Nearly all insects are in some degree beset with hair-like structures of varying length and stiffness and density and frequently of varing color. So much is familiar to every entomologist, even to those who have never examined an insect with a magnification higher than that of a hand lens.

Similar percentages of parasitized adults and of females of Phyllotreta cruciferae (Goeze) were collected in traps baited with allyl isothiocyanate and in a D-Vac vacuum insect net early in spring and in August–September, when non-reproducing adults predominated. In contrast, a lower percentage of parasitized adults and a higher percentage of females were collected in the traps than in the D-Vac during the beetles’ reproductive period, May–July. A similar difference between the traps and D-Vac was recorded for Phyllotreta striolata (F.) during April–May, when this species begins to reproduce. Therefore, the results indicate that traps used in this study are unsuitable for measuring parasitism and sex ratio of reproducing P. cruciferae and P. striolata.

Parthenogenesis in North American mayflies occurs in Ameletus ludens Needham (Clemens 1922), Ephoron album (Say) (Britt 1962), Stenonema fermoratum (Say) (McCafferty and Huff 1974), S. interpunctatum (Say), S. pulchellum (Walsh), and S. vicarium (Walker) (Huff and McCafferty 1974). Attempts to determine its occurrence in the genus Hexagenia are reported for H. limbata occulta Walker (Neave 1932), H. limbata (Serville) (Hunt 1953), and H. bilineata (Say) (Thomforde and Fremling 1968). The purpose of this note is to report hatching in unfertilized eggs of H. rigida McDunnough.

Field tests were made of the fungal inoculation method of Reid et al. which assesses the potential of individual lodgepole pine trees (Pinus contorta Dougl var. latifolia Engelm.) to resist attacks by mountain pine beetle (Dendroctonus ponderosae Hopk.). Four hundred and eighty-four trees were inoculated with one of the beetle’s mutualistic blue-staining fungi (Europhium clavigerum Robinson and Davidson), tree responses were determined, and the potential of each tree to resist D. ponderosae was predicted. Two months later, after mountain pine beetles had attacked some of these same trees, most of the predictions based on the fungal assay system proved to be incorrect. Most of the trees which were attacked and which had been rated potentially resistant did not prevent successful bark beetle reproduction. These results, contrary to those of Shrimpton and Reid, suggest that some improvement is needed in the fungal assay method of assessing resistance of lodgepole pine to mountain pine beetle. Measures of tree resistance based on success of mountain pine beetle reproduction showed no difference in the proportion of non-resistant trees between epidemic and endemic areas.

Female spruce seed moths, Cydia strobilella (L.) (Lepidoptera: Tortricidae), oviposit on seed cones of most North American spruces (Picea spp.) (Pinaceae) at the time of pollination, and larvae feed on seeds in the maturing cones. We tested the hypothesis that host-seeking moths respond to volatiles from both host and nonhost trees. In coupled gas chromatographic – electroantennographic detection (GC–EAD) analyses of extracts of spruce seed cone volatiles, > 17 compounds elicited antennal responses from male and female C. strobilella. A blend of seven compounds, including (−)-α-pinene and (−)-β-pinene, α-longipinene and α-humulene, Z3-hexenol, methyl eugenol, and cymen-8-ol, was more attractive to female C. strobilella in laboratory bioassay experiments than the complete seed cone volatile blend, containing these compounds at equivalent quantities and ratios. In GC–EAD analyses of volatile extracts from nonhost angiosperm trees, EAD-activity was associated with compounds present in (almost) every volatile source, including trembling aspen, Populus tremuloides (Michx.) (Salicaceae), paper birch, Betula papyrifera (Marsh.) (Betulaceae), black Cottonwood, Populus balsamifera trichocarpa (Torr. and Gray) (Salicaceae), and bigleaf maple, Acer macrophyllum (Pursh.) (Aceraceae). In a field experiment in the interior of British Columbia, the antennally active nonhost aldehydes, alcohols, and (±)-conophthorin all reduced captures of male C. strobilella in pheromone-baited traps. Collectively, our data suggest that host selection by C. strobilella is mediated, in part, by semiochemicals from both host and nonhost trees.

During the summer of 1947 n project was initiated with the object of determining the earliest and latest dates of appearance and the period of appearance of maximum numbers of the various species of insects which emerge as adults from the Dundas Marsh, Hamilton, Ontario. Previous to this, during the summer of 1946, observations were made on the occurrence of various insects on the marsh. Such observations were continued during 1947 and are reported herewith.

