The use of false-underground hives (surface hives with tunnels attached to their entrances) when and where the desired species of bumblebees were common made the task of obtaining colonies for pollination purposes comparatively easy. False-underground hives were much less costly to set out than underground hives and attracted many more queens of surface-nesting and versatile species, as well as underground-nesting species, than did surface hives. Apparently the surface-nesting species will accept a nest that is entered through an upward-sloping tunnel but not one that must be reached through a downward-sloping tunnel; underground-nesting species require a tunnel but are not influenced by the direction of its slope.

Setting occupied hives on posts with moats protected the queens or their broods from flooding, ants, ground squirrels, skunks, mice, shrews, and ungulates, but not from Psithyrus, even when odoriferous substances were put in the moats to mask the odor of the broods.

There is no consensus on the overwintering strategy used by the diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae). As a result, the topic of diamondback moth overwintering in temperate climates remains controversial. However, there has been general agreement that the diamondback moth does not overwinter in diapause. This review compiles data on low temperature survival to determine cold tolerance mechanisms and the cold tolerance strategy of the diamondback moth. According to cold tolerance data and observations from key overwintering studies in eastern North America, the diamondback moth likely overwinters in a quiescent state in no specific overwintering stage and is chill susceptible. Observations from key overwintering studies suggest a northern overwintering limit for diamondback moth of ~43°N in eastern North America. Climate change may alter winter conditions in temperate climates, making temperate regions susceptible to potential diamondback moth overwintering and recurring outbreaks.

Surveys of dung beetles establish the dominance of exotic taxa associated with cattle dung on native grasslands in southern Alberta, Canada. Of the 12 species recovered, eight were of European origin and comprised 92.2% of the total catch of 187 963 beetles. Most common were Chilothorax distinctus (Müller), Onthophagus nuchicornis (Linnaeus), and Colobopterus erraticus (Linnaeus) (Coleoptera: Scarabaeidae). The abundance of C. distinctus has been known in the region since the 1920s, whereas that of O. nuchicornis only was first reported in the 1990s. The abundance of C. erraticus has not previously been observed in the region and identifies the species as the newest addition to the endemic fauna. The diversity of native species on pastures in southern Canada and adjacent states is depauperate, such that the establishment of European taxa has appreciably increased levels of bioturbation in pasture ecosystems. The success of these exotic species on northern pastures may reflect a level of cold-tolerance greater than that of most native species.

The effect of coprophilic insects on horn fly (Haematobia irritans irritans (L.)) production from cattle dung was measured at Kamloops, B.C. Adult female flies were trapped after oviposition on fresh dung pads during 24-h sample periods. The pads were then either exposed to field insects for 24 h or covered with frames excluding insects for the same period, and removed to a greenhouse where all fauna emerged.

Horn fly females did not show a definite diurnal rhythm in oviposition. There was a single peak in adult abundance during the summer. Numbers of progeny produced per female fly from covered pads showed an apparent peak from 0300 to 0600 h while lowest numbers were produced in the early evening. Throughout the summer the progeny production from pads exposed to other insects was uniformly and significantly lower than from covered pads of the same age. Insects chiefly responsible for this suppression are probably the predators Philonthus cruentatus Gmelin, Sphaeridium scarabaeoides (L.), and S. lunatum (F.). Parasites of horn fly and dung-burying beetles (Scarabaeinae) are scarce and so there is still plenty of opportunity for manipulation of horn fly populations by use of other biological agents.

The sequential mode of operation of the various valves and pumps in the foregut of the blowfly Phormia regina Meigen is described for the crop-emptying process. The results of the study are discussed in relation to the results of Gelperin, who showed that the rate of crop emptying was determined by the crop volume and the blood solute concentration. A mechanism by which synchronization of function may be achieved, based on the results of Nagai, and Thomson and Holling, is proposed, i.e. synchronization depends on the activity of stretch-sensitive muscle fibres.

Details of a method of mass rearing eggs and larvae of the cabbage root maggot, Hylemya brassicae (Bouché) for bioassay and of continuous propagation of all stages of the pest are described. The technique was equally suitable for rearing the onion maggot H. antiqua (Meig.), the seed corn maggot H. calicruraliturata (Rond.) and the carrot rust fly, Psila rosa (L.). Under the conditions described, 2000-2500 eggs or first-instar larvae of H. brassicae were obtained from 50-60 female flies in 24 hours, or 1000-1200 mature larvae or pupae were reared from eggs produced by 25 female flies in approximately 20 days.

Strong westerly winds occurring during autumnal migration of the eastern population of the monarch butterfly in North America, affect those butterflies migrating from areas east of long. 90°. The following aberrant migratory routes are presented: (1) Migrants moving down the Atlantic coast pass through the Florida peninsula to western Cuba thence to the overwintering site in Guatemala and Honduras; (2) migrants forced over the Atlantic ocean eventually reach the Bahama islands and thence to Yucatan, or Honduras via Jamaica and other islands of the Caribbean Sea, to the overwintering site in Guatemala and Honduras; (3) migrants arriving in the eastern islands of the Greater Antilles may eventually arrive in the Cordilleran mountains of Columbia and northwestern Venezuela; (4) migrants from the Lesser Antilles may return, along with members of a first generation, in the spring without establishing an overwintering site—the fate of these few occasional spring migrants is unknown.

