The corn earworm, Heliothis zea (Boddie), is seldom a pest of economic importance in tomatoes in southern Ontario. However, in 1953 the harvest of tomatoes for processing was prematurely terminated because of the presence of this pest in the ripe fruits. In that year almost all the fields in Kent and Essex counties, involving approximately 12,000 acres, were infested, the infestations being as high as 11 per cent in individual fields. The situation was aggravated because excellent-appearing fruits with no visible larval entry holes often contained earworms. This condition occurred when the newly hatched larvae had burrowed immediately into the fruits and there completed their larval development. The entry holes soon healed, leaving small scars that were almost impossible to detect, particularly on a busy production line.

Early in July, 1953, a yellowish mite was observed feeding on active forms of the European red mite, Metatetranychus ulmi (Koch), in an orchard at Rougement, Qué., where a minimum of pesticides (insecticides and acaricides) detrimental to the natural fauna had been used for two years. The mite increased considerably in numbers during 1954 and 1955, contributing noticeably to the control of the European red mite.

Certain kinds of micro-organisms occurring in close internal association with insects, and often harboured in apparently specialized organs, are, at least in some species, of benefit to the insects in supplying them with needed dietary constituents, e.g., vitamins of the B complex (3).

During the past twenty years conflicting statements have been made about the presence of mycetomal micro-organisms in Sitophilus granarius (6, 11). Recently some general clarification has been achieved (9). It seems that while this species commonly harbours such micro-organisms, there exists an Egyptian strain apparently free of them. Furthermore, a variety africana, distinguishable by its smaller size and lighter colour, has been described from the Nile Valley (1, 5).

Dyar (1913) listed Diathrausta reconditalis (Walker) as a “form” of the South American D. nerinalis (Walker) and described as new the “form” harlequinalis from Arizona. From the context it is evident that in that paper Dyar used “form” as equivalent to geographic race, and the form names he proposed there can accordingly be treated as valid trinomina. Haimbach (1915), apparently in ignorance of Dyar's paper, described Diathrausta montana from Colorado. This was sunk by Barnes and McDunnough (1917) as a synonym of harlequinalis. Barnes and McDunnough listed harlequinalis as a geographical race of reconditalis, but did not follow Dyar in uniting these with nerinalis.

Interest in the growth of insect head capsules was aroused by the observation of Dyar (2) that for a number of lepidopterous larvae the ratio of the width of the larval head capsule in a given instar to that in the following instar tends to be constant throughout development, This observation, generally known as “Dyar's Law” or “Dyar's Rule”, has proven valid for many lepidopterous larvae, for whch it was proposed. Many attempts have been made to apply Dyar's Rule to insects of other orders. Various authors, notably Miles (6) and Taylor (71, have considered the application of Dyar's Rule to sawfly larvae, and although they report some inconsistencies, they conclude that the rule is useful if its application is restricted to checking upon the number of feeding instars. The head capsules of non-feeding prcpupal sawfly larvae are generally of the same size as those of the last feeding instar, so that this stage is not expected to satisfy Dyar's Rule.

Recent studies of the genus Culicoides have exposed many new species and presented taxonomists with a difficult problem in using accepted characters or obtaining new differentiating characters clear-cut enough to provide suitable separation.

One such new character is the tibial comb, a structure found on the distal tip of the hind tibia of both sexes of ceratopogonid midges. Fox (1952) illustrated the tibial comb of several Puerto Rican Culicoides and (in litt.) suggested that this character might prove useful in separating other species of this genus. The present study appears to bear out this suggestion. Moreover the study indicates that the character might prove useful in other genera as well.

No detailed description of the larva of any member of the genus Lithocolletis exists in the literature, although various aspects of the structure of one or more species have been described by Wood (1900), Trägårdh (1913), Fracker (1913), and Peterson (1948), and the relation between structure and habits has been examined by Needham (1928) and Hering (1951). Martin (1956) has discussed the bionomics of L. salicifoliella Cham. The present contribution forms a complementary study of the immature stages of this same species.

This paper presents descriptions of four new species of the genus Psylla, brief notes on their biology and records the encyrtid Prionomitus mitratus (Dalm.) as a parasite of Psylla ribesiae (Crawford). Of particular interest is the fact that two of the four new species occur on Ribes spp. and previously were not distinguished from the common species, ribesiae, which has been known in western United States since 1911.

The present paper is the second of a series arising from a continuing study of the balsam woolly aphid, Adelges piceae (Ratz.), and its biological control. The history of this introduced insect has been described (Balch, 1952). During the course of our studies a number of records of species associated with A. piceae have been obtained.

The relative importance as pollinators of alfalfa of each of the 14 species of Megachile that occur in southern Alberta has been assessed on the basis of Alberta distribution, frequency and abundance in mixed prairie, nesting habits, pollen preferences, and flight period; two ground-nesting species of the subgenus Xanthosarus Rob., Megachile perihirta Ckll. and M. dentitarsus Slad., were judged the principal pollinators (Hobbs and Lilly, 1954).

Two, or possibly three, types of stimuli that may influence host selection by entomophagous insects are produced by movements of the host or the prey. Movement may provide visual or tactile stimuli. Vibration caused by host movement may stimulate some species.

Tactile stimuli are produced by a host if it moves when touched by a parasite and are usually provided by a host that is enclosed in a case or a cocoon. Ullyert (1936), working with Dahlbominus fuscipennis (Zett.), and Williams (1951) and Thorpe and Jones (1937), working with Idechthis canescens (Grav.), found tactile stimuli an important factor in host selection, but Simmonds (1943) and Thompson and Parker (1927) concluded it was of little importance in I. canescens and Melittobia acasta Walk. respectively. Movement of potential prey upon contact stimulates attack by foraging ants (Vowels, 1955). Tactile stimuli produced by movement of the host may indicate an unsuitable host to the egg parasite Trichogramma evanescens Westw. (Salt, 1938).

