The effect of temperature on the rate of development of Anax junius Drury was studied. Monthly larval samples were carried out for 2 years and laboratory experiments were conducted at constant temperatures. Field studies, at a eutrophic pond near Toronto, showed that in Canada populations of A. junius are not only maintained by migrants each year but also by residents. Two distinct populations were found, a summer (non-resident) population which developed from oviposition to emergence in approximately 3 months, from June to September, and an overwintering (resident) population which overwintered as half-grown larvae and developed in approximately 11 months from mid-July of one calendar year to the end of June of the next year. The former population was larger and comprised approximately 48% males and the latter was smaller and comprised approximately 41% males. A threshold temperature of development of 8.7° ± 0.1 °C was determined in the laboratory for the development of final-instar larvae of the summer population. The rate of development of final-instar larvae, reared at constant temperature, was similar to that of the entire summer aquatic stages which developed in fluctuating temperature. An average of 1332 degree-days ± 1% was required for development from the onset of oviposition to the onset of emergence of the summer population; whereas 20.5% more degree-days were required for the development of the overwintering population, employing the threshold temperature of 8.7 °C as determined for the summer population.It is recommended that correlation between degree-day totals and duration of larval development be used in further studies as a means for understanding the migration pattern and also the climatic limit of distribution for A. junius.

Females of Nasonia vitripennis (Walk.) (Hymenoptera: Pteromalidae) discriminate between unparasitized housefly pupae (Musca domestica L.) and those parasitized by either Muscidifurax raptor G. & S. or Spalangia cameroni Perk. (Hymenoptera: Pteromalidae) and lay fewer eggs on parasitized hosts. Oviposirion restraint is more pronounced towards hosts attacked by M. raptor than towards those attacked by S. cameroni, but less than that exhibited towards pupae previously parasitized by N. vitripennis. Damage to the fly pupae, from piercing by the female’s ovipositor and probably also from a "venom" injected by the female, is responsible for inter- as well as ultra-specific discrimination and restraint.

Very little work has been done on the life history or habits of Mallophaga. Only two papers have heen published since 1913 which give even a general discussion of the life history of these parasites. The number of instars through which the insects pass was not determined in either case. For the experiments reported in this paper, the pigeon louse (Columbicola columbae [Linnaeus]) was chosen because of the ease of obtaining and handling the common host, Columba livia Linn.

The cabbage seedpod weevil, Ceutorhynchus obstrictus (Marsham), was discovered infesting canola [Brassica napus L. and Brassica rapa L. (Brassicaceae)] in southern Alberta in 1995, and by 1999 its populations had reached outbreak densities. The weevil has dispersed rapidly through cropland in the southern prairies, prompting this study to assess its potential for establishment in Canada's primary region of canola production in the Moist Mixed Grassland and Aspen Parkland ecoregions. In this study, both short- (24 h) and long-term (4 years) distribution patterns of cabbage seedpod weevil were examined, and these data were combined with previously published ecological findings and meteorological data in CLIMEX™ software to predict regions of western Canada where economically important infestations are likely to occur. Adult temporal distributions over 24 h on canola in bud and flower remained restricted primarily to the inflorescence rather than on stems and leaves regardless of time of day. Surveys conducted in commercial canola fields from 1997 to 2000 recorded rapid dispersal of the species to the north and east from the region of southern Alberta where it was initially found. Dispersal occurred at a rate of approximately 55 km/year, and in 2000 C. obstrictus populations were found in Saskatchewan for the first time. The CLIMEX™ model predicts that the distribution of C. obstrictus will eventually encompass the entire region of canola production in western Canada.

Females of Muscidifurax zaraptor K. & L. oviposit on unparasitized housefly (Musca domestica L.) pupae in preference to those attacked by M. zaraptor, Nasonia vitripennis (Walk.), or Spalangia cameroni Perk. (Hymenoptera: Pteromalidae). The discrimination against parasitized houseflies is greatest in the case of those attacked by M. zaraptor and least for those parasitized by S. cameroni. Discrimination is based on differences between unparasitized and parasitized pupae that the female parasites detect after they pierce the pupae with the ovipositor. Death of parasitized hosts, or a change resulting directly therefrom, is not responsible for the differences. The fact that hosts pierced at or near the original drilling site are more likely to be rejected than those attacked elsewhere supports the hypothesis that a ’venom’ injected by the female parasites during oviposition diffuses throughout the host and is responsible for oviposition restraint.

In two well-kept but nonsprayed orchards, the European red mite, Panonychus ulmi (Koch), was more numerous and caused more leaf damage to Delicious than to Spartan or McIntosh apple trees. The predacious phytoseiid mites, Metaseiulus occidentalis (Nesbitt) and Neoseiulus caudiglans (Schuster), were more numerous on both Spartan and McIntosh than on Delicious. The differences in the external structure of the leaves may be the reason for the greater abundance of phytoseiids on Spartan and McIntosh.

