The present paper brings together the latest knowledge on the species of Mecormmu known to occur in the Nearctic region. Study of the genitalia, external structures, and distribution, show that species vary considerably in structure and colour, and these variations have contributed in the past to the confusion in naming the species of Mecomma. Lack of specimens in collections has also hindered the study of this group and it is only within the last few years that large collections made in Canada and the United States have helped to solve somc of the problems.

In 1954 Delucchi erected the genera Enaysma and Epilampsis in an attempt to extend and clarify the generic concepts in the Derostenus Westwood-Chrysocharis Förster complex of the subfamily Entedontinae. As the type of Enaysma he designated Enaysma zwolferi Delucchi. Later in rhe same year (Delucchi 1954a) he revised the entire complex as he understood it in the Palaearctic region giving keys to the genera and species he included. Subsequently (Delucchi 1957) he supplemented his original description of the genus Enaysma and expanded his concept of it, adding Enaysma aenea Delucchi, Enaysma parva Delucchi, 1956, and two new species with a revised key to all the Palaearctic species then included by him in the genus. Recently Graham (1959) published a key to the British species in which he erected the new subgenus Pentenaysma, selecting as its type Eulophus latreillii Curtis.

The apple maggot overwinters as a pupa within a puparium and develops to this stage in the fall five days after the larva enters the ground. It usually undergoes no visible morphological change until late the following spring or early summer (Dean, 1942). The adult emerges from late June to early September. Some pupae, however, remain dormant in the soil and the adults do not emerge until the second or third summer after pupation (Lathrop, 1955). Also, in some areas, a few adults emerge about two months after pupation (Phipps and Dirks, 193 3).

Cremifania nigrocellulata Cz. is one of the complex of predators that attacks A. piceae (Ratz.) in Europe. After studies on its morphology, biology, and distribution were made by Delucchi and Pschorn-Walcher (1954), C. nigrocellulata was reared in Europe by the Commonwealth Institute of Biological Control and introduced into New Brunswick via the Entomology Research Institute for Biological Control, Belleville, Ontario.

During an investigation of California Tortricinae, I had the opportunity to study Archipsini in the Canadian National Collection from western North America, and the following two species became evident. It seems appropriate to describe them at the present time because of their potential concern to Canadian forest entomologists and in order to make the names availalble for N. S. Obraztsov's projected generic revision and catalogue of Nearctic Tortricinae.

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.

Severe defoliation of aspen stands by the forest tent caterpillar, Malacosoma disstria Hbn., became apparent in 1948 in three widely separated regions in Ontario, and by 1949 it was clear that another general outbreak of this defoliator had begun. In 1950 the Forest Insect Survey (cf. McGugan, 1958) initiated an intensive program of observation, collecting, and rearing to record the progress of the outbreak and study the parasite complex of the insect. This paper compares the outbreak in the early ‘fifties’ with earlier ones, and attempts to describe the pattern of build-up and decline of forest tent caterpillar populations within extensive forested areas.

Species of the New World genus Stenopterina Macquart (1835, Hist. Nat. Dipt. 2: 453. Senopterina - lapsus) occur mostly in the tropics and subtropics. They are moderately slender metallic blue-green or cupreous flies, up to 12 mm. long with large head and rather long narrow wings, the latter parterncd in various ways with dark brown or black markings. In the type species, Dacus brevipes Fab., 1805 and its closest allies, the wing-pattern consists essentially of three separate areas of infuscation. First, a narrow uninterrupted black costal border extending from the apex of the auxiliary vein to the apex of the fourth. Second, a black streak filling the first basal cell and sometimes invading the cells adjoining it in front and behind. Third, a narrow black cloud on the posterior crossvein. Hendel (1914) in reviewing the genus, considered brevipes a variable species ranging from Texas to Brazil. The recent discovery in British Columbia of a species of Stenopterina with similar wing-pattern has led me to reexamine the status of species placed by Hendel as synonyms of brevipes, particularly Stenopterina caerulescens Lw., 1873, from Texas.

The woolly pine needle aphid, Schizolachnus pini-radiatae, was described in 1909 by Davidson as Lachnus pini-radiatae from specimens collected near Stanford University, California. In revising the subtribe Cinarina, Gillette and Palmer (1931) placed this species in the genus Schizolachnus. Detailed descriptions of the species were given by Davidson (1909), Gillette and Palmer (1931), and Palmer (1952), but none of the earlier workers studied the life history of this aphid. The present study was carried out during 1960 in a seven-year-oId red pine stand in kirkwood Township, about 50 miles east of Sault Ste. Marie, Ontario.

This paper deals with the influence of bark moisture and temperature on the hehaviour of the egg-laying female within the host. Fecundity of the insect will he discussed, as well as internal changes associated with the behavioural pattern. The life-cycle, brood development, and time of flight was described in Part I of the present series. The behaviour during mating, egg laying, and gallery construction were described earlier (Reid 1958b).

The effects of exposure to sub-freezing temperatures on the survival of insects have been studied experimentally mainly in three types of insect. One is the beetles associated with stored products, including Bruchus obtectus (Carter, 1925), and Tribolium confusum (Nagel and Shepard, 1934, and Salt, 1936). A leaf feeding beetle, Popillia japonica (Payne, 1928) has also been studied. The emphasis of these studies has been on the possibility of physical control of these pests. The second type includes the hitch-hikers on aircraft. Knippling and Sullivan (1957) studied the survival of six species of insects and a tick which were exposured to 0, −5, −10, −15, −20, and −30°C. for one hour, and that of one of the insects, the house fly, to −20° for different durations up to 60 minutes. Their objective was to determine the possibility of these arthropods being transported alive by aircraft. Thus, the conditions which they tested were those which may be encountered by the arthropods in the unheated parts of jet aircraft during flights in the stratosphere. The third type of insects is Drosophila, mainly D. melanogaster. Since the present paper deals also with this insect, pertinent facts reported by earlier authors are summarized in Table I.

