The quantities of excreta produced by aphids (Auclair, 1957) and locusts (Dadd, 1960) have been used to estimate the relative consumption of different food materials. Likewise the quantities of food consumed by some other insects have been conveniently estimated by counting fecal pellets (Thorsteinson, 1953; Ito, 1960). Ito (1960) stated without supporting data “there is a highly significant correlation between the amount of mulberry leaves ingested and numbers of feces produced”. Nevertheless there appear to be no published quantitative measurements made on individual insects that show the relationship between the quantities of food consumed and excreta passed. This note gives the relationship between the quantities of dry matter (D. M.) consumed and excreted for three larval instars of the pale western cutworm, Agrotis orthogonia Morr., fed two varieties of etiolated wheat sprouts, Thatcher (Triticum aestivum L. emend Thell.) and Golden Ball (T. durum Desf.). In addition the relationship between D. M. consumed and numbers of fecal pellets produced or D. M. excreted by fifth-instar larvae were determined for two diets that differed considerably in nutritional value.

Sugar beets are grown on approximately 38,000 acres of irrigated land in southern Alberta and their culture is a stabilizing influence on the economy of the irrigated districts. The sugar-beet root maggot, Tetanops myopaeformis (Röder), has been a pest of sugar heets in the sandy soil areas of southern Alberta since 1955 and caused serious damage in the same area from 1934 to 1937. This insect has been a problem also in Manitoba, North Dakota, Idaho, Montana, Wyoming, Utah, and Colorado (Allen et al., 1959; Callenbach et al., 1957; Hawley, 1922; Jones et al., 1952; Maxson, 1948). Considerable experimental work has been done on the control of this pest in Alberta (Harper et al., 1961a; Harper et al., 1961b; Lilly et al., 1961), but there have been no detailed studies published on the life history of the insect in Canada and there is very little information from elsewhere. In 1922 Hawley published notes on the biology of the insect in Utah. The present paper describes the life history of T. myopaeformis in southern Alberta.

Spring wheat varieties with the Sm1 gene for resistance to wheat midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), were compared with susceptible wheat (Triticum Linnaeus; Poaceae) with respect to sources of yield loss and reduction in market value from wheat midge feeding damage. Four resistant varietal blends (90% Sm1 wheat plus 10% susceptible refuge) and four susceptible cultivars were grown in replicated experiments at eight locations in western Canada. Frequencies and 1000-kernel weights of undamaged and midge-damaged seeds were assessed before harvest by dissecting samples of ripe spikes, and after harvest in samples of cleaned grain. Spike data were used to estimate yield losses from reduced weight of damaged seeds and loss of severely damaged seeds (⩽8 mg) at harvest. Among midge-damaged seeds in spikes, few were severely damaged in resistant varietal blends, whereas most were severely damaged in susceptible cultivars. Cleaned, harvested grain of resistant varietal blends and susceptible cultivars had similar frequencies of midge damage and were assessed similar market grades. The primary benefit of midge-resistant wheat was reduced yield loss due to seed damage by wheat midge larvae. Resistant wheat did not protect against loss of market grade, but market value could increase due to larger yields.

Although the species that were closely related had similar adult feeding habits, they varied in their specific dietary requirements for mating and for the initiation of oviposition. In Chrysopa lanata, which is not predacious in the adult stage, the females required a protein-carbohydrate diet in order to mate; on the other hand, Chrysopa downesi males and females, which also are not predacious, mated when fed a diet consisting only of sugar and water. Chrysopa nigricornis males and females both required prey (Myzus persicae) before they would mate; whereas Chrysopa quadripunctata and Sympherobius amiculus, both of which are predacious as adults, did not need a diet other than sugar and water for mating.

All five species depended on prey or a synthetic protein-carbohydrate diet for sustained oviposition; however, S. amiculus initiated oviposition when fed only sugar. When the synthetic protein-carbohydrate diet was substituted for prey, 40% of the C. quadripunctata females began to oviposit. The same diet did not promote oviposition in the predacious C. nigricornis adults.

