Wood and bark extracts from balsam fir, red cedar, spruce, hemlock, and pine were assayed for juvenile hormone-mimicking activity on pupae of the wax moth. All the extracts showed noticeable activity; the wood extracts were generally more active than the bark extracts. The results suggest that the purification of the extracts from these conifers might lead to the isolation of compounds with high hormone-mimicking potential.

Directional cone-orifice traps were suitable for monitoring population densities of five Lepidoptera species, provided the captured moths were removed from the traps on a regular basis of at least once a week throughout the flight period. Omni-directional traps with circular screen barriers in the entrance area and a slow-release insecticide in the receiver to kill the captured moths functioned well over extended periods of unattended use. These traps would be useful for monitoring and mass trapping purposes. Similar traps without the circular screen barriers were less efficient but, due to their simplicity, they would also be suitable for monitoring purposes. The optimum quantity of pheromone per dispenser was the same for the directional cone-orifice and omni-directional traps.

Most modern European writers follow Tulleburg in placing all the Collembola in the family Poduridœ, and including the Poduridœ, Lipuridœ and Anouridœ of Lubbock in the subfamily Lipurinœ. It would seem more natural to restrict the name Poduridœ to those genera bearing the saltatory apparatus on the antepenultimate abdominal segment, instead of the penultimate, and then to include those genera in which the saltatorial apparatus is wanting under the name Aphoruridœ*

Cocoons of the larch sawfly normally spend from nine to ten months in the ground per annum under conditions existing in western Canada. For this reason biotic and abiotic soil factors are of paramount importance in the epidemiology of this insect. Preliminary observations and experiments indicate that ground water is one of the most important of these factors in that it not only affects sawfly development directly but also is significant in regulating sawfly predators and possibly parasites.

Populations of the mayfly Heptagenia hebe McDunnough in areas of New Brunswick air-sprayed with DDT for budworm control for eight successive years, when tested as nymphs taken from the streams, showed LC50 levels 3 times as high as those in untreated areas. Populations surviving an airspray in 1965 proved to be 12 to 40 times as DDT-resistant as the normal. Pre-spray populations of Stenonema fuscum (Clemens) showed a 5-fold resistance, and post-spray populations of Stenonema interpunctatum (Say) showed a 10-fold DDT resistance when those from treated areas were compared with those from untreated. The DDT-resistant nymphs of H. hebe detoxified DDT to DDE 15 times faster than the normal nymphs; DDE was also the metabolite in S. interpunctatum. In both these species the DDT-resistant nymphs absorbed roughly twice as much DDT as the normal.

In 1937 Schwarze and Huber (3) reported the variety of Rubus idaeus L named “Lloyd George” to be totally resistant to the aphid Amphorophora rubi Kalt. This fact was of some economic significance because the aphid in question had been shown to be an active vector of Rubus viruses in North America. It was suggested that the aphid-resistant qualities of Lloyd George should be incorporated in plant-breeding programmes with a view to producing hybrids, with desirable commercial qualities, which would escape infection by the viruses.

Certain kinds of micro-organisms occurring in close internal association with insects, and often harboured in apparently specialized organs, are, at least in some species, of benefit to the insects in supplying them with needed dietary constituents, e.g., vitamins of the B complex (3).

During the past twenty years conflicting statements have been made about the presence of mycetomal micro-organisms in Sitophilus granarius (6, 11). Recently some general clarification has been achieved (9). It seems that while this species commonly harbours such micro-organisms, there exists an Egyptian strain apparently free of them. Furthermore, a variety africana, distinguishable by its smaller size and lighter colour, has been described from the Nile Valley (1, 5).

A double application of Disparvirus, a nuclear polyhidrosis virus, at 1.25 × 1012 polyhedral inclusion bodies (PIB) per hectare, giving a total of 2.5 × 1012 PIB per hectare, was applied aerially on three plots in an emitted volume of 10.0 L per hectare. The two applications were 3 days apart and most larvae were in the first instar. Three plots were selected as untreated checks; each was paired with a treated plot on the basis of pre-spray gypsy moth egg-mass numbers and locality. The pre-spray egg-mass counts ranged from 1430 to 8520 per hectare in the six plots. Assessment of the treatment was based on numbers of pupae and fall egg masses as well as on estimates of defoliation and on microscopic examination of larvae collected at weekly intervals to determine the incidence of virus infection. Between 12 and 19 days post-spray, 49, 61, and 85% of the larvae were infected with virus in the three treated plots compared with 3, 7, and 14%, respectively, of larvae in the check plots. Red oak was 14% defoliated in two of the treated plots compared with 82 and 90% in their corresponding check plots. The third plot suffered 46% defoliation due to leaf-eating caterpillars other than gypsy moth; defoliation in its corresponding check plot was 31%. Reductions in egg-mass numbers in the treated plots were 76, 93, and 98% compared with an increase of 56% and decreases of 50 and 70%, respectively, in corresponding check plots. Corrected population reductions (Abbott’s formula) were 84, 85, and 92% in the three treated plots.

