The writer (Judd, 1954) reported upon the results of a survey of mosquitoes conducted at London, Ontario in 1952, during which seventeen species were found to occur. Larvae and pupae were taken from pools in six areas in London and its vicinity and were reared to the adult stage at room temperature in the laboratory. Each larva or pupa to be reared was placed in a separate small jar covered with cheesecloth and containing some of the water from the pool from which the specimen had been taken. As the insect went through its series of moults the exuviae were preserved and a record was kept of the dates on which moults occurred. One hundred and seven larvae, representing ten species, successfully passed through the pupal stage to produce adults. The data accumulated from these rearings thus give information concerning the length of the pupal period of the species represented. This information was not included in the publication referred to above and is presented herewith in Table 1.

This paper is a report on the discovery of distinct morphological differences between DDT-resistant and non-DDT-resistant strains of the house fly, Musca domestica L. Since DDT-resistant house flies were first reported in Italy in 1945-46, such differences have been sought by a number of workers (e.g. Wiesmann, 1947; D'Alessandro et al., 1949; March and Lewallen, 1950; Anon., 1950). Various slight differences have been detected but none of a magnitude comparable to those described in this paper has so far been reported.

The absence of adequate chemical and enzymological micro-methods for the estimation of residues of the chlorinated hydrocarbon insecticides increases the need for reliable bioassay methods. The purpose of the work reported below was an investigation of the influences of cultural and testing techniques on the sensitivity and dependability of the toxicological response of the fruit fly, Drosophila melanogaster.

Paper partition chromatography is a physico-chemical technique that enables the investigator to separate inorganic and organic constituents of various kinds, e.g., amino acids, purines, pyrimidines and related substances, sugars and their derivatives, organic acids, vitamins, antibiotics, and chemical elemens, and measure them quantitatively.

In tests of bacteria pathogenic for defoliating insects, previous workers used water suspensions of the microorganisms and contaminated the foliage fed to the insects hy dipping or spraying (1, 2). Where a quantitative result is sought such procedures have some limitations. The waxy cutin present on leaf surfaces, and this is especially true of the foliage of coniferous trees, encourages the formation of surface droplets and makes it extremely difficult to achieve uniform spreading of the bacterial suspension. In addition; the cutin interferes with the adhesion of the dried suspension to the leaf surface. To overcome these difficulties, certain adhesive agents, such as peptones, milk solids, albumin, etc., have been used, but these too are open to objection. If it is desired to reproduce as closely as possible a natural infective process, the use of protein products introduces a new variable and occasionally renders the foliage unpalatable to the insect.

On June 8, 1910, in the woods near Brookline, Massachusetts, W. F. Fiske, then in charge of the Gipsy Moth Parasite Laboratory, collected an adult of the rare beetle Chromatia amoena Say (determination by the late Dr. E. A. Schwarz). Having no killing bottle, he placed the specimen in a match box. On the following day he found that the larva of a Dipternus parasite had issued and pupated in the box. The adult failed to emerge and the puparium was unfortunately discarded. In an attempt to determine something of the life history of the parasite, I dissected the dead host and found in it the first and second stage mouth hooks and the second stage posterior spiracles which were of such unusual structure that they seemed worth while describing. A short paper on the parasite was therefore published in 1913l in the journal published by Professor F. Silvestri, in whose laboratory I was then working.

Investigations at Fredericton requiring specific instars of the cabbage maggot, Hylemya brassicae (Bouché), led to studies of laboratory methods for rearing this insect. Previous attempts to rear H. brassicae had proved unsuccessful since the species does not reproduce readily under artificial conditions. Slingerland (1894) was unable to obtain eggs of this species, though his cages contained hundreds of adults. Washburn (1906) reported that adults that had matured in the field would oviposit in cages. Schoene (1916) used adults that had emerged in the laboratory as well as some fresh-looking individuals captured at large. These were supplied with water and some cruciferous plants, as well as banana, sugar, water, and blossoms of weeds common in his community. Adults fed readily upon the sweetened mixture and decaying banana, and lived four to eight weeks. One female was dissected and found to contain 13 full-sized eggs, but no reference to oviposition was made.

Body and wings pale buff, lightly dusted with darker; all markings obscure. Fore wing with antemedial line brown, very indistinct or obsolete; when discernible short, dentate, its general course at right angles to costa. Orbicular minute, punctiform, fuscous; reniform single, linear, concave outwards, fuscous. Postmedial line narrow, rather weak, fuscous, strongly and regularly dentate; its general course oblique outwardly from costa to M2, thence gently curved basad to Cu2 from which it proceeds perpendicularly, with one conspicuous angulation, to the inner margin. Beyond the postmedial a brown, strongly dentate, subterminal shade. Terminal line brown, broken between the veins; fringe pale buff. Hind wing with diffuse, dentate antmedial line and diffuse medial shades; postmedial, subterminal, and terminal markings as on fore wing. Under side as above, but with less brown shading; antemedial line absent, reniform and orbicular spots weak, postmedial line more diffuse and less strongly dentate than above.

