An outbreak of the European spruce sawfly, Diprion hercyniae (Htg.), occurring in Eastern Canada between 1930 and 1942, was controlled by a virus disease (Balch and Bird, 1944). The sawfly has been kept at a low level by the disease and by parasitic insects introduced from Europe (Bird and Elgee, 1957).

An infestation of the sawfly was discovered in 1947 near Sault Ste. Marie, Ontario, by the Forest Insect Survey Section of the Forest Biology Laboratory at Sault Ste. Marie. This infestation was about 100 miles beyond the previously known western distribution of the insect. Intensive larval sampling in 1949 showed that it was free from virus and practically free from introduced parasites. Thus, an excellent opportunity was provided to introduce the virus into a disease-free population, to study its establishment and spread, and to compare the long term effects of virus alone on population trends with the effects that virus plus introduced parasites were shown to have on population trends in New Brunswick (Bird and Elgee, 1957). The virus was introduced into the infestation in 1950 and studies were carried out each year from 1950 to 1959.

The females of many species of chalcids, braconids, pteromalids, and ichneumonids feed on the body fluids or hemolymph of their host. The fact that the adult males do not partake of this food indicates that such feeding may be associated with egg production. Carbohydrate foods, in addition to the body fluids of the host, are essential to egg production in certain species. Feeding on the host by females of certain hymenopterous parasites increases their value as control agents. This feeding sometimes may be more important than parasitism as a cause of host mortality. Itoplectis conquisitor (Say), a host feeding parasite, is considered in this paper.

The two-spotted spider mite, Tetranychus telarius (L.), is a well known pest of many plants in greenhouses. It is notoriously difficult to conarol, especially when resistant populations develop, and usually requires frequent acaricidal treatment during the growing season. Biological control has sometimes been suggested in view of the success that was achieved by this method against other greenhouse pests and because the environment is controllable to some extent, but only a few attempts have been made.

Felt (1940) mentioned a midge in Douglas-fir needles which he called Cecidomyia sp.; this reference was quoted by Barnes (1951). Denton (1954) reported that a midge, identified by the Division of Insect Identification, United States Bureau of Entomology and Plant Quarantine as Cecidomyia sp., occurred in needles of Douglas fir in northeastern Washington, northern Idaho, and northeastern Montana. In 1954 the author reared some adults which H. F. Barnes (in litt. 1957) referred to the genus Contarinia Rond. Unpublished records from 1935 to date indicate unidentified needle-inhabiting gall midges throughout most of the host range. Recently the author found indications of a species comples which were confirmed by further rearings of adults. This paper presents the description of three new species of Contarinia Rond., reared under similar conditions, from material obtained at Oyama, B.C.

In the vicinity of Tuolumne Meadows, Yosemite National Park, California, an outbreak of the lodgepole needle miner, Evagora milleri (Busck), (new combination, Freeman 1960 = Recurvaria milleri Busck – Lepidoptera: Gelechiidae), continues unabated subsequent to its discovery in 1947. Although the outbreak is the third in this area since 1940, factors causing periodic increases and declines of E. milleri have not been determined. Climatic changes were found to have initiated and terminated an outbreak of an allied species, Evagora starki (Freeman), (new combination, Freeman 1960 = Recurvaria starki Freeman), on lodgepole pine in Canada (Stark 1959). However, an apparently sustained favorable climate at Yosemite, while perhaps capable of encouraging needle miner outbreaks cannot, as yet, be held responsible for their declines in this region.

Hille Ris Lambers (1960) erected the genus Toxopterella for his new species, canadensis, collected in Ontario and New Brunswick from Crataegus. At that time he had seen only the alate form of the species from Sorbus described herein, not the fundatrix, which is almost indistinguishable from the fundatrix of Toxopterella canadensis H.R.L. Because of the similarities in the fundatrices and because of the unique characters that they have in common in this morph, we place the aphid from Sorbus in the genus Toxopterella H.R.L., 1960. But the alatae of the two species are distinctly different and we therefore place this species from Sorbus in a new subgenus Sorbobium.

The Annapolis Valley is about 100 miles long and is one of the largest and most important of the agricultural areas of the province. The general relief is undulating to gently rolling, with general slopes from the North and South Mountains to the Annapolis and Cornwallis Rivers. The soils of the Annapolis Valley and Hants County were described by Harlow and Whiteside (6) and Cann, Hilchey and Smith (1). A wireworm survey was conducted between 1951 and 1958 since it was suspected that economically important species of European wireworms, namely Agriotes sputator (L.), A. obscurus (L.), and A. lineatus (L.), which occur elsewhere in the province, might be invading the area. The results of this survey are reported here.