Relationships between temperature and development rates of eggs, overwintered second-instar larvae, and all larval stages of Choristoneura fumiferana (Clem.) fed on artificial diet were determined. Egg development was observed at eight constant temperatures between 7 and 32°C. It was fastest at 30°C, and showed relatively little variability. The rate of emergence of overwintered second-instar larvae was observed at 10 constant temperatures between 4 and 33°C. Maximum development rates occurred at 30°C. Variability in emergence rates was large, but unimodal. Development rates of the second to sixth larval instars were measured at 10 constant temperatures between 7 and 36°C, and maximum rates were observed, again, at 30°C. Variability in the development rates of the larvae was large, with no correlations between the development rates of the various larval instars. The results of computer simulations of the insect’s seasonal history are presented and discussed.

Monochamol (2-undecyloxy-1-ethanol) is a male-produced aggregation pheromone for several Monochamus Dejean (Coleoptera: Cerambycidae) species. We conducted trapping experiments in Canada, Poland, and China to test whether monochamol was attractive to additional Monochamus species and if attraction was synergised by plant volatiles and bark beetle (Coleoptera: Curculionidae) pheromones. We provide the first evidence of attraction for M. urussovii (Fischer) and M. saltuarius (Gebler) to monochamol or monochamol+kairomones. The highest numbers of M. urussovii were captured in traps baited with monochamol+plant volatiles (Manuka oil, ethanol and (95/5±) α−pinene). Captures of M. saltuarius were highest in traps baited with monochamol, with the addition of cubeb oil tending to reduce captures. The highest numbers of M. scutellatus (Say) were captured in traps baited with monochamol+kairomones. A similar pattern in trap captures was found for M. notatus (Drury), M. marmorator Kirby, M. carolinensis (Olivier), and M. mutator LeConte. Detection rates, that is, proportion of traps capturing at least one specimen, was highest for traps baited with monochamol plus kairomones, particularly for less-common species. These results support the emerging hypothesis that pheromone compounds can attract related cerambycid species with cumulative evidence for attraction to monochamol for 12 species of Monochamus worldwide.

The bee fauna (Hymenoptera: Apoidea) of the Niagara Peninsula, at the eastern end of the Carolinian Zone in Ontario, Canada, is poorly known. From April to October 2003, we studied bee abundance and diversity in set-aside grasslands at Brock University and the Glenridge Quarry Naturalization Site in southern St. Catharines, Ontario. Using three sampling methods (pan traps, sweep nets, and aerial nets), we collected and identified 15 733 specimens of 124 species and morphospecies representing all bee families, except Melittidae, found in North America. Abundance-based diversity estimators suggested bee species richness to be as high as 148 species. There were three seasonal peaks in bee abundance (early spring, late spring, and mid-summer) with a lull in activity shortly after the summer solstice. Several indicators suggested substantial impacts of disturbance on the Niagara bee community, including evidence of high dominance by the most abundant species. Comparison of the sampling methods indicated considerable catch variation among taxa; Halictidae and Apidae were dominant in pan trap samples and in sweep–aerial net samples, respectively. However, bee abundances in pan traps and sweep nets were highly correlated, suggesting that both methods fairly sample local bee abundances.

This study assesses the effects of the veterinary medical product ivermectin (IVM) in a range of concentrations on adult reproductive physiology and larval mortality of the dung beetle Euoniticellus intermedius (Reiche) (Coleoptera: Scarabaeidae). The ecotoxicological tests comprised eight treatments, including two controls and six increasing ivermectina concentrations (3.16, 10.0, 31.6, 63.2, 100, and 316 µg IVM/kg fresh dung). After 10 days of exposure, the females were dissected and the brood balls counted (fecundity). The brood balls were opened 15 days later and live larvae were counted to estimate larval mortality. Ivermectin altered the morphology of the ovary and stopped vitellogenesis, causing oocyte resorption and thus decreasing fecundity. The 30% threshold of decline in fecundity was reached at 115.9 µg IVM/kg dung, with no observed effect concentration (NOEC) and lowest observed effect concentration (LOEC) values of 10.0 and 31.6 µg IVM/kg dung, respectively. Larval sensitivity to ivermectin was higher, with a lethal concentration required to kill 50% of the population of 85.9 μg IVM/kg dung, and NOEC and LOEC of 3.16 and 10.0 µg IVM/kg dung, respectively. After cattle were treated with ivermectin at the recommended dose, the ivermectin concentration in their dung during the two first weeks after administration far exceeded the thresholds determined for E. intermedius.