It has been suggested (Wright, 1958) that attractants or repellents for insects which normally fly to their destination should be tested against insects that are in flight during the tests. Moreover, the conditions of the flight should be as nearly natural as possible. This requires that the observation chamber should be large (to minimize wall effects), the illumination should be controllable, and the air movement and the odorous or other signals should be presented in a natural way. Finally, the movements of the insects should be recorded in three dimensions, and in as much detail as possible.

Of the fruits grown in the Kootenay Valley of British Columbia, pears are third in importance; in the more arid Okanagan Valley 300 miles to the wrest they are second. During 1959 the pear psylla, Psylla pyricola Foerster, caused severe losses for fruit growers in the Okanagan Valley. The damage was much greater than had occurred during the previous 17 years. It became clear that the insect was a major economic pest, and that it was not being adequately controlled by the recommended insecticides. Obviously, more information was needed on the biological aspects of the situation. The roie of climatic conditions was particularly in question. In 1960 a start was made on a biological study of the pear psylla at Creston in the Kootenay Valley. This paper deals with observations thnf were made there.

Pending completion of the writer's current bumblebee work, the following information should be of interest and use to others who are now devoting attention to the taxonomy of this group in the Western Hemisphere and who contemplate publishing. The existing and recognizable types of all the accepted names referred to beyond were studied except the Gribodo types which were well reviewed by Richards (1929), inrhose homotype of volucelloides was examined at the British Museum (N.H.) in London. The condition and where-abouts of most of the type specimens on which are based the various conclusions presented here, have already been discussed by the writer (1960). There are, however, other types of infraspecific taxa that were not treated at that time, and it is emphasized that a reliable knowledge of these is also important for the present synonymies and other taxonomic considerations.

During a study on the life history and ecology of the woolly pine needle aphid, Schizolachnus pini-radiatae (Davidson), in a seven-year-old pine stand in Kirkwood township, Ontario, during the summer of 1960 (Grobler, 1962), a number of dead aphids were found the first week in September. These aphids, mummified in appearance, were shown to be infected by the fungus Empusa (= Entomophthora) aphidis Hoffman.

The arm test for mosquito repellency (King, 1954) is a useful criterion for selecting compounds that are both persistent and repellent and therefore potentially useful in the field. However, if repellency is to be correlated with other molecular properties, a criterion must be found by which intrinsic repellency can be recognized independently of properties like volatility or solubility in sweat (Wright, 1958). Since the prime requirement of a good mosquito repellent is that it shall prevent alightment, some motion pictures were taken of mosquitoes in the act of alighting or failing to alight on variously treated surfaces. The photographs revealed an alteration in the flight posture which was then investigated in detail.

In Nova Scotia, a spray program that integrates chemical and natural control of apple pests has been evolved which is both economical and satisfactory. Among the natural enemies of injurious arthropods that have been favoured by this program are a number of general predators. Further investigation of the ecological principles on which integration is based requires a more intensive knowledge of the factors that influence the densities of these predators. Because of the difficulties of investigating these factors in the orchard, methods of simplifying the predator-prey systems have been sought (Lord, 1956, 1962). These attempts assessed the effects of low dosages of DDT on the interrelationships of phytophagous mites and their natural enemies.

During the summers of 1948 and 1949 the writer investigated the biology of the maple leaf cutter, Paraclemensia acerifoliella (Fitch), near Merivale, Ontario. Various aspects of the bionomics of the stages of the maple leaf cutter are summarized in this paper. Unpublished material in the annual reports prepared by Mr. J. J. de Gryse were kindly made accessible; data are quoted from them and acknowledged herein. Sincere thanks are extended to Howard A. Tripp for his assistance in recording data during field investigations.

Many authors noted the attraction of the males of several species of mosquitoes to sound (references summarized by Roth, 1948). The frequencies of sound to which the males respond were investigated by Roth (1948) and the frequencies and intensities by Wishart and Riordan (1959). Tischner (1953) applied electrophysiological methods to the reception of sound in the male of Anopheles subpictus Grassi and advanced a theory to explain the ability of the male of this species to orient itself toward the sound source. In his theory he dismissed the use of phase differences between the two receptors because of the relatively small distance between the two antennae and concluded that each is capable of functioning alone by detecting the relationship bemeen the fundamental and the second harmonic in the microplionics produced by the Johnston's organ. He did not demonstrate this by behaviour experiments nor, do we believe, did he produce sufficient electrophysiological evidence. The present paper is a further examination of this subject in the mosquito Aedes aegypti (L.), in an attempt to reconcile the data from electrophysiological experiments with those of behaviour in an explanation of the orientation of male mosquitoes towards sound.

The rove beetle, Aleochara bilineata Gyll., is known as a predator and a parasite of the cabbage maggot, Hylemya brassicae (Bouché), in most areas where the latter is an economic pest of cruciferous crops (Wishart, 1957; Wishart et al., 1956, 1957; Hughes, 1959). However, although A. bilineata is an extremely prolific insect (Colhoun, 1953; Wishart et al., 1956), in that the adult beetles destroy root maggot eggs and larvae and the parasite larvae destroy root magpt pupae, little has been reported concerning the economic value of the predator-parasite as a natural control agent. Preliminary studies in Prince Edward Island indicated that the predator destroved large numbers of root maggots but it did not appear to sive economic control (Read, 1960). Details of the biology of this predator have been presented by Colhoun (1953). This is a report of studies conducted to determine the potential value of A. bilineata as a natural control agent, and includes observations on the comparative life histories of host and parasite and notes on predation and parasitism in the greenhouse and on parasitism in the field.