The importance of predators in the natural control of mosquitoes has been suggested by a number of workers. Comprehensive reviews have been presented by Hinman (1934) and Gerberich (1946). The conclusions are open to some question, however, since the investigations were confined for the most part to studies in laboratory aquaria. These environments create conditions such as crowding, absence of prey shelter, and lack of alternative prey, which prevent an analysis of predation in terms of field conditions. An accurate assessment of predation in nature requires a technique to identify predators that have consumed prey. This is a report on an attempt to analyse the predator-prey relationships of animals in a natural mosquito pool in a woodland swamp near Chatterton, in Hastings County, Ontario, in April and May, 1953, by means of a radioactive tracer.

On September 21, 1953 the writer collected several egg capsules of the wood-roach, Parcoblatta pennsylvanica (DeGeer), from beneath the bark of dead, fallen trees in Rondeau Park, Kent County, Ontario. The capsules were put in a jar for rearing. During December 7 and 8, 1953 eight chalcidoid wasps, two males and six females, emerged from the capsules. They were identified as Systellogaster ovivora Gahan (family Pteromalidae) by Dr. 0. Peck, Systematic Entomology, Department of Agriculture, Ottawa, who pointed out that this was the first Canadian record of this genus. One male and three females from this collection are deposited in the Canadian National Collection.

The use of residual insecticides is increasing in insect control programs. In practice all insects do not receive lethal dosages, possibly because of uneven application of insecticide and the failure of some insects to come in contact with treated surfaces. This study was designed to determine the rate of oviposition of adult females of Tribolium confusum Duv. surviving exposure to DDT residues and to compare this rate with that of unexposed females.

Occasions frequently arise in laboratory work when it is necessary to insulate a delicate piece of apparatus, such as a sensitive balance, from vibration. Various tables designed to eliminate vibration have been described (anonymous). Most of these tables require the attachment of iron supports to a load-bearing wall or the sinking of a support into bed rock. Occasionally the building construction or the type of underlying strata, or both, make such methods of mounting ineffective. The instrument stand shown in Fig. 1 requires no attachments. It consists of rigid table 34 inches high, 30 inches wide, and 18 inches deep. The legs are made from 4 × 4 inch lumber sheathed with cluarter-inch plywood to form hollow sides; these sides are loaded with lead shot, steel stampings, or any other easily handled, heavy material. When loaded, the table weights can easily be rembved through openings at the tops of the hollow sides, under the cover.

Black, uniformly dark brown- or grey-pollinose. Thorax obscurely quadrivittate. Legs short-haired. Wings milk-white in both sexes.

Head black; frons and occiput, viewed from above, velvety with dark-brown tinge; bristles and hairs fine, black, the former about as long as third antennal segment less style. Antenna black, slightly shorter than head; style about half as long as third segment. Palpus and proboscis black.

As part of a comprehensive investigation on insects affecting the low-bush blueberry in New Brunswick, a study has been made since 1950 of the saw-flies present in blueberry fields in Charlotte County. Of the 19 species collected by sweeping, onIv three Neopareophora litura (Klug), Pristiphora idiota (Nort.), and Pristiphora sp., feed on blueberry; the remainder feed on other plants growing in or near the blueberry fields. Blueberry sawflies are common in New Brunswick but do not cause any serious injury. However, in Maine, Phipps (1930, pp. 107-232) reported complete defoliation of 50 acres of blueberries by sawfly larvae.

The usual criterion of insectidal effectiveness is the mortality suffered by test insects exposed to insecticides. Often, investigators disregard the sex ratio when selecting test insects for exposure. Demonstrated differences in susceptibility between male and female insects require evaluation of the sex ratio in studies on insecticidal effectiveness.

During the past spring and summer glass barrier traps have been used as a means of sampling the flying populations of an ambrosia beetle, Trypodendron sp., and other scolytid beetles. The “window” trap has functioned well enough to warrant its brief description. A piece of window glass (2 × 2 ft.) is set in a three-sided wooden frame from which a sheet metal trough is hung. The trough is filled with fuel oil or water to which a wetting agent is added. Screened outlets provide for drainage of excess rain water in the laner case and when oil is present an inverted “L” tube drains this water from beneath the oil. Insects are collected by removing the trough and pouring its contents through a strainer. Traps are hung from various types of pole framework depending on their location, and guy wires are used to keep them from swinging.

