A study of halictine nests in a habitat near Toronto leads to the discovery of an undescribed species of the genus Dialictus that shares morphological resemblances with Dialictus rohweri (Ellis) and architectural similarities with Augochlorella striata (Provancher).

An infestation by the grape cane girdler, Ampeloglypter ater LeConte, near Niagara-on-the-Lake, Ontario, was reported to this laboratory on 2 June 1965. The species was identified by Mr. W. J. Brown, Taxonomic Section, Entomology Research Institute, Canada Department of Agriculture, Ottawa, from 17 aduit specimens reared or recovered from infested shoots collected in the vinevard between 11 August and 5 September 1965. There are no published records of the occurrence of this species in Canada, though two specimens collectcd at Point Pelee, Ontario, host unspecified, are in the Canadian National Collection (Brown, in lit.). The species occurs in many of the eastern United States (Brooks 1909, Whitcomb 1956).

Females of I. conquisitor were conditioned to associate colour with the presence of hosts. Conditioning was important only during searching and did not affect the distribution of attacks once hosts were found. The ability of this species to associate colour with the presence of hosts could increase its efficiency as a parasite. Females of I. conquisitor showed an innate preference for blue over yellow.

The capture of Itoplectis conquisitor (Say) is being reported as the first record of this ichneumonid as a parasite of the European corn borer Ostrinia nubilalis (Hübner) in Canada.

This paper describes four new species, Dialictus perpunctatulus, D. perspicuus, D. disabanci and D. paradmirandus together with the previously unknown female of D. basilicus (Sandhouse) and the male of D. atlanticus Mitchell. D. banksi Mitchell is sunk as a synonym of D. heterognathus Mitchell.

Using a series of photographs, the mechanism of host location and oviposition by Rhyssa lineolata (Kirby) are described.

Both Nearctic species of Subterraneobombus occur in southern Alberta, but Bombus (Subterraneobombus) appositus Cress. is confined to the wooded areas whereas B. (S.) borealis Kby. is confined to the prairie. Both are adaptable in their nest-selecting habits and are among the latest species of Bombus to emerge and establish nests in their respective habitats.

Both species made large first broods; B. appositus averaged 13 ± 3 cocoons in 119 first broods. B. appositus never had more than two broods of workers, and B. borealis had only one. Both constructed pollen pockets beside and beneath the young larvae of the second and succeeding broods. Queens of B. appositus required about 23 days to rear the first workers. The largest workers of both species were considerably smaller than average-sized queens. Colonies of both species were relatively small; those of B. appositus averaged less than 100 individuals, the largest being 246. Both species were apparently sparse producers of wax.

Queens of both species apparently mated with males in the nest or immediately upon leaving the nest. New queens of B. appositus dug about one inch into the ground to hibernate.

Females of the cuckoo bee, Psithyrus insularis (Sm.), succeeded in having their young reared to maturity in nests of B. appositus.

The eggs, larvae, and pupae of Steremnius carinatus (Boh.) are described and characters given to distinguish them from those of Steremnius tuberosus Boh. A key separates the larvae and pupae of S. carinatus from those of S. tuberosus, species of Pissodes, and Scolytidae. The relationship of Steremnius to Pissodes and Hylobius is discussed briefly.

From a study of the ecology of the insect invasions occurring in the Maritime Provinces the following generalizations are made: (1) The Maritimes have served as a focal point of many invasions because they have several international ports that are surrounded by diverse human modified environments. (2) Plant and animal communities of the Maritimes are relatively simple, which makes invasions easier and more successful. (3) The lack of evolved homeostasis between the invader and its adopted community may have been one of the prime reasons for outbreaks in the species populations newly introduced. (4) Both native and introduced parasites and predators have provided effective control of introduced pests.

Two new species of Keltonia Knight are described. These are clinopodii from Florida and knighti from Mexico. There are now a total of six known species in the genus. A key is provided and male genitalia of five species are illustrated.

Five new species of Cyclocephala are described as follows: C. miamiensis from Florida, U.S.A., C. arenosa from Sonora, Mexico, C. sinaloae from the west coast of Mexico from Sonora to Jalisco, C. forcipulata from Sinaloa and Nayarit, Mexico, and C. virkkii from San Salvador, El Salvador.

The dispersal flight of the Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, is oriented toward fresh windthrown and cut trees when these are present in the stand, the beetle being attracted by oleoresin, particularly its alpha-pinene, camphene, and limonene fractions. In the absence of such material the pioneer beetle dispersal appears to be rather uniform throughout the stand. This host attraction precedes the beetle attraction which is produced by unmated females shortly after entering the host and which results in mass concentration of beetles around the center of attraction. Of these two phases in the attraction process, the secondary attraction is far stronger than that caused by the fractions of the host oleoresin.

Attraction centers are established only in freshly downed trees and in standing trees of subnormal physiological condition under both latent and epizootic conditions; however, under epizootic conditions, the beetles can invade even vigorous trees in the perimeter of attraction. The survival of such trees depends on their ability to exude oleoresin, which in turn is influenced greatly by environmental factors. The susceptibility of trees to successful beetle invasion is characterized by their oleoresin exudation pressure, which reflects water disturbances in the tree. Diurnal and seasonal fluctuations of the resin pressure are discussed in relation to beetle flight and invasion, and the resin effects upon the beetle (both mechanical and chemical) are considered. The beetles are found to be repelled by Douglas-fir resin and its fractions, i.e. alpha- and beta-pinene, camphene, limonene, terpineol and geraniol, when tested at close range in the laboratory.

That insect blood pH can be altered by air ions was shown when larvae of the wax moth, Galleria mellonella L., were exposed to air ions at ion currents of 3 × 10−9 amp. Negative ions significantly raised the pH value over that of controls. Positive ions tended to depress the pH values, but the difference from the controls was slight and not significant. It is suggested that altered pH may be reflected in increased activity of insects when exposed to ionized air.

Larvae of the larch sawfly, Pristiphora erichsonii (Htg.), were collected in Alaska in 1965. This is the first record of this insect in Alaska. On 26 and 27 July 1965, stands of tamarack, Larix laricina (Du Roi) K. Koch, were examined at 16 locations along the Richardson Highway southeast of Fairbanks. Larch sawfly larvae were collected from 12 of the stands examined. Collection locations are shown in Fig. 1.