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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
161

The Orthoptera of Nova Scotia.

Vickery, Vernon. R. January 1957 (has links)
Orthoptera in Nova Scotia are not generally considered to be economic pests. However the records show that many infestations of economic proportions have occurred in the province. The present study was not initiated because of the economic status of the group but rather because of the interesting variation encountered in the relatively small number of species representing this Order. This paper includes a brief resume of the classification of the Order Orthoptera and the Orthoptera found in Nova Scotia, including keys, illustrations, descriptions, range, habits, habitat and common synonyms.
162

the Comparative Action of Acaricides on the Two-Spotted Spider Mite, Tetranychus Telarius (L.), (Acarina: Tetranychidae).

Mailloux, Marcel. January 1960 (has links)
Phytophagous mites have recently become increasingly important economic pests in many parts of the world. This increase in importance is considered by many as due to the widespread use of insecticides which have killed the predators that previously kept mites under control. It has created a need for specific acaricides of relatively low toxicity to insects. Many such have appeared on the market. Some have been adequately tested, many have not.
163

The identification of larvae of some species of bark beetles breeding in coniferous trees in eastern Canada.

Thomas, James. B. January 1954 (has links)
The use of the external anatomy of the larvae of bark beetles for the purpose of generic and specific identification has been neglected in the past. One reason for lack of interest in this particular phase of the study of bark beetles may lie in the biology of this group of insects where, in many cases, adults are present together with the larvae throughout most of the developmental period. However, there are occasions where larvae of more than one species feed in the same area of bark, and even though adults of all species represented are present, the percentage of each species cannot be estimated.
164

Occurrence of the Swaine jack-pine sawfly and external anatomy of the mature, feeding larvae.

Wallace, Donald. R. January 1959 (has links)
The diprionid sawflies, the group to which Neodiprion swainei Middleton belongs, have been known to science for many years. Linnaeus listed two species in the Tenth Edition of his Systema Naturae published in 1758, and Ratzeburg in 1844 devoted thirty-four pages of his text to a discussion of the fifteen species he recognized. Thus long known as serious pests of the Pinaceae in Europe, the diprionids have attracted increasing attention in North America since the early decades of the twentieth century, coincident with the increased planting of large areas to pines and the rapid increase in exploitation of virgin forests.
165

The B vitamin requirements of the house cricket.

Ritchot, Claude. January 1960 (has links)
McFarlane, J.The house cricket Acheta domesticus (L.) is a very convenient laboratory insect; it is easy to rear (Ghouri and McFarlane 1958), it has a sufficiently short life cycle, the eggs and young nymphs are large enough not to necessitate any special apparatus to be manipulated, and, finally, neither diseases nor parasites are factors influencing the results. Nevertheless, A. domesticus has not been used very often by research workers, and the first to study seriously some aspects or its nutrition were Ghouri and McFarlane (1958), and McFarlane et al. (1959).
166

The effect of DDT on codling moth adults (Carpocapsa pomonella L.) (Lepidoptera: Olethreutidae).

Hikichi, Akira. January 1956 (has links)
The codling moth, Carpocapsa pomonella (L.) a persistent pest in apple orchards throughout the North-American continent, has been a source of concern tor over a century. For many years lead arsenate was used to control but gradually became less effective as the insect developed resistance (Hough, 1929). DDT, after its introduction in 1945, gave excellent control and is now the most widely used insecticide against the pest. Its use, however, has not been without some disadvantages, chief of which are an upsurge of phytophagus mites, and to a less extent other pests such as the red-banded leafroller, due in large part to the destruction of natural enemies.
167

Population Behaviour of the Sheep Ked, Melophagus Ovinus (L.), in Relation to Endocrine Mechanisms in Sheep.

Nelson, W.A. January 1900 (has links)
Compared with the advances of the past twenty years in special branches of insect physiology, and in biology of insects attacking plants and stored products, progress in veterinary entomology has been indeed slow. This is particularly true of the obligate parasites which spend all or a major part of their lives on or in the host animal. [...]
168

Water absorption and metabolism during the embryonic development of the house cricket Acheta domesticus (L.) (Gryllidae, Orthoptera).

Kennard, Charles. P. January 1957 (has links)
The eggs of certain species of insects, many of which are of great economic importance, absorb water from the external environment. Water uptake in these insects occurs in a definite stage in embryonic development. Previous studies on the egg or the house cricket, Acheta domesticus (L.), have shown that contact water is necessary for the development of the egg. The stage of embryonic development at which water absorption occurs, and the mechanism or absorption, however, have not been studied. In the present investigation, water uptake by the egg is studied, the stage of embryonic development at which this uptake occurs is determined, and the mechanism or absorption is analyzed.
169

A study of the clover root borer, Hylastinus obscurus (Marsham) (Coleoptera: Scholytidae).

Gustafson, Jean. M. January 1958 (has links)
By far the most important legume grown on Quebec farms is red clover, Trifolium pratense L. It has, however, been falling short of its potential productivity in this area. Within recent years, considerable research has been conducted with a view to evaluating the effects of various factors on the longevity and vigour of the red clover plant. The current view is that a complex of interacting factors, including varietal differences, weather conditions, and the attack of a large number of insect species, fungus diseases and possibly nematodes is involved in reducing the yield of this crop.
170

an Embryological Study of the Spruce Budworm, Choristoneura fumiferana (Clements), (Lep., Tortricidae).

Stairs, Gordon R. January 1958 (has links)
The most complete accounts of Lepidoperon embryology are by Toyama (1902), Eastham. (1927), Johannsen (1929), Gross and Howland (1940), Rempel (1951) and Presser and Rutschky (1957). There are many other papers that either deal with the development of only one or a few structures or review knowledge of a specific subject. [...]

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