In biological research it is often desirable to rear and handle animals free from microorganisms. This is particularly true in nutritional studies in which it is generally recognized that certain orgnisms in the digestive tract can supply nutritional factors which might otherwise be lacking in the diet. The possibility of this intervention makes it necessary to devise techniques for rearing and handling insects aseptically, in so far is the fauna and flora of their intestinal tract and of their environment are concerned. Consequently, a technique used throughout the present series of studies was developed making use of specially designed equipment by means of which nymphs of the cockroach, Blattella germanica (L.), were hatched and maintained under aseptic conditions, fed aseptic food, and kept aseptic throughout a series of measurements to evaluate their weight increment. The equipment and methods used constitute the basis of the present paper.

The effects from treating populations of predacious mites with a number of spray chemicals are tabulated. The species include Phytoseiidae: Typhlodromus pyri Scheuten, T. rhenanus (Oudms.), Amblyseius fallacis (Garman), Phytoseiulus macropilis (Banks), Amblyseius finlandicus (Oudms.); and Raphignathidae: Mediolatta novae-scotiae Nes. The chemicals include fungicides, acaricides and insecticides.

Suspected predatory invertebrates associated with the larch sawfly, Pristiphora erichsonii (Hartig), on tamarack were confined in cages with sawfly eggs or larvae to determine which species were predaceous. Most of the insects were found to feed on larch sawfly eggs or larvae under these conditions, but very few spiders ate larch sawfly. The amount of food eaten by various predators is presented.

Seasonal population trends of the more common predators and prey available to them were determined from samples of tamarack branches taken at weekly intervals. Associations between the numbers of various predators and prey per 20-branch sample were investigated, and a number of significant predator–prey correlations were obtained. These included correlations between Deraeocoris and sawfly eggs, Plagiognathus and sawfly eggs, and Tetraphleps and sawfly eggs. However, estimates of larch sawfly egg mortality under field conditions showed that egg mortality was largely independent of egg density in the range of populations studied, and showed little relationship to predator density per 20-branch sample. This is because the distribution of larch sawfly egg predators per individual branch was random and appeared to be independent of egg density. Single factor analysis of annual egg populations and egg survival indicated that survival in the egg stage is of no value in predicting population trends of the larch sawfly.

Small females of the parasite Nasonia vitripennis (Walk.) parasitized fewer hosts (housefly, Musca domestica L.) than larger ones during their lifetime because they had both a shorter life span and a lower rate of parasitization. The latter resulted primarily from a lower egg maturation rate. As females reared from superparasitized hosts are on the average smaller than those reared from non-superparasitized ones, these effects of parasite size reduce the rate of increase of N. vitripennis at high parasite:host ratios and result in greater stability in the interaction between the two species.

Two new species of Canthidium Erichson, 1847 (Coleoptera: Scarabaeidae: Scarabaeinae) from Mexico are described: Canthidium nebularum Moctezuma, Sánchez-Huerta, and Halffter, new species; and C. chimalapense Moctezuma and Halffter, new species. An updated key for the North American species is included, with a brief discussion on taxonomic and biogeographic relevance of the new taxa.

Cabbage seedpod weevil (Ceutorhynchus obstrictus Marsham; Coleoptera: Curculionidae) and Lygus Hahn (Hemiptera: Miridae) species are part of the late season insect pest complex of canola (Brassica Linnaeus; Brassicacea) in the southern prairies of Canada. From 2010 to 2013, large strips in 73 commercial fields were studied in southern Alberta to validate action thresholds for cabbage seedpod weevil and assess the impact of insecticide spraying at the early flower stage for cabbage seedpod weevils on abundance of Lygus at the pod stage. Only fields planted in April accumulated the damaging populations of cabbage seedpod weevils, such that the application of an insecticide resulted in significant yield protection. The economic injury level for the cabbage seedpod weevil was calculated at 20 cabbage seedpod weevils per 10 sweeps, but an action threshold of 25–40 is recommended because sampling mainly occurs along the edge where cabbage seedpod weevils are initially concentrated. At the pod stage, Lygus were lower in strips sprayed with insecticides at the early flower stage than in those not sprayed, but the differences were not statistically significant. Furthermore, Lygus were generally below economically damaging levels in early seeded fields. Therefore, there is no benefit of spraying early seeded fields to attempt to prevent Lygus outbreaks when cabbage seedpod weevils are below thresholds because Lygus may pose a risk only in fields planted later in the season.