Monochamus notatus (Drury) and M. scutellatus (Say) are both common wood-boring beetles in the coniferous forests of eastern Canada. The two species are usually separated on the basis of colour. The first is dark brown with lighter brown elytra, and is covered with white and brown pubescence, while the second , is typicaliy shining black. The scutellum of each bears a dense white pubescence which, in the case of M. notatus, is divided by a bare median line. Such a line also occurs in M. scutellatus but is usually incomplete. The writer has found that the presence or absence of a fringe of white hair around the compound eye constitutes the most consistent anatomical difference between the two species, it being present only in M. notatus. The elytra of the females of both species are generally marked with elongate spots. Body length is also used to separate the two species, but no clear-cut difference in length ranges occurs; instead, there is considerable overlap.

Eight larvae of the new subspecies Coryphista meadi atlantica Munroe, the barberry geometrid, were reared from eggs. Hatched eggs, first-instar larvae, head capsules of the various instars, one last-instar skin, and seven last-instar larvae were preserved for the present study. The head capsules indicated only four instars. The female adults were identified by Dr. E. G. Munroe, Systematic Entomology Unit, Entomology Division.

Numerous reports have been received from growers in Manitoba and Saskatchewan that the sweetclover weevil, Sitona cylindricollis Fahr., greatly reduces sweet clover seed yields by feeding on the seed or by causing it to drop. It is known that weevil populations are often very high in clover fields that are left for seed. To determine the amount of damage that might be caused to seed by the weevil, a number of tests were conducted in 1951 and 1952.

The genus Catallagia Rothschild was considered to be strictly Nearctic until C. dacenkoi was described by Ioff in 1940 from the Altai Mountains of the U.S.S.R. In 1950, Skalon described two additional species, C. ioffi and C. striatus, from the Transbaikal and other areas of the U.S.S.R. All three of the Russian species are apparently parasitic upon mice, particularly of the genus Clethrionomys (=Evotomys).

The senior author conducted this investigation during 1937 and 1938 in the Sandilands Forest Reserve, Manitoba. The results were presented in an unpublished report (Rablrin, 1938). Owing to the current importance of this insect in Manitoba and the Lake States of the United States, it was considered advisable to publish those aspects of the work relating to life history and dispersal. This was undertaken by the junior author.

Occasions frequently arise in entomological work when it is necessary to hold an insect absolutely still in order to operate upon it. A year ago an apparatus was devised for holding sawfly larvae for injection. It has now been improved and is being currently used to hold sawfly larvae quiet while substances are introduced into the midgut, The apparatus, shown in the accompanying figure, consists of a grooved plastic platform with small holes in the base. These holes are connected to a vacuum line. A water pump may be substituted very nicely. The larva can be placed in any position on the platform by lifting it on a stick and pressing it lightly over the holes on the platform. The larva can be freed immediately by releasing the vacuum. As long as the vacuum is regulated carefully, there are no harmful effects upon the larva.

It is important that the species of leafhoppers of the genus Macropsis that feed on fruit trees should be readily identifiable, as at least one of them transmits the plant virus that produces the symptoms known as peach yellows and little peach. There has been some confusion between the Prunus-feeding species because it is frequently not possible to name adult specimens on external characters alone, and the male genitalia, which usually provide reliable specific characters, have not been illustrated or adequately described. Moreover, there is a form in this group whose status, as a species or as a variety, has been uncertain; and there is established in British Columbia a Rubus-feeding species that has not been recorded previously from North America.

An instance of the California pine engraver (Ips plastographus Leconte) hibernating in short tunnels in the sapwood of host trees was observed during an examination of a windfelled lodgepole pine forest at the 6,100-foot elevation on Parsnip Mountain, Kootenai National Forest (Lincoln County), Montana on September 27, 1950. The above examination disclosed that (1) the new adult beetles were overwintering in windfelled trees previously unattacked, and (2) the adults were seeking shelter in short tunnels that penetrated the bole sapwood of these trees.

This paper deals with two sawfly species, Neodiprion americanus banksianae Roh. and N. lecontei (Fitch), important defoliators of pines in eastern North America. It is concerned chiefly with the reactions of the larvae to light and forms part of an investigation of their behaviour in response to physical factors of the environment.

In my paper “The Introduction of the Termite into Ontario” (Can. Ent., No. 8, 1953) I stated that “insofar as records based on collected specimens are concerned, the termite, Reticulitermes flavipes, is to be found in no other part of eastern Canada, with the exception of Pelee Island (where this particular species has been present for many years).” I further stated that “it is forecast that it will continue to spread over the entire area of eastern Toronto including greater Toronto” and further that “its appearance in other parts of the Province is to be expected, and it will no doubt occur in isolated populations similar in pattern, but on a larger scale, to what has been witnessed in Toronto during the past fourteen years.”

The possible uses of the serological precipitin test for investigating certain entomological problems have been reported previously by West (6). It was suggested that the precipitin test offered a new tool which together with such tools as the electron microscope, paper chromatography and radioisotopes would contribute materially to future advancement in entomology. It is evident to everyone that progress in many branches of entomology is being made currently by the use of new and improved procedures.