Through an analysis of the primary setae and pores (campaniform sensilla) of first-instar larvae of 32 species of Colymbetinae, 33 species belonging to other dytiscid subfamilies, and seven species belonging to other families of Hydradephaga, the ancestral system of primary setae and pores of the legs, the last abdominal segment, and the urogomphi of Colymbetinae is deduced. Seventy-four setae and 24 pores have been assigned to the generalized colymbetine larva: 51 setae and 18 pores on the legs, 15 setae and three pores on the last abdominal segment, and eight setae and three pores on each urogomphus. A comparison with the ground-plan pattern of the subfamily Hydroporinae is provided. Members of Colymbetinae differ from those of Hydroporinae by the presence of setae TR3, AB14, and AB15, the absence of pore ABd, and the presence of a variable number of additional setae on the femur. A tentative phylogenetic reconstruction of the colymbetine genera provided is based on 24 larval characteristics. The monophyletic origin of the subfamily Colymbetinae is confirmed based on the shared presence of seta AB14. Two monophyletic lineages unite basally: (1) [(Agabus Leach + Ilybius Erichson) + Agabinus Crotch], and (2) {[Colymbetes Clairville + (Rhantus Dejean + Neoscutopterus Balfour-Browne)] + Matus Aubé}. The genera Agabinus and Matus are postulated as a sister-group of (Agabus + Ilybius) and [(Colymbetes + (Rhantus + Neoscutopterus)], respectively. Compared with other Colymbetinae, both Neoscutopterus and Matus stand out by the presence of several strikingly peculiar features. The subgenus Rhantus (Nartus) is postulated to be the sister-group of Neoscutopterus based on the shared presence of additional setae on the dorsal margin of the femur.

A chemically defined, synthetic medium that induces oviposition in the parasite Itoplectis conquisitor (Say) has been developed. The medium contains serine (0.5 M), arginine (0.05 M), leucine (0.065 M), and magnesium chloride (0.025 M); and it is more effective than host haemolymph in inducing oviposition. This completely artificial oviposition stimulant was developed to facilitate the mass rearing of the parasite on an artificial diet.

Earlier work indicated that food plants of the tenthredinid sawflies attacked by Drino bohemica Mesn. and Bessa harveyi Tns. influence host-finding by these tachinid parasites (Monteith, 1955, 1958a). There is a high degree of interaction between stimuli produced by the host larvae and by their food plants (Monteith, 1955, 1958b).

It was observed during field studies that the percentage parastism by B. harveyi of the larch sawfly, Pristiphora erichsonii (Htg.), varied with increasing height above the ground and in different sections of tamarack trees, Larix larician (DuRoi) K. Koch, on which the sawfly larvae were feeding. It appeared that shrubs and trees other than L. laricina influenced host-finding by B. harveyi.

Analyses of pentane extracts of frass, whole beetles, and volatiles trapped on Porapak-Q from Pityophthorus Eichhoff spp. fed on Pinus radiata D. Don demonstrated that (E)-pityol [2-(1-hydroxy-1-methylethyl)-5-methyltetrahydrofuran] was produced by male Pityophthorus carmeli Swaine, female Pityophthorus nitidulus (Mannerheim), and female Pityophthorus setosus Blackman. (E)-(−)-Conophthorin) [(5S,7S)-(−)-7-methyl-1,6-dioxaspiro[4.5]decane] was produced by male P. carmeli and male P. nitidulus. Only the (2R,5S)-(+) stereoisomer of (E)-pityol was produced by male P. carmeli and female P. setosus. In field bioassays in central coastal California, P. setosus was attracted to (E)-(+)-pityol, whereas P. carmeli responded only to a combination of (E)-(−)-conophthorin and (E)-(+)-pityol. Male P. setosus and female P. carmeli responded to these treatments with larger numbers than opposite-sex conspecifics. (E)-(−)-Conophthorin alone did not attract species of Pityophthorus but significantly reduced catches of P. setosus to (E)-(+)-pityol. Lasconotus pertenuis Casey (Coleoptera: Colydiidae) and Ips mexicanus (Hopkins) (Coleoptera: Scolytidae) were attracted to a combination of (E)-(−)-conophthorin and (E)-(+)-pityol, and showed a trend for attraction to all (E)-(−)-conophthorin-containing treatments. (E)-(−)-Pityol was neither attractive nor interruptive for any taxon. (E)-(+)-Pityol is shown to be an aggregation pheromone component for P. carmeli and P. setosus. (E)-(−)-Conophthorin functions as a pheromone component for P. carmeli and may also function as a synomone that decreases competition of P. carmeli and P. nitidulus with P. setosus and as a kairomone for L. pertenuis. These semiochemicals have been useful in studying relationships among twig insects and the pathogen Fusarium circinatum (Nirenberg and O’Donnell), causal agent of pitch canker disease in P. radiata.