Since the monumental work of Rose (1938) on the essential amino acids for growth in the rat, similar studies have been made on other vertebrates. It has been shown that most of these animals have the same pattern of amino acid requirements for growth of the immature form and for maintenance of nitrogen equilibrium in the adult. The amino acids usually required are arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophane, and valine. These studies have been adequately reviewed in recent texts (Bourne and Kidder 1953, Albanese 1950).

The genus Diastictis Hübner (1818: 21) has as monotype D. argyralis Hübner. Warren (1892: 434), neglecting the original publication, proposed Anomostictis as a substitute name for Diastictis Hübner, 1825, which is preoccupied by the geometrid genus Diastictis Hübner, 1823. Warren's selection of argyralis as type of Diastictis Hübner, 1825, is an effective type designation for Anomostictis, which therefore is a junior objective synonym of Diastictis Hübner, 1818.

When working with the stereoscopic microscope it is often desirable to use both hands for continuous manipulation of dissecting instruments or material under observation. In many instances, however, as when using the higher magnifications to study internal organs of insects, repeated focus adjustments are needed. The use of one hand for focus control is then a source of inefficiency and annoyance because it means frequent change of an instrument from its carefully adjusted position in the microscope field. Eyestrain and unsatisfactory performance follow attempts to reduce the number of adiustments made.

This insect was first noticed during the summer of 1939 in a young red pine plantation in the vicinity of Berthierville, Que. A large number of mature larvae were collected at the end of the same season and placed on the foliage of small red pine trees enclosed in wire cages in the field. The larvae soon left the trees to enter the soil for overwintering. The following spring, numerous adults emerged in the cages, and in order to obtain an identification, several specimens were sent to Dr. O. Peck, Entomology Division, Ottawa, who considered that this was apparently a new species of the genus Cephalcia. Later, many specimens were sent to Dr. W. W. Middlekauff, of the University of California, who described the species under the name C. marginata (1953).

Two things make it difficult to write an account of Canada in relation to insect life: the vast size and varied nature of the country and the relatively small amount of work that has been done on its insects. Those familiar with the intensely worked biota of Western Europe or even of many parts of the United States will find this description meagre indeed. In general, Canadian environments are known better than the insects that inhabit them. In only a few orders of insects is our knowledge even of species taxonomy reasonably adequate; for all orders our knowledge of geographical distribution in Canada is sketchy or fragmentary and our knowledge of ecological relations almost non-existent. Serious collecting and study of insects has been carried out in only a few centres. The National Collection itself has been developed actively only since 1919, and on a large scale only in the last few years. There is no close network of amateur and professional workers such as exists in better-studied countries. What I have tried to do, therefore, is to give a brief geographic account of the main environmental factors as seen by an entomologist, to give a short outline of the possible history of the fauna, to give examples of the main distributional types, and to provide a tentative classification of entomological regions, with notes on some characteristic insects of each. The main feature that will undoubtedly be impressed on the reader, as it has been impressed on me, is our ignorance and the need for further investigation of the insect fauna.

In a recent paper Taylor (1955) has discussed the status of biological control with particular reference to its present and future value as a method of control of insect pests. A number of his remarks are questionable, and his conclusions that present methods of biological control are of little value are not valid. His broad thesis is that insect pests with which the biological control method is effective have already been satisfactorily dealt with and that there no longer remain problems where spectacular results may be expected: moreover, that with the modern insecticides available, biological control has in many cases been rendered useless. It would be as well therefore to examine carefully his main contentions, and it should be pointed out at the outset that Taylor's criticisms of the methods of biological control, and of the claims made by entomologists working in this field, are vague, and although he does not actually say so he insinuates that biological control workers make or have made unjustified claims as to the success of a number of projects undertaken.

Aedes melanimon was described by Dyar (1924) from specimens collected at Bakersfield, California, as closely resembling Aedes dorsalis (Meigen) but differing in color, wing-scale pattern, and in the male genitalia. Freeborn (1926) considered A. melanimon to be an “aberrant form” or “race” of A. dorsalis. Two species closely related to A. dorsalis are the American Aedes campestris Dyar and Knab, and Aedes caspius (Pallas) of Europe, Asia, and Africa.

Professor John Stanley of McGill University recently asked the National Research Council for assistance in specifying the colors of flour beetles (Tribolium). These insem are small (3 or 4 mm. long), rounded, dark, and shiny, and therefore present a somewhat unusual colorimetric problem. It is felt that the solution of this problem may be of some general interest.

The small size of the specimens seemed to preclude physical methods of colorimetry. It was felt that the most likely visual method would be direct comparison with Munsell papers or other standard colored surfaces. The difficulty with this was the very different appearance of the smooth, flat paper and the shiny. rounded beetle.

The hemlock looper, Lambdina fiscellaria fiscellaria (Guen.), has been an important forest pest in Newfoundland for many years. Outbreaks have been reported from widely separated parts of the Island and in most cases the mortality of balsam fir, Abies balsamea (L.) Mill, has been high.

An investigation of the biology of the insect was commenced in 1950 at Lake St. George where two separate infestations had appeared in 1949. These infestations died out in 1951 and only limited information was obtained on some aspects of the investigation. As there is little prospect of continuing field studies in the near future, the results to date are being reported.