In southern Alberta there are several species of aphids that produce galls on poplar trees (Harper, 1959). These aphids are all in the subfamily Eriosomatinae and in the genera Pemphigus Hartig, Thecabius Koch, and Mordwilkoja Del. G. Two of the species are of economic importance, Pemphigus betae Doane, a pest of sugar beets in Alberta and parts of United States (Harper, 1957; Maxson, 1916; Parker, 1915), and Pemphigus populitransversus Riley, a serious pest of crucifers in Texas (Wene and White, 1953). Both species overwinter on poplar as eggs. In spring the fundatrix emerges from the egg and feeds on the poplar leaf, initiating a gall in which the winged fundatrigeniae are produced. During the summer the fundatrigeniae migrate to the secondary host where they produce the wingless alienicolae; in the fall these in turn produce the winged sexuparae, which migrate to the poplars where they produce the wingless sexuales. The female sexuales, after mating, deposit eggs on the poplars to complete the life cycle (Harper, 1957; Jones and Gillette, 1918; Parker, 1914).

Among the numerous insects attacking the leaves of birch in North America are Profenusa alumna (MacG.) and Fenusa pusilla (Lep.), both of which are leaf-miners belonging to the tribe Fenusini. Various attempts have been made to separate the known fenusine larvae, all of which are very similar (Yuasa, 1922; Ripper, 1931; Lorenz and Kraus, 1957; Lindquist, 1959), but the larval morphology of F. pusilla only has been described in detail (Friend, 1933; Daviault, 1937). In this paper the larval morphology of P. alumna is described from material collected some 60 miles north of Sault Ste. Marie, Ontario, in 1955.

The relationship between the fate of cocoons of the larch sawfly, Pristiphora erichsonii (Htg.), and distance from small-mammal tunnels was studied during 1958 in the Whiteshell Forest Reserve of eastern Manitoba. The objects were to determine the distance that small mammals can detect cocoons and to observe possible effects of the interactions of small-mammal predation and other natural mortality factors of the insect. Additional analyses of the data provided information on the behaviour of the predators and the ecology of the prey insect.

The balsam woolly aphid, Adelges piceae (Ratz.) (Adelgidae, Homoptera), originally introduced from Europe, was reported on grand fir, Abies grandis (Doug.) Lindl., in the Willamette Valley by Keen (5) around 1930. Serious outbreaks of this insect were first recorded on subalpine fir, A. lasiocarpa (Hook.) Nutt., in Oregon and Pacific silver fir, A. amabilis (Doug].) Forb., in Washington in 1954 ( 3 ) . At present about 600,000 acres of subalpine and Pacific silver firs are heavily infested in the Pacific Northwest.

Studies of the effects of widespread DDT spraying on the parasite complex of the spruce budworm constitute part of a comprehensive program of biological assessment of the New Brunswick forest spraying operations that began in 1952. In the years 1952-1958 these operations covered over 9,000 square miles, practically all the forested area of the northern part of the Province. Almost all areas have been treated two or more times; approximately 80 square miles of the original outbreak area has been sprayed five times, and an experimental plot has been sprayed in each of the seven pears. This has involved the use of over 7,000,000 pounda of DDT, applied mostly at the rate of one-half pound per acre in one-half U.S. gallon of oil solvent.

Large species; thoracic dorsum conspicuously trivittate; mesopleural membrane bare; basal section of radius bare; tibiae without bright niveous patches; fore tarsal sepments not much dilated. Female: head and thorax thickly cinereouspollinose; mouth parts adapted for biting; tarsal claws simple; posterior margin of seventh abdominal sternite with conspicuous fringe of long hairs; paraproct (anal lobe) with large, highly polished ventral prolongation; ovipositor lobes very widely separated. Male: style without apical tooth; ventral plate broadly cleft almost to base. Pupa: respirator organ with nine uniformly radiating, somewhat inflated, rather short filaments; abdominal armature lacking on fifth to seventh tergites; cocoon fabric loosely reticulate, porous, with greatly elevated opening. Larva: exceptionally long and slender, evenly expanding posteriorly, seventh abdominal segment strongly bulbous ventrally; antenna six-segmented; submentum with eight to 11 hairs on each side

The behaviour to moisture of a number of stored-product insects; Tenebrio molitor (Pielou and Gunn, 1940), Ptinus tectus (Bentley, 1944), Tribolium castaneum (Willis and Roth, 1950) and Tribolium confusum (Roth and Willis, 1951) have been studied. All these species live in a dry environment in flour and all have shown a preference for the drier of any two humidity alternatives. The moisture reactions of the granary weevil were studied since this species develops in a relatively moist environment (Richards, 1947) and should show a contrast to the reactions of the above species. The supplementary studies of this investigation were to determine the effect of moisture conditioning on the moisture reactions and to study the interaction between light and moisture.

