The results obtained in the experiments just described indicate that the discriminative ability of the female parasite operates to enable the parasite to distinguish between hosts which have been parasitized previously, not only by itself but by other members of the species, and perfectly health; hosts. If this were not the case, series in which the densities of the female parasite populations were high would have given results which were more nearly approximate to a random distribution of progeny among the available hosts. As we have seen, the tendency was for the parasite to avoid superparasitism under all conditions, i.e., to exercise a deliberate choice of hosts.

In observations on the root maggots of garden crops in Canada made by A.R. Brooks in 1947 and later mimeographed (1) for officers of the Division of Entomology, Mr. Brooks indicated that there is frequently a complex of species in a field sample of larval Diptera; that the species and their numerical proportions are likely to vary both seasonally and geographically; and that not just one but 15 species of Diptera have been found in the roots of cabbage and as many as 14 in onions. He observed further that certain species of maggots appear directly responsible for the plant injury; others play a secondary role so that there is sometimes an involved ecological succession of species.

In the writer's list of the Odonata of Ontario fifty species were recorded from the Kenora District of Ontario and only one from the Rainy River District. Thirty-five are reported from the vast northern part of the District known as the “Patricia Portion” and twenty-three from the southern part. The records from the Patricia portion are all from three widely separated localities but probably give a fair general picture of the odonate fauna of these northern latitudes. The records from the southern part of the District, on the other hand, are almost entirely from one locality, Minaki (approx. 50° N. Lat., 9° W. Long.) and are quite inadequate even for that one locality, some of the commonest regional species not being included.

The hide beetle, Dermestes maculatus Degeer, is a cosmopolitan insect which each year causes considerable losses to stored products throughout the world. The economic importance of this species is due especially to the habit which the mature larvae have of boring into many commodities in order to pupate. However, the larvae and adults also feed on and thus damage a wide variety of substances with a high protein content (4), e.g., bones, carcasses, skins and hides of all kinds, etc.