.nov. In Hecalini, 10 species in Hecalus, 3 in Neohecalus, and 15 in Memnonia are recognized, including 20 species formerly in Parabolocratus Fieber, plus Hecalus finnamoreisp.nov., Neohecalus magnificussp.nov., Memnonia anthalopussp.nov., Memnonia maiasp.nov., and Memnonia panzerisp.nov. from the northern prairies and Memnonia leptaleasp.nov. from the Gulf states. Parabolocratus continuus DeLong, 1938 and Parabolocratus planus Shaw, 1932 are reduced to subspecific status in Hecalus montanus, and three names are synonymized: Parabolocratus inflatus DeLong, 1938 = Hecalus montanus (Ball, 1900); Parabolocratus rotundus DeLong, 1938 = Hecalus major (Osborn, 1915); and Parabolocratus elongatus DeLong, 1938 = Memnonia grandis (Shaw, 1932) syn.nov.

Haemocytes of the Pacific beetle cockroach, Diploptera punctata (Esch.), are described and figured as they appear in vivo and in stained blood films. Although the haemocyte complex in this species is comprised of the same main categories as found commonly in other cockroaches, it is somewhat unusual due to morphological specialization among one category, the granular haemocytes. Most of the cells in this category are similar to those in other species, but some contain distinctive vesicles of mainly proteinaceous material, some are ovoid and contain spherule-size granules, and some are large, fusiform cells that are actively amoeboid in vivo. The other main categories, prohaemocytes, plasmatocytes, and spherule cells are fairly typical.

Larvae of the larch sawfly, Pristiphora erichsonii (Htg.), were fed foliage of tamarack, Larix laricina (Du Roi) K. Koch, treated with solutions of the vital dyes, Nile blue sulphate, rhodamine B, and coriphosphine O, to determine their suitability as markers. Coriphosphine O was highly toxic at the concentrations administered but successful tagging was obtained with the other two dyes. Optimal dye retention and survival were obtained when larvae were fed for 3 days early in the last stadium using Nile blue sulphate and throughout the last stadium using rhodamine B.

Both dyes persisted throughout development and were incorporated in the cocoons and the oviposited eggs. They could be readily seen in all stages except for the cocoons and for eggs that contained rhodamine B. The dyes could be detected in cocoons by treating them with cold KOH followed by ethanol. The presence of rhodamine B in the eggs could be ascertained by its yellow fluorescence in ultraviolet.

The dyes incorporated in the cocoons are relatively stable and laboratory tests indicate they probably can withstand weathering under normal field conditions over a 1-year period.

The use of these dyes for internal marking should prove useful in studying adult dispersal and flight range and as a technique for use in population studies of the larch sawfly.

A taxonomic treatment of the adults of the 12 known species of Neoleucopis Malloch, a subgenus of Leucopis Meigen, whose larvae prey on Adelgidae, is presented. The genotype, N. pinicola Malloch from North America, and two European species, N. atratula (Ratzeburg) and N. obscure Haliday, are redescribed; a neotype is designated for the former species and a lectotype is selected for the latter one. N. tapiae Blanchard, described from Argentina but known from many parts of the world, and N. manii Tanasijtshuk from India, are also redescribed. Seven new species are described: aciliosa (Japan), ancilla (Oregon), freyi (Switzerland, Finland), militia (Pakistan), nigraluna (India), orbiseta (Finland), and setigera (Chile). The paper includes a key to adults, and 40 figures.

Deraeocoris brevis piceatus Knight overwinters in the adult stage on pear and several other plants. Within pear orchards there are apparently two generations of D. brevis per year. Under laboratory conditions the developmental time from first instar to adult is about 25 days. During this period D. b. piceatus consumed nearly 400 eggs and nymphs of the pear psylla, Psylla pyricola Foerster. Most organophosphate pesticides tested were highly toxic to D. b. piceatus when applied directly to nymphs or adults but 7-day-old residues of these chemicals were only moderately toxic. Nonphosphate pesticides allowed fair to good survival of D. b. piceatus but do not fit into the total summer control program for pear pest control.

Trials using four different sex combinations of Colorado potato beetle, Leptinotarsa decemlineata Say, demonstrated that male beetles move upwind towards females, whereas no attraction was seen between any of the other combinations. Attraction was not found to increase significantly after the female reached 10 days old. Visual stimuli appear to be unimportant from a distance of 50 cm. Orientation behaviour by the male beetle was observed as it walked upwind towards the female; no identifiable calling behaviour by the female was observed. The data indicate a sex pheromone is being produced by the female and is used by the male for mate location from a distance.

Aleurodes Marlatti, n. sp.

Egg.— Size about. 1 mm. × .2 mm., exclusive of stalk, which is quite short, holding egg in upright position of leaf; regularly elliptical in outline. Colour, dirty yellowish brown, as seen on leaf; under transmitted light, yellowish. Shell without markings or sculpturing of any kind.

Larva.— Broadly elliptical. Colour, except in first stage which is yellowish, brownish to brownish black, varying in some specimens to an iridescent blue black; in later stages, margined all around with a short, rather squarely-trimmed, white waxy secretion, from the marginal wax tubes.

