Sampling to obtain valid estimates of the degree of parasitism in natural populations of insects presents a difficult problem to the quantitative-minded investigator. The method used must adhere to the principles of random sampling, yet it must be truly representative with respect to the occurrence of the parasite in its sampling universe, the host insect, in both time and space.

The purposes of this paper are: (1) to validate a considerable number of lectotype selections made in the course of a revisional study of the Scopariinae, and (2) to give, for the convenience of students, a list of Meyrick holotypes and lectotypes in the collection of the British Museum (Natural History), which now contains the types of all but five of the large number of species described by Meyrick in this group. The Hawaiian species have been omitted as volume 8 of Zimmerman's Insects of Hawaii gives full particulars of the type material of Hawaiian Scopariinae, including Zimmerman's lectotype selections.

The genus Allothrombium Berlese, 1903, is an heterogeneous assemblage of about 45 species of mites, of which 13 species have been described from both the Palaearctic and Ethiopian realms, nine from the Australian and three from the Oriental. Five species are Neotropical, while to date only two species have been reported from the Nearctic. A. brevitarsum (Berlese), 1888, A. sericoideum Berlese, 1910, A. crassicomum Berlese, 1910, and A. succinctum Berlese, 1917, are listed by Thor and Willmann (1941) from South America; A. metae Boshell and Kerr, 1942 was described from Colombia and subsequently recorded from Panama (Michener, 1946). Ewing (1909, 1917) described two species from the United States: A. missouriense (Ewing), 1909, from Missouri and A. pulvinum Ewing, 1917, from Illinois. The characters of the mite described below are distinct from those of the Palaearctic species. Its affinities appear to be to the Neotropical and Nearctic forms but it differs from them in the following particulars: from A. sericoideum, A. crassicomum, A. succinctum and A. metae in having shorter body setae clothed with longer pectinations; from A. brevitarsum in having a wider crista metopica and more slender pedipalps; from A. missouriense in having a body over three times greater in length and width. A. pulvinum is similar to the species herein described in some respects but as the original description does not mention characters such as crista metopica or tarsus length it is imposible to be certain of this. Furthermore, no quantitative measurements are given save overall length (3.30 mm.) and width (2.50 mm.). These measurements fall within the ranges observed for the species described below but should not be used as absolute criteria because of pronounced intraspecific variability produced by the integumental flexibility. Howard (1918) figures the pedipalps, chelicerae and body setae of A. pulvinum; the former appendages appear much more slender and elongate, while the body setae possess shorter pectinations. Considering as well the facts of geographic distribution and habitat, I am inclined to consider the two as distinct species.

A nuclear polyhedrosis virus has been isolated from the spruce budworm, Choristoneura fumiferana (Clemens) (Bergold, 1949; Bird, 1949; Bergold, 1951; Bird and Whalen, 1954; Bird, 1959), but no similar virus has been recovered from the jack pine budworm, Choristoneura pinus Freeman. Since these two species are very closely related (Smith, 1953) it was of interest to determine if C. pinus is susceptible to the C. fumiferana virus.

Although the live weights of the successive stages of some of the old world Acrididae are known (Bodenheimer, 1929; Key, 1936; Duarte, 1938; Husain, et al., 1946; Davey, 1954; Richards and Waloff, 1954), this information has been obtained only for Melanoplus bilituratus (Wlk.) among the grasshopper species of Western Canada (Smith, 1958). In addition to the establishment of growth curves, weight data are useful for computing the biomass of acridid fauna in any situation. As data accumulate to permit the development of a generalized relationship of food consumed to body weight, (e.g. Davey, 1954; Misra, 1956; Gangwere, 1958; Smith, 1958; Putnam, unpublished data), live weight could become a useful quantity for estimating the damage potential of any acridid population.

The literature on Orthoptera (sens. lat.) includes a number of cursory notes describing laboratory drinking in various species, but an extended discussion of this behaviour is not available. The author has spent the past seven years studying the feeding behaviour of Michigan Orthoptera, during which time he has also made observations and conducted experiments on intake of water. Findings with respect to the latter, although of a preliminary nature, are given in the following paper.