In Canada biological control of grasshoppers has been studied since the 1930s. Previous attempts at "classical" introductions have not been successful. Native parasitoids, especially sarcophagid flies, have a significant impact on grasshopper populations during certain times but the required conditions and regulatory potential are not understood. Sarcophagids, especially Kellymyia kellyi (Aldrich), and the mermithid nematodes Agamermis decaudate Cobb, Steiner, and Christie and Mermis subnigricans Cobb have some potential as inundative agents. Invertebrate predators appear to impact on egg and early-instar nymphal grasshoppers, and vertebrates, especially birds, help to regulate later instars and adults. The role of microbial pathogens in the population dynamics of grasshoppers in western Canada has long been recognized, particularly with regard to entomophthoran fungi. The possibility of utilizing the microsporidan Nosema locustae Canning for suppression of grasshopper populations has been postulated since the 1970s and field evaluations of its potential have been conducted in Saskatchewan and Alberta. More recently, considerable work, both basic and applied, has demonstrated the potential of various fungus isolates pathogenic to grasshoppers as both "classical" and inundative control agents. Entomopoxvirus isolates from grasshoppers also show potential as biological control agents of grasshoppers but this potential has yet to be investigated in field situations. It is clear, however, that no single microbial pathogen will be the panacea of grasshopper control. It is suggested that future biological control research focus on acquiring a better understanding of the requirements and quantitative effects of parasitoids and predators on grasshopper populations. Emphasis should also be placed on developing integrated pest management programs that utilize local natural enemies (nematodes and microorganisms) for inundative control during outbreaks.

In its territorial behavior, the “tricolor” form of Hetaerina titia differs markedly from both typical H. titia and H. americana. Territoriality between “tricolor” and americana males is initiated only by the latter, and affects the spatial structure of a breeding population of “tricolor” males. Territoriality between americana and typical titia is initiated by either species, and usually leads to displacement of the americana male; this has no visible effect however on the population structure of americana.

H. titia and the “tricolor” form are suggested as separate species because of: (1) differences in breeding and territorial behavior (in both intra- and interspecific flights), and differential habitat selection by females for opposition. (2) existence of different and consistent female body color patterns and the breeding of these females with their specific male type. (3) the strong likelihood that the male wing color patterns are genetically governed with the implication that genes are not interchanged between titia and “tricolor”.

Both males and females of Rhagoletis pomonella (Walsh) showed three distinct modes of aggressive behavior: (1) a wing-waving display, (2) charging headlong into another fly, and (3) "pawing" with the prothoracic legs. The flies were aggressive toward their own and the opposite sex. The aggressive patterns were similar to those of R. suavis (Loew) and R. completa Cresson.

Snow depth is the most important environmental factor in the survival of overwintering Rheumaptera hastata (L.) pupae in interior Alaska. Pupae spend the winter in the leaf litter where litter temperatures are directly related to snow depth at given air temperatures. Winter survival is also dependent on the cessation of pupal development (diapause) and the development of cold-hardiness which is induced by certain physiological processes such as supercooling and changes in glycerol and carbohydrate levels. Glycerol content and supercooling are dependent on changes in carbohydrate levels which in turn are directly related to changes in the rate of pupal development prior to diapause.

It has been demonstrated that changes in the composition of a plant influence the insects that feed upon the plant (Lipke and Fraenkel, 1956). The quantitative composition of plants can be changed by the use of fertilizers (Mulder, 1950; Rennie, 1956), and populations of insects feeding on the plants may increase or decrease (Daniels, 1957; Adkisson, 1958; Joyce, 1958). These changes in numbers of insects have been attributed to such factors as changes in nitrogen, protein, and carbohydrate content (Evans, 1938; Fritzsche et al., 1957) or various mineral constituents (Creighton, 1938).

The suitability of nine species of Cruciferae as hosts for the larvae of the red turnip beetle, Entomoscelis americana Brown, was tested in the laboratory using excised cotyledons or true leaves as food and rape (Brassica campestris L.) as the standard. The three types of commercial mustards grown in Canada (yellow-seeded (oriental mustard) and brown-seeded (brown mustard) forms of Brassica juncea (L.) Czern.; and yellow mustard, B. hirta Moench) and three weeds (Capsella bursa-pastoris (L.) Medic, shepherd’s purse; Erucastrum gallicum (Willd.) O.E. Schulz, dog mustard; and Sinapis arvensis L., wild mustard) were suitable food plants. Brassica nigra (L.) Koch (black mustard), Descurainia sophia (L.) Webb (flixweed), and Sisymbrium loeselii L. (tall hedge mustard) were marginally suitable. Thlaspi arvense L. (stinkweed) was a non-host plant. These observations suggest that an important element of the pest management system for the red turnip beetle should be the elimination of volunteer commercial mustards and the cruciferous weeds, except T. arvense, in April and May to prevent population build-up.

