Microctonus aethiops (Nees) auctt. (Fig. 1) and Perilitus rutilus (Nees) are parasites of adult Sitona weevils in Europe. They were released in Canada as control agents of the sweetclover weevil, Sitona cylindricollis Fahr. (Fig. 2). The immature stages and biology of the species were studied as a prerequisite to attempts at biological control. A similar investigation of the braconid Pygostolus falcatus (Nees) was completed (Loan and Holdaway, 1961). Jackson (1928) described some aspects of the biology of P. rutilus, and additional data are given in the present paper.

The effects of fiood od the fecundity and longevity of the adults of hymenopterous parasites vary remarkably, not only between species that are host feeders and those that are not host feeders, but also within these groups. It is known, for example, that the females of Itoplectis conquisitor (Say) develop only few eggs without feeding on body fluids of their host. In the present investigations it is shown that the females of Scambus buolianae (Htg.) are not able to deposit any eggs without first feeding on the tissues of their host. Such information is important for the successful establishment of newly-imported parasites.

La distribution géographique circompolaire et très étendue de la mouche à scie du peuplier comprend toute l'Europe et la partie septentrionale de l'Amérique du Nord. Au Canada on a signalé sa présence de l'Atlantique au Pacifique.

Dans le Québec, cet insecte n'avait jamais été signalé cornme très nuisible avant 1956, alors qu'il se multiplia soudainement d'une façon excessive occasionnant des défoliations importantes sur les peupliers ornamentaux, dans certains secteurs de la ville de Québec.

The European pine shoot moth, Rhyacionia buoliana (Schiff.), has been recognized as a pest of pine plantations since it was described in 1776. Neugebauer (1952) stated that 32 susceptible pine species were known and that scarcely any species were rejected by the insect. Following its accidental introduction into North America about 50 years ago (Busck, 1914) the shoot moth became a serious pest of red pine, Pinus resinosa Ait., which appears to be the most susceptible species (Heikkenen and Miller, 1959). Watson (1947) described the shoot moth as “the most destructive insect affecting hard pines in southern Ontario, and the most difficult to control”. Plantations have been damaged so severely that the planting of red pine has been virtually discontinued within the pest's range.

Prosimulium fuscum Syme and Davies, P. mixtum S. and D. and P. fontanum S. and D. form a complex of closely-related and largely sympatric species formerly known in North America (Twinn, 1936; Stone and Jamnback, 1955) under the single name P. hirtipes Fries, a well known species in the northern Palaearctic. The first step in demonstrating the multiple nature of the forms grouped under this name in North America was taken by Rothfels (1956) who showed by study of rhe larval salivary gland chromosomes that at least three non-interbreeding forms were present in eastern Canada. L. Davies (1957a) concluded from a study of specimens of all life-stages that none of the North American forms agreed with European P. hirtipes. A further step in the process was afforded by the work of Syme and D. M. Davies (1958), which erected the three species named above as a result of anatomical study of cytologically defined material, and showed that adult females of P. fuscum and P. mixtum could be reliably separated, mainly by features of the genitalia. The present work may be considered as a further step in the study of the common Prosimulium of eastern North America, by providing information on their ecology, thus amplifying the cytological and anatomical conclusions arrived at in the papers cited above.

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.

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 adult populations where females are in excess of males, the ability of the males to mate more than once is an imporcant consideration when predicting the descendant population. Pointing (1961) found that under insectary conditions Rhyacionia buoliana (Schiff.) males are capable of inseminating mlore than one female. Stehr (1954) srates, with reference to a method of mating Choristoneura fumiferana (Clem.) in the laboratory, “Aftcr mating, the male may be discarded; only rarely will it mate succesfully with a second female.” During genetic studies conducted in an insectary on the reproductive capacity of four species of Choristoneura, a technique was used in which individual males were mated to several females. The purpose of the study was to gain genetic information and not to measure sexual activity so that maximum mating opportunities for che males were not provided. In the light of Stehr's observation, it was decided to publish these results since they provide valid but limited information concerning the polygamous capabilities of Choristoneura males.

Pullus impexus (Muls.) is one of many species of predators that have been introduced into Eastern Canada since 1933 as part of a biological control program against the balsam woolly aphid, Adelges piceae (Ratz.) Delucchi (1954) has published many details of the systematics, biology, and natural control of this species in Europe where he found it to be associated with all A. piceae infestations. According to Pschorn-Walcher and Zwölfer (1960), it is one of a group of predators that are usually associated with lower population densities of A. piceae and other related adelgids, rhan are Aphidoletes thompsoni Möhn and Laricobius erichsonii Rosen. Because it is common on adelgid infestations in Europe and because it can easily be reared en masse, large numbers have been released in North America. The purpose of the present paper is to bring together available information on releases, life-history and natural control, and control value of this species, obtained from studies carried out over the past nine years in New Brunswick.