Two metal granaries each containing 27.3 tonnes of dry wheat (13–14% m.c.) were artificially infested with Cryptolestes ferrugineus (Stephens) and sampled for up to 4 years to determine fluctuations in insect density as influenced by changes in grain temperature and moisture content during storage. Density remained low (fewer than 5 insects/kg) throughout the period of study. Most insects were found at the floor near the wall on the south side of the granary. The temperature in the centre of the grain mass ranged from −5° to 22 °C during the 4 years. During a single season, moisture content varied as much as 5% at the centre near the surface of each grain mass, but did not vary more than 1% at other locations. In the first year of storage, the viability of the wheat ranged from 80% to 96%, and after 3 years in storage, 68% to 100%. Since no significant change was recorded in the temperature, moisture content, or germination of the wheat in the granaries, it was concluded that the biological activity of a low density population of C. ferrugineus does not initiate heating that occasionally occurs in farm-stored grain in Canada.

The banded woollybear, Pyrrharctia (Isia) isabella (J. E. Smith,) was reared under laboratory conditions from egg to adult. Individually reared larvae were fed one of six artificial diets and fresh plantain at 26 °C, light/dark (h) 15/9. The times of moulting, larval and pupal weights, and adult characteristics (fertility, sex) were recorded.

Larvae were easily reared on bean, wheat germ, casein – wheat germ and fresh plantain, while casein, alfalfa, and plantain diets proved unsatisfactory. Rearing procedure and developmental characteristics are discussed.

Only soil temperatures below −7°C are likely to cause significant pupal mortality of M. configurata in the field, and only if exposure periods are sufficiently prolonged. At −17°C, a temperature not uncommonly encountered in the soil at 10 cm during the prairie winter, near total mortality occurred within 1 week in laboratory tests and significant mortality (20–30%) occurred within 1 day. The survival time at −12°C was considerably longer, and 50% mortality occurred after about 6 weeks of exposure. Pupal mortality caused by cold might thus vary from 0 to 100% depending on local climatic and field conditions and therefore is an essential component of a survival model for the species.

Exposure to cold accelerates diapause development by as much as four orders of magnitude for the lowest temperature tested (−17°C). However, the acceleration of diapause development by sub-zero temperatures appears to be of limited phenological significance, since in western Canada the pupae spend at least 40 weeks in the soil and can easily complete diapause development within this time at 0° to 5°C. Further evidence for a major reorganization of the endocrine system of M. configurata pupae during stage 2 of diapause development is presented.

Resistance of 360 varieties of Phaseolus vulgaris L. to Empoasca kraemeri (Ross and Moore) was tested in the greenhouse. Thirty promising varieties were subsequently evaluated for resistance in the field when 30 days old. Seedlings in the greenhouse were infested with field collected adults for 3 days, and the resistance was tested against first generation nymphs. A highly significant positive correlation existed under greenhouse conditions between the numbers of nymphs present on the plant and the plant damage (expressed as quality) under low, but not high infestation pressure. No such relation was found in the field. There was no correlation between numbers of nymphs found on the 30 varieties in the greenhouse and the field, but there was a highly significant correlation in the damage (quality). No correlation was found in the field between the numbers of nymphs and the plant height or volume. A rank correlation test showed that quality (resistance) of the plants was highly significantly related in the greenhouse and field tests.

Diapause induction studies showed that face flies, Musca autumnalis De Geer, from a recently established colony, entered diapause more readily than those that had been colonized for many years. Photoperiods of less than 16 h of light induced diapause at 16° and 27 °C but more flies entered diapause at 16°C. Maximum numbers of flies entered diapause under total darkness at 16°C, but the critical photoperiod corresponding to natural periods of daylight in late summer was 15 h of light at 16°C. Diapause termination studies indicated that 4 months’ exposure to 5 °C under total darkness was required for the termination of diapause.