Behaviour of locally occurring adult females of seven species of coccinellids was assessed on wooden dowel and paper models that mimicked branching patterns and arrangements of leaf attachments to stems. Ambient temperature and hunger of the beetles were controlled. The movements up or down the main branch of the branch models when contacted from a side branch, duration of searching, and method of leaving leaf models were recorded for 20 beetles of each species.Each species responded to the seven models with different frequencies of behaviours that reflected species-specific modifications of the taxes that lead coccinellids to the tops and terminal parts of plants. Some beetles consistently modified the pattern of responses on die models that was displayed by die species as a whole. The individual modifications could be selected for. The differences in frequencies of behaviours were judged to be sufficient to result in differences in the efficiency with which plants with different architectures were searched.

Camponotus pennsylvanicus (De Geer) workers concentrate their foraging efforts in the vicinity of a new food source. Experiments with artificial “trees” confirm that these ants lay chemical trails when they locate food and under other circumstances. Marks left by ants travelling over smoked paper indicate that the trail consists of a series of streaks, sometimes variable in length, and that ants following trails make regular alternate deviations. Trails are laid extensively in the immediate vicinity of food. A trail is not reinforced by all gorged workers passing over it.

The trails activate other workers and provide a means of orientation but are clearly non-directional. A bioassay with various organs indicated that the hind gut is the source of the trail substance.

When a strong direct light is available, attention to trails dwindles and ants eventually use light orientation to reach the food, often following more direct routes at that time. Physical contact between workers may activate them but provides no directional information and may lead to temporary disorientation.

Both the striped flea beetle, Phyllotreta striolata (Fabricius), and crucifer flea beetle, Phyllotreta cruciferae (Goeze) (Coleoptera: Chrysomelidae), are invasive alien species to North America. In western Canada, they are the most significant insect pests of cruciferous (Brassicaceae) crops. Climate is the one of the most dominant factors regulating the geographic distribution and population density of most insect species. Recent bioclimatic simulation models of the two flea beetle species fostered a better understanding of how the two species responded to selected climate variables. They demonstrated that selected climate variables increased population densities and geographic range of the two species. General circulation model inputs were applied in this study to assess the impact of a changing climate on the response of P. cruciferae and P. striolata populations. Model output, using the climate change scenarios, predicted that both P. cruciferae and P. striolata populations will shift north in future climates and the degree of geographic overlap between these two species will be greater than for current climate. This suggests that the two species could potentially cause economic losses over an expanded area in the future.

Einfeldia synchrona Oliver is univoltine in a small, shallow, highly eutrophic pond near Ottawa (45°N.). Adult emergence is synchronized with slight protandry in May, and from this small pond exceeded 145,000 individuals in 1970. Emergence is inhibited experimentally at short photoperiods. More than one egg mass is produced, during a period of several days following emergence. First instar larvae, which lack ventral tubules, are at first pelagic but build cases before moulting. The remaining three larval instars possess 1 pair of ventral tubules. Larvae show a preference for central areas of the pond over 40 cm deep, and show some mobility in response to seasonal depth changes. There are arrests in the development of larvae both in winter and during summer, with cessation of feeding, penetration into the mud, and construction in winter of special sealed cocoons. Marked year to year differences in the stage reached by winter, and in the larval population level, were detected. Many of these biological features are probably widespread in Chironomini and hence of some importance in the interpretation of studies of the bottom fauna.

Criteria is presented for selecting ant species as predators of insect pests, and a comparison is made between species occurring in Quebec and central Europe. In conclusion it is stated that none of the ants found in Quebec are promising as control agents against forest pests.

The foraging behaviour of honey bees (Apis mellifera L.) on inflorescences of staghorn sumac [Rhus hirta Sudworth (ex-typhina L.)] was studied using a “choice table” placed in natural stands of this plant. The choice table consisted of a wooden grid with alternated male and female inflorescences of sumac. Honey bee activity was recorded also on inflorescences of naturally growing plants in which the secretion of nectar was measured and the anther dehiscence recorded. Honey bees were the only common pollinators observed on sumac in the study area. During the morning, both plant sexes secreted little nectar, and pollen was available after the dehiscence of the anthers which took place between 1000 and 1100 hours. Female inflorescences secreted great amounts of nectar during the afternoon, but in male inflorescences there was little secretion. Honey bees seemed to forage according to the circadian availability of resources. Most of their activity concentrated on male inflorescences in the morning and on female ones during the afternoon. Both the occurrence of bees with pollen loads in their corbiculae and the length of the visits to each sex also seemed to be in accordance to the kind of resource exploited at particular times of the day. Most of the bees with pollen loads were observed during the morning and the longest visits to any inflorescences were registered on female ones during the afternoon (by bees foraging for nectar). Despite our results suggesting that the pollination success of staghorn sumac would be impaired by the foraging pattern of honey bees, an explanation is proposed for its reproductive success.

