The Douglas-fir hylesinus, Pseudohylesinus nebulosus (Leconte), is a common bark beetle in western North America from British Columbia to Mexico. Although Douglas fir, Pseudotsuga menziesii (Mirb.) Franco, is the preferred host, the beetle has been collected also from western red cedar, Thuja plicata Donn, grand fir, Abies grandis (Dougl.) Lindl., amabilis fir, Abies amabilis (Dougl.) Forb., and western hemlock, Tsuga heterophylla (Raf.) Sarg., on the west coast of British Columbia, and from western hemlock and western yellow pine, Pinus ponderosa Laws., in the interior of the Province. Swaine (1918) describes Pseudohylesinus nebulosus (Lec.) as “a slender species, with strong colour-markings in dark and light reddish-brown; the male very densely clothed with stout scales; the epistomal lobe strongly developed; length, 2.8 mm.; width, 1.2 mm. The supposed female has interspace 9 on the declivity less strongly serrate, and the elytral scales decidedly elongate and becoming plumose towards the base.”

The terminology pertaining to the structure of the male genitalia of the Hymenoptera has been subject to much confusion. Several systems, many purely descriptive in nature, have previously been set forch. Others were based on the various concepts of the ontogeny of the male genitalia, or on the comparative morphology of the adults. The investigation reported here began as an attempt to synthesize the various terminolopies and to evolve a workable set of terms pertaining to the structure of the male genitalia of the megachilid bees. Accordingly, a study was conducted on the myology of the group with the thought that perhaps an understanding of the comparative musculature might be of value in determining the homologies of the insect genitalia. This paper reports the results of a phase of the investigation on the morphology of the male metasoma, the muscular mechanism of the male metasoma and genitalia, and the gross structure of the internal reproductive organs of Megachile (Phaenosarsus) fortis Cresson. A second portion of the study, pertaining to the comparative morphology of the male genitalia and associated sterna of the Mecgachilidae, will be published later.

Many species of the genus Silba Macquart (= Carpolonchaea Bezzi) are important pests of fruits and vegetables during their larval stages but taxonomically the adults are poorly known. Representatives of 15 species of the genus from widely separated localities in the Old World have come to hand during studies on the family. This paper clarifies the identities of the males of these 15 species, six being described as new to science.

The Forest Insect Survey of the Maritime Provinces has been observing an outbreak of the winter moth, Operophtera brumata (Linn.), since its discovery in Nova Scotia in 1949. In addition to noting annual changes in distribution, the Survey has made population counts on 8 to 20 tagged trees of red oak, Quercus rubra L., at each of seven locations along the south shore of the Province. These trees were sampled each year to show the abundance of larvae of the winter moth and the fall cankerworm, Alsophila pometaria (Harr.). Both species are commonly found on the same trees, and their life histories are similar. The collections and subsequent rearings also showed the degree of parasitism by native or introduced species of parasites. The defoliation of the trees was estimated at the time of sampling and again at the end of the feeding period to determine the relationship between larval population and defoliation. Some of the sampling data, which were collected from 1952 to 1955, are used to develap the sequential plan of sampling described herein. Use of the plan at the sampling stations should reduce the number of samples while retaining accuracy within predetermined limits.

It is well known that the accidental introduction of some plants into certain parts of the world has later led to noxious weed problems of varying degrees of acuteness. Concrol of such alien plants by cultural or chemical methods may be unsatisfactory or economically impracticable and recourse is made to biological methods in the form of insect enemies etc. It was in circumstances of this nature that the Government of Nigeria requested the C.I.B.C. to investigate the possibilities of the biological control of the weed Acanthospermum hispidum D.C. Despite the discouraging facts that the weed is an annual and related to plants of economic importance in the family Compositae, and that the entomological method is appropriately regarded as being of very restricted application in these instances, the nature of thc problem for Nigerian agriculture was such that a preliminary investigation of the status of the plant in its native South American home seemed warranted.

