This review article starts with the discovery of Bacillus thuringiensis Berliner in Japan at the turn of the century and notes that the observations of the early Japanese workers clearly show that they were aware of the toxin-mediated nature of the activity of B. thuringiensis toward insect larvae. The early work in Europe with B. thuringiensis against Ostrinia nubilalis (Hubner) showed that the bacterium had promise as a microbial control agent. The commercial development of B. thuringiensis in France in the late 1930s, and in Eastern Europe and the United States in the 1950s, is traced.

The success of introducing natural enemies for biological control was found to be about 75% higher employing new parasite–host (predator–prey) associations than those based on long-evolved associations between parasites and hosts. The lack of evolved interspecific balance in new species associations appears to explain the higher success rate. New exploiter–victim associations expand opportunities for the biological control of both introduced and native pests and should be used as the preferred method in selecting biological control agents.

Any realistic mathematical model of insect pest population dynamics to be used in maximizing control efficiency must mimic the effects of weather, the habitat, other organisms of various specles, food, and chemicals applied by man. However. before such a model can be constructed. suitable mathematical formulations for the mechanismof each type of factor must be developed.

Methanol, acetaldehyde, and ethanol have been identified in extracts of attractive wood and bark. The attractancy induced by anaerobic treatment in both sapwood and phloem of conifers and broadleaf trees was characterized by ethanol as the most concentrated component. In laboratory bioassays, ethanol was attractive at low concentration to both sexes of Trypodendron lineatum (Olivier). Methanol and acetaldehyde, at the concentrations found, apparently play no role in attraction. Monoterpenes had a repellent effect on T. lineatum.

We assessed bee diversity and abundance in urban areas of Vancouver, British Columbia, Canada, to determine how urban environments can support bees. Habitats examined were community and botanical gardens, urban wild areas, Naturescape flower beds and backyards, and traditional flower beds and backyards. A total of 56 bee species (Hymenoptera), including species of the genera Andrena Fabr. (Andrenidae), Bombus Latr. (Apidae), Osmia Panzer and Megachile Latr. (Megachilidae), and Halictus Latr. and Dialictus Pauly (Halictidae), were collected. Abundance exhibited strong seasonal variation. Wild bees were most abundant during late spring, whereas honey bees peaked at the end of the summer. The most abundant species seen was the managed honey bee Apis mellifera L. (Apidae), followed by wild Bombus flavifrons Cresson. Community and botanical gardens, and plants such as cotoneaster (Cotoneaster Medik. sp.) and blackberry (Rubus discolor Weihe & Nees) (Rosaceae), centaurea (Centaurea L. sp.; Asteraceae), buttercup (Ranunculus L. sp.; Ranunculaceae), and foxglove (Digitalis L. sp.; Scrophulariaceae), had the highest abundance of bees, while bee populations in wild areas were the most diverse. Weeds such as dandelions (Taraxacum officinale G.H. Weber ex Wiggers; Asteraceae) dominated these wild areas and had one of the highest diversities of bee visitors. Traditional flower beds with tulips (Tulipa L. sp.; Liliaceae) and petunias (Petunia Juss. sp.; Solanaceae) had relatively poor diversity and abundance of bees throughout the year. Our study suggests that urban areas have the potential to be important pollinator reservoirs, especially if both bloom and habitat heterogeneity are maintained and enhanced through sustainable urban planning.

Little attention has been given to the selection of the most effective agents for the biological control of weeds. The consequence has been a needlessly high failure rate and cost. Seven methods for their selection are discussed and a scoring system proposed as a means of incorporating their best features.

The acetone-soluble fraction of phloem tissue samples from 78 lodgepole pines was examined prior to and following artificial inoculation with Europhium clavigerum, a fungus transmitted by the mountain pine beetle. All trees showed quantitative increases in the concentration of extractives within 3 days after treatment. Further increases continued for at least 7 days. By this time qualitative changes in the chemical composition of the host tissue had also occurred.

Trees were defined as resistant or susceptible depending on whether they survived beetle attack under natural conditions. The composition of the acetone-soluble extracts was similar for the constitutive tissue of resistant and susceptible trees, but the total quantity of acetone extractives of reaction tissue was higher in resistant trees.

The ability of trees to respond to fungal inoculation is diminished by mass attack. Trees responded more extensively to inoculation prior to, than during, aggregation under field conditions. An experiment was conducted to simulate this relationship under controlled conditions by examining the effect of multiple fungal inoculations on the production of monoterpenes during the wound response. Individual trees showed a weaker quantitative response on stem sections administered high inoculation densities than on stem sections administered only a single inoculation. Those trees which responded most extensively to a single invasion by the pathogen were more responsive at all inoculum densities.