Four species of Tychius have been introduced into North America from Europe: Tychius picirostris (Fabricius) (host plants: Trifolium spp.), widespread in North America; T. cuprifer (Panzer) (host plants: Trifolium spp., Teline monspessulana L.), known only from Maryland, USA; T. meliloti Stephens, new North American record (host plants: Melilotus spp.), known from scattered localities in Saskatchewan, Manitoba, Ontario, and Quebec, Canada; and T. stephensi Schoenherr (host plants: Trifolium spp.), widespread in North America. Keys to separate the species are presented.

Differential survival and development rates were obtained for the bertha armyworm, Mamestra configurata Wlk., reared at nine constant temperatures. Eggs and larvae had high survival rates at temperatures ranging from 8 °C to 32 °C and pupae showed good survival between 8 °C and 28 °C. Eggs and larvae did not complete development at 6° and 36 °C; and 32 °C was lethal for pupae. Duration of the egg, larval, and pupal stages decreased as the temperature increased from 8 °C to 28 °C. When duration and developmental rates were plotted against temperatures, the observed points did not differ significantly from curves formulated from the logistic equation 1/y = K/(1 + ea−bx). With a developmental threshold of 7 °C, 82, 356, and 352 accumulated day-degrees above the threshold were required for development of eggs, larvae, and pupae, respectively.

We examined the effect of biopesticides used alone, mixed with other biopesticides, or in conjunction with an imidacloprid against wireworms (Coleoptera: Elateridae) in spring wheat Triticum aestivum Linnaeus (Poaceae) (variety: Duclair). The study was conducted at Ledger and Valier, Montana, United States of America in 2015 and 2016. Ten biopesticides (spinosad, azadirachtin, pyrethrin, Beauveria bassiana (Balsamo-Crivelli) Vuillemin (Fungi: Clavicipitaceae) GHA (Mycotrol), B. bassiana ANT-03 (BioCeres), Chromobacterium subtsugae Martin et al. (Bacteria: Neisseriaceae), Burkholderia Yabuuchi et al. (Burkholderiaceae) species, Metarhizium brunneum Petch (Fungi: Clavicipitaceae) ESC1 (MbESC1), and M. brunneum F52 (MetF52) as microsclerotial and corn grit-based granules) were tested in addition to thimet and imidacloprid. Treatment efficacy was based on plant stand protection, wireworm populations, and yield. In 2015, there was considerable variation between sites in treatment efficacy. Mycotrol, BioCeres, MetF52+spinosad, and MetF52+imidacloprid applications protected seedlings from wireworm damage better than the control at Ledger, while only MetF52 at Valier. Wireworm populations were significantly higher with Mycotrol, spinosad, MetF52+spinosad, MbESC1 (25 g/L), and MetF52 treatments, compared with control, at 14 and 28 days post application at Ledger, but without effect at Valier, 2015. We found significantly higher yield in plots treated with imidacloprid+MetF52 and Mycotrol+azadirachtin (Xpulse) compared with control at Ledger. In 2016, no significant treatment effects were observed at either site. In summary, this study provides insight on what treatments should be explored in more detail despite variable results.

Mated females of the aphid parasite Aphidius smithi produced only unfertilized eggs (i.e. sons) for the first 2–3 h after copulation and a variable proportion of fertilized eggs (i.e. daughters) thereafter. As a result, the mean proportion of daughters among the offspring of single females was always less than unity, even in a highly favourable environment; the limiting value of the sex ratio was estimated at approximately 85% females. An argument is presented that in haplodiploid species with a variable and environmentally controlled sex ratio a male-producing mechanism is required to ensure the production of a sufficient number of males for the fertilization of all females.

A local population of P. apachus in California was studied to determine population structure and colony survival during the first 3 months of colony development. Only 24.2% of the colonies survived to the end of July. Bird predation on colonies (60.6%) and loss of foundresses (12.1%) were the main causes of colony failure. Bird attacks occurred approximately 2 weeks prior to the emergence of workers and the scrub jay, Aphelocoma coerulescens, was identified as one of the avain predators. All colonies that survived this initial period persisted until observations were discontinued in late July.

The world species of Urolepis Walker are reviewed and a key is given to differentiate females of Urolepis singularis (Ashmead) and males and females of Urolepis maritima (Walker) and Urolepis rufipes (Ashmead). Lectotypes are designated for U. rufipes and U. singularis. Biological literature relating to parasitism of house flies and stable flies by U. maritima and U. rufipes is summarized, and known hosts of the three species and collection records within the Nearctic region are given. Urolepis maritima is recorded for the first time from the Nearctic region, and U. rufipes is confirmed from northern Europe (Denmark and Germany).

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.