When an apple orchard is abandoned in Eastern Canada the trees may continue to grow reasonably well for many years. As a rule the fruit is ruined by apple scab, but damage from insects or mites may be relatively minor. Under such conditions, phytophagous insects and mites are commonly held to an acceptable commercial level by natural control factors. On the other hand, when an apple orchard is abandoned in the semi-arid, southern interior of British Columbia the trees generally die from desiccation in a short time. Occasionally, when particularly favoured by sub-irrigation, they may survive for ten years or more. But they produce no marketable fruit; invariably it is ruined by insects. Unlike the abandoned eastern orchard. that in British Columbia his little natural protection from the codling moth, Carpocapsa pomonella (L.), and the blister mite, Eriophyes pyri (Pgst.), to mention but two common pests.

The satin moth, Stilpnotia salicis (L.), has been a pest of shade trees in the Maritime Provinces for about 25 years. Surveys of its distribution were started by the Division of Plant Protection (9) immediately following the discovery of this introduced species in 1930 and later carried out annually by members of the Fredericton Laboratory and the sub-laboratories at Debert, N.S., and Corner Brook, Newfoundland. The surveys have been accompanied by periodic collections and rearings, but only the larger and more representative of these are discussed in the present paper.

The subject of this paper was selected with enthusiasm. The law of natural compensations seemed most intriguing and the part played by forest insects in its enforcement appeared to afford unusual opportunity for discussion. Now that the time has arrived for its presentation there is a sense of trepidation, because the drawing of generalizations is always dangerous. However, without generalizations we should inevitably be confused by the mass of information concerning populations of insects, their parasites, predators, and host plants, and the responses of these organisms to their habitat. Therefore, it may be appropriate to present this somewhat old story from a different angle to illustrate the viewpoint of one forest entomologist, using some old and some hitherto unreported examples. Most of the examples that will be cited, whether old or new, have been observed first hand.

The International Congresses of Entomology appear to have arisen in the first instance as a development of the International Congresses of Zoology of which the first was created in 1889 by the Zoological Society of France. The first Entomological Congress however, came to be through the personal initiative of Dr. Karl Jordan. Dr. Jordan felt that although entomology has a place in Zoological Congresses this was not commensurate with its importance. He considered that entomology was suffering from the absence of a representative organization where entomologists could meet and discuss their common problems. He noted that many important entomological works, large collections and even the name of distinguished specialists remained quite unknown to non-entomological zoologists. He observed that here and there ill feeling had developed among members of the entomological profession to the great damage of biological science. He found that although entomologists were very numerous and had produced a tremendous mass of work a good deal of this had little scientific value. Finally he complained that in Europe, at least, few of the scientific entomologists were at all interested in the insects of importance to agriculture and to health. Some of the colleagues he consulted doubted that an Entomological Congress could be organized but all agreed that it would undoubtedly be beneficial to entomology.

In this paper 13 new species and a new genus (Phloeocleptus) of scolytid beetles of the tribe Micracini are described from Mexico and Honduras. Unless stated otherwise, the specimens taken in Mexico were collected by the author while with the 1953 expedition of the Francis Huntington Snow Entomological Museum (University of Kansas, Lawrence). The new species represent the following genera: Hylocurus (6), Phloeocleptus (2), Micracis (4), and Pseudothysanoes (1).

The following contribution to our knowledge of the Ichneumoninae of the boreal parts of Canada and of Alaska is based mainly on material obtained by the Northern Insect Survey, which is a co-operative project of the Canada Department of Agriculture and the Defence Research Board, Canada Department of National Defence.

The contribution brings forward 12 new species and subspecies 3 of them being represented by both sexes, 9 by the female sex only. Some arctic species already named before or regarded as holarctic elements will be treated in a separate publication.

The black army cutwarm, Actebia fennica (Tausch.), is the most important pest of foliage of the low-bush blueberry in New Brunswick. Although usually of minor importance, it periodically appears in outbreak proportions and destroys the entire crop in heavily infested helds. Such an outbreak occurred in Charlotte County in 1944 and 1945, when the present study was initiated.

The data presented in this paper are based on insectary-reared material, supplemented where possible by field observations. Larvae were reared individually in jelly jars or waxed cardboard cups and fed daily on fresh blueberry foliage. Observations on oviposition were made possible by mating reared moths.

Attempts to maintain large cultures of the onion maggot, Hylemya antiqua (Mg.), have led to the development of special glass cages (Perron et al., 1953). Under oar laboratory conditions the lights used to obtain the degree of illumination necessary for acceptable oviposition rates raised the temperature and lowered the humidity excessively within the cage. Reasonable control of these factors was obtained by atomizing cold water into a current of air blown through the cage.