Two manners in which parasitic Hymenoptera gather reproductive proteins are described. Hydropic species gather all protein necessary for reproduction as larvae. Only 5–10% of the material necessary to form a viable first instar larva is put into each egg; the remainder is gathered by the egg within the host. Egg storage is in the lateral oviducts, handling times are short and egg production is independent of host density. Three Bathyplectes spp. are examples of hydropic parasitoids. Anhydropic species gather some or all protein as adults, often by host feeding. All the material necessary for the formation of a viable first instar larva is stored within the egg. The eggs are held in the ovary until laid. Handling times are longer and continued egg production is dependent upon host density. Tetrastichus incertus (Ratzeburg) is an anhydropic parasitoid.

Hydropic parasitoids appear best suited for biological control efforts in ephemeral situations (i.e. cotton or alfalfa). Anhydropic parasitoids appear best suited for biological control efforts in stable situations (i.e. citrus or walnuts).

The surface features and the fine structure of the chorion of the bumblebee egg are described. The egg is covered by a reticulum of polygonal cells with elevated walls and with variously shaped protuberances at the wall junctions, except at each pole where the reticulum evanesces, Differences in the shape, size, and surface sculpturing of the protuberances and in the appearance of the walls are species-specific and a key to the eggs of the nine species is provided. The very thin chorion is composed of two parts with a third part comprising the walls of the polygonal cells; the egg possesses no aeropylar openings and micropylar openings were not found.

Knight (1925) erected the genus Neoborella for his species tumida, collected in Arizona and Colorado. Later (1927) he indicated that the species was collected on mistletoe, Arceuthobium sp. growing on pines at Mt. Lemmon, Ariz., and on A. cryptopodium Engelm. growing on Pinus scopulorum Engelm. (= Pinus ponderosa Laws.) at Estes Park, Colo. The genus remained monobasic until Herring (1972) described Neoborella xanthenes collected on A. americanum Nuttall. The specimens were collected by R. E. Stevens, U.S.D.A., Forestry Service, Fort Collins, Colo. He (in litt.) confirmed that the host pine was Pinus contorta Dougl. Carvalho and Schaffner (1974) described a third species, brevirostris, from Brazil, but the host plant of this species is not known.

Direct observation (DO) of arthropods on soybean plants was compared with another absolute method, clam trap (CT), and with sweepnet (SW) sampling during a season-long investigation of the colonization by arthropods of two east central Illinois soybean fields. In terms of number of species detected, DO vs. CT showed good agreement between the two fields, while DO vs. SW showed poor between-field agreement. Proportion of similarity (PS) and quotient of similarity (QS) values were higher in a DO-CT comparison than in a DO-SW comparison. Performance similar to that of the other absolute method, consistency of results, ability to use the method throughout the entire season, relatively high numbers of species and individuals detected per unit area sampled, relatively short time required to sample a site, and the capability of yielding a precise record of important interactions among soybean arthropods indicate that direct observation is an effective method for sampling the arthropod community on a row crop such as soybean.

Dendroctonus terebrans (Olivier) adults may be accurately sexed by means of the seventh abdominal tergite. Stridulation sound and stridulation movement are useful especially in field observations but not completely accurate because some male beetles do not stridulate and some females do.

Laboratory rearing is accomplished by the introduction of parent beetles to fresh pine bolts. Development takes ca. 78 days at 23 °C ± 2 °C or ca. 1302 degree days of effective temperature.

The 26 North and Central American species of Thraulodes are discussed, and synonymies and other pertinent data are presented for all species. On the basis of nymphal gill characters two groups of related species are recognized. Thraulodes brunneus, T. speciosus, T. sp. A, T. sp. B, and T. sp. G are included in the brunneus-group, and T. gonzalesi, T. lunatus, T. packeri, T. salinus. T. zonalis, T. sp. C, T. sp. D. T. sp. E, and T. sp. F form the gonzalesi-group, The 14 species of nymphs are included in an illustrated key and on distribution maps, and the account of each includes complete synonymy, nymphal description, and collection records. Nymphs designated as Thraulodes spp. A, B, C, D, E, F, and G are described, and new descriptions are presented for nymphs of T. packeri and T. zonalis.

