The effects of fiood od the fecundity and longevity of the adults of hymenopterous parasites vary remarkably, not only between species that are host feeders and those that are not host feeders, but also within these groups. It is known, for example, that the females of Itoplectis conquisitor (Say) develop only few eggs without feeding on body fluids of their host. In the present investigations it is shown that the females of Scambus buolianae (Htg.) are not able to deposit any eggs without first feeding on the tissues of their host. Such information is important for the successful establishment of newly-imported parasites.

Extensive collections of synanthropic fly parasitoids in animal excrement accumulations in the United States, Mexico, Costa Rica, Puerto Rico, Uruguay, Chile, Denmark, Israel, and South Africa yielded seven forms of a Muscidifurax complex which were totally or partially reproductively isolated. Morphological studies of female and male parasitoids coupled with biological and zoogeographical information permitted the identification of five sibling species. Muscidifurax raptor Girault and Sanders 1910 is redescribed and four additional species are described as new: M. zaraptor, from the southwestern United States; M. raptoroides from Central America and Mexico; M. uniraptor from Puerto Rico, and M. raptorellus from Uruguay and Chile. Biological notes are added to the descriptions, and it was postulated that the genus is undergoing a process of speciation with local populations slowly becoming reproductively isolated and eventually giving rise to morphologically distinguishable entities. Most evidence suggests the establishment of Muscidifurax in the New World, concomitant with or shortly following the establishment of muscoid flies in accumulated excrement. Scanning electronmicroscopy was used in the analysis of some morphological structures.

Effects of temperature and resin on hatch of mountain pine beetle eggs were investigated. Per cent hatch was related to total degree-hours above 40°F, the average being 5113 for 50% hatch under field conditions. Average supercooling point was 1.3°F. Higher temperatures in the freezing range were lethal with long exposure. Atmosphere saturated with volatiles from liquid resin had very little effect on egg hatch, but direct contact with liquid resin greatly reduced egg hatch.

A generalized competition model for predators or parasites was developed from data obtained from a specific parasite–host system. It was structured in three parts. The first simulates the effects of exploitation, where the number of attacks and their distribution among prey or hosts determine how many prey or hosts survive. Since the negative binomial distribution described these distributions consistently, the exploitation submodel was developed from it. The second portion of the competition model concerned interference between searching predators and parasites. Although interference is a universal phenomenon, we were able to show that its effects become important only at predator densities much higher than those that occur in nature. Thus the interference component can be essentially ignored. The third and final component concerned the outcome of competition between parasite progeny within their host. It was developed from Fujii’s competition model which allows for the simulation of both scramble and contest types of competition.These three submodels of competition were combined and coupled with a previously published model of the effects of prey density on attack. In this way the full consequences of different prey and predator densities could be simulated using a model whose constituent parts had been carefully tested for descriptive adequacy. The simulations showed the way individual predator attack, per cent predation, and progeny production were affected by different degrees of contagion in the distribution of attacks, by scramble vs. contest competition, and by the degree to which parasites could avoid hosts already attacked.

A new species of sarcophagid, Colcondamyia auditrix, is described, which locates its cicada host by sound. The fly was shown to respond to the mating song of the male cicada, and the majority of parasitized cicadas were male. Parasitism of females occasionally occurs when they are attracted to males simultaneously with the parasite. Levels of parasitism varied from 18.6% in 1962 to 0.2% in 1967 to 14.1% in 1973. Male cicadas lost their sound producing capability following parasitization, rendering them inaccessible to further female flies and thus apparently preventing multiple parasitism.

A simple model for growth and development of the ladybird beetle (Hippodamia convergens G-M.) which partitions aphid biomass eaten into components of excretion, assimilation, growth and/or reproduction, and metabolic costs associated with searching and maintenance respiration is reported. All parameters in the model were estimated from simple minimal laboratory experiments, and have biological and/or physical meaning. The effects of predator nutrition on aging, survival, and emigration were also modelled. Most rates in the model for growth, reproduction, and respiration are controlled by the interplay between prey consumption and maximum prey biomass demands. The model for biomass flow is related to standard predator/prey theory.

Saproxylic insect assemblages inhabiting dead wood in Canadian forests are highly diverse and variable but quite poorly understood. Adequate assessment of these assemblages poses significant challenges with respect to sampling, taxonomy, and analysis. Their assessment is nonetheless critical to attaining the broad goals of sustainable forest management because such species are disproportionately threatened elsewhere by the reductions in dead wood generally associated with commercial exploitation of northern forests. The composition of the saproxylic fauna is influenced by many factors, including tree species, degree of decay, stand age, and cause of tree death. Wildfire and forest harvesting have differential impacts on saproxylic insect assemblages and on their recovery in postdisturbance stands. Exploration of saproxylic insect responses to variable retention harvesting and experimental burns is contributing to the development of prescriptions for conserving saproxylic insects in boreal forests. Understanding of processes that determine diversity patterns and responses of saproxylic insects would benefit from increased attention to natural history. Such work should aim to provide a habitat-classification system for dead wood to better identify habitats (and associated species) at risk as a result of forest management. This tool could also be used to improve strategies to better maintain saproxylic organisms and their central nutrient-cycling functions in managed forests.