The intromission of the male's long, flexible, threadlike phallus into the female's similarly long, thin, S-shaped vagina in tephritid flies is mechanically challenging. The male of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann, 1824), folds the basal portion of his phallus back on itself, inserts the folded portion into the female, and then gradually unfolds his phallus inside her vagina. The site of the fold in the phallus gradually moves distally, deeper into the female, dragging the distal portion of the phallus into her vagina. At the same time, the male pulls the tip of the female's ovipositor distally with his surstyli, straightening her vagina. The male uses his phallapodeme and asymmetrical syntergosternite to periodically clamp and release portions of his phallus that have not yet entered the female. Once the entire distal portion of the male's phallus is inside the female, he unfolds it and then moves its distal tip even deeper, reaching the inner end of her copulatory bursa. Straightening movements of the phallus due to increases in fluid pressure probably supply at least part of the force that drives the phallus into the female.

The wheat midge, Sitodiplosis mosellana (Géhin), is an infrequent but devastating pest that has been present in western North America for at least 100 years. This note provides the first published report of the presence of the wheat midge and its parasitoid, Macroglenes penetrans (Kirby), in Montana. Annual surveys were conducted in Daniels, Roosevelt, Sheridan, and Valley counties of northeastern Montana for 5 years (2000–2004) using a systematic soil sampling method to collect overwintering wheat midge larvae. In addition, in 2004, infested wheat heads were collected from 10 fields in Sheridan County, and wheat midges and parasitoids were reared. The wheat midge occurred in all four counties, though at relatively low levels. Densities fluctuated across years and locations, with the highest densities (>200 midge larvae/m2) occurring in Sheridan and Roosevelt counties. Macroglenes penetrans was found at all 10 sample sites and constituted up to 52% of the emerged adults (midges + parasitoids).

At constant temperatures between 10.0° and 32.2°C with 16 h photoperiod development of eggs and nymphs was slowest at 10.0° (61.8 days av.) and most rapid at 26.7°C (27.0 days av.). Mortality of eggs and nymphs was moderate (43.7%) at 10.0°, least (24.2%) at 21.1°, and 100% at 32.2°C. Between 15.6° and 35.0°C, 16 h photoperiod, fecundity of winter form adults was greatest (486.3 eggs av) at 15.6° and lowest (0.0 eggs) at 35.0°C. For summer form adults fecundity was moderate (212.4 eggs av.) at 15.6°, maximum (444.9 and 447.3 eggs av., respectively) at 21.1° and 26.7°C, and least (2.8 eggs av.) at 35.0°C. Longevity of male and female winter and summer forms was greatest at the low temperature and least at the high temperature. These data are discussed with relation to field observations of natural pear psylla populations and control programs.

The effects of aerially sprayed fenitrothion (210 g/ha) and aminocarb (70 g/ha) on several hymenopteran taxa in New Brunswick are reported. Exposure cage experiments showed fenitrothion to cause as high mortality among solitary bees and vespid wasps as that previously reported for bumble bees. Exposure cage experiments under aminocarb sprays revealed no detectably increased mortality for bumble bees, but a significant effect on solitary bees. Experiments in which whole bumble bee colonies were set out in fenitrothion and aminocarb spray blocks a few days before spraying gave comparable results to those from the exposure cage experiments.

A series of comparisons of bumble bee densities in sprayed and unsprayed areas confirmed our earlier finding that populations are greatly reduced after fenitrothion application. Population recovery during the rest of the season appears to be influenced by meteorological conditions. The ecological replacement of early-emerging by late-emerging Bombus species in fenitrothion spray blocks is further documented. No relationship between bee densities and aminocarb application was found.

A method for retrospective assessment of pollinator activity by measuring nectar levels in Clintonia borealis was successfully carried out on a small-scale basis.

A 2-year study on management of apple pests was carried out on six orchards in the interior of British Columbia. Sample techniques and treatment thresholds were satisfactory for most pests with the exception of fruittree leafroller, Archips argyrospilus (Walker), western flower thrips, Frankliniella occidentalis (Pergande), and the mirid Campylomma verbasci (Meyer). The number of chemical sprays per orchard averaged eight when the study was initiated. In 1973, the sprays required for pest control were reduced to an average of 5.6 per orchard, and in 1974, this figure was further reduced to 3.1. This reduction in chemical sprays was accomplished without an increase in insect or mite injury to fruit or foliage.