Hille Ris Lambers (1939) erected the genus Masonaphis with Macrosiphum rhododendri Wilson, 1918, as typus generis. When I revised this genus (1958) there was no opportunity to examine authentic material of the genotype. Since then Dr. A. A. Granovsky, University of Minnesota, Saint Paul, Minnesota, has kindly supplied to me cotype slide 2 of the species and cotype slide 5 to Miss L. M. Russell, United States Department of Agriculture, Washington, D.C. I have examined and remounted both slides which were labelled: Macrosiphum rhododendri n. sp.; Newport, Oregon; June 15, 1915; Rhododendron californicum leaves; H. F. Wilson; 509 cotype. Slide 2 contained sexuales and an alate viviparous female; slide 5 contained alate males and an apterous and an alate viviparous female. In addition Miss Russell provided me with material containing all morphs collected in Washington, Oregon, and California.

This is the second in a series of papers on the taxonomy of the 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 after the parasites have emerged. The structures of taxonomic significance in the separation of the species were described and discussed in a previous paper (Finlayson, 1960). The present paper deals with the known Canadian parasites of the European spruce sawfly, Diprion hercyniae (Htg.). Parasites of D. hercyniae that were dealt with in the previous paper are not described or illustrated here.

The concern caused by extensive killing of marketable Douglas-fir Pseudotsuga menziesii (Mirb.) Franco, in the interior of British Columbia by the Douglas-fir beetle, Dendroctonus pseudotsugae Hopk., has necessitated studies on many phases of the beetles' biology and behaviour. Among these has been a study of the beetles' flight. Although this insect flies for only a few brief periods during its life, these periods are vital in terms of the extension and location of areas of infestation.

The discovery of Camilla glabra (Fallen) in Ottawa, Canada, is the first record of the existence in the New World of any member of the interesting little family Camillidae. A single male specimen taken June 15, 1954, by D. G. F. Cobb while collecting insects in her garden, would seem to indicate the species is established here.

The family Camillidae consists of the single genus Camilla Haliday, which for many years was assigned to the family Drosophilidae. Frey, (1921) considered it sufficiently differentiated from the Drosophilidae to warrant separate status and erected the family Camillidae to receive it. Duda (1934), Wheeler (1952, p. 164), and Collin (1956) all recognized the group as a family distinct from the Drosophilidae. More recently, Hennig (1958, p. 665) placed it as a separate family in the Drosophiloidea, pointing out that while it has certain characters in common with Curtonotidae and Drosophilidae, it shows even more affinities with Diastatidae and Ephydridae.

In the course of studies on Neodiprion swainei Midd. carried out in 1958 and 1959 in the region of Lake St. John, Que., mass migrations of Neodiprion swainei Midd. were observed. This paper gives a brief description of this phenomenon, which has never been reported heretofore, and discusses some of its implications.

On hatching from the eggs which are laid on the needles of the current growth of jack pine, Pinus banksiana Lamb., N. swainei larvae crawl to the old foliage where they feed in colonies of 40 to 70 individuals. At times, when larval populations become so great that all the foliage is destroyed, mass migration begins. The larvae gather in large clusters at the top of the tree where they remain for two or three days. At this time some of the larvae moult. The larvae then abandon the tree by crawling down the tnink or by dropping to the ground. They then creep on the ground, up and down stumps, in search of jack-pine trees with foliage. The migrating larvae are pale yellow in colonr, probably as a result of their starved condition, and large nutnbers perish before they can become established on proper food. Those that manage to reach new food supplies quickly recover their original dark-green pigmentation.

Previous studies have shown that some varieties of rutabagas in the field have resistance to the cabbage maggot, Hylemya brassicae (Bouché) (Swailes, 1959). It was evident that at least two factors were involved in resistance: (1) larvae encountered difficulties in initiating feeding and (2) larvae encountered resistance to growth. The latter factor was considered in the present study.