Chemicals must be used to control the codling moth, Carpocapsa pomonella (L.), in most apple and pear growing areas throughout the world. Unfortunately, this practice has caused or contributed to greatly increased mite populations, decimation of many beneficial insects, insecticide resistance, soil poisoning, and other problems. Successful use of the sterile male technique against the codling moth would eliminate or alleviate a number of these problems. This technique consists essentially in the sustained over-flooding of the native population with sexually sterile males. The main prerequisites for its use include: (1) a method of inducing sterility or dominant lethality in the sperm without affecting normal behaviour or longevity of the male, (2) the released insects themselves must not be injurious or noxious, ( 3 ) the method of release should permit intimate mingling of the sterile males with the native population, and (4) the availability of an economical method of mass culturing the insect. Photographs illustrate how these prerequisites were investigated for the codling moth.

Thirty-one geographic entities comprising 17 species of Calligrapha were examined cytologically. In the bisexual species rowena, philadelphica, pnirsa, amator, alni, confluens, californica, bidenticola, multipunctata, verrucosa, and pruni, the diploid number of chromosomes was 23 in males and 24 in females. The sex mechanism consisted of a single X chromosome in males and two X chromosomes in females. No Y chromosome was present. During reduction division in testicular tissue 11 bivalents were formed and a single heterochromatic X chromosome lay to one side of the bivalents which showed congression at metaphase I. The basic chromosomal formula 11 + XO can therefore be assigned to this group. The formula is modified in some populations according to the following circumstances.

In 1944 a forest research project involving industry and two levels of government was set up to integrate entomological, pathological, silvicultural and management studies aimed at the control of the spruce budworm through forest management. The entomological phase of this praject, called the ‘Green River Project’, was initiated in 1945, and by 1949 was deeply involved in the budworm outbreak that occurred in northern New Brunswick during the period 1949-59. The basic aim was to elucidate the population dynamics of the budworm during an outbreak.

Weevils of the genus Sitophilus are known to harbour within them certain structures (supposedly micro-organisms) that seem, on present evidence, to supply the host weevil with beneficial but not essential nutrients: the phenomenon of either symbiosis or mutualism.

The micro-organisms occur in cells called “mycetocytes”. In the larval weevil the mycetocytes are clustered together to form a mycetome. During metamorphosis from larva to prepupa to pupa to adult the mycetome breaks up into its constituent mycetocytes. The mycetocytes are found in the midguts of male and female adults and in the gonads of female adults. From the female gonads they are passed to the eggs and thence to the next generation of weevils.

The responses of insects to olfactory stimuli and to air-borne signals generally can be correctly understood only when the stimulus is presented in a natural way, and, moreover, one which is fully understood by the experimenter.

Molecular diffusion is an extremely slow process, and diffusion gradients are relatively unimportant in providing directional guidance. Aluch more important are the mass movements of the scented air, so that, for example, Drosophila melanogaster give one kind of response to an attractive scent when it is presented in a moving air current and a comp1etely different response to the same smell when the air is still.

Some of the changes in esterase content which occur during embryogenesis of the large milkweed bug, Oncopeltus fasciatus (Dallas), have been considered in relation to the stage of development and commencement of function of specific organs and tissues. A similar study involving the changes in protein as well as in esterase content during moulting and metamorphosis, has been made with larvae, pupae and adults of the tomato hornworm, Protoparce quinquemaculata.

The wing folding mechanism was investigated after a detailed study of the wing base morphology had been made (Sharplin, Canad. Ent. 95: 1024; 1121). Living moths were observed with a binocular microscope equipped with a micrometer eyepiece.

The first and second axillary sclerites do not move anteroposteriorly; only the distal half of the wing base is involved in wing folding. The folding muscle originates on the pleural ridge and inserts on the third axillary sclerite. The movement of the third axillary is communicated to the bases of the anterior veins through the median plates. The radial plate rotates around the ventral second axillary sclerite which lies underneath the radial bridge at point p, (Fig. 1). Bending cuticle allows the radial bridge to buckle when the wing is folded. The first median plate ( Ml ) rotates about its articulation ( f ) with the dorsal second axillary sclerite. The distal median plate (M2) passes underneath the second cubitus and is fused to the radius. This connection to the radius restricts the backward movement of the second median plate so that point e instead of following the wider arc eg of a circle with its centre at f, must follow the arc cegd drawn about pivot p. The median plates are bent upwards during wing folding and their effective length is shortened so that they can follow the shallow arc epg. When point e is in position g the posterior margin of the median plates is straight, although the anterior margin remains arched causing the median plates to be buckled, (Fig. 2).

