Further study, following submission for publication of the generic revision and species list (Frick, 1952), has resulted in changing the generic position of nine species, in making five synonymies, and in the addition of three subgenera and fifteen species to the list.

Malloch (1913, 1914) was reluctant to synonymize many North American species with European species due to the lack of positive identifications. Palaearctic species in the family Agromyzidae are now well defined as a result of the efforts of Hering, de Meijere, and Hendel (Hendel, 1931-1936). Therefore, the writer has not hesitated to snonymize North American species when there was an opporrunity to study specimens, including leaf mines as well as adults, of the species in question.

Depuis la découverte du pouvoir insecticide du DDT, des recherches intensives ont été faites sur d'autres composés synthétisés à partir de la charpente squelettique du DDT, à savoir le 1,1-diphényléthane:

De ces composés analogues au DDT, certains montrent une valeur insecticide supérieure à celle du DDT; d'autres s'avèrent inférieurs. du moins dans les conditions expérimentales que nous avons choisies. Nous présentons ici les résultats que nous avons obtenus dans nos expériences sur la toxicologie du dérivé cyanuré du DDT. Ce composé a été synthétisé pour la première fois par Perron (4,5) à l'Institut de Chimie de l'Université de Montréal. Nous avons utilisé la méthode mise au point par cet auteur pour préparer les quantités dont nous avions besoin pour notre travail.

In the two years which have elapsed since I last wrote (Martin, 1950) of the potential uses of systemic insecticides, a deeper knowledge of the properties of these materials has become available to provide a sounder basis for their practical employment. A wide use of these materials has so far been hindered by scant information, particularly of the risks of harm following the consumption of treated food crops plants. Poisonous residues of the older insecticides which, by accident, remain on the plant surface are largely removed in the usual processes of preparation for the table such as washing, peeling, or discarding the outer leaves. These precautions fail with systemic compounds which not only pass into the plant tissue but which tend to accumulate in the storage organs and in the tenderer new growth, the very parts of the plant which serve for food. Clearly then an accurate and complete knowledge of the fate of the poisonous systemic insecticide must be available before its use on food crops can be recommended.

Methods for preserving biological material in transparent plastics were first published some 15 years ago (Hibben, 1937), and have now come into quite wide use. Accounts have heen published of several suitable techniques, mostly rather similar, in both the scientific (Knight, 1937; Puckett, 1940, 1941; Raizenne, 1949) and the commercial literature (Sheehan & Stewart, 1947; General Biological Supply House. 1950; Ward's, 1947). Although these materials are peculiarly suitable for the preservation of insect material, only one short mimeographed publication (Silver, 1948), has appeared describing a method specifically designed for use with an insect group. This method is essentially similar to the procedures described for soft tissues, all of which are much more elaborate than is necessary for insect material. Sheehan and Stewart (1947) mention that dried insect material may be immersed directly in the plastic monomer in the process which they describe.

During the summer of 1916, a few specimens of a tortricid were submitted to Ottawa for identification. The larvae were abundant on cabbage leaves in the vicinity of St. John's, Newfoundland. At that time the insects were not definitely identified as a European species and were described as new by A. Gibson, who proposed the name Tortrix oleraceana Gibs. (1916. Can. Ent. 48: 373). Some time ago it was realized that oleraceana belonged to the genus Cnephasia. After additional material was received recently from Mr. A. H. Butler, St. John's, Newfoundland, comparison with European specimens in the collection of Dr. B. P. Beirne showed that the species in question is Cnephasia virgaureana Treit.

The W. S. Blatchley collection of Coleoptera, now at Purdue University, Lafayette, Indiana, contains thirteen primary types of Hydradephaga described by Blatchley. Some of the species represented have not been recognized by subsequent workers, while others have been synonymized without the original types having been seen. The following notes and comments therefore seem pertinent, and may prove of value to others engaged in the study of this group of insects.

Early in the summer of 1949 reports were received that in various parts of Ontario and Quebec, particularly about dairy barns and stables, DDT residual sprays were not controlling the house fly, Musca domestica L. A preliminary investigation of these areas during that summer confirmed chat, in most instances, DDT applied as a residual spray was not giving satisfactory control. The DDT residual applications had been used at these dairy farms since 1946 and, in general, the insecticide had been properly applied. NevertheIess, a decline in control was noticed during 1948, even though the insecticide was applied more frequently than in previous years. Accordingly, studies were conducted on collections of these flies to ascertain whether shains of flies resistant to DDT had developed in Canada and, if so, to what degree.

Almost all of the members of the subfamily Ethopolyinae occur in western North America, a few Pacific islands, the Orient and Europe, but only one established species had been known from North America east of the Rocky Mountains. This widespread and very common form, Bothropolys multidentatus (Newport), ranges throughout the East as far west as Missouri. The present new species is therefore of special interest in that it is the second endemic member of the subfamily to he recorded from east of the Rockies. The only other members of Zygethopolys, a genus closely allied to Bothropolys, are known only from Alaska, British Columbia, and thk state of Washington.

The prevailing method of preparing glycerine mounts of nematodes consists essentially of transferring the specimens from the fixative to 1.5-2.0 per cent glycerine in water and then allowing the water to evaporate very slowly until the nematodes are in pure glycerine. By this method evaporation is completed in not less than four weeks as any attempt to hurry this process will distort the specimens. A desiccator is used to complete the removal of the water from the glycerine.