Insect eggs and small organisms may be removed from foliage or bark with solvents and recovered on filter paper. Tests with Acleris variana (Fern.) showed that 96 per cent of eggs were recovered compared to 47–70 per cent counted on foliage. Tests indicated that the extraction method required one-third to one-tenth the time spent in counting the organisms on foliage. The extraction method was more consistent than counts on foliage, and less affected by differences in personnel and working conditions. The method and the solvent must be selected and modified to suit the organism.

The family Acroceridae (Insecta: Diptera; "Small Headed Flies") are a seldom seen yet cosmopolitan group of endoparasitoids of spiders. Recent host and distribution records are presented here for six species of acrocerids: Ogcodes borealis Cole, 1919; Ogcodes pallidipennis (Loew, 1866); Opcodes sp.; Acrocera bimaculata Loew, 1866; Turbopsebius sulphuripes (Loew, 1869); and Exetasis eickstedtae Schlinger, 1972. New hosts for each fly species are; O. borealis—Schizocosa rovneri Uetz and Dondale, 1979, Pardosa spp.; O. pallidipennis—Schizocosa rovneri, Schizocosa spp.; OgcodesSp.—Anyphaena californica (Banks, 1904); Acrocera bimaculata—Coras montanus (Emerton, 1890b); T. sulphuripes—C. montanus.Detailed field measurements and behavioral observations of host spiders and fly development are described and compared with known data. Examination of these comparisons suggests that host–parasitoid relationships follow spider guild associations (i.e. ground/surface dwelling hosts or those building webs in close contact with surfaces), especially with the spider family Agelenidae. These affiliations probably result from a combination of the spider’s web building, web maintenance, hunting behaviors, and fly oviposition activities, which dispose spiders exhibiting these behaviors to greater chances for parasitoidism. These factors act in concert to increase probabilities for host–parasitoid interactions. Compiled data indicate duration of pupation may be related to ambient temperature. Evidence is presented that acrocerid larvae may alter their hosts’ behavior to increase the parasitoids’ probability of survival.

Relationships among catches of corn earworm moths, Helicoverpa (= Heliothis) zea (Boddie), in pheromone traps, numbers of corn earworm eggs, and corn ears with fresh silks were investigated in eight corn fields during a 2-year period in Brazos River Valley, Texas. Cross-correlation analysis indicated that the catches of corn earworm moths in pheromone traps were closely associated with egg numbers in seven of eight fields with a time differential varying between −1 to +2 days. Cross-correlation peaks for new silks versus eggs occurred with time differentials being mostly positive, indicating that corn earworm egg numbers reached a maximum after corn produced large numbers of fresh silks on ears.

There was a weak but significant linear relationship between egg numbers and corn earworm catches in pheromone traps when corn was in the whorl stage of growth. A stepwise regression model of the form: log (eggs/ha + 1) = 3.71 + 0.22*log(S + 1)*log(T + 1) − 0.3*log(S + 1), where S = numbers of corn ears with new silks per hectare, and T = mean corn earworm moths per trap, explained 52.5% of the variance. These results emphasize the mediating effects of fresh silks on corn earworm oviposition on corn.

The genus Praon is revised. Thirteen North American species north of Mexico are recognized, including one new to science: P. carinum sp. nov. Praon cerasaphis (Fitch) and P. coloradense Ashmead are retained as Species inquirende. The female of P. alaskense Ashmead and the male of P. artemisaphis Smith are described for the first time. Praon nanus Baker, P. exsoletum palitans Muesebeck, P. aguti Smith, and P. negundinus Smith are placed in synonymy. The genus Parapraon Stary is considered a synonym of Praon Haliday. A generic diagnosis of Praon Haliday is given, and a key, diagnoses, and illustrations of North American species are provided.

A temperature-dependent multiple cohort simulation model was used to predict emergence of western corn rootworms, Diabrotica virgifera virgifera LeConte, from the soil. Hourly 10-cm-depth soil temperatures were used as input to the model. Hourly soil temperatures were predicted from daily minimum and maximum 10-cm-depth soil temperatures using a half-sine-wave approximation, or from minimum and maximum daily 1-m-height air temperatures using a model for predicting soil temperature from air temperature. The mean difference in the number of days between predicted and observed 50% emergence was 0.22 days using soil temperatures and 0.00 days using air temperatures. Linear regressions of predicted versus observed Julian dates of 10, 50, and 90% cumulative beetle emergence from the soil indicated that model predictions were reasonably accurate and precise using both soil and air temperatures.