Members of the genus Eurytoma Illiger show a great diversity of feeding habits. There are approximately 90 species or subspecies listed in the synoptic catalogue of the Hymenoptera (Muesebeck et al., 1951) and the first supplement to this catalogue (Krombein et al., 1958), and about 40 per cent of these have been listed with entomophagous hosts. The habitats of another 28 species are listed as galls and the lack of information on their hosts is made clear by Bugbee (1951) who states, “It should be clearly understood that where hosts are given in this paper, all that is indicated is that the parasites were bred or emerged from that particular host gall.” Seven species are listed as phytophagous on seeds and berries and the remainder have no specified hosts.

The two most important economic species of Elateridae in Saskatchewan are Ctenicera aeripennis destructor (Brown) and Hypolithus bicolor Esch. Adults of both species have been observed moving on the soil surface, but the extent and the seasonal duration of this movement has never been fully investigated.

The activity of several species of wireworm adults has been studied by trapping with baits, or by collection from underneath various types of cover where they seek refuge (Hawkins 1936, Campbell and Stone 1939 and Cohen 1942). This type of trap however, gives no assurance that the beetles will stay under the refuge for any definite period, and docs not permit a quantitative estimate nf the population.

The armyworm, Pseudaletia unipuncta (Haw.), has been an important pest of grasses in North America for many years, largely in the eastern half of the Continent, from the more southerly regions of Canada to the southern United States. The larvae skeletonize rhe surface of the leaf blades or rhe inner surface of the sheaths during the early instars, and later feed from the margins of the leaves, consuming all the tissues. The inflorescence is seldom damaged unless leaf foliage is scarce but in some grasses, notably timothy, the green heads are often readily consumed by the older larvae even when foliage is abundant. Normally, populations of the armyworm are small, attracting little attention, but at irregular intervals of five to 20 years widespread outbreaks have occured simultaneously in Canada and the united States; eight such outbreaks have been recorded since 1860. In some of the intervening years smaller and more localized outbreaks have occurred. During the outbreak, damage to forage grasses and cereal crops has been so severe that the armyworm constitutes one of the most important insects attacking these crops. The latest great outbreak occurred on the North American Continent in 1954; this was preceded by a smaller but severe attack in 1953, largely in the central United States east of the Mississippi River. In Canada, in 1954, all the provinces from eastern Saskatchewan to Newfoundland were involved.

In a recent discussion of the subject of insect resistance to insecticides, Brown (1958) has claimed that true resistance is characterized by a five-fold to ten-fold decrease in susceptibility. It is a genetic phenomenon arising as a result of selection. There is no evidence that insecticides are mutagenic, nor can resistance be induced by exposing insects to sublethal doses. A decrease in susceptibility that cannot be regarded as resistance is regarded as a condition of tolerance. In addition, the term “vigour tolerance”, intioduced by Hoskins and Gordon (see Brown, 1958) defines instances of enhanced tolerance due to extra vigour: true specific resistance is marked by a change of slope in the dosage-mortality regression line, while “vigour tolerance” is suggested if the regression line shifts but does not change in slope.

This is a report on a program to sample the European corn borer, Ostrinia nubilalis (Hbn.), with the object of obtaining reliable statistics for life tables (see e.g. Morris, 1955; LeRoux and Reimer, 1959).

Basic studies on factors determining abundance of the European corn borer are few, some of the most notable having been carried out by Barber (1926), Huber et al. (1928), Thompson and Parker (1928), Stirrett (1938), Vance (1943), Baker et al. (1949), Bigger and Petty (1953), Everett et al. (1958) and Chiang and Hodson (1959). None of these studies was a thorough study of mortality factors in development of the European corn borer from endemic to epidemic levels. A number of specific factors known to be important in the epidemiology of this species have been investigated by Arbuthnot (1949), Neiswander (1952), Goleman (1954), Chiang and Holdaway (1955), and Chiang (1959), and the application of biometric techniques to the sampling of corn borer populations has been studied by Beard (1943), McGuire (1954), and Bankcroft and Brindley (1956). None of the latter authors have, however, investigated sampling techniques relating to the development of life tables for this species.

Small, inexpensive air-conditioned cabinets that are easy to construct, maintain and adjust, are needed in many laboratories. Commercially available equipment is not specifically designed to maintain moderate and precise conditions for long periods.

This paper describes the design and physical performance of a laboratory air-conditioned cabinet 40 cu. ft. in volume with a miniature air-conditioning system fitted to it. Air motion and distribution as well as temperature and humidity are precisely controlled. Temperature can be held at any desired level from 65 to 85 ± 0.5°F. and humidity from 45 to 85 per cent with accuracy of ± 1 per cent R.H. provided the ambient conditions are from 65 to 85°F. and 5 to 85 per cent R.H.

