It is a well known fact, noticed by many workers engaged in breeding hymenopterous parasites, that there is a tendency in many bisexual species for the sex-ratio to decrease as the breeding work proceeds over a series of generations. In a number of cases the sex-ratio decreases to an extent where only males are produced, and the stock dies out.

Concerning the light reactions of the adults, it may be noted that males are photopositive when in a dark-adapted state, but they rapidly become adapted to any light intensity and become extremely sluggish. Females in the dark-adapted state exbihit either photonegative behaviour or compassing behaviour, with no evidence that there is any orderly transition from one type of behaviour to the other. Light-compass orientation of flying females makes it possible to collect some at light traps, despite their normally negative response.

For reasons which will be given in a forthcoming taxonomic paper, the spruce budworm, Archips fumiferana (Clem.), is here transferred to the genus Choristoneura Lederer, 1859, Wien Ent. Monatschr., 3:242. Genotype: Tortrix rusticana Treitschke, designated by Fernald, 1908, The genera of the Tortricidae and their types, p. 53. The transfer is made at present in order that this species may be properly referred to in a following paper dealing with its external anatomy.

Cocoons of the larch sawfly normally spend from nine to ten months in the ground per annum under conditions existing in western Canada. For this reason biotic and abiotic soil factors are of paramount importance in the epidemiology of this insect. Preliminary observations and experiments indicate that ground water is one of the most important of these factors in that it not only affects sawfly development directly but also is significant in regulating sawfly predators and possibly parasites.

Beetle collectors are lucky. Weather permitting, they can hunt almost the year through, for many species of Coleoptera hibernate as adults. When snows are deep our treasure houses are old stumps, and dead trees with the bark still on but loose. Better yet are November days when early frosts have sent the lakeshore forms to shelter, and every driftwood log is home to a dozen species.

The seasonal history of an insect has an important relationship to the success or failure of any efforts to usr parasites in its control. In the work on parasites of thr European corn borer, Pyrausta nubilalis Hubn., over a period of years, the writer has had an opportunity to observe the changes which have taken place in the seasonal history of this insect in Western Ontario. It was shown by the writer (Wislwt, 1942, 1944) that there was a gradual and rather consistent increase in the proportion of the population which had two generations instead of one. The present paper presents further data pertinent to this subject.

As a group, the wasps which inhabit the North American continent have not attracted very widespread interest, despite the excellent accounts of the habits of various species which have been published by such careful observers as the Raus, the Peckhams and other writers.

This, possibly, is due to the fact that relatively few of the numerous species appear to have a very direct relationship with insects that are consided to be of great economic importance. Exceptions to this general rule are found in such genera as Podalonia (Ammophila) and Sphex, which are conspicuous in their activities while hunting for cutworms and in, subsequently, dragging them to their subterranean nests.

Experiments conducted in cabinets in the greenhouse during the winter of 1945 showed that temperature had a marked effect on the toxicity of DDT to larvae of the diamondback moth. Plutella maculipennis (Curt.), and the greenhouse leaf tier, Phlyctaenia rubigalis (Guen.), the mortality decreasing as the temperature increased within the range of the tests. The optimum temperature for maximum kill has not yet been determined because it was not possible to run tests at all desired temperatures with the equipment available.

This project arose out of studies of the European spruce sawfly, Gilpinia hercyniae (Htg.), in connection with the Canadian Forest Insect Survey at the Dominion Entomological Laboratories, Fredericton, N.B. Bessa selecta (Mg.) had been observed as a parasite of the larch sawfly, Pristiphora erichsoni (Htg.), but particular interest was aroused in it as a parasite occurring on the European spruce sawfly. The latter host was frequently found to bear the eggs and integumental funnels of B. selecta. The object was to study its biology and effectivness as a possible control factor of the spruce sawfly. However, great difficulty was experienced in rearing the host due to high mortality caused by disease. Hence the original aims were not attained to the entire satisfaction of the author.

In 1946, a water-dispersible powder (formulation P. 530) containing 6% gamma benzene hexachloride and 50% goulac (lignin pitch) was tested in the field for control of black cherry aphid (Myzus cerasi (F.)), apple aphid (Aphis pomi Deg.), mealy plum aphid (Hyalopterus arundinis (F.)), wooly apple aphid (Eriosoma lanigerum (Hausm.)) and pear psylla (Psylla pyricola Foerst.). The material was compared at 0.25 lb. gamma isomer per 100 gal. in (1) water alone, and (2) plus 0.5 gal. of either distillate oil (42. S.S.U. Vis. 100° F., 77% U.R.) or summer oil (60-64 S.S.U. Vis. 100° F., 78% U.R.). Three gallons of each mixture were applied by bucket pump and two trials were made, the first beginning July 10 and the second July 16. Results are given in Table 1.