Sex anomalies have been used in an attempt to homologize the male and female genitalia of insects. Studies of some sex anomalies (Michener, C. D., Ann. Ent. Soc. Am. 37: 336-351.1944) suggest that the second valvifers are homologous with the gonocoxites (phallobase); the second valvulae probably are homologous with the penis valves; and the third valvulae are homologous with the gonostyli (parameres). Homologues of the first valvifers and first valvulae of the female are absent in the males of Pterygota.

The aspen blotch miner, Lithocolletis salicifoliella, Cham., has been abundant on trembling aspen, Populus tremuloides Michx., throughout central Canada for the past few years. The mines of this species are found on the underside of the leaves, and are often abundant enough to cause premature browning of the foliage. This insect first came to the attention of the Forest Insect Survey of Ontario in the vicinity of Lake Nipigon in 1944. By 1950, the infestation covered all but the southern part of Ontario, and was reported in most aspen stands in Manitoba and Saskatchewan. The intensity of the infestation in the northern part of Ontario began to decline by 1952, and in 1954 damage was negligible.

This paper includes descriptions of a new species of Cinara and one of Micromyzus.

The species of Cinara belongs to the species group in which the base of the cornicle hears both heavy and fine setae. In other members of this group the heavy and fine setae are evenly distributed over the surface of the base of the cornicle, but in the species described here the fine setae are clustered around the orifice and the heavy ones are closer to the margin of the base than in related species (Fig. 4). Another difference is that the dorsum of the abdomen is heavily sclerotized rather than having the small, isolated sclerites characteristic of the other members of this species group.

In 1947, while a caragana breeding improvement program was being carried out on the Forest Nursery Station, Indian Head, Saskatchewan, it was discovered that a large percentage of seed was being destroyed by an insect. This insect, the caragana seed chalcid, which interfered seriously with the plant breeding work, is apparently identical with the Russian Bruchophagus caraganae (Nik.) (Nikol'skaya, 1952).

Although many forest insects feed in or on trees, a larger number live on the shrubs and herbs of the forest floor. The shrub and herb feeders should not be overlooked since they comprise an important part of the fauna and may serve as reservoir hosts of parasites of the more destructive forest insects. Some larvae of the genus Itame are tree feeders but many of them feed on shrubs. These larvae are frequently collected within the Boreal Zone of Canada. As no means for the identification of the larvae could be found in the literature this paper was written. It consists of an account of the life history and external morphology of the larvae of the genus, a key to separate the mature larvae and descriptions of ten species. These species are: I. ribearia (Fitch), I. evagaria (Hlst.), I. brunneata (Thunb.), I. andersoni Swett, I. occiduaria (Pack.), I. anataria (Swett), I. exauspicata (Wlk.), I. bitactata (Wlk.), I. denticulodes (Hlst.), and I. decorata (Hlst.). Studies of the first four species are based on material obtained on loans and studies of the other species were made on material reared by the Forest Insect Survey of the Forest Zoology Laboratory, Calgary, Alberta.

Entomology in Canada began about the middle of the nineteenth century with a small but able group of hobbyists. They became active shortly before confederation in what was then the Province of Canada, a temporary union of the present provinces of Ontario and Quebec. Today, a century later, the science is firmly founded throughout the coilntry with over 400 professional entomologists, more than 50 well-equipped research centres, 16 institutions giving formal instruction, and eight profesional societies. Entomological advisory services are estahlished in several provinces and federal legislation protects the public against the spread of nosious insects and the fraudulent or dangerous sale of materials for their control.

In this paper 12 new species and a new genus (Prochramesus) of scolytid beetles are described from Mexico, and one species is described from Honduras. Notes concerning geographical distributions of a few other Mexican species are included. The specimens taken in Mexico were all collected by the author while with the 1953 expedition of the Francis Huntington Snow Entomological Museum (University of Kansas, Lawrence). The new species represent the following genera: Pseudohylesinus (1), Phrixisoma (1), Leperisinus (1), Phloeosinus (1), Chaetophloeus (1), Renocis (1), Phloeotribus (1), Prochramesus (1), and Chramesus (4).