In Saskatchewan, Lestes unguiculatus Hagen, L. disjunctus disjunctus Walk., and L. dryas Kirby overwinter as eggs in a late stage of embryonic development. The embryos enter diapause in September and, in this condition, can survive exposure to temperatures as low as −20 °C. Under field conditions adequate snow cover is necessary to prevent egg mortality due to desiccation or exposure to air temperatures lower than −20 °C. Post-diapause development can take place at 0 °C but does not occur until the eggs are wetted as the pond fills with runoff water in the spring. Hatching in L. disjunctus and L. unguiculatus is highly synchronous and occurs when the water temperature is about 10 °C. Larval development is completed in about 60 days. Emergence is highly synchronous and is virtually complete within 10 days. Sexual maturation requires 16 to 18 days. Oviposition immediately follows copulation while the pair is still in tandem. Eggs are laid only in green stems of Scirpus L., between 5 and 60 cm above the water surface. The stems selected are those either growing in small groups or bordering larger stands. The significance of the observations is discussed in terms of the species’ ability to survive the climatic extremes of central Canada.

An aqueous suspension of the nuclear polyhedrosis virus of Lymantria dispar (L.), LdNPV, was fed to third-instar caterpillars of L. dispar and 46 species of nontarget Lepidoptera in four successive. 24- to 48-h doses of 3 × 104 polyhedral inclusion bodies (PIBs) in 2 μL applied to small pellets of artificial diet or isolated surfaces of foliage. Adults of the fly Cyrtophleba coquilletti Aldr., and adult males of the bee Megachile rotundata (Fabr.), were assayed with a single dose of 1.2 × 105 PIBs in 2 μL of 30% sucrose solution. Only those specimens that completely consumed the dose(s) were transferred to appropriate maintenance conditions for 7–10 days whereupon they were frozen. Samples of macerates of experimental specimens were dot-blotted onto nylon membranes on which whole genomic LdNPV DNA-probing and chemiluminescence techniques were used lo show presence of LdNPV DNA. With reference to positive and negative controls, the 48 nontarget species were diagnosed as nonpermissive of LdNPV but the target species was clearly infected. This study demonstrates a high degree of host-specificity of LdNPV.

A three-year study on the seasonal occurrence of ground beetles was conducted in five fields with different crop rotations. More than 10,000 individuals representing 102 species were captured in pitfall traps. The relatively high total number of species collected the first year probably resulted from the particular location of the traps along field margins and close to woodlands. The variation observed between the areas studied was not necessarily related to the kind of crop. A progressive augmentation in beetle activity and population appeared to coincide with an increase in the humidity of the habitats and with the cultures in the following order: pasture grass, forage, cultivated, and cereal crops. This indicates that the nature of the crop influences beetle numbers, and from this it may he inferred that it also influences the extent to which the beetles exert a control influence on pest species. Of the eight species present every year and found in practically every field, Pterostichus melanarius Ill., Harpalus pennsylvanicus DeG., and H. compar Lec. were the most numerous.

The viral activity of soil treated with polyhedra of the cabbage looper, Trichoplusia ni (Hübner), was determined at intervals by bioassay. Soil in plots treated in 1961 at a rate of 6.4 × 1010 polyhedra per square meter of surface contained about 25% of the original infective virus more than 5 years after treatment. A similar rate of decline in viral activity occurred in plots treated with polyhedra in 1963. Viral activity of soil retained under artificial conditions decreased more rapidly.

Field and laboratory tests showed that foliage of cruciferous plants grown in soil treated with polyhedra was contaminated with the virus, probably largely by virus-laden soil being splashed onto foliage by rain.

An analysis of the primary setae and pores (campaniform sensilla) of first instars of 32 species of Colymbetinae, 61 species belonging to other dytiscid subfamilies, and seven species belonging to other families of Hydradephaga was performed to deduce the ancestral system of primary setae and pores of the head capsule and head appendages of Colymbetinae. Sixty-one setae and 46 pores have been assigned to the ground-plan pattern of the colymbetine larva, 27 setae and 20 pores on the head capsule and 34 setae and 26 pores on the cephalic appendages. The pattern proposed for the Colymbetinae is remarkably consistent and similar to the condition observed within the Carabidae. However, members of the Colymbetinae differ strongly from those of Hydroporinae which are characterized by several secondary losses. A preliminary phylogenetic reconstruction of the relationships of colymbetine genera studied based on 41 larval features suggests that the Nearctic fauna includes two monophyletic lineages: (1) (Agabus Leach + Ilybius Erichson) + Agabinus Crotch, and (2) {[Colymbetes Clairville + (Rhantus Dejean + Neoscutopterus Balfour-Browne)] + Matus Aubé}.