In most species of Euxoa a high proportion of the females mate more than once. The mean number of matings per mated female in natural populations of 13 species ranged from 1.65 to 10.86. Mating frequency data for laboratory populations of three of these species indicate that laboratory rearing and confinement does not significantly alter the incidence and level of multiple mating. The propensity for multiple mating is species characteristic although the observed level in samples from the field can vary significantly depending on the age structure of the populations sampled and probably also on other parameters of populations or environmental factors. Since species differences in the tendency for multiple mating are probably manifestations of different reproductive strategies some of the possible advantages of this behavior are discussed.

Larvae of 13 species representing eight genera and seven families of Arrenuroidea are described, including those of Momonia marciae Habeeb, Midea expansa Marshall, Midea alaris Young (? = M. determina Marshall), Laversia berulophila Cook, Mideopsis (s.s.) crassipes Soar, Mideopsis (s.s.) borealis Habeeb, Mideopsis (s.s.) marshallae Cook, and Mideopsis (Xystonotus) aspera (Wolcott) for the first time. Diagnoses and keys are provided for the genera, subgenera, and species groups involved. Information on host associations is given for each species. Observations on morphology and host associations of these larvae provide the basis for an original, though preliminary, outline of phylogeny in the superfamily.

Factors affecting the winter survival of temperate-zone insects are reviewed. Certain species suffer high winter mortality especially in cold years, or in years with below normal amounts of insulating snow.

Survival depends on the choice of winter microhabitat and on cold-hardiness, but also on biological features that have not previously been emphasized. These include behaviour that results in placement of overwintering eggs in less severe sites and manufacture of cocoons or other structures that retard inoculation by ice, or desiccation. The possible role of habitat heterogeneity in facilitating population survival is stressed.

Microhabitats are characterized mainly with respect to temperature. They differ markedly among geographic areas and not only in midwinter conditions (including the extent of variation), but also in the time at which entry to the microhabitat in fall is necessary to avoid the risk of frost. The cues that govern entry into these microhabitats include negative phototaxis in many species but have not been subjected to quantitative analysis. Deeper layers are warmer in winter but warm up more slowly in spring and therefore some species, especially in arctic habitats where rapid vernal development is advantageous because the season is short, overwinter in superficial or insolated sites.

Supposed mechanisms of cold- and freezing-injury and its avoidance are reviewed. There are several theories of freezing-injury: many modem theories focus on damage to the cell membrane, apparently caused by changes in cell volume induced during freezing. Injury is avoided by suppression of haemolymph nucleators (enhancing supercooling); or by a variety of methods, especially those involving solutes, minimising damage to frozen tissues. Among these solutes, the prevalence of glycerol in overwintering insects is not unexpected since glycerol is a normal metabolite in animals and can play several possible roles in cryoprotection.

Cold-hardiness is metabolically costly because of these solute adjustments. The cold-hardiness of a taxon depends partly on climatic history during its evolution. Faunal composition at the highest latitudes reflects this dependence.

The winter survival of many high-latitude insects varies rather widely from year to year; but the many detailed studies on cold-hardiness that have been made in the laboratory have seldom been related to natural mortality.

The overwintering stage depends partly on the taxon. It is often fixed within a genus, but less closely within higher taxa. Proportionately more species overwinter as larvae at higher latitudes, especially when the life cycle lasts more than one year. Habitat also influences the overwintering stage: aquatic species generally overwinter as larvae, although species of temporary pools frequently overwinter as eggs. Overwintering in more than one stage is not common.