Larvae are reared on a synthetic diet in 1 oz. ribbed plastic cups. To eliminate the task of placing individual larvae on food, small gauze patches containing 25–40 larvae are placed in the cups prior to emergence from hibernacula. Larvae establish feeding sites between the ribs and are relatively undisturbed by others in the cup until the fifth instar. For maintenance of rearing stock the number of larvae is reduced to six to eight per cup, and they are allowed to pupate in the cups. Up to 100 pairs of pupae are placed in screened cages for adult emergence, mating, and oviposition. When the adults emerge balsam fir foliage is introduced and most of the eggs are deposited on the needles. Needles or twigs with egg clusters are transferred to large dishes the inside of which is painted black. The dish is tightly sealed with parafilm to which small gauze patches are attached and then placed under artificial lighting. The newly-hatched larvae are attracted toward the light and spin hibernacula in the gauze. The parafilm and gauze are sealed in plastic bags for cold storage treatment. By this system up to 10,000 larvae per week are easily produced.A discussion on the selection of rearing stock, rearing conditions, rearing containers, and the use of anti-fungal agents is included in the report.

The structure of the sclerous parts of representative Rhynchota is analyzed and compared with those of Psocoptera and Thysanoptera. Known data on embryology and musculature are also considered in deriving homologies of the structures. The term "suture" is redefined. Standardized terms for the sclerous parts of the head capsules of Rhynchota are recommended and compared with those of previous authors. A phylogenetic synthesis is presented, demonstrating the evolution of the homopterous head capsule through intermediate stages represented in the modern fauna by Psocoptera, Thysanoptera, and Hemiptera–Gymnocerata. Evidence is presented that Coleorrhyncha are related to Hemiptera rather than to Homoptera, that the Gymnocerata and Cryptocerata are natural groups within the Hemiptera and that Cicadomorpha, Aphidomorpha, and Fulgoromorpha are natural groups within the Homoptera.

Historical and recently published information on the parasitic associations of larval water mites with insect hosts is critically reviewed and summarized. A number of problematical published host records are either confirmed or rejected, and many newly discovered associations are reported. Associations of parasitic larvae with insect hosts are confirmed for species of water mites representing 70 of the nearly 300 described genera, in 28 of the 45 currently recognized families, and all 7 superfamilies. Life history, behavioral, ecological, and phylogenetic data on water mites of genera with known larvae are summarized to provide the basis for interpreting the evolutionary significance of observed host associations. Previously established hypotheses are evaluated in the light of a greatly expanded list of verified observations.

All four major southern pines can be killed by the southern pine beetle, but loblolly and shortleaf are much more susceptible than longleaf and slash. Oleoresin from more than 50 trees of each species was tested for composition and amount of monoterpenes and resin acids, viscosity, flow (rate, duration, and amount), and rate of crystallization. Discriminant function analyses were used to classify the loblolly and shortleaf trees as to probable resistance. The best classification used physical properties (total flow, flow rate, viscosity, time to crystallization). Supposedly resistant and susceptible trees were subjected to controlled attack, and the chemical and physical properties of four loblolly pines that survived natural attack were measured. Resistance is strongly related to the physical properties of the oleoresin, and can be predicted by these properties. Loblolly and shortleaf trees with “average” properties usually succumb to 100 or more attacks per sq. m of bark surface. Several trees classified as resistant survived a much higher rate of attack.

A rearing method, based upon an artificial diet, has proved successful in establishing laboratory colonies of 36 species of the genus Euxoa. The diet is described, along with methods for controlling disease, particularly by the use of antimicrobial agents.

Many of the 36 species of Euxoa have not been reared before and their habits and life histories are little known. The data derived from their development under laboratory conditions and which can be related to seasonal distribution are recorded. Particular emphasis is given to the overwintering stage and to the occurrence of an aestivating stage.

Outbreaks of insect pests periodically cause large losses of volume in Canada’s forests. Compounded with climate change, outbreaks create significant challenges for managing the sustainable delivery of ecosystem services. Current methods to monitor damage by these pests involve both field and aerial surveys. While relatively cost effective and timely, aerial survey consistency and spatial coverage may be insufficient for detailed monitoring across Canada’s vast forest-land base. Remote sensing can augment these methods and extend monitoring capabilities in time and space by incorporating knowledge of pest-host interactions and of how damage translates into a remote sensing signal for detection and mapping. This review provides a brief introduction to major forest insect pests in Canada (two bark beetles (Coleoptera: Curculionidae) and six defoliators) and the damage they cause, a synthesis of the literature involving aerial survey and remote sensing, and a discussion of how these two approaches could be integrated into future pest monitoring from a Canadian perspective. We offer some lessons learned, outline roles that remote sensing could serve in a management context, and discuss what ongoing and upcoming technological advances may offer to future forest health monitoring.

The use of olfactory repellents, especially against biting insects, is an important protective measure. It is also a matter of common knowledge that certain insects are able to locate their mates or their prey largely through the agency of attractive scents. Concerning these latter, Dethier remarks that, “we recognize the fact that no one attractant alone performs the service of guiding an organism to its proper habitat, or mate, or food. The desired end is achieved by a complex array of stimuli working in harmony. In chemical attractants, however, one finds precision guidance. The action of others, as light, temperature, humidity, is comparatively gross, approximating as it does usually, a vicinity. The extreme value of chemical attractants to an organism lies in the specificity and accuracy of operation.” (1).

