Caddisfly collections from 25 springs across Canada reveal some general trends and some regional and habitat-related differences in spring faunas. In general the number of caddisfly species present in springs increases with habitat diversity. Limnocrenes and rheocrenes with low current and small-sized substrate particles support few caddisfly species, but may have large populations of individual species. Species categorized as grazers, shredders, and predators are common in springs, but filter-feeders are rare.Eastern and western springs have many genera but few species in common. About 35% of the species recorded in this study are from the family Limnephilidae, but the most frequently encountered genus was Parapsyche (Hydropsychidae), usually P. apicalis (Banks) in the east and P. elsis Milne in the west (British Columbia and Alberta). Other common genera in both east and west were Neophylax, Lepidostoma, and Rhyacophila. Common genera collected only in the west were Anagapetus, Homophylax, Psychoglypha, and Neothremma, and Frenesia and Pseudostenophylax were taken only in the east. Three analytical techniques — ordination by detrended correspondence analysