In Rhysodini the greatly enlarged mentum forms the entering edge as the beetle wedge-pushes its way through wood. The mandibles cannot bite either wood fibers or food items, but function as a cover for the other mouthparts. The palpi are completely retractile. Each maxilla bears two stylets, the galea and lacinia, and the ligula consists of two bilobed structures. These are apparently the sole feeding structures enabling the beetles to prey on the amoeboid stage of slime molds. The large internal cavity of the head is interpreted as a compromise between a greatly reduced head volume, resulting from reduced jaw musculature, and the need to retain the surface of a full-sized head as part of the wedge-pushing apparatus.

Entomology in Canada began about the middle of the nineteenth century with a small but able group of hobbyists. They became active shortly before confederation in what was then the Province of Canada, a temporary union ofthe present provinces of Ontario and Quebec. Today, a century later, the science is firmly founded throughout the coilntry with over 400 professional entomologists, more than 50 well-equipped research centres, 16 institutions giving formal instruction, and eight profesional societies. Entomological advisory services are estahlished in several provinces and federal legislation protects the public against the spread of nosious insects and the fraudulent or dangerous sale of materials for their control.

The cabbage maggot, Hylemya brassicae, has a facultative diapause induced by the appropriate conditions of light and temperature: 16 hours of light per 24 hours at 20 °C produce nondiapause pupae while 12 hours of light per 24 hours at 20 °C produce diapause pupae. Diapause can be terminated if the pupae are exposed to temperatures from 0 to 5 °C for 4–5 months. Discrepancies in the literature with regard to the foregoing facts are explained.

The sampling of bark beetles and their natural enemies requires that bark be removed for examination of broods contained in the phloem. Counts of populations on bark samples are used to evaluate infestations for purposes of control and for studying population dynamics in the field. Bark samples have been cut from western conifers by chopping, sawing, or a combination of these operations. However, both these methods have disadvantages. Chopping produces ragged samples of varying size, and a saw tends to catch in the bark when cutting boundaries parallel to the trunk. Also, with either chopping or sawins, sample boundaries must be measured and marked as a guide during the cutting.

Melanolophia imitata (Walker) has been colloquially referred to as the green-striped forest looper, in reference to its appearance and habitat. The spring-flying adults and the consistently large numbers of larvae attract considerable attention annually. Although the moths evince little migratory movement, their comparatively large size and pale colour, in association with their quantity, combine to create the basis for occasional alarming reports of forest insects. It is not infrequent to hear of clouds of moths scattering about a forest traveller and viewed throughout the woods. Ordinarily the adults fly during late evening, and are less attracted to light than many moths.

The 70 species of Platycheirus (including Carposcalis, Pyrophaena, and much of Melanostoma of North American authors) occurring in the Nearctic Region north of Mexico are revised. Twenty-three species are described as new and new names are proposed for two species. Eighteen new synonyms and 14 new combinations are proposed; one variety name is given specific status. Six palaearctic species are recorded from North America for the first time, and one nearctic species from Europe, for a total of 23 holarctic species.

Patterns of locomotion of arctiid caterpillars, Diacrisia virginica Fabr., deprived of all external chemosensory organs were recorded in a field where there was patchy distribution of two of the most favored food plants, Plantago major L. and Taraxacum officinale Walker, on a background of grass and mixed forbs. Each track traced in the field was retraced on a digitizing tablet from its point of origin in the center of a circle of 30 cm radius to the circumference. The length of the path was a measure of tortuosity. The patterns of paths followed by normal, antennectomized, maxillectomized, and antennectomized + maxillectomized larvae were compared. No differences in meander were found. The ability of larvae of each class to locate, discriminate among, and feed upon food plants was tested in field-plot tests and cafeteria tests. Different degrees of chemosensory deprivation did not affect ability to locate and begin feeding on plants but did impair ability to discriminate among species. Execution of normal patterns of meandering by chemosensorily deprived larvae and successful encounters with food plants support the hypothesis that food-related search behavior by this species of caterpillar is neither initiated nor steered by chemical stimuli provided by food plants.

Sterilization of male and female Ips confusus (Coleoptera: Scolytidae) exposed to gamma radiation (Co60) as newly emerged adults was almost complete at levels exceeding 7500 r and 10,000 r, respectively. Mating behavior of males as expressed by sperm transfer was unaffected by dosages up to 60,000 r. The capacity of beetles of either sex to establish galleries was not affected significantly below this dosage, but female gallery pattern was altered above 15,000 r. Longevity was reduced at levels greater than 5000 r. LD50 for males occurred at 11.5 days at 7500 r and 29 days in the controls. Mortality of progeny resulting from males irradiated at substerilization levels was higher than in the controls. The dosage to achieve significant population reduction with minimum effect on longevity and other biological activity is estimated to lie between 6000 and 7500 r.

These studies indicate that this sterilization technique may have promise in the control of bark beetles. The necessity for rearing large numbers on artificial media could be circumvented by mass trapping utilizing their natural sex attractant and by mass rearing in cut host material in the laboratory.

Within the Lygaeid subfamily Rhyparochrominae, a number of species are placed in genera to which they do not belong. Changes in systematic position of a number of these have been published in the first number of this series. However, others cannot be placed in known genera and so new genera are necessary to contain these. Twelve new genera are here described to contain already described species.

