Dioryctria tumicolella, from pine blister rust, Peridermium spp., swellings on Pinus ponderosa Lawson and Son in British Columbia, Washington, Montana, and Colorado; D. contortella, from Peridermium swellings on P. contorta Douglas in British Columbia, Alberta, and Washington; D. monticolella, from trunks of P. monticola Douglas in British Columbia; and D. banksiella, from trunks of P. banksiana Lambert in Alberta, Northwest Territories and eastward, are described as new species and distinguished from the western D. cambiicola (Dyar) and the eastern D. zimmermani (Grote).

In feeding choice tests, first- and second-instar larvae of Calosoma sycophanta L. preferred gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), pupae as prey but third-instar larvae most often consumed caterpillars. All beetle larvae preferred female pupae over male pupae. In non-choice feeding tests, older predator larvae consumed more gypsy moth fifth-instar larvae than the larger sixth-instar larvae, but the total weights of prey eaten in both cases were similar. First-instar larvae of C. sycophanta only partially consumed prey, and caterpillar size did not affect the total numbers eaten. Beetle larvae ate as many female gypsy moth pupae as male pupae, but larger larvae consumed greater weights of the former than of the latter. As a consequence, C. sycophanta larvae fed female pupae were larger than those provided with male pupae. However, for a given increase in size, third-instar larval beetles ingested the same weight of food no matter what the prey size was. Conversely, young beetle larvae seemed to require greater amounts of the body contents of large prey for a given size increase, probably because fluids from large prey were lost during predator attack. The information gained in this study may make it possible to use sizes of field-observed C. sycophanta larvae to predict numbers of prey they have killed.

A technique for rearing Neodiprion sertifer (Geoff.) in individual isolation from egg to adult is described. Larvae so reared under optimal conditions experience mortality only slightly greater than that sustained by larvae growing in the normal feeding aggregations. The comparative capacity of the isolated larvae to withstand even slight departures from optimal conditions of food, temperature and humidity is low. These observations together with data on the responses of isolated and normal larvae to physical factors are discussed in their ecological context.

The diversity of Agromyzidae (Diptera) associated with disjunct xeric grasslands was studied at six south-facing slopes in the southern Yukon Territory, Canada. Agromyzidae was the most diverse of 32 families of Brachycera at the sites, with 34 species (485 specimens) collected. Eight new species are described: Liriomyza naressp.nov., Metopomyza adretanasp.nov., Phytoliriomyza depriceisp.nov., Phytoliriomyza triangulatasp.nov., Phytomyza conglomeratasp.nov., Phytomyza dionisp.nov., Phytomyza klondikensissp.nov., and Phytomyza takhiniensissp.nov. Twenty previously described species were identified and six other unnamed species were represented by females only. Fourteen of the 20 previously described species are recorded from the Yukon for the first time; ecological and systematic notes are given for each species. Although the vegetation of the sample sites was often similar, there were pronounced differences in the species assemblage of Agromyzidae collected at each site. Thirteen of the previously known species are widespread in the Nearctic region (including Holarctic species), six species are restricted to the western Nearctic, and one species is known from the Palaearctic and western Nearctic. Several major range extensions are noted.

To use gizzard analysis quantitatively, in the assessment of bird predation on insect populations, information is needed on the time that identifiable remains of the prey can be found in the gizzard and on the rate at which these remains disappear. The digestion rate, measured by the disappearance of mandibles or cremasters, has been studied for larvae and pupae of the spruce budworm, Choristoneura fumiferana (Clem.), when eaten by the olive-backed thrush, Hylocichla ustulata swainsoni (Tschudi).

Aphis loniceræ Monell. Riley & Monell, Notes on the Aphididæ, U. S. Geol. and Geogr. Survey, Vol. v., Jan., 1879, p. 6.

This species is the one mentioned by Prof. Thomas in the eighth Ill. Ent. Rept. p. 104, under the name of Chaitophorus lonicerœ Mon'l Mss.

Phorodon mahalek Fonsc. This European species has been very abundant at the Missouri Botanical Gardens, St. Louis. I believe that it has not before been definitely reported as occurring in the United States.

Methods of rearing various stages of the pale western cutworm, Agrotis orthogonia Morr., in the laboratory have been described (Hocking, 1952; Jacobson, 1952; King and Atkinson, 1927; Lindsay. 1954; Parker et al, 1921; Seamans and McMillan, 1935). From these a very satisfactory method has been evolved at the Lethbridge laboratory that this insect to be reared for several generations, providing a source of experimental material at any stage of development. The rearing may be done very satisfactorily a t room temperature but, if desired, the method is adaptable to rearing at various conditions of constant temperature and relative humidity.

Evidence for a female-produced sex pheromone in the white pine cone beetle, Conophthorus coniperda (Schwarz), and the red pine cone beetle, C. resinosae Hopkins, was obtained from laboratory bioassays and field experiments conducted with C. coniperda beetles from Ontario and North Carolina. In an olfactometer, males from both species responded significantly more to volatiles from females than to volatiles from males or cones. Generally, females did not differ in their response to female-, male-, or cone-produced volatiles. Both sexes responded to host volatiles. The strong response by male C. coniperda to females was confirmed in field tests.