That section of the genus Itame to which have been assigned the names argillacearia and occiduaria of Packard, modestaria and olivalis of Hulst and andersoni Swett has provoked many a sigh of exasperation among collectors and systematists trying to organize their material. The present paper represents several years of intermittent study and observation, and although no drastic changes in nomenclature or arrangement seem warranted, I shall set forth my conclusions for what they are worth. This may actually be regarded as a supplement to Dr. J. McDunnough's remarks on the group in a paper of 1924 (Notes on the Ribearia Group of the Genus Itame. Can. Ent., Vol. 56, p. 271), additional material having been examined that was not available to him at that time.

Shortly after the publication of my paper on this species, (Can. Ent., Vol. LXXXV, No. 1) I received a letter from Mr. R. W. Smith, of the Belleville Laboratory, giving some of the results obtained in a study of leucoptera in the parsnip webworm, Depressaria heracleana L., in 1926. In this study, writes Mr. Smith, “first-stage larvae were found in fifth and sixth instar hosts. Their most frequent location was in the musculature of the rectal region of the hind gut”.

Within the next few years those of us who have been directly concerned with the first appearance of termites in the Province of Ontario will either have forgotten some of the earlier details of this introduction or wiil have passed beyond the field of such earthly considerations. The present paper has been wrinen so that those who mav be interested in the earlv history of the introduction of termites into Ontario in the years that lie ahead wll have at least one authoritative paper upon which to hase their studies or investigations.

During the third week of July, 1952, adults of the tarnished plant bug, Lygus lineolaris P. de B. [–L. oblineatus (Say)], suddenly became very numerous in a field of young cucumber, variety straight Eight, near Ottawa, Ontario. The insect fed voraciously, attacking the tender, terminal growth of the vines. Little distortion of the foliage resulted, but numerous holes appeared in the leaves when they expanded.

While rearing Galleria mellonella L. to further studies by Mankiewicz (1952) on the wax splitting enzymes which they produce and the action of these enzymes on Myctobacterium tuberculosis, it proved difficult to secure a constant supply of honey and comb, the natural food and habitat of this species. Haydak's (1936) summary of earlier work on rearing this wax moth indicated that success had been attained with several artificial media. The writers, therefore, tried an artificial medium and attempted to assess its effect on the nature of the enzymes later extracted from the larvae.

The Tortricid Archips cerasivorana, described in 1856 by Fitch and usually known by the rather cumbersome name of the Cherry-Tree Ugly Nest Tortricid, is a well known insect, widely distributed in the United States and Canada. Its life-history and habits are described in many of the standard textbooks. The account given is usually rather vague but a more complete and satisfactory treatment is to be found in a paper published by A. B. Baird in 1918. The insect hibernates in the egg stage. The eggs hatch in the latter part of May and during early June. The larvae construct a web which they gradually extend over the foliage on which they feed. In the web they construct silk lined cells in which they live individually when not at work. They are full grown by about the middle of July or later. Their principal food plant is the choke-cherry but occasionally they attack the cultivated cherry.

According to Dobzhansky (1951a, p. 262) “Species are … groups of populations the gene exchange between which is limited or prevented by one, or by a combination of several, reproductive isolating mechanisms”. This definition follows from his concept of a species not as a static unit but as a stage in the process of evolutionary divergence. Limitation or prevention of gene exchange is a property of geographic and reproductive isolation (Mayr, 1912), the various types of which Dobzhansky lists as follows:

I. Geographic or Spatial Isolation

II. Reproductive Isolation

A. Ecological Isolation

B. Seasonal or Temporal Isolation

C. Sexual, Psychological or Ethnological Isolation

D. Mechanical Isolation

E. Gametic Isolation

F. Hybrid Inviability

G. Hybrid Sterility

H. Hybrid Breakdown

The pine needle scale is a serious pest of spruce and pine in shelter-belt and ornamental plantings in the agricultural region of the Prairie Provinces of Canada. The present study was made to provide accurate data on the life cycle, habits, and seasonal development of the pine needle scale in this region. This information is essential for investigations of artificial control.

Observations were made at Indian Head, Sask., in 1947. The populations sampled were on Scotch pine in a shelter belt and white spruce in an ornamental planting. Other populations were sampled when further information was required.

The following list of hymenopterous parasites of Choristoneura pinus Free. is based on an analysis of two collections that the writer recently received through the kindness of Dr. T. N. Freeman. The first collection consisted of 116 mature larvae and pupae of C. pinus taken by Dr. Freeman at Normandale (Norfolk Co.), Ont., early in July, 1951, in a plantation of Pinus banksiana Lamb. Rearings from this lot, at Ottawa, by Dr. Freeman and the writer yielded 48 moths and 41 specimens of parasites, the latter comprising 10 species. There was a pupal mortality of 27 specimens. The second collection consisted of 75 adult parasites that were reared at Ottawa by Dr. Freeman from a lot of 456 pupae of C. pinus taken by Mr. V. Hildahl at Beauséjour, Man., during July, 1951, on P. banksiana. There were five species of parasites in this collection, three of which are not represented in the Normandale material.