In June, 1954, hawthorn trees and shrubs in St. John's, Newfoundland, were severely attacked by small leaf-eating caterpillars. Larvae were talzen from a hawthorn tree, Cratageus sp., at Bowring Park, St. John's West, during the first week of July, 1954, and reared in the laboratory. Moths that emerged were identified as of Swammerdamia lutarea (Haw.) by Dr. T. N. Freeman, Entomology Research Institute, Canada Department of Agriculture, Ottawa, who also noted (in litt.) that this was apparently the first record of the species in North America. Dr. L. G. Davis (in litt.), Economic Insect Survey Section, United States Department of Agriculture, Washington, D.C., later confirmed this observation. Swammerdamia lutarea is now common throughout St. John's and has also been found at Brigus, approximately 50 miles to the west.

During 1958 a general infestation of Pineus coloradensis (Gillette) was observed on red or Norway pine, Pinus resinosa Ait. This insect is widely distributed throughout western United States where it attacks a number of pines. The Annand collection has a slide with specimens of P. coloradensis (Gillette) taken from red pine on the Universitv of California campus dated February 10, 1925. However, there are few reports of any Pineus species attacking red pine in its natural range from the region of the Great Lakes to the Atlantic coast. Shenefelt and Benjamin (1955) have reported the white pine bark aphid or a closely related form on red pines in Wisconsin. Bean and Godwin (1955) also mentioned the presence of an unidentified species of Pineus on red pine.

Live insects have been shipped from the Belleville laboratory for many years by rail in wooden chests insulated with cork, lined with metal and cooled with natural ice. These chests were cumbersome and had to be re-iced en route or heavy mortality resulted. In 1959, a more reliable method was developed for shipping adult Aphidoletes thompsoni Moehn (Diptera: Cecidomyjidae), a predator of the balsam woolly aphid, Adelges piceae (Ratz.) (Homoptera: Aphididae) by air express. It incorporates the use of a lightweight container and a patented coolant in cans. Although it was developed specifically for A. thompsoni it was also used successfully for shipping other species.

Aptesis biasizona (Grav.) is a common and widely distributed parasite of diprionid sawflies in central, western, and northern Europe, with parasitism varying from three to 90 per cent on different hosts and in different areas. One of these sawflies, Neodiprion sertifer (Geoff.), is very commonly attacked, with parasitism of 30 to 80 per cent in Czechoslovakia, 10 to 52 per cent in Hungary, and 17.5 to 40 per cent in Sweden (Morris et al., 1937).

Since Neodiprion swainei Midd. overwinters within cocoons in the soil, it is necessary for the population ecologist to sample the forest floor. One-footsquare units of soil have been used for sampling cocoons in population studies of N. swainei in the Province of Quebec. After removal from the forest floor the samples were placed individually in cotton bags for shipment to the laboratory. The ordinary method to extract cocoons required that the samples be first broken up by hand, then passed over various-sized screens to eliminate the sand and other small particles. Following this, each sample was carefully manipulated and scrutinized by one worker and the cocoons removed, then similarly re-examined by another worker. Best results were obtained when the samples were dry.

Although many possible vectors of the Dutch elm disease, Ceratocystis ulmi (Buism.) C. Moreau, have been listed by Collins et al. (1936) and others, only two, Scolytus multistriatus (Marsh.), the European elm bark beetle, and Hylurgopinus rufipes (Eichh.), the native elm bark beetle, are known to transmit the disease with any regularity. In this capacity alone thcse two species of beetles are important pests of elm. The persistent spread of the Dutch elm disease in southern Ontario (Hord and Quirke, 1955) made it imperative that adequate surveys be maintained to indicate yearly changes in the occurrence of the introduced vector, and to ascertain more precisely the distribution of the native vector relative to the distribution of elm in Ontario. Consequently the Forest Insect Survey of the Forest Insect Laboratory, Sault Ste. Marie, intensified its elm bark beetle program in 1956, and from then to 1959, 138 positive samples of these two scolytid beetles have been received. An analvsis of these records and their relationihip to the current incidence of the Dutch elm disease in Ontario are presented in this paper.

The abdomen, as in other muscoid flies, is composed of a preabdomen of five pregenital segments, of which terga 1 and 2 are fused, thus giving the appearance of four segments. Sterna 1-7 or 1-8 form a relatively narrow chain of ventral segments (Fig. 11). The postabdomen, or genital segments, comprise segments 6-10, some of which are reduced, absent, or modified in other ways. The post-abdomen of the Sarcophagidae and Tachinidae usually is “fixed” (not retractable), whereas in the Muscidae and Calliphoridae it commonly is in the form of a retractable ovipositor, which is narrow and elongated when extended but in repose telescoped within the abdomen.