The chordotonal organs of insects and especially those of the Acrididae are well known. Slifer (1936) lists 76 scoloparia which are distrilluted throughout the body of Melanoplus differentialis. Although the sense organs of Melanoplus mexicanus described in this study are, in general, similar to thnse found by Slifer, her summary account would seem to warrant a more detaited consideration of their structure.

The organ of Johnston in the second segment of the antenna is included because of its structural similarity to the chordotonal organs, although it is usually considered to have a special sensory functinn distinct from that of the chordotonal type.

During investigations on the natural enemies of root maggots attacking Cruciferae, the beetle Baryodma ontarionis Casey was reared from puparia of the cabbage maggot, Hylemya brassicae (Bouché). This was not unexpected, for Gibson and Treherne (1916) had reported a similar occurrence; the staphylinid beetles reared at that time were identified by Casey (1916), who decided that they belonged to the verna group of Baryodma and assigned the name Baryodma ontarionis. Casey (loc. cit.) considered the species rather common and stated that it did not seem to resemble any European species; but Mr. W. J. Brown (in litt.), Systematic Entomology, Division of Entomology, Ottawa, who identified the beetles collected in 1950, is of the opinion that B. ontarionis is synonymous with Aleochara bilineata Gyll., tvhich attaclrs the cabbage maggot in Europe. Wadsworth (1915) dealt with the biology of A. bilineata, giving detailed descriptions of the immature stages. A study of the biology of B. ontarionis was carried out at the Belleville laboratory as part of n program of parasite introduction with the purpose in view of using the information to evaluate the beetle as a factor in the control of root maggots that are severe pests of cabbage, cauliflower, turnip, and radish.

During the summers of 1949 and 1950, studies on the biology of mosquitoes were carried out at Whitehorse, Y.T.

At Whitehorse, the principal area under study centred about the Royal Canadian Air Force Station. Some additional collections were made along the Northwest Staging Route, at Fort St. John and Fort Nelson, B.C., and Watson Lake, Y.T.

The term “protocephalon” as used by Snodgrass (1938) applies to that portion of the head which lies anterior to the mandibular segment. As defined by him it is composed of the “prostomial acron” and a postantennal segment. The term “acron” has been used in somewhat different senses by different authors and to avoid confusion I have introduced the term “blastocephalon” instead. The blastocephalon may be defined as that portion of the head which includes the labrum, clypeus and occulo-antenna1 region. In the germ band it appears as an expanded anterior region, the cephalic lobes, which forms a sort of early embryonic head, hence the name. The posterior trunk-like region of the germ band may then be called the blastocorm.

Despite the recognized economic inrportance of many members of the order Hemiptera the majority of species in this group are not of great interest either to the economic entomologist or to the general collector. For this reason relatively little is known about the distribution of many species throughout Canada. This lack of information is evident with regard to records of captures which have been made in Alberta. During the many years in which the Entomological Record was published, less than 80 entries referred to Albertan Hemiptera. Of these, only eleven concerned the suborder Homoptera. The order, as a whole, has fared hardly better in the Canadian Entomologist. Apart from a list H. H. Knight, recording Anthochoridae and Miridae collected by J. H. McDunnough at Waterton and Nordegg, and three papers by the present writer discussing Fulgoridae and Chermidae which are native to Alberta, there are only incidental references to the fact that other species of Hemiptera have been captured anywhere in this province.

The widespread presence of the pitch nodule maker in pine plantations and jack-pine regeneration in Manitoba and Saskatchewan stimulated this investigation. Although this insect is not causing serious damage at present it could become a problem should the area of pine plantations be increased in Manitoba and Saskatchewan.

Escherich (7) was the first to report a polyhedral virus disease affecting the European pine sawfly, Neodiprion sertifer (Geoffr.). Later Forsslund (8) observed that populations of this insect in Sweden were controlled by a virus disease. In 1948, H. S. Hanson. Entomologist of the Forestry Commission, England, observed mortality among N. sertifer in England which was due to a polyhedral virus disease (10). In 1949 virus-killed larvae collected in Sweden by Forsslund, were sent to the Laboratory of Insect Pathology, Sault Ste. Marie by G. R. Wyatt of this laboratory and the virus from these insects was propagated and used in the biological control of N. sertifer in southern Ontario (3, 5). This paper describes some aspects of the laboratory studies of the disease, namely: the infection process in cells susceptible to the virus, incubation period of the disease, and the isolation and electron microscope study of the causal agent.

This paper has been extracted mainly from the manuscript of a revision of the tortricid subfamily Archipinae, to make available a scientific name for an injurious, undescribed Choristoneura species that feeds in the larval stage upon pines, particularly jack pine, Pinkus banksiana Lamb., and red pine, P. resinosa Ait. This insect and the closely allied Choristorneura fumiferana Clem. are compared under the following topics: taxonomic history, maculation, morphology, and distribution. References are cited only if they contain information of taxonomic significance; the vast amount of economic literature dealing with these species has been omitted. This paper is followed by a comparative study of the larvae of the two species by Miss M. MacKay, by one by Miss C. E. Cox on the mathematical significance of the anatomical differences in the larvae and adults of both species, by a discussion of some of the parasites of the pine species by G. S. Walley, and by a discussion by S. G. Smith of the isolating mechanisms aperating between the two species.

This paper deals with a few examples of abnormalities found in a few insects which have come to the writer's observation.

In all the Phyla or major groups of the animal kingdom there are cases of abnormalities, monstrosities, anomalies or whatever term you choose to use which indicates a deviation from the normal trend in the development of an organism. Man himself is not exempt.