This review suggests that winter survival of a group depends on latitude (or its climatic equivalent), habitat, and evolutionary history. It might therefore be especially useful to compare cold-hardiness, developmental rates, control of the life cycle and other features among species at the same latitude from each extreme of a series, that contrasts cold-hardy groups in stable habitats (such as Chironomidae) with aerial or vegetation dwelling groups that are not cold-hardy (such as Orthoptera). Future study of winter survival also demands more ecological data (overwintering stage, microhabitat, and conditions experienced there) for a larger sample of the fauna, and the simultaneous measurement of cold-hardiness.

The chaetotactic nomenclature proposed by Lindquist and Evans (1965) for the Gamasina, using the family Ascidae as examplar, is adopted for use in the family Phytoseiidae. Probable setal homologies were determined by: examining and comparing ontogenetic relationships in both the Phytoseiidae and Ascidae; standardizing the shape and size of the dorsal shield of exemplars from 7 genera of Phytoseiidae and one of Ascidae in order to compare standardized, transformed setal positions; examining the spatial relationships between setal and pore positions. The technique used to standardize the shape and size of the dorsal shield is described. The setal nomenclature adopted for each of the genera of Phytoseiidae is discussed and presented in diagrammatic form. Ventral chaetotaxy in the Ascidae and Phytoseiidae is also discussed.

Using Dyar’s Law the number of larval stages in the life cycle of the European skipper, Thymelicus lineola, was determined in Quebec (1974, 1975, 1976), Ontario (1976), and Prince Edward Island (1976). In all regions five larval stages were observed, as in Europe, and not six as previously reported in Ontario. Apparently in this latter case an erroneous interpretation of the significant differences existing between the sexes (relating to head capsule width and developmental time) resulted in male and female fifth stage larvae being considered as fifth and sixth stages respectively.

The addition of chitinase at the rate of 1000–4000 nephelometric units/U.S. gallon to Bacillus thuringiensis insecticide for use against spruce budworm has been advocated.

Bioassays of V instar spruce budworm larvae against seven levels of Thuricide® at four levels of chitinase corresponding to 0, 22, 220, and 2200 nephelometric units/U.S. gallon were conducted by placing larvae on balsam fir foliage (Abies balsamea) dipped in appropriate dilutions of Thuricide® with chitinase. Mortality was assessed 6 days later. An additional replicated assay at a relatively massive dose of chitinase, 33,000 nephelometric units/U.S. gallon, was compared simultaneously with a 0 chitinase control. The data were homogeneous and linear by statistical standards. No effect of chitinase on LC50 or slope of the regression line was observed.

The development of Ceuthorrhynchidius horridus (Panzer) was observed on five diets consisting of less than 15% dry weight of host-plant material. Adult yields per inoculated larvae were low (less than 1%), although yields from uncontaminated last instars reached as high as 16.6%. Comparisons of diet versus plant-reared weevils showed that (1) larval weight gain at 28 days was significantly greater for plant-reared larvae, (2) plant-reared adults were significantly larger than diet-grown weevils, but there was no difference in fertility, and (3) egg size, viability, and first instar head capsule widths were not significantly different for progeny from diet and plant-reared weevils.

Predatory activity of Formica lugubris was studied from May through August 1976, to determine the variety of prey collected and the relative abundance of different groups of prey throughout the season. Prey consisted entirely of invertebrates, more than 95% being insects. Lepidoptera, especially Tortricidae, accounted for the major portion of prey during the sampling period. Using comparative rates of day and night prédation it was estimated that a large number of spruce bud worm were removed from the population by ant predators. It was also observed that prevailing weather conditions had a marked effect on predatory activity.

Laboratory tests, at constant temperatures, were conducted to evaluate quantitatively the influence of temperature on development of the Oriental fruit moth, Grapholitha molesta (Busck). The results showed that at the highest temperature (30°C) some larvae had four instars and some had five, indicating a mixed population. Fifth instar larvae developed only at the highest temperature (30°C) where larval development was also most rapid. It can, therefore, be assumed that the Oriental fruit moth has four distinct larval instars when reared in the laboratory at 15°–24 °C.