The known distribution of Thymelicus lineola (Ochs.) now includes large areas in Ontario. Spot infestations are recorded from such widely separated areas as Lanoraie and Montreal, Quebec; Ottawa, Sault Ste. Marie, and Fort William, Ontario; and Terrace, British Columbia.

Infestations of T. lineola can be reduced by cutting infested areas during June, before adults emerge, or by spraying with Thuricide 90T at the rate of 2 pints per acre. The biology of the European parasite Stenichneumon scutellator Grav. is being studied prior to possible release.

The aphidophagous midge, Aphidoletes aphidimyza (Rondani), is a promising biological control agent for aphids in agricultural crops, although its low fecundity has been cited as a disadvantage (Harris 1982; Chambers 1986). In previous studies, fecundity was reported as 70 eggs (Uygun 1971), 100 eggs (Harris 1973), and 6–38 eggs per female (Ushchekov 1975). Recently, Gilkeson and Hill (1986) reported a mean of 156.6 eggs per female from a laboratory line reared under optimum conditions (17-h day, 25°C, ample food supply). These differences in fecundity could be due to variation in genetic makeup, rearing conditions, or larval nutrition, which has been shown to influence adult fecundity (Kuo 1982; Havelka and Růžička 1984). While conducting a project on commercial application of A. aphidimyza, I have recently found that providing a source of drinking water in oviposition cages resulted in higher egg production than has been previously reported.

From 1976 to 1978, 1300 mated females of Olesicampe geniculatae Quednau and Lim were released near Quebec City during a severe infestation of the mountain ash sawfly, Pristiphora geniculata (Hartig). Both cage and open releases were made. The interactions among the mountain ash sawfly, the imported primary parasite O. geniculatae, and the indigenous hyperparasite Mesochorus globulator (Thunb.), and the effect of O. geniculatae on the host population during and after the establishment phase, are reported. In 1984, O. geniculatae was recovered from all over southern Quebec. Parasitism ranged from 6 to 94%. Concurrently, infestation levels by the mountain ash sawfly declined significantly, and since 1985, the insect has almost disappeared in Quebec. With an annual spread of about 50 km per year after successful establishment, O. geniculatae now covers an area 1000 km in diameter. No major infestation by the mountain ash sawfly has been recorded in Quebec during the past 7 years. The introduction of O. geniculatae is rated as a complete success in classical biological control.

Olesicampe (Holocremnus) sp. nr. nematorum (Tschek) has become established at two locations in Manitoba, and has built up rapidly in both. In 1965 at Pine Falls, where it was released in 1961, 61% of the hosts were parasitized in the vicinity of the release point, and at Riverton, where it was released in 1962–1963, 87% were parasitized. A number of characteristics seem to endow this parasite with a marked ability to act against the larch sawfly. These include good synchronization, longevity and searching capacity; low superparasitism; absence of hyperparasitism, and lack of host resistance by encapsulation. O. sp. nr. nematorum has dispersed at least one mile at Riverton and one-half mile at Pine Falls. The percentage parasitism decreases rapidly from the release points to these limits.

Neodiprion swainei Middleton is the most serious defoliator of jack pine, Pinus bamksiana Lambert, in Canada. The damage to stands of this species in northern Quebec has been extensive and has resulted in considerable forest-fire hazard. Virus infected sawflies were found in the Lac Gagnon area in Quebec in 1956, and a study of the disease was begun by the Quebec Laboratory in 1957. Laboratory propagation methods were developed and resulted in the production of a quantity of polyhedral concentrate of a virulent strain. Concentrations of polyhedral bodies needed in a spray formulation to infect and kill larvae of various ages were determined in the laboratory and field tests demonstrated the potentialities of this disease as a biological control agent (Smirnoff 1960b, 1961a). These studies served as a basis for the experiment in the dissemination of the disease by aircraft described in this paper.

It has long been known that a series of late-instar larvae of Choristoneura fumiferana (Clem.) may be distinguished from one of C. pinus Free. by colour differences of the head and prothoracic shield: specimens of the former usually have dark heads and light prothoracic shields; specimens of the latter usually have light heads and dark prothoracic shields. However, intensive study of the larvae, including numerous specimens of C. fumiferana from the spruce-balsam fir areas of Algonquin Park, Ontario, and of C. pinus from jack-pine areas at Normandale, Ontario, has shown that there are highly significant structural differences in the head; these differences serve to identify small series of either species and most single specimens.