Baker and Wharton (1952) elevated the Phytoseiidae, formerly a subfamily in the Laelaptidae, to family rank and included two subfamilies: the Phytoseiinae and the Podocininae. Evans (1957) subsequently elevated the latter to family rank also, leaving only the subfamily Phytoseiinae in the Phytoseiidae.

Both Evans (1958) and Chant (in press) characterized the Phytoseiidae as having a two-tined palpal claw, a single dorsal shield in the adult, not more than 21 pairs of setae on the dorsal shield, and a ventrianal shield, or remnant thereof, in the adults of both sexes. One of the present authors (H.A.D.) recently collected specimens of a mite that has this combination of characters except that the dorsal shield of the adults is divided into two sub-equal parts instead of being single. Most of the features of this mite indicate that it cannot reasonably be separated from the Phytoseiidae and that the presence of two dorsal shields justifies the erection of a new subfamily, described below.

The reactions of resistant and susceptible Abies grandis to attacks by Scolytus ventralis are described. Resistant reactions were characterized by the production of secondary resin in the cells of the phloem parenchyma and the formation of callus tissue and traumatic resin cavities at the cambium–sapwood interface. S. ventralis exhibited varying degrees of gallery establishment on resistant hosts. Some individuals were repelled by phloem resinosis before reaching the vascular cambium while others were able to construct galleries of varying length before they were repelled by resin flow from the phloem and traumatic cavities. The degree of gallery establishment appeared to be inversely associated with the rapidity of the host’s response. Necrotic resinous lesions developed around the attack and extended vertically to various distances from the attack. Callus tissue, produced at the margins of this lesion, eventually grew over and healed the wound. Vulnerable grand firs were characterized by the lack of resinosis in the phloem parenchyma, and the absence of extensive callus production and traumatic cavity formation.

Body size and mass variation of queen bumble bees (Bombus Latr. spp.) were analyzed in relationship to hibernation survival and optimal body size. Body mass and size (measured by radial cell length) were significantly correlated in six of eight species. Also, spring queens of B. occidentalis Greene were, on average, significantly larger yet lighter than young fall queens. These observations were consistent with weight loss known to occur during hibernation coupled with greater mortality of small queens over the winter. Thus large queens may be at an advantage for this and other reasons (e.g. foraging efficiency, usurpation). However, an optimality model showed that an intermediate body size was optimal if the reproductive success of a colony (foundress queen and workers) was considered. The assumptions were that fitness did not increase linearly with body size but was a convex function, and that colonies only had a fixed amount of energy to invest in reproductive offspring leading to a trade-off between size and number.

The spruce beetle, Dendroctonus rufipennis (Kirby), has possible life cycles of 1 or 2 years. Empirical and experimental evidence suggest that temperature is the primary regulator of these life-history pathways. These different life cycles potentially result in substantial differences in population dynamics and subsequent spruce mortality. A multiyear field study was conducted in Utah, Colorado, and Alaska, to monitor spruce beetle development under a variety of field conditions with concurrent air temperature measurements. This information was used to model the tree- or stand-level proportion of univoltine beetles as a function of air temperature. Temperatures were summarized as averages, cumulative time, and accumulated heat units above specified thresholds over various seasonal intervals. Sampled proportions of univoltine insects were regressed against the summarized temperature values in logistic models. The best predictive variable, as evaluated by Akaike’s Information Criterion, was found to be cumulative hours above a threshold of 17 °C elapsed from 40 to 90 days following peak adult funnel-trap captures. Because the model can be used to forecast trends in spruce beetle populations and associated spruce mortality, it is a tool for forest planning.

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.

We provide keys for identifying the 26 bumble bee species (Bombus and Psithyrus) found in Canada east of Manitoba, and information on their ecology and distribution. The keys are designed for field use and rely primarily on colour patterns rather than on microscopic features.

It is well known that no living organism can continue to multiply indefinitely. Sooner or later environmental factors combine to slow down the rate of increase and eventually bring it to a halt. This is the phenomenon we call “natural control”. Among the environmental factors responsible for the natural control of insect pests, parasitic and predacious insects sometimes play an important part.

The North American species of the genus Olophrum Erichson are revised. Seven species are recognized, the holarctic species O. latum Mäklin, O. boreale Gyllenhal, O. consimile Gyllenhal, and O. rotundicolle C. R. Sahlberg; the eastern North American species O. obtectum Erichson, and the new species O. cascadeuse known from northern California and eastern Oregon and O. idahoense known from southern Idaho.

Lectotypes are designated for O. marginatum Mäklin (= O. consimile), O. parvulum Mäklin (= O. consimile), O. convexum Mäklin (= O. rotundicolle), and O. convexicolle LeConte (= O. rotundicolle). The following new synonymy was established: O. bernhauerianum Scheerpeltz, O. recticolle Scheerpeltz, O. recticolle curtipenne Scheerpeltz are synonyms of O. consimile; O. quesneli Hatch is a synonym of O. boreale; and O. brevicolle Bernhauer is a synonym of O. latum. All species are described and illustrated with scanning electron photomicrographs and line drawings, five maps showing the North American distribution of each species are provided, and a key is presented to aid in the identification of the species. All available records and biological data for the species are provided.