In this paper, Angarotipula Savchenko, 1961 (Diptera: Tipulidae) is redescribed and differentiated from other genera in Tipulidae and subgenera of Tipula Linnaeus, 1758, where this taxon was previously placed. Angarotipula tumidicornis (Lundström, 1907) is synonymised with Angarotipula parrioides (Alexander, 1919) (new synonym), the latter is a junior synonym. A lectotype is designated for A. tumidicornis. The female and first instar of Angarotipula illustris (Doane, 1901) and the pupa of A. tumidicornis are described and illustrated for the first time. Keys to adults, larvae, and pupae of the two North American species are presented. A close relationship between Angarotipula and Prionocera Loew, 1844 is suggested based on shared character states.

Each fall, honey bee (Apis mellifera L. (Hymenoptera: Apidae)) colonies in northern temperate regions rear a population of long-lived winter bees that maintains a broodless nest throughout the winter and resumes brood-rearing activities in the spring. Pollen supply in colonies is closely tied to this phenomenon; winter bees sequester large reservoirs of pollen-derived nutrients in their bodies and the brood-rearing capacity of colonies is dictated by the availability of pollen. We determined the effects of manipulating pollen supply during the fall on the number of winter bees present in colonies by spring, their mass and protein content before and after winter, and their capacity to rear brood during the spring. Colonies were either supplemented with or partially deprived of pollen during the fall, while a third group of colonies was not manipulated (control). We found that the performance of winter bees was not enhanced by supplementing colonies with pollen in the fall, nor did worker function suffer if pollen supply was restricted. Similar numbers of winter bees survived to spring in colonies and workers had similar physiology and brood-rearing efficiencies. These results suggest that beekeepers would not benefit by investing in fall pollen supplements to maximize colony growth in early spring.

Induction of diapause under laboratory conditions is a valuable tool for the study of dormancy in economic pests such as the swede midge, Contarinia nasturtii Kieffer (Diptera: Cecidomyiidae). In the present study, diapause in larval swede midge was achieved via manipulation of rearing photoperiod and temperature. Frequency of diapause was assessed by sieve separation of diapause cocoons from pre-sifted peat substrate following emergence of pupating individuals. Mean diapause frequency for swede midge larvae reared under cool conditions with short day length or cool conditions with decreasing day lengths were 45.2% and 19.5%, respectively. Only 1.2% of swede midge reared under warm, long day length conditions entered diapause. A small percentage of larvae neither pupated nor entered diapause and remained in substrate long after other individuals had emerged as adults. This behaviour was more prevalent under cool and short or decreasing day length rearing conditions. Approximately 76% of the larvae used for diapause induction were recovered with the present larval and cocoon retrieval method, and premature (larval and pupal) mortality averaged 18.2%. Although diapause occurred in the present study, conditions resulting in higher diapause frequencies should be investigated and attempts should be made to improve survival and recovery of individuals.

The egg-laying habits of the pest species of grasshoppers in Western Canada have been known, in their essential characteristics, since the work of Criddle (1920). Methods used in routine surveys in the Prairie Provinces have been based on this knowledge since 1932, when surveys as they are now known were first made. For example, the habit of the principal pest species, Melanoplus mexicanus mexicanus (Sauss.), of distributing its egg-pods widely in fields of ripening or harvested small grains, and not in native grasslands or highly restricted, selected sites, was known. Likewise, the habit of another important grasshopper, Camnula pellucida (Scudd.), of concentrating its eggs in areas of native sod adjoining cultivated fields was recognized.

The black-headed budworm has long been known as an endemic resident and occasional epidemic defoliator of coniferous forests in Canada and parts of northern United States. The moth is distributed across the whole of the northern forest area from Cape Breton Island to the west coast of Canada and Alaska. It is a serious and recurrent defoliator particularly in British Columbia and Washington (Silver, 1960). The larvae feed on various conifers of the genera Abies, Larix, Picea, Pseudotsuga, and Tsuga, and different hosts are preferred in different parts of the range. Thus, Schaffner (1950) gives Abies balsamea as the most important host in eastern areas, Raizenne (1952) indicates that species of spruce (Picea) are most often utilized in southern Ontario, while Tsuga heterophylla has been found to be preferred in coastal British Columbia (Leech, 1933; Keen, 1952; Evans and Silver, 1954; Silver, 1960).

The measurement of insect attraction by the number of specimens collected in a certain time, or by the duration of the attractive effect, does not distinguish between the roles of intrinsic attraction and the attractant concentration. It is shown that the number of D. melanogaster responding to a food odor is proportional to the logarithm of the attractant concentration, in conformity with the Weber–Fechner Law. The implications of this result are discussed.