On July 6, 1946, Game Warden, J. P. C. Atwood, of Vernon, B. C., saw a number of crows (Corvus brachyrhynchos hesperis) in coniferous trees adjacent to the highway, near where the Monte Creck road meets the Vernon-Kamloops road. He shot one on the wing, killing it in the air. The bird must have landed on its crop, for on reaching it he found its beak held wide open by a mass of beetles which also filled its throat and spilled out onto the ground.

A male of Diachlorus ferrugatus (Fabr.) was recently captured at London, Ontario, by Mr. F. J. Hudson, an inspector for the Plant Protection Division, Science Service, of the Dominion Department of Agriculture. The specimen was taken during inspection of a case of Peperomia imported from the John's Nurseries, Apopka, Florida. As this seems to be the first recorded capture of this sex of the species, the following description of the specimen is offered. The Canadian National Collection contains two females, in poor condition, from Ellis Lake, Havelock, N.C., and these specimens together with Stone's description of the female have been utilized for purposes of comparison.

Since the writer's report on “The Subarctic Odonata of North America” was published, several collections have been received from localities included within the territory covered in that paper, which add materially to our knowledge of the dragonfly fauna of the Hudsonian Zone on this Continent. Most of these collections are from the Northwest Territories but a few are from northern Alberta and Newfoundland.

Extensive stands of young tamarack throughout the forested areas of the Prairie Provinces are currently menaced by the depredations of this serious defoliator. Owing to the importance of the insect, this paper was prepared with the object of: (1) reviewing briefly available information concerning the present outbreak in the Prairie Provinces, (2) clarifying some of the main issues frequently raised, and (3) describing the investigations in progress in the Prairie Region.

In March, 1946, the writers reported in Scientific Agriculture (1) that benzene hexachloride showed pronounced fumigant action and that air currents as slow as 2 m.p.h. lowered its effectiveness against insects to a marked extent. The present paper deals with further experiments with benzene hexachloride and gives preliminary data on the fumigant action and effect of air currents on three other chlorinated hydrocarbons, viz., DDT, Hercules Toxicant 3956 (a chlorinated terpene) and Velsicol 1068 (a mixture of isomers with the empirical formul C10 H6 Cl8).

Recent developments in the insecticide field have made available to the economic entomologist a wide variety of chemical compounds which exhibit high toxicity to certain species or groups of insects. The pyrethrins rotenone and nicotine, reinforced by the dinitro compounds and thiocyanates of prewar times, have now been joined by the chlorinated aromatic hydro-carbons: DDT, gammexane, chlordane and toxapohene.

In the first paper of this series (5) the ecologica1 approach to apple orchard insect problems was discussed and it was pointed out that the spray program must be considered as an ecological factor. It is obvious that because of the complex relationships of the plant and animal species in an orchard it is impossible to change the relationships of any single species without, in greatcr or lesser degree, altering the whole community. In some cases the disturbed relationship may show immediately in the repression of one pest and the rise of another, while in other cases the changes are much more obscure and the economic effects nlay not appear for a long time. The cause of these change is that a spray aimed at some particular species also, directly or indirectly, aifects many other species in the orchard environment and thus may be expected to alter the numerical relationship of many predacious and parasitic forms to certain pests or potential pests which are their prey. The oystershell scale, Lepidosaphes ulmi (L.), and the European red mite, Metatetranychus ulmi (Koch) = (Paratetranychus pilosus (C & F)) are examples of species which react quickly to changes in spray treatments owing to the large populations they may build up in a short time and to the rapid increase of their predators and parasites when not hindered by the spray treatments.

I had recently the pleasure of receiving from Mr. J. I. Beaulne of Quebec City an interesting dipterous insect for identification. The locality label attached to the specimen read “Lachine, Que., 4, IX, 43, J. I. Beaulne.” The insect belonged to the genus Acrocera of the family Acroceridae and did not match any of the specimens in the collection of the University of Montreal. I sent it to Mr. G. E. Shewell of the Department of Agriculture, Ottawa, for identification. Mr. Shewell kindly replied, stating that the fly was Acrocern steyskali Sabr., a new record for Quebec. He further stated that the species was described quite recently from northeastern United States material and that he did not think it had been recorded from anywhere in Canada.

Machaerilaemus Harrison: Parasitology, VII, p. 389 (1915).

Machaerilaemus Harrison: Harrison, Parasitology, IX, p. 60 (1916)

Hirundoecus Ewing: Proc. U. S. N. M., LXXVII, Art. 20, p. 12 (1931).

Machaerilaemus Harrison: Bedford, 18th Rept. Dir. Vet. Serv. and Anim. Ind. Un. S. Africa, p. 377 (1932).

Hirundoecus Ewing: Bedford, ibid, p. 380.