Synergus pacificus McCracken and Egbert (Hymenoptera: Cynipidae) is an inquiline of oak gall cynipids in the Pacific Coast area from southern British Columbia to central California. Approximately 1,000 specimens were examined during the course of this study. Descriptions of the egg and larval stages are given, and information on life history and ecology is presented.

Alfalfa weevil (Coleoptera:Curculionidae) is a major pest of alfalfa throughout the United States of America. Biological control research has disproportionately focussed on introduced parasitoids. Generalist predators may also be important, but experimental work evaluating their impacts is lacking. I combined a cross-site survey with a predator exclusion experiment to identify key predators, and test for impacts on weevil survival and plant defoliation levels in Montana and North Dakota, United States of America. Spiders (Araneae) dominated the complex, followed by Nabidae (Hemiptera) and Coccinellidae (Coleoptera). None of the dominant predators showed aggregative responses to weevil (Hypera postica (Gyllenhal); Coleoptera: Curculionidae) or pea aphid (Acyrthosiphon pisum (Harris); Hemiptera: Aphididae) densities across 10 sites surveyed. However, weevil densities were positively correlated with both coccinellid and nabid densities across transects at the experimental site. Thus, predator groups traditionally associated with aphids can show strong aggregative numerical responses to alfalfa weevil larvae at smaller scales. Predator exclusion revealed no significant predator effects on larval survival or alfalfa damage. However, final densities of pea aphids were significantly higher in exclusion treatments relative to controls. The results suggest that even under conditions where predators exert significant pressure on aphids, they may still have minimal impacts on weevils. Additional experimental work is necessary to determine the broader potential of generalist predators as alfalfa weevil control agents.

Lamyctes sp. (Chilopoda) is a predator of Scutigerella immaculata Newport and rapidly decimates symphylan soil storage cultures. In a limited soil environment this centipede controls symphylan populations to a level allowing for normal plant growth. Field populations of this predator are too small to effectively control symphylan injury to seeds and transplants.

Copris incertus Say, 1835 (Coleoptera: Scarabaeidae: Scarabaeinae: Coprini) has been described as a New World coprophagous scarab distributed from Mexico to Ecuador with large discontinuities in its range between the Yucatán province and Costa Rica. The C. incertus species complex of the Copris minutus (Drury, 1773) species group consists of C. incertus, Copris laeviceps Harold, 1869, and Copris lugubris Boheman, 1858. Based on external morphology and male genitalia, we discovered that multiple species have been classified as C. incertus. Of these species, five are new: Copris amazonicusnew species, Copris brevicornisnew species, Copris davidinew species, Copris moroninew species, and Copris susanaenew species. Herein, we revise the organisation of the C. incertus species complex and propose a new species complex, the C. laeviceps species complex, which includes: C. davidi, Copris igualensis Warner, 1990, and C. laeviceps, formerly included in the C. incertus species complex. We provide an identification key along with species distribution maps, images of habitus, and diagnostic characters.

Microscopic examinations revealed that free-floating hard black bodies in larvae, pupae and adults of the Swaine jack-pine sawfly, Neodiprion swainei Midd., often contained polyhedra. A simple and rapid method for detecting the presence of the virus infection before gross symptoms appear is described.

A summary of distribution and biology of the five species of Galapagos Dytiscidae is given, along with a key for identification. Rhantus galapagoensis sp.nov. Balke and Peck is described from San Cristobal Island, Galapagos; important features are illustrated. The source of the dytiscid fauna is tropical America. The limited diversity of the dytiscid fauna is probably caused less by problems of dispersal and more by problems of colonization of islands that experience intense periodic drought.

Methods of finding, capturing, and transporting prey by the ants Formica obscuriventris Mayr, Myrmica americana Weber, and Crematogaster lineolata (Say) were studied under laboratory conditions. Each species found its prey by random searching but once the prey was attacked by one ant a definite attraction was created for other ants in the immediate area of attack. C. lineolata and M. americana workers were also recruited by means of a trail laid to the nest. The number of ants attacking each prey varied directly with the size and general resistance offered by the prey. The worker efficiency in prey transport by F. obscuriventris and M. americana varied inversely with the number of workers involved. C. lineolata did not attempt to transport the prey but fed upon it where captured.

The sex ratios of codling moth winter larvae, adults, and summer larvae changed inversely with codling moth density changes in commercial orchards over a 17-year period.

The Tipulidae occurring in madicolous habitats of eastern North America are briefly discussed. Biological information is given for Dactylolabis montana (Osten Sacken) and D. hudsonica Alexander. A larval key to separate them is provided, as well as descriptions of larvae and pupae for both species.

The mountain pine beetle, Dendroctonus ponderosae Hopk., causes extensive mortality of lodgepole pine, Pinus contorta var. latifolia Engelm., throughout western North America (Van Sickle 1982). The Prince Rupert Forest Region, in the northwest of British Columbia, initiated an aggressive beetle management program in 1981. Logging of infested stands, and winter felling and burning of individual infested trees are the most common direct control techniques.

The “Bristol Lake” infestation developed in the Bulkley Forest District, approximately 55 km northwest of Smithers, B.C., on a steep rocky ridge within the valley of Harold Price Creek. The area contained large volumes of mature lodgepole pine, and control of the infestation was therefore considered critical to the local beetle management plan, but the size (50 ha) and rough topography of the infested area precluded normal direct control measures.