Though historically noted as one of the most noxious pests of vines in Europe, California, and other places where vinifera-type grapes are grown extensively, the grape phylloxera, Phylloxera vitifoliae (Fitch), was for many years of little concern to grape growers in Canada. In the Niagara Peninsula, where more than 98% of Ontario grapes, and more than 95% of Canadian wine grapes, are grown, the insect has been known for many years in its most conspicuous form, in galls on the leaves of wild grapes and a few unimportant cultivated varieties. The more infamous root form was known to be present, but the resistance of the older American varieties growing in most of the vineyards was regarded as sufficient protection from a native American pest that at one time threatened to destroy the French wine industry.

The classification of the flower flies often referred to Syrphus s.l. has long been confused. European workers have usually placed all species in Syrphus or in Syrphus and Epistrophe; until 1950, American workers usually recognized the genera Syrphus, Metasyrphus, Epistrophe and Allograpta. Earlier attempts to revise the classification were in large part successful as far as many of the smaller, more distinctive groups of the tribe Syrphini were concerned, but Syrphus s.l. remained in a very unsatisfactory condition. In 1950 Fluke proposed a new classification of Syrphus s.l. based almost entirely on the male terminalia and treating particularly the New World species. It was a great advance on preceding attempts but left one large group in an unsatisfactory state. However, because no key to genera was provided, and because characters other than those of the terminalia were neglected, his arrangement was not generally accepted.

Parmi les espèces de bactéries comprises dans le groupe “cereus”, il en existe une très pathogène pour certaines espèces d'insectes, c'est le Bacillus thuringiensis Berliner. Ce bacille produit des spores et des cristaux toxiques dans la cellule et excrète diverses substances toxiques dans son milieu de culture. L'action du B. thuringiensis varie avec les espèces d'insectes; chez certaines il provoque une septicémie typique, chez d'autres il cause une intoxication, alors que quelques espèces sont réfractaires à ses attaques. Depuis quelques années notre laboratoire envisage la possibilité d'utiliser le B. thuringiensis et d'autres espèces proche parentes dans la lutte à certains insectes forestiers fort nuisibles tels que la tordeuse des bourgeons de l'épinette (Choristoneura fumiferana (Clem.)), l'un des plus graves ravageurs des forês de conifères dans l'est de l'Amérique du Nord. En laboratoire avec une suspension contenant 200 gr. du pathogène par gallon d'eau, toutes les chenilles en expérience sont mortes de septicémie typique dans l'espace de 8 jours. Lors d'expériences conduites dans un peuplement hébergeant une forte population de I'insecte et dans des conditions climatiques optimales, 84 pour 100 de la population larvaire fut détruite en dedans de 24 jours après l'application d'une suspension contenant 80 gr. du pathogène par gallon d'eau. Ces premiers résultats nous incitérent à rechercher une lignée du B. thuringiensis plus pathogène pour le C. fumiferana surtout aux basses températures, et capable de résister à l'action bactéricide et bactériostatique de certaines substances produites par le feuillage du sapin et de l'épinette.

Pour la première fois en 1953 un virus fut décelé parmi les populations larvaires de N. swainei, une tenthréde extrêmement nuisible au pin gris dans la province de Québec. Ce virus à polyhèdres appartient au genre Borrelinavirus et se développe dans le noyau des cellules épithéliales de l'intestin moyen. Des recherches conduites depuis 1957 au laboratoire de Québec ont permis de sélectionner une lignée très virulente de ce pathogène et de mettre au point une technique pour sa productoin en quantité suffisante pour effectuer des traitements à une échelle considérable. On s'est préoccupé également de la mise au point de formules économiques et pratiques pour son application suivant les conditions particulières de chaque lieu et des moyens d'assurer une dispersion adéquate du pathogène lors des traitements aériens et terrestres.

An outbreak of needle miner on lodgepole pine occurred in the late 1940's, decreased to low levels in the 1950's. but increased aeain recently. In both outbreaks, populations were highest in a band along the middle of the slopes of the valleys.

The moths are crepuscular with most of the flight, feeding, and laying activities taking place at sundown. Temperatures and wind at this time are critical for these activities. Low temperatures and wind which are more common at higher elevations probably reduce oviposition rates. Some downward drift of the moths also probably takes place making the rate of increase through the adult and egg stages much higher at valley bottom than further up the slope.

For the past forty years there have been virtually no introductions of honeybee stock from foreign countries into Canada or the United States. This has been due to the stringent restrictions on importing honeybees which have been in force since 1922, as a safeguard against the introduction of acarine disease. The mite which is responsible for the disease, Acarapis woodi, is present in many parts of Europe, and has also been reported from Asia, Africa and South America. It has not so far been found in North America, although external mites of the same genus (A. dorsalis and A. externus) are now known to occur fairly commonly throughout Canada and the United States.