On the warm morning of May 27, 1956 at the Trinity Valley field station near Lumby, B.C., some laundry hanging out to dry attracted large numbers of a strange Cerambycid-like beetle. Closer examination showed this insect to be Priacma serrata (Lec.) of the family Cupesidae (Fig. 1), an interesting and infrequently collected species.

The family Cupesidae seems to have no economic importance, having only two genera and five species in North America that have been described (Blatchley, 1910). The larvae are reported to live in rotten wood; dissection of some adults collected at this time produced an entirely empty and deflated gut. The females and larvae of the closely related Micromalthus debilis Lec. are found in rotting wood in North America and were reported from decaying mine timbers far under ground in Johannesburg.

By comparing the number of moths caught in box-type traps, attractant light sources can be arranged in the following order of efficiency: 15-watt fluorescent rubes emitting ultraviolet and visible light > 15-watt fluorescent tubes emitting cool white light ≥ germicidal rubes behind glass > 15-watt fluorescent tubes emitting ultraviolet but little visible light ≥ 100-watt mercury-vapour bulbs emitting ultraviolet but little visible light. Noctuoid and large geometroid (sent. lat.) moths discriminate between these light sources on the basis of their spectral content, but pyraloids, other small microlepidoptera and some geometroids probably do not. Pyraloid moths escaped in significant numbers from traps with normal apertures (13/4-inch), after sunrise. They freely entered traps with narrow apertures (1/2-inch) but these traps caught fewer large moths.

Very few papers have been published on the life history of pseudoscorpions. The literature has been summarized by Kätner (1927), J. C. Chamberlin (1931), Beier (1932) and Roewer (1936-1940). The following contributions are based upon observation of two species of pseudoscorpions which were kept in captivity.

I should like to give sincere thanks to Dr. J. C. Chamberlin for reading the paper and giving valuable suggestions, to Dr. C. C. Hoff for determining the chernetid pseudoscorpions, to Mrs. Rosalie Rogers Talbert for assistance in maintaining and feeding the pseudoscorpions; and to my wife who has aided in the work.

Parasitoid studies were conducted concurrently with a pilot control project to test the efficacy of Dipel® WP, a formulation of Bacillus thuringiensis Berliner, in reducing western spruce budworm, Choristoneura occidentalis Freeman, populations. Twenty-one species of parasitoids were recovered in rearings of the budworm and an associated defoliator, the spruce coneworm, Dioryctria reniculelloides Mutuura and Munroe. Parasitoid population alterations occurred following application. Parasitism by Apanteles fumiferanae Vier. and Glypta fumiferanae (Vier.), which attack prediapausing first-instar budworm, was significantly higher in treatment blocks following B.t. application. Parasitism by Phaeogenes hariolus (Cr.), Cermoasia auricaudata Tns., and Madremyia saundersii (Will), parasitoids of late instars and pupae, was significantly lower following treatment. Comparisons of parasitoid populations were made between pre- and post-spray sampling periods and between treatment and check blocks.

A mathematical model is developed which simulates the effect of the number of eggs in females, food source, and soil conditions, on ovogenesis and oviposition of Japanese beetle populations. The number of eggs in females is used as the state indicator, and simulated trends are compared to field data. Potential applications in pest management are discussed.

Transport and dispersal of odours by air currents is considered an important factor in scolytid response to attractant sources. This viewpoint provides explanations for some puzzling field observations and data, and helps identify significant questions about scolytid flight behaviour. There is a need for "odour meteorology", which would be concerned with the rates and types of odour distribution near the ground, and would provide a basis for the most effective use of chemical attractants in natural environments.

Removal sampling, sweepnet sampling, and visual count sampling conducted while walking at constant velocity through a field were used to sample populations of adults of five coccinellid species in plots established in spring wheat fields, Triticum aestivum L. Estimates of absolute population density obtained from two 20-min removal samples taken from each of six 5- by 5-m sub-plots per plot proved reliable and were used to convert estimates obtained from sweepnet sampling (180 sweeps per plot) and visual counts (36 min per plot walking at 10 m/min) into absolute estimates of population density. Population density estimates obtained by removal sampling were quite precise except for species with low capture efficiencies and low population densities.

Crop plant growth stage influenced the numbers of beetles caught in sweepnet samples and was incorporated in regression models for converting sweepnet catch to absolute density. Values of R2 of regressions ranged from 0.51 to 0.90, depending on species. Visual counts were influenced by temperature and aphid density, and these variables were incorporated in regression models. Values of R2 for regressions relating visual counts to population densities ranged from 0.63 to 0.94, depending on species.

Trichogramma pretiosum Riley was released in the field for suppression of corn earworm, Heliothis zea (Boddie), egg populations in Nova Scotia in 1985–1987. Trichogramma pretiosum reduced com earworm populations 7.4–53% compared with chemical treatments reductions of 19–100%. Trichogramma pretiosum were not as effective as insecticides, especially when populations of the corn earworm were low (less than five larvae per 1000 ears). Timing of T. pretiosum releases and spray applications were determined by blacklight trap catches and were considered critical for effective control.