We document a novel exotic bee for North America, Hylaeus (Hylaeus) communis Nylander, 1852 (Hymenoptera: Colletidae), and determine whether it is likely to spread widely across the continent. To evaluate the extent to which H. communis behaves as a generalist and would be able to adapt to novel North American environments, we compare the breadth of its climatic, floral, habitat, and nesting preferences between its native European range and sites where it was first discovered in southern Québec, Canada. Specifically, we calculate the paired difference index, which approximates species generalism, from a set of bipartite networks linking Hylaeus Fabricius, 1793 species to their respective floral hosts and habitats. Results indicate that H. communis is the most adaptable bee of the European Hylaeus fauna and will likely acclimate to its new environment, being a greater generalist than an already widely established exotic bee, H. hyalinatus Smith, 1842. In southern Québec, we find that, despite visiting a wide variety of flowering species, it exhibits a strong association with non-native plants and resides almost exclusively in urban settings. We hypothesise that H. communis will be able to spread widely throughout North America via multiple human-mediated but accidental dispersal events and by following the distribution of European weeds and horticultural plants.

The first investigations of the mite fauna of Sable Island, Nova Scotia, Canada, are reported. Fourteen species have been found. Uropoda orbicularis (Müller) (Uropodidae) and Scarabaspis inexpectatus (Oudemans) (Eviphididae) are newly recorded for North America, Macrocheles nemerdarius Krantz and Whitaker (Macrochelidae) is newly recorded for Canada, and Trichoribates striatus Hammer (Ceratozetidae) is recorded for the first time south of the subarctic zone. Colonization, dispersal, and the zoogeographic origins of the fauna are discussed in the context of the biological, geological, and human history of the island.

The prairie grasslands have been transformed to become the primary source of agricultural production in Canada. Soon after its establishment, the Biological Survey of Canada recognised the urgent need to document the arthropods of the prairie grasslands, especially in the few pristine remnants. Although this initiative has yielded considerable progress in documenting the species present in the Prairies Ecozone, comprehensive ecological studies are sparse. Landscape effects on arthropods are well studied elsewhere, but no equivalent studies have been published for the Canadian Prairies. Crop rotation varies landscape composition annually, changes host plant resources in fields, and interacts with other agricultural inputs to disturb pest and beneficial arthropods. Despite only a handful of studies on grazing, there is an emerging pattern: moderate grazing increases arthropod diversity and benefits certain arthropod guilds. Abiotic inputs elicit variable responses from different arthropod taxa; Carabidae (Coleoptera) are best studied, with some information available for ants (Hymenoptera: Formicidae) and aquatic arthropods. Biotic inputs include arthropods released for biocontrol of weed and insect pests; evidence indicates that biocontrol agents of insects have a greater potential for impact on native communities of arthropods. The studies reviewed here reveal important trends and research gaps to be addressed in the future.

Parasite studies were carried out in two residual spruce budworm outbreaks in Quebec. Investigations were conducted during the last three years of the outbreak in the Lower St. Lawrence region and during the last year of the one in the Saguenay region. In the Lower St. Lawrence region decline of the insect population was initiated through aerial application of DDT over a period of three years, while in the Saguenay region the unfavourable condition of the forest stands apparently kept budworm numbers below peak outbreak levels. The incidence of mortality through the action of parasites was very high during the last year of both of these outbreaks and probably contributed to bringing about their collapse. Meteorus trachynotus Vier. has repeatedly been recovered in abundance during the last year of a number of budworm outbreaks and it was amongst the important parasites recovered in both outbreaks under discussion. Other species, however, that were abundant in one or the other of these two outbreaks had not been recovered in numbers before. The parasite complex and the relative abundance of each parasite species during budworm outbreaks is fairly constant at the time of peak host populations, but it is now apparent that they vary considerably at the time of outbreak collapse. Variations in the presence and relative abundance of alternate hosts probably account for this situation.

Examination of 122 specimens of Xanthogramma Schiner, 1861 (Diptera: Syrphidae) from varied localities in Europe (+Turkey) resulted in the description of two new species (X. aeginae Ricarte, Nedeljković, and Vujić new species and X. pilosum Nedeljković, Ricarte, and Vujić new species), as well as new data on six other species. Most of the examined material originated from the Balkan Peninsula and Greek islands. New species concepts were supported by morphological and molecular evidence. Relationships among the eight studied species were analysed and discussed based on the data of nuclear (ITS2) and mitochondrial (COI) genes sequences. An identification key to the European species of Xanthogramma is provided. Lectotypes are designated for Doros decoratum Zetterstedt, 1843, Lasiophthicus novus Rondani, 1857, Syrphus laetus Fabricius, 1794, Syrphus ornatus Meigen, 1822, and Xanthogramma nobilitatum Frey, 1946.

Barrier-pitfall traps and tree bands were used to sample adult carabid beetles in five forest stands of different tree species composition and spruce budworm infestation levels. Twenty genera and 37 species were collected over the 2-year period. Adult carabid populations were highest in the red spruce stand while carabid species diversity was greater in hardwood and fir stands having the most tree species diversity. Potential adult carabid predators of spruce budworm were identified using 5 criteria: number of individuals, habitat preferences, seasonal abundance, size, and food. We conclude that adults of Pterostichus pensylvanicus (Lec.) had the highest potential as predators of spruce budworm followed by Platynus decentis Say, Calosoma frigidum Kby., Pterostichus tristis (Dej.), Cymindis cribricollis Dej., Pterostichus rostratus (Newm.), Calathus ingratus Dej., and Pterostichus adoxus (Say).