Heterogenetic holocyclic species in Adelgidae consist of the five generations: sexuales (♂, ♀), fundatrix (F), alata-migrans (M), hiemosistens (H), alata- remigrans or sexupara (R), of which the (♂, ♀) and (F) live on the primary host (Pinaceae: Picea), (H) on the secondary host (Pinaceae: Pinus, Abies, Tsuga, Pseudotsuga or Larix), and the two winged generations (M) and (R) maintain the migration cycle from and to the other host. The range of such a species is controlled by the occurrence together of both the primary and the secondary host. It seems that the evolution of the Aldelgidae has been closely associated with the phylogeny and distribution of the conifer-family Pinaceae, and that speciation of the parasite has followed the speciation of the host plant.

Conventional and modified methods of obtaining supercooling points of immature stages of insects have been utilized in studies of the cold-hardiness of the European pine shoot moth and the European pinesawfly. A method has been developed to permit visual observation of the freezing process of more than one specimen at a time. A freezing chamber consisting of a hole one inch in depth and one-half inch in diameter is located in the upper end of an aluminum rod partially submerged in a dry ice-alcohol mixture. A small filter paper disc, used as the insect platform, rests upon a #40 copper-constantan thermocouple located near the base of the freezing chamber. The thermocouple enters the chamber through a hole in the wall after several circuits around the circumference of the rod to prevent temperature anomalies attributable to thermal conduction within the wire. The thermocouple is connected to a sensitive recording potentiometer. The wall of the freezing chamber is blackened to prevent reflection of light from obscuring the view of the freezing process, through a binocular microscope mounted above the freezing chamber. The moment of freezing is readily recorded on the temperature trace provided by the potentiometer. At a cooling rate of approximately 5°F. per minute, a correction factor of 2.5°F. must be added to the indicated freezing point to obtain the actual temperature at the surface of the platform. When this correction is applied, the results provide data applicable to statistical analysis of freezing point determinations.

Relatively little is known of the life history, ecology and behaviour of most species of Tabanidae. Knowledge of their immature stages is particularly deficient. The larvae of only 46, or about ⅛, of the North American species have been described and many of these descriptions are inadequate. The present research was initiated in 1960 to describe and classify tabanid larvae and to contribute information on larval habitats and life histories.

The larch sawfly, Pristiphora erichsonii (Htg.), has been studied in Manitoba for over 50 years, since the first outbreaks led to the introduction of the European parasite, Mesoleius tenthredinis Morley. This parasite was credited with reducing the severity of early outbreaks but when host populations again increased in the early 1940's, it was found that M. tenthredinis was ineffective due to the ability of host larvae to encapsulate parasite eggs. Intensive studies of individual mortality factors were initiated at the Winnipeg Laboratory as staff and facilities were expanded in the late 1940's. Development of the life-table concept of recording population data (Morris and Miller 1954) led to co-ordination of several projects until by 1955 a team of research officers was engaged in comprehensive studies of general ecological relationships, parasitism, vertebrate predation, and the effect of defoliation on host stands. Members of the team currently engaged in population dynamics studies and responsible for this exhibit are: Dr.C. H. Buckner, vertebrate predators; W. G. H. Ives, quantitative methods and natural control; L. D. Nairn, interrelations with host tree; Dr. W. J. Turnock, natural and biological control, bioclimatology. Other Winnipeg officers working on related larch sawfly projects are Dr. R. J. Heron, physiological studies, and J. A. Muldrew, biological control with particular reference to immunity to M. tenthredinis.

Preliminary observations show that the pigmentation of eggs and other tissues in conifer sawflies is a valuable taxonomic criterion when the colour can be described objectively in such a way as to allow mathematical analysis of the data. Reproducible semi-integral attenuance spectra covering the spectrsl range 30 kc./cm. to 13 kc./cm. are obtained usins Shibata's opal glass technique for the examination of translucent material. Tfiese spectra are plotted as the log of the semi-integral attenuance and analyzed both qualitatively for positions of maxima and minima, and quantitatively for the relative attenuance level at given spectral positions. The homogeneity of quantitative data from different samples is tested graphically by the triangular co-ordinate method.

One of the outstanding problems now involving North American Trichoptera is that about 80% of the species are still totally unknown in the immature stages. As in many other insect groups, most initial work has been concerned with species differentiation, classification and distribution, and has dealt largely with adults. There are now about 1000 species of caddisflies known from Canada and the United States, but larvae, the best known of the immature stages, have been described for only about 190 of them. Lack of information concerning larvae is especially conspicnous in the Limnephilidae, our largest family, where this stage is known in only about one-half of the genera. Although inadequate knowledge about the immature stages of insects is not uncommon there are, for the study of Trichoptera, several reasons why much could be gained by overcoming it.

In wireworms most of the sensory nerve system terminates peripherally in seven types and 20 sub-types of sense organs. All are represented in the head and its appendages. The main types of sensilla are thick-walled hair, campaniform, mandibular pore canal, scolopophorous, peg or thin-walled hair, and sensory plate organs, and a large antennal sensory appendix. The first three types are innervated by one, the fourth by two, the fifth and sixth by four, and the last by more than four neurones.