This is the first of a series of papers dealing with investigations that were commenced in 1956 at Summerland, British Columbia, to determine if the codling moth, Carpocapsa pomonella (L.), could be eradicated in the interior of British Columbia by the release of sexually sterile male moths.

One of the most important prerequisites for the success of this method is the development of a technique that will sterilize the male without seriously affecting its behaviour, particularly mating ability and longevity. Complete or almost complete sterility has been induced in one or both sexes of certain species of insects by feeding them chemicals (LaBrecque et al., 1960), or by exposing them to X- or gamma rays (Bushland and Hopkins, 1953), or by subjecting them to abnormally high temperatures (Riordan, 1957).

Typhlodromus pyri Scheuten (= T. tiliae Oudms.) is the predominant species of predacious mite on apples in Nova Scotia. It feeds on a wide range of prey species (Herbert, 1959). Chant (1960) investigated the life-history and habits of this species in southeastern England and Herbert (1956) studied its life-history under controlled laboratory conditions. A knowledge of the life-histories of various components of the fauna is basic to an evaluation of predation; therefore, a study of the life-history and habits of T. pyri in the field was undertaken. This was supplemented by a laboratory study in which an attempt was made to duplicate field temperarures. The results of these studies are presented here.

The larch sawfly, Pristiphora erichsonii (Htg.), has been under observation in Manitoba and Saskatchewan since early in the present century. Recorded observations were somewhat fragmentary until 1937; since then systematic and detailed annual reports have been provided by the Forest Insect Survey and since 1948 intensive ecological and life table studies have been conducted by staff of the Winnipeg Laboratory at the Whiteshell Forest Reserve, Manitoba.

This contribution is the eighth in a series of papers on sampling techniques used in population studies of the larch sawfly (Ives, 1955; Ives and Prentice, 1958; Buckner, 1959; Ives, 1959; Ives and Prentice, 1959; Ives and Turnock, 1959; and Turnock, 1960). Although the greatest proportionate mortality usually occurs in the cocoon stage of this insect, the largest amount of mortality in terms of absolute numbers occurs between oviposition and the completion of larval feeding. This paper presents a method for estimating seasonal increments to the egg and larval populations and alternative methods for estimating mortality during these stages. Examples are also provided of the integration of these methods with previously developed techniques for estimating egg populations and foliage weight.

The sugar-beet root magsot, Tetanops myopaeformis (Röder), is one of the most important pests of sugar-beets in southern Alberta. From 1956 to 1960 studies were made of various phases of its life history (unpublished). In this paper, napping adults of T. myopaeformis by insecticide and water traps is judged for reliahility in determining dates of emergence and sex ratio when compared with data obtained from emergence cages in the field. Information is also given on the influence of color and a wetting agent on the number of flies caught in water traps.

This is the third paper of a series on the taxonomy of cocoons and puparia, cast larval skins, and other remains of parasitic Hymenoptera and Diptera that are found in or near the remains of parasitized hosts hfter the parasites have emerged. It deals with the known Canadian parasites of the introduced pine sawfly, Diprion similis (Htg.); previous papers dealt with the known Canadian parasites of the European pine sawfly, Neodiprion sertifer (Geoff.) (Finlayson, 1960a) and the European spruce sawfly, Diprion hercyniae (Mtg.) (Finlayson, 1960b). Parasites of D. similis that werk encountered in either of the nvd previous papers in the series are not described or illustrated here.

In a recent paper, Pointing (8) described the distribution of the European pine shoot moth, Rhyacionia buoliana (Schiff.), in Ontario. Since first discovered in the Toronto area in 1925, the insect has become widely dispersed, so that at the present time, it appears in almost continuous distribution wherever red and Scots pines grow in southwestern Ontario. Two main factors are responsible for the rapid spread of the infestations, (a) the chance planting of infested nursery stock, and (b) the natural dispersal tendencies of the species. This, and the succeeding paper of this series, will be concerned with the natural dispersal of the shoot moth; dispersal, as used throughout both papers, describing movement beyond the tree on which the insect hatched from the egg.

In the first paper of this series (3), the factors affecting flight, and the flight potential of egg-laden females of the European pine shoot moth, Rhyacionia buoliona (Schiff.), were discussed. It was shown that the adults are relatively strong fliers, with a potential flight range greater than indicated in much of the earlier literature. It was also pointed out that natural dispersal of this species is dependent upon flight and subsequent oviposition by gravid females because unmated females seldom fly, and little, if any, population dispersal occurs through the long range movements of early instars drifting on silk. This final paper of the series deals with field studies designed to obtain information concerning the dispersal tendencies of gravid females under natural field conditions.

The European pine shoot moth, Rhyacionia buoliana (Schiff.), was first discovered in North America on Long Island, New York, in 1914 (Busck, 1914). Since that time it has spread throughout most of the northeastern United States, becoming one of the most important insect pests of pine plantations. In Ontario, it was first discovered in the Toronto area (McLaine, 1926) and since that time has dispersed throughout southern Ontario, appearing regvlarly south of a line from the southern end of Gcorgian Bay to a point just east of Lake Ontario (Fig. 1). Isolated occurrences of the shoot moth have been reported north of this line but these have been short-lived on small plantation trees, or have persisted in cities and towns on ornamentals protected by snow cover during the winter. The continuous distribution of the insect has remained relatively static since 1951, and it appears that the northern limit of its range in Ontario has been reached.