In Canada mosquitoes are of importance primarily as pests of man and livestock. Their role as vectors of disease is confined solely to the virus of western equine encephalitis. Lacking a public health impetus, study of mosquito biology in Canada has lagged behind that of other countries where diseases such as malaria, yellow fever, filariasis and dengue exist. [...]

DDT in its own right and as a typical representative of that class of insecticides now known as chlorinated hydrocarbons has proved one of our most important and interesting insect toxicants. Its mode of action though extensively studied still eludes us. [...]

Root maggots attacking cruciferous crops were prevalent in Europe during the early part of the nineteenth century. One of the most serious of these pests, the cabbage root maggot, Hylemya brassicae (Bouché), was first reported in 1829 in England and it was first found in North America in the Boston area, U.S.A., in 1835. [...]

Cottony scale is a pest of peach, that although not annually numerous or troublesome, nevertheless, poses a constant threat to the peach growers in the Niagara peninsula. Its capacity to build up a population rapidly when conditions are favourable and thus to cause extensive injury before a grower is aware of its presence, makes it a pest that requires to be carefully controlled even in light infestations. [...]

The spruce bud moth Zeiraphera ratzeburgiana (Ratz.) is native to North and Central Europe, and has apparently been introduced in the northern part of the United States of America and Canada. The yellow spruce budworm Zeiraphera fortunana (Kft.) is indigenous to the North American continent and is generally found associated with Z. ratzeburgiana, causing the same type of damage. [...]

The New Zealand Faronitae was revised at the species level, and a phylogenetic study was performed based on morphological and molecular data. Eight new genera and 143 new species were discovered. Three new genera, Brounea, Ahnea and Pseudoexeirarthra were designated based on the species originally described in the genus Sagola. Five new genera, Aucklandea, Chandlerea, Nunnea, Leschenea and Pseudostenosagola were designated by new species. Three known genera, Exeirarthra, Stenosagola and Sagola were also revised at species level. Eighty four names were synonymized, two in Exeirarthra, four in Stenosagola and 78 in Sagola. Lectotypes of seven species, Sagola terricola Broun, S. rugifrons Broun, S. valida Broun, S. arboricola Broun, S. notabilis Broun, S. eminens Broun, and S. robustula Broun, were designated. These revisional results bring the numbers of New Zealand Faronitae from 145 species within 3 genera to 203 species in 11 genera. The largest faronite genus Sagola includes 143 species, 48 redescriptions and 95 new descriptions and is divided into 30 species groups based on diagnostic characters. Phylogenetic studies were performed based on morphological and molecular data. A morphological parsimony tree was reconstructed based on 49 taxa and 42 adult morphological data. Two most parsimonious trees resulted, and those do not support the genus Sagola as a monophyletic group. The Brounea and Aucklandea clades are placed within the Sagola clade. Three molecular trees, parsimony, maximum likelihood and Bayesian, were inferred using 32 taxa and ca. 4200 base pairs within 4 genes (COI, 18S, 28S and wg), and these indicated that the genus Sagola is paraphyletic. All molecular trees have a genus Ahnea within the Sagola clades, and two genera, Brounea and Pseudoexeirarthra are excluded. Except for the three genera, Brounea, Aucklandea, and Ahnea, all trees supported the monophyly of the genus Sagola. One Australian Sagola species, Sagola rugicornis was excluded from the New Zealand Sagola clade in both morphology

The discovery, during the Second World war, of the insecticidal properties of DDT (Lauger et al. 1944) was heralded by entomologists as a panacea for the problems encountered in insect control measures. The high toxicity of this compound to several species of insects and its relative harmlessness to warm-blooded animals led to its rapid adoption and widespread use. Several insect species were, however, subsequently reported (cf. Weisman 1947; Sacca 1947; Mosna 1947; Johnson and Hill 1948; Deonier et al. 1950) which showed a greater or smaller degree of tolerance to the insecticide.

The work described in this thesis has contributed to scientific knowledge in the following ways: (1) For the first time it has been shown that the response of insect to poison gas at reduced pressures may follow a complex rather than a regular curve when mortality is related to pressure. (2) A zone of high resistance between 30 and 50 mm. has been demonstrated with larvae and adults of Tenebroides mauritanicus (L.). Resistance in this zone is related to the effects of reduced pressure and is connected in some way with reduction of the visible activity of the insects at these pressures. The response in this zone is apparently independant of humidity. (3) It has been shown that at pressures lower than the zone of high resistance the mortality of T. mauritanicus is due more to dessication than to the action of the fumigant.

Plant feeding Acarina have become, in recent years, increasingly more important pests. This trend has led to the development of numerous chemical acaricides directed at the control of these pests. The study of these acaricides has revealed that in some chemical groups, such as the chlorinated hydrocarbons, extremely closely related chemicals may be highly insecticidal and non-acaricidal on one hand and highly acaricidal but non-insecticidal on the other.

The Mississagi region of Central Ontario lies, roughly, north of the towns of Blind River and Thessalon on the north shore of Lake Huron. In the spring and early summer of 1948, this area was generally swept by a major conflagration that began on May 25 and was finally brought under control on July 23. Officially known as fire No. 9 of the 1948 season in the Sault Ste. Marie District, the blaze covered only one-quarter of an acre when it was discovered, but, because of adverse weather conditions, it was impossible to bring it under control. When, finally, the last ember had been put out, the fire had spread over 27 different townships or 281,388 acres in all.