The larch sawfly, Pristiphora erichsonii (Htg.), like the European spruce sawfly, Diprion (Gilpinia) hercyniae (Htg.), is an obligatoty parthenogenetic ‘species’, that is, it is endowed with the capacity of reproducing without recourse to mating. Wlde this absence of cross-fertilization with the attendant uniformity of progeny it assures renders such species ideally suited for experiments requiring the use of controls, it would at first sight appear ro preclude the adoption of conventional genetic procedures in studying them, other than by circuitous means: it is the main purpose of this contribution to suggest a possible means of circumventing the difficulty.

During an investigation into the importance of fungal disease as a factor in the control of orchard pests throughout the Annapolis Valley, Nova Scotia, the haemocoele of large numbers of Macrosiphum pisi (Kaltenbach) was found to be infected with a fungal growth that resulted in death. This fungus was identified from mounted specimens as Empusa (= Entomophthora) aphidis Hoffman.

Considerable confusion exists concerning the identification of larvae of the genus Anoplonyx in North America. Larvae of two species collected in Eastern Canada have been generally identified as one species, A. laricis (Martatt). A published larval description of the other species, A. canadensis Harrington, is not available. Keen's (1938) published descriptions of the western species (A. occidens Ross and A. laricivorus Rohwer and Middleton) apparently had the wrong association between larvae and adults. This study was undertaken to provide more detailed larval descriptions of nearctic species of Anoplonyx as listed by Ross (1951).

Hübner ([1824-25] p. 357) defined the genus Epipagis, citing three species. Hampson (1918: 277) chose fenestralis Hübner as type, and sank Sameodes Snellen to Epipagis. The arrangement of the British Museum Pyralidae shows that Hampson thought fenestralis Hübner was the same as phyllisalis Walker; but so far as I know this synonymy was never published. Actually, Hübner's figure of fenestralis represents a female of the genus usually known as Stenophyes Lederer, wrongly synonymized by Hampson (1899) with Crocidophora Lederer. The size and coloration suggest that the species Hübner figured is the common North American one universally called buronalis Guenée.

Taxonomically, the Cecidomyiidae (Gall Midges) are a difficult group. Many species have been described using colour of freshly killed specimens as the principal criterion for identification (Felt, 1907a). As dead specimens seldom retain their original colour, subsequent determinations based on this characteristic are almost impossible. Morphological characteristics which separate the genera are fairly distinct and therefore acceptable but those used to separate the species, namely, the number and shape of the antenna1 segments (Barnes, 1932), were found to be quite variable in the species studied. Species are more easily identified if, in addition to their morphology, something is known of their biology. In this paper, descriptions and notes on the biology of five gall midges from white spruce cones are given. In addition, the literature on all species from white spruce is reviewed.

Various authors have given general descriptions of the immature stages of various species of Stethorus, and Böving (1917) described certain morphological festures of the larvae of S. punctum (Leconte) and S. utilis (Horn), but no complete account of the morphology of these stages in any species of the genus has apparently been published. Clement (1880) gave the most thorough of the earlier descriptions of the immature stages of S. punctillum Weise.

In The Canadian Entomologist for January 1953 (pp. 19-30) the writer described the larval forms of Dichaetoneura leucoptera Johns. and discussed the relationship of the genus Dichaetoneura which was regarded by Johnson (1907) as closely related to Phytomyptera Rond. and later reduced to a synonym of this genus by Curran (1934). He pointed out that there are rather marked differences between the two genera in adult characters and expressed a doubt that Dichaetoneura could be classed with the Actiines as in the Manual of Myiology of Townsend (Manual of Myiology, IV.). He further remarked on the similarity between the adults of Phytomyptera and Schizactia noting briefly some of the larval characters of Schizotachina and Schizactia which are quite different from those of Dichaetoneura. In a later paper on Hyalomyodes triangulifera Loew (Can. Ent., Vol. LXXXVI, No. 3) he gave data on the larval forms of Schizotachina, Schizactia and Psalidopteryx.

In investigations on the life-history of the onion maggot, Hylemya antiqua (Mg.), at St. Jean, several types of emergence cages were devised and tested. The composite emergence cage described below was found very satisfactory for the collecting of adults.

At a locality nine miles southwest of Fresnillo, Zacatecas, Mexico, a number of females of Dasymutilla formicalia Rohwer and males of D. pallida Mickel were observed around our campsite during the second week of August, 1954. However, all of the males and most of the females were active only in the early morning and late afternoon. On August 10th, in a dirt roadway about three-quarters of a mile from camp an unusually large concentration of these mutillids was discovered at about 6 p.m. Since but a single species of Dasymutilla appeared to be involved the following observations on the activities of the males and females were recorded.