The pine bark adelgid, Pineus strobi (Hartig) (Hemiptera: Adelgidae), is an herbivore native to eastern North America that specialises on eastern white pine, Pinus strobus Linnaeus (Pinaceae). Little is known about P. strobi, especially in its southern range in the Appalachian Mountains, United States of America, and the composition of its predator complex has not yet been documented in this region. The current study identifies arthropod predators associated with P. strobi in Appalachian forests of Virginia based on a two-year survey. Predators were identified using morphology and DNA barcoding. Predator species include: Laricobius rubidus LeConte (Coleoptera: Derodontidae), Leucopis piniperda Malloch (Diptera: Chamaemyiidae), and Leucopis argenticollis Zetterstedt (Diptera: Chamaemyiidae), that are known adelgid specialists. Also found were predators from the families Cecidomyiidae (Diptera), Coccinellidae (Coleoptera), Chrysopidae (Neuroptera), Hemerobiidae (Neuroptera), and Syrphidae (Diptera). The Cecidomyiidae were especially diverse, with 14 different species inferred from their DNA barcodes. Knowledge of this predator complex is particularly valuable for anticipation and detection of potential interactions between native predator species and those that are being considered for the introduction for biological control of invasive adelgid pests within the southern Appalachian ecosystem.

Morgan and Anderson (1957) discussed in detail the synonymy of the Bryobia praetiosa Koch complex. They raised the apple inhabiting form to species status, and gave it the name, brown mite, Bryobia arborea.

The brown mite from apple trees in Nova Scotia was examined by C. V. G. Morgan, Summerland, British Columbia, and found to be morphologically similar to the B. arborea on apple in British Columbia. It is possible, however, that the Nova Scotian form may be a geographical race.

Eggs of western blackheaded budworm, Acleris gloverana (Walsingham), are laid on the lower surface of western hemlock, Tsuga heterophylla (Raf.) Sarg., needles. A comparison was made of the following measures of sample branch size as a basis for expressing egg density: fresh branch weight, branch area, total twig length, branch volume, and number of buds. The criteria for selection of these measures were as follows: correlations of branch size with dry needle weight, variances of egg density and their relative contribution to sample size, and ease of measurement. Fresh branch weight was the best choice. A sequential sampling system was developed on this basis and was related to a scale of predicted defoliation. In addition, a transformation was provided for use in data analysis.

The San José scale, Aspidiotus perniciosus Comstock, died within 84 to 140 days on Winesap apples harvested in early October and placed in standard cold storage or controlled atmosphere storage under laboratory or commercial conditions. The scale died more quickly in controlled atmosphere storage than in standard cold storage. The black caps of the first instar stage were the most resistant to mortality factors in cold storage. It is suggested that Winesap apples infested with the San José scale can be given an inspection certificate for export that guarantees freedom from live scale if the fruit has been stored for specified periods.

The San José scale on Italian prunes died within 34 days when the harvested fruit was kept in standard cold storage.

A complete mortality of the European fruit scale, Aspidiotus ostreaeformis Curtis, on Hyslop crab, McIntosh, or Newtown apples, could not be obtained, in any type of storage.

Aedes melanimon was described by Dyar (1924) from specimens collected at Bakersfield, California, as closely resembling Aedes dorsalis (Meigen) but differing in color, wing-scale pattern, and in the male genitalia. Freeborn (1926) considered A. melanimon to be an “aberrant form” or “race” of A. dorsalis. Two species closely related to A. dorsalis are the American Aedes campestris Dyar and Knab, and Aedes caspius (Pallas) of Europe, Asia, and Africa.

Larvae of Arrenurus bartonensis Cook, Arrenurus birgei Marshall, Arrenurus neobirgei Cook, and Arrenurus rotundus Marshall are described for the first time. Larvae of A. rotundus can be distinguished reliably from the other three by differences in morphology. Larvae of A. bartonensis, A. birgei, and A. neobirgei are very similar, but can be separated by comparing shape and size of the excretory pore plate, and by measurements of the dorsal plate and the tarsus of the third leg.

Increased seed yields often result when alfalfa fields are burned in spring. The main pollinator of seed alfalfa in Alberta is the alfalfa leafcutter bee, Megachile rotundata (F.), that cuts pieces of leaves to build thimble-like cells. One hypothesis for increased seed yield is that alfalfa leaves from burned fields may be easier for the bees to cut. Cutting of leaf pieces causes progressive wear to the mandibles, which could decrease bee efficiency, resulting in reduced pollination and lower seed yields. An image analysis method was used to measure the mandibular wear of leafcutter bees from burned and unburned alfalfa fields. No consistent difference in the amount of wear between bees foraging in burned or unburned fields was found.