The sexual behavior of 11 species of Pyrota is described. Analysis of the functional significance of anatomical secondary sexual characters in these species and a survey of similar modifications in others indicates that the general pattern observed is characteristic of the genus. Adults exhibit little aggressive behavior, and courtship involves prolonged physical contact between the sexes. Male courtship activities follow a regular cyclic pattern, as he alternately mounts above the female to perform one series of acts (palpation, dorsal antennation, and rocking) and orients behind her to perform another (leg grasp, palpal insertion beneath her elytra, lifting of her body, posterior antennation, abdominal curvature and stroke, and genital hold). Copulation entails abdominal pumping by the male.

As a prelude to comparative studies, a new classification of the Meloidae is proposed. Characters of sexual and related behavior at the subfamilial level and anatomical characters associated with them are discussed in an evolutionary context. Nemognathinae and, by inference, Eleticinae have simple courtship behavior, copulate dorso-ventrally for short periods of time, and do not prepare sites for oviposition. Meloinae have more elaborate courtship, copulate in a linear position for extended periods, and oviposit in specially prepared cavities in the ground.

Compared with that in other Meloidae, courtship behavior in Pyrota is both complex and highly distinctive. Interspecific differences, considered in detail for six species, involve variation in the precise manner of performance of acts and their temporal relationships. Systematically the ethological data are in reasonable accord with those from other sources except that the courtship behavior of P. concinna is more divergent from that of its presumed relatives than would be expected on the basis of anatomical and ecological characters. An explanation of this discrepancy is proposed in terms of the evolutionary reinforcement of ethological differences functioning in interspecific reproductive isolation.

High fecundity from Chrysopa carnea was obtained from an inexpensive diet containing a commercially available product of dried, inactive Saccharomyces fragilis yeast and whey proteins. The effective diet consists of this product mixed with sucrose and water. S. fragilis autolysed 17 hours was more effective in diets than when autolysed for 36 hours or unautolysed, and was as effective as autolysed brewers’ yeast, S. cerevisiae.

Hot spots may develop quickly in farm stored grain under Canadian winter conditions. Heavy infestations of mites, insects and fungi may accompany such hot spots (Stirrett and Arnott, 1933; Watters, 1955). Once the heating process is initiated, whatever its cause, it brings about a rapid deterioration of grain, tluough charring of kernels, and reduction of their germinability, and by providing optimum conditions for the growth and reproduction of storage fungi, insects and mites.

The fauna of the sporophores of the perennial bracket fungus Fomes fomentarius (L. ex Fr.) Kickx were examined in a 3-year study. One species of molluscs and more than 152 species of arthropods excluding mites, representing 13 orders, 70 families, and 5400 individuals, emerged from or were found on or in, 1448 sporophores detached from dead birch trees; the sporophores were collected each year in Gatineau Park, Que., kept individually in screen-topped glass jars in a laboratory, and examined for several months. Mites, which were recorded quantitatively only in the final year, added 4 orders, 19 families, and 30 species to the preceding totals. Mites were the most frequently occurring and probably the most numerous arthropods, followed by Coleoptera, Psocoptera, Collembola, Hymenoptera, and Diptera.The key organisms of the fauna were five species of beetles that were primarily responsible for tunnelling and destruction of the sporophores and would therefore exert great influence on the composition of the community. Their tunnels provided shelter and food for many smaller arthropods or facilitated their feeding. Some beetle species tunnelled the sporophores for one season and others, for several, but many living sporophores and most dead ones tunnelled by beetles were tunnelled in the same season by more than one species of beetles.There was considerable latitude in types of sporophores inhabited by various arthropods but some species were particularly attracted to living or dead, to younger or older, and to smaller or larger, sporophores. Some species were also attracted to certain regions of the sporophore more than were other species.Possible economic implications of observations made in the study are discussed.

Arctic arthropods are essential prey for many vertebrates, including birds, but arthropod populations and phenology are susceptible to climate change. The objective of this research was to model the relationship between seasonal changes in arthropod abundance and weather variables using data from a collaborative pan-Canadian (Southampton, Herschel, Bylot, and Ellesmere Islands) study on terrestrial arthropods. Arthropods were captured with passive traps that provided a combined measure of abundance and activity (a proxy for arthropod availability to foraging birds). We found that 70% of the deviance in daily arthropod availability was explained by three temperature covariates: mean daily temperature, thaw degree-day, and thaw degree-day2. Models had an adjusted R2 of 0.29–0.95 with an average among sites and arthropod families of 0.67. This indicates a moderate to strong fit to the raw data. The models for arthropod families with synchronous emergence, such as Tipulidae (Diptera), had a better fit (average adjusted R2 of 0.80) than less synchronous taxa, such as Araneae (R2 = 0.60). Arthropod abundance was typically higher in wet than in mesic habitats. Our models will serve as tools for researchers who want to correlate insectivorous bird breeding data to arthropod availability in the Canadian Arctic.