The reproductive and demographic statistics of Aphidius smithi Sharma & Subba Rao parasitizing third-instar pea aphids, Acyrthosiphon pisum Harris, were determined under constant laboratory conditions. At host densities of 5, 10, 20, 40, 60 or 100 aphids/day, the parasite lived an average of 7 days at 20.5 °C. At host densities of ≤20 aphids/day, the total number of eggs laid and the total number of hosts attacked were limited by the numbers of hosts available. Fecundity was highest with an average of 870 eggs/female at density 100; the maximum number of eggs laid by any female was 1770. Superparasitism was common at all densities, resulting in up to 84% (at density 5) of all eggs being wasted. The relationship between host density and the number of aphids attacked per egg laid was linear for densities of ≥20 aphids/day. The intrinsic rate of natural increase (r) varied with the host density. It reached maximum value at density 100, calculated as 0.358 female/female/day and assuming an overall sex ratio of 1:1 males:females. Regression equations describing r as a function of host density and parasite sex ratio are provided. It is shown that the potential rate of increase of A. smithi exceeds that of the pea aphid over a broad range of average conditions. The parasite's functional response was convex (Holling type II) and decelerated with increasing density. The intrinsic attack rate (a′) and handling time (Th) were estimated from the functional response curve as a′ = 6.62 days−1 and Th = 0.0033 day (4.7 min). The ‘random parasite’ equation satisfactorily predicted the number of aphids attacked at each density.

In aquatic insects, emergence (ecdysis to the adult or subimaginal stage) varies widely in temporal pattern. The comparative study of this pattern is feasible and informative in orders such as Plecoptera, Ephemeroptera, Odonata, Diptera and Trichoptera in which all members of a population pass through the water-surface when emerging. Methods by which emergence rate can be measured are discussed. Four basic temporal patterns of emergence exist. Emergence may be (1) continuous with irregular fluctuations in rate; (2) rhythmic, with a lunar period; (3) sporadic, occurring at irregular intervals of a few days; or (4) seasonal. Examples of each of these patterns are given, and reference is made to the proximate and ultimate environmental factors which may be maintaining the patterns observed. Diurnal rhythms of emergence are excluded from consideration. When emergence is restricted seasonally in temperate latitudes, the degree of its synchronization within the emergence period varies widely but is usually constant and typical for a given species. This has provided the basis for an ecological classification of British Odonata, the validity of which is examined in the light of recent research.

The sex of the western pine beetle (Dendroctonus brevicomis Lec.) and the mountain pine beetle (Dendroctonus monticolae Hopk.) can be ascertained easily and with 100 percent accuracy by means of a secondary sex character on the seventh abdominal tergite of the male. This character can probably be used with equal accuracy to identify sex in all species of the genus Dendroctonus.

The need to distinguish between the sexes of adult bark beetles often arises in studies of biology, behavior, or response. The sexing procedure is laborious when large numbers of beetles are involved and external markings of sex are not known. It is then necessary to dissect each beetle to check the genitalia. Dissection is impossible when iniury to the insect must be avoided.

During a study of the effects of spray chemicals on the arthropod communities of peach orchards in the Niagara Peninsula, Ontario, begun in 1946, Stethorus punctillum Weise was found to be one of the more important predators of tetranychid mites. An investigation of its biology was undertaken in 1949 and continued through 1952. This paper presents chiefly the life-history, behaviour, and ecological aspects.

There is ample evidence that many plants overwintering in cold regions undergo a hardening process in the fall that enables them to survive lower temperatures than they otherwise could (Levitt, 1941). It is generally assumed by entomologists that a similar acquisition of cold hardiness protects those insects that require it. It is the purpose of this paper to examine the evidence that insects develop cold hardiness, and to present new evidence regarding its acquisition and loss.

The character-state distribution of various external and internal pro- and mesothoracic structures of Hymenoptera is described. Structures discussed are the transscutal articulation, axillae, notauli, median mesoscutal sulcus, parapsidal lines, pronotal lobe, postspiracular sclerite, prepectus, netrion, epicnemium, basalare, pronotal-mesothor-acic attachment mechanism, and 2 mesothoracic muscles, viz. mesotrochanteral depressor and second-phragmal flexor. Ancestral state and transformation of the characters are hypothesized, and shared derived states of higher taxa are determined. Hypotheses of synapomorphy are based on the shared derived states, and these hypotheses used to test previous hypotheses of relationship and classification. Relationships of Symphyta to Apocrita and of Aculeata to Terebrantes are discussed, and various aspects of classification of Symphyta and Terebrantes are examined. Finally, prior use of terms is reviewed for the thoracic structures studied. A single set of terms is selected for use throughout the order based on original use of each term and on hypotheses of homology.