Apple clearwing moth, Synanthedon myopaeformis (Borkhausen) (Lepidoptera: Sesiidae), is an invasive species in Canada and a destructive pest of commercial apple trees in British Columbia. Adult mass trapping is being developed to help organic apple producers manage this pest. We manipulated and measured spectral reflectance from delta traps, unitraps, and bottle traps used to deploy sex pheromone, phenylacetaldehyde, and grape juice mass-trapping baits and compared catches in baited traps having different reflectance properties. Synanthedon myopaeformis did not discriminate among pheromone-baited delta traps painted yellow, green, or white, from those left clear (group 1), nor among those painted purple, blue, red, or black (group 2). Catches by all treatments in group 1 were significantly greater than all in group 2. Catches in pheromone-baited delta traps were positively correlated with their intensity of green wavelength reflectance (500–550 nm). Fluorescent yellow delta traps reflected more green and ultraviolet (300–400 nm) light than standard yellow or green traps but caught significantly fewer moths when baited with pheromone, implying an antagonistic interaction of green versus ultraviolet-sensitive behaviours. Pheromone-baited all-yellow unitraps caught significantly more moths than equivalent all-green, all-white, or all-red unitraps. Catches in pheromone-baited all-yellow unitraps decreased when any component (lid, funnel, or bucket) was replaced with a green one. Changing the intensity or quality of reflectance from funnels had the greatest impact on unitrap catches (82% reduction). Spectral preferences were modulated by odours eliciting different behaviours (mating versus feeding). When baited with the floral feeding odour phenylacetaldehyde, yellow and green delta traps were among the least attractive, whereas black and blue traps were among the most attractive. When baited with grape juice food baits, black bottle traps caught significantly more moths than any other colour except white, and the former are recommended for maximising mass trapping of females while minimising nontarget impacts of juice baits.

Agapeta zoegana L. (Lepidoptera: Cochylidae) is a Eurasian root-mining moth introduced into North America for control of spotted knapweed, Centaurea maculosa Larnarck. The biology and host specificity of the moth were described by Müller et al. (1988, 1989). Early-instar larvae mine the epidermal tissues of the root crown. Older larvae mine the root cortex and endodermis and cause considerable damage, especially to small plants or when several larvae infest a single large plant. Larvae can migrate below ground to a new host plant if the initial knapweed plant has been destroyed. The moth overwinters as a larva in the root and emerges as an adult in June through August. Several generations per year may occur.

Ommatissus lybicus de Bergevin (Hemiptera: Tropiduchidae) is a key pest of date palm (Phoenix dactylifera Linnaeus; Arecaceae) with worldwide distribution and various management strategies. To study genetic diversity of date palm hopper, a series of experiments was conducted on genetic structure and genetic diversity of 15 geographic populations of O. lybicus (Abu Musa, Bam, Bushehr, Behbahan, Tezerj, Fin, Jiroft, Shahdad, Jahrom, Ghire Karzin, Ghasre Shirin, Iran; Pakistan; Oman; Egypt; and Tunisia) by amplified fragment length polymorphism, cytochrome c oxidase subunit I (COI), and 28S rRNA markers. Analysis of molecular variance analysis of amplified fragment length polymorphism data and COI sequences revealed a significant variation among O. lybicus populations (94.12% and 65.08% similarities for amplified fragment length polymorphism and COI, respectively). The 28S rDNA sequences from different populations were identical. Phylogenetic network inferred from amplified fragment length polymorphism data and COI sequences grouped two geographically close populations (Tezerj and Bam) in the two distinct clades while far apart geographical populations bunched in the same or close clades. These two populations experience repeated exposure to heavy pesticide applications annually. In conclusion, study of the genetic structure revealed a considerable variation between O. lybicus populations under intensive chemical strategies.

Eucosma rescissoriana Heinrich is highly destructive to cones and seed of western white pine, Pinus monticola Douglas, and is distributed throughout the geographic range of this host species in northern Idaho. One generation is passed per year with emergence in late May. Egg and larval stages arc generally found in June and July; the pupal stage overwinters. Stand density and elevation were used as variables in ecological studies of population sine. All stages of E. rescissoriana were correlated to phenological data in 1962.

A laboratory system was developed that allowed populations of the house fly, Musca domestica, and its hymenopterous, wasp parasitoid, Nasonia vitripennis, to interact and fluctuate in numbers, subject only to an upper limit on Musca density. In one (experimental) treatment, the selection pressure from Nasonia was allowed to operate, while in the control all Musca adults were replaced in each generation by individuals from a Musca population not exposed to Nasonia. Evolution for resistance of Musca to Nasonia became noticeable within four generations in the experimental treatment. Measured changes finally included increased fly pupal weight (although larval development period was not allowed to increase), less time spent as pupa, increased pupal mortality, and reduced fecundity of adults. Total per-generation increase of both control and experimental Nasonia was much reduced on experimental compared with control Musca. This was caused by reductions both in the longevity of female Nasonia and in the number of progeny they produced each day. From early in the experiment the increased resistance of Musca produced lower Nasonia densities in the experimental treatment. During the first 20 or so generations no difference could be detected in mean Musca density between the two treatments. After that time the density of adult Musca became greater, and fluctuated less, in the experimental than in the control treatment. This situation continued until the experiment ended at 50 generations.