Stands of black spruce, Picea mariana (Mill.) B.S.P., in Northern Manitoba and Saskatchewan were defoliated by insects from 1954 to 1955 (Prentice and Hildahl, 1955). The defoliation was sufficient to show reddening of the tops from the ground as well as from aircraft at an elevation of 1,000 feet. Collections showed clearly that the most abundant species was the black-headed budworm, Acleris variana (Fern.); larvae could be found at all crown levels. Other species of insects were also common in the tops of trees with dense compact foliage such as often found in “club-tops” of black spruce. The reddening of foliage was not noticeable after the decline of the black-headed budworm populations in 1956, but the numbers of the other insects, which formed a “complex” of species, persisted at varying levels of abundance in the tops of black spruce.

The larvae of leaf-mining insects are difficult to rear in the laboratory and large-scale insect surveys must often rely on the identification of immature stages for their information. The need for a larval key to the birch leaf-mining saw-flies in Ontario became apparent when a complex of three species, Profenusa alumna (MacG.), Fenusa pusilla (Lep.), and Heterarthrus nemoratus (Fall.), was first discovered in 1955 (Lindquist 1955). Larvae of the three mentioned species have been described in recent years by Watson (1959), Friend (1933), and Peirson and Brower (1936), respectively. Additional descriptions of the larvae of F. pusilla and H. nemoratus were made by Daviault (1937). Information on distribution and seasonal occurrence was obtained from collections made by forest biology rangers over a 3-year period. Brief notes on the biology of the species, for comparison purposes, follows the larval key.

In a number of the systematic studies of caddisflies with which I have been concerned, it has been necessary to rear larvae to the adult stage in the laboratory. Several methods proposed for rearing aquatic insects were considered, but these seemed open to some improvement, mainly because, for my purpose, it was necessary to rear large numbers of larvae in individual containers. For this reason the rearing equipment described here was designed. The principal advantage gained through its use is that relatively little maintenance is required to achieve fairly constant rearing conditions for large numbers of larvae, with each larva in a separate cage. By combining a number of individual cages into a unit, with its own supply of water and compressed air, attention to the needs of each individual cage is reduced considerably. By adding additional units, the capacity of the equipment can be doubled or trebled, while the corresponding increase in the maintenance requirements is proportionately much lower. In addition to providing an efficient means of rearing larvae in the laboratory, the same equipment can be used in the field under various conditions. Although caddisflies have been the only insects reared up to now, it is altogether likely that similar equipment would be suitable for other aquatic groups as well.

Insect flight can be divided into four basic components which lend themselves to independent study. These are: (1) flight preparation and response; (2) the body movements and their resultant forces; (3) the flight capacity; and (4) flight orientation. Many authors have dealt with these various phases of flight and studies have been made on a wide variety of insects. Nevertheless, on reviewing the literature two deficiencies become apparent. First, there are very few cases where a complete study of flight has been made for a single species, an outstanding exception being the studies on locust flight by Weis-Fogh and Jensen (1956). Secondly, beetles, particularly the Scolytidae, have been neglected as experimental material in flight studies

This study was undertaken as part of an investigation of the physical and biological requirements of the white pine weevil Pissodes strobi Peck. The broad aspects of the main problem will be given in a later paper and it need only be mentioned here that the immediate objective was to define the requirements of the weevil in terms of measurable factors of the environment. During the field studies, observed variations in behaviour between individual weevils within the limits of a single habitat indicated the need for additional studies that would permit analysis of behaviour in relation to previous conditioning. The responses of the adult weevils to diffuse and discrete light sources, and the effect of temperature on these responses, were investigated in conjunction with field studies of behavioural changes during relatively stable and variable weather conditions, in an attempt to explain observed weevil movements.

The literature contains numerous references to observations and investigations on various aspects of the biology of many species of black flies. During recent studies on the blackfly fauna of Utah, observations were made on mating, feeding, and oviposition of several species of black flies for which such data are fragmentary or completely lacking.

The pine bud moth, Exoteleia dodecella L., is a serious pest of pine throughout much of Europe. In North America, its presence was first reported in 1928 in nurseries at Fonthill and Ridgeville in the Niagara Peninsula (Annual Report, Minister of Agriculture, Ottawa, Canada, 1929). The occurrence and spread of this species was followed closely until 1933 (Sheppard, 1930; Ross and Caesar, 1931; Caesar and Ross, 1932, and Twinn, 1933), in connection with the European pine shoot moth eradication program which was then in progress.