From the fact that the external morphology of the organism is noticeably changed, there must also be some internal abnormal conditions to bring about these changes. Each time this occurs in an organ of a specialized organ system it tends to change the symmetry of that particular organ.

The lecanium scale was introduced into Vancouver with nursery stock from England in 1903, and by 1910 had become firmly established. Severe injury to broad-leaved maple, vine maple and horse chestnut was reported in 1923, and chemical control operations were undertaken from 1924 to 1930, but with very transitory effects (9, 10). The encyrtid wasp, Blastothrix sericea (Dalm.), imported from England in 1928 and 1929, quickly became established at the liberation points in Sorth Vancouver, and by June, 1930 had dispersed over an area of about 20 square miles. In April, 1931, twigs with parasitized scales from North Vancouver were distributed at intervals throughout the main area of lecanium infestation south and east of Vancouver, and by June of that year the parasite was known to be established over an area of about 100 square miles. By 1932, the percentage of parasitism in the mature lecanium females reached 90 to 100 per cent, and host population density was at very low levels (12, 13).

This is the species referred to in the first Faper on the parasites of Archips cerasivorana (Can. Ent., Vol. LXXXV, No. 1, pp. 19-30) under the name Zenillia blanda. The genus Eusisyropa was created by Townsend (Smiths. Misc. Colls., Vol. 51, p. 97, 1908) with blanda O.S. as type. In it he also included boamiae Coq.. Aldrich and Webber (Proc. U.S. Nat. Mus., Vol. 63, Art. 7, 1924) placed these in Zenillia R.-D. but most workers agree that they collected a very heterogeneous assemblage of species under this name. As will be explained later, the efforts to subdivide the group on adult characters have not been entirely satisfactory. It seems best to use the restricted genera available until the matter has been studied in detail.

The usefulness of radioactive isotopes as tracers in studies of insect biology has been demonstrated on a number of occasions during the past few years. Tracer techniques have made possible the collection of accurate data on the dispersal and flight range of insects (2), and other specific behaviour traits which would otherwise be difficult or impossible to determine (1).

Very few papers have been published on the life history of pseudoscorpions. The literature has been summarized by Kätner (1927), J. C. Chamberlin (1931), Beier (1932) and Roewer (1936-1940). The following contributions are based upon observation of two species of pseudoscorpions which were kept in captivity.

I should like to give sincere thanks to Dr. J. C. Chamberlin for reading the paper and giving valuable suggestions, to Dr. C. C. Hoff for determining the chernetid pseudoscorpions, to Mrs. Rosalie Rogers Talbert for assistance in maintaining and feeding the pseudoscorpions; and to my wife who has aided in the work.

Une région aussi étendue et variée que le parc du Mont Tremblant fournit à l'entomologiste comme à tout naturaliste d'ailleurs, un domaine quasi illimitt à de patientes et fructueuses recherches. La superficie actuelle de ce territoire forestier voisine les 700 milles carrés. Les plus hauts sommets des Laurentides, au nord de Montréal, émergent de cette région. La partie méridionale est formée par les bassins supérieurs de cinq rivières d'importance: les rivières Rouge, Macaza, Cachée, du Diable et Boulé; d'autre part, toute la partie septentrionale envoie ses eaux dans la rivière Mattawin, affluent du Saint-Maurice. Les hauts plateaux du parc servent donc de réservoir à six grandes rivières. Ses bornes se trouvent entre les 46° et 47° de latitude et les 74° et 75° de longitude.

It is a commonplace entomological observation that each phytophagous insect is restricted in its feeding to a small fraction only of the plant species that grow in any area. This phenomenon is generally referred to as “host selection”. The ecological significance of host plant selection among insects is manifest principally in an effect on the geographical distribution of insect species since phytophagous insects can occur only where suitable host plants are available.

A bacterium, Bacillus cereus F. and F., which was isolated from diseased larvae of the codling moth, Carpocapsa pomonella (L.), is pathogenic to the codling moth in laboratory experiments (Stephens, 1952).

A series of trials was set up at Kentville to test the effectiveness of this bacterium against codling moth larvae in the field. B. cereus spores were propagated according to the method of Reed and McKercher (1948) and shipped to the field as spore suspensions.

When Manns (1939) reported that the meadow spittlebug, Philaenus leucophthalmus (L.), was a vector of peach yellows, the investigations on the bionomics of vectors of peach virus diseases then being carried on in the Niagara Peninsula were expanded to include this species. During the rearing of large numbers of nymphs to determine the host plants and habitats of P. leucophthalmus some other species of cercopids were also encountered.

In routine work on leafhoppers of the genus Cicadula Zetterstedt (1840, p. 296) (=Cyperana DeLong, 1936, p. 218) it was impossible to name many specimens satisfactory. The chief reasons were the inadequacy of the descriptions in the literature and the fact that the extent of the individual and the local variation had not been appreciated. Because of the latter, some species apparently had been described under several names.

The European pine sawfly, Neodiprion sertifer (Geoffr.), is a serious defoliator of pine in many parts of Europe and Asia. Infestations of this insect have been controlled by weather, and frequently high percentages are destroyed by parasitic and predacinus insects, by small mammals, and by birds. Infectious diseases are most frequently reported as having controlled outbreaks, namely: virus disease (4, 5), bacterial disease (12). fungus disease (8), bacterial and fungus diseases (7, 11), a disease not diagnosed (9).