The European pine shoot moth, Rhyacionia buoliana (Schiff.), was introduced accidentally into Ontario about 1925, and has since spread throughout the southwestern part of the province south of a line from the south shores of Georgian Bay on the west to Brockville on the east (Fig. 1). Damage to the host is done by the larvae, the feeding of which results in the deformation of the branches and main stems, reducing the potential value of the trees as timber and, in heavy infestations, making young trees unsuitable for the Christmas tree trade. Several species of exotic and native pines are attacked; red pine, Pinus resinosa hit,, Scots pine. P. sylvestris L., and Mugho pine, P. mugho Turra, being the most susceptible. Because of the extensive planting of Scots and red pine in southern Ontario, especially during the last 25 years, the increasing numbers of European pine shoot moth in this area present a problem of great importance. Contributing to an understanding of this important pest, this paper presents a detailed review of the parasites obtained in Ontario since 1954, with some notes on earlier surveys.

The following descriptions are based on material collected during a field trip to the east coast of Vancouver Island, British Columbia in June 1955. Most of the streams concerned are in the vicinity of Qualicum Bay, a summer resort midway between the cities of Nanaimo and Courtenay. Lying in the lee of the mountainous interior of the island, this narrow strip of coastal forest has a climate somewhat drier than is normal for the region as a whole. The annual precipitation is less than 50 inches and there is a pronounced dry period in July and August. The short coastal rivers are in spate in the fall and winter months when the heaviest rainfall occurs. They are fast and shallow with clean beds of gravel or small boulders. Because of limited water storage in the hinterland,flash-flooding is frequent after rain storms. Vegetation of the forest floor is lush and the courses of the smaller streams are often concealed by dense thickets of salmonberry (Rubus spectabilis Pursh.), thimbleberry (Rubus parviflorus Nutt.) and other shrubs that overhang the banks. During the spring and earlysummer, conditions appear to be very favourable for the propagation of black flies. In late May, one of the Prosimulium species described herein was already past its peak of emergence and the occurrence of even earlier species seems probable.

The artificial feeding of aphids has received renewed attention in recent years and many attempts met with limited success. Maltais (1952) reported on a simple apparatus for feeding aphids aseptically on chemically defined diets. At the time, several investigators on the artificial feeding of homopterous insects had succeeded in getting the insects to feed temporarily on special food mixtures through different types of membranes, but the insects had neither grown nor reproduced.

In southwestern Ontario the European corn borer, Ostrinia nubilalis (Hbn.), produces two flights annually. The first flight, beginning in June, consists of moths from larvae that have overwintered. The midsummer, or second, flight begins late in July or early in August, and its moths are the progeny of the first flight. Until about 20 years ago the borer produced only one annual flight and was thought to be univoltine. The change in the seasonal history of the borer in Ontario was described by Wressell (1953) and Miller (1956). The literature describing similar changes in parts of the United States has been reviewed by Lees (1955) and Everett et al. (1958). Wressell (1953) summarized light trap collection data of moth flights in the Chatham, Ontario, area for the years 1932 to 1951. The summary includes the percentage of the moths that were from the midsummer flight, and it is evident that the size of this flight varies greatly from year to year. Aside from its intrinsic interest, it would be of some economic value to know what governs the size of the midsummer flight. This is a report of studies undertaken to examine the case, and to relate the findings to the larger problem of why the borer now produces a second flight where formerly it produced only one.

Horse flies and deer flies were collected throughout the spring and summer of 1955 by the author and others in the vicinity of the Wildlife Research Station, Algonquin Park, Ontario. These collections include 2,712 females of 15 Chrysops species, three males and 278 females of 13 Tabanus species and one female of Stonemyia tranquilla (O. S.). However, tabanids collected in other years from the Park have been studied as well. In 1955 T . trepidus McD. (35%) and T. epistates O. S. (15%) together accounted for half the Tabanus species collected, and C. vittata Wied. (23%), C. montana O. S. (16%) and C. wiedemanni Kröber (15%) for more than half the species of Chrysops (Table 11).

Female. Frons slightly produced, with a rudimentary median carina. Head, body and forewing above pale luteous, hind wing above and under side whitish. Abdomen above with narrow white basal band and with three or four obscure blackish-powdered mid-dorsal spots. Fore coxa, femur and tibia brown anteriorly. Forewing above with narrow, obscure, dark, irregularly dentate ante- and post-medial lines. Antemedial oblique outward to origin of Cu1, then sharply angled and oblique inward to inner margin. Postmedial nearly parallel to outer margin, weakly indented along submedian fold. An hourglass-shaped mark at the end of the cell. All these markings surrounded by faint fulvous clouding. Outer margin with minute black dots at ends of veins. Fringe concolorous. Hind wing with one or two dark dots in submedian fold and with black terminal dots at the veins. Under side of forewing with lunate discocellular mark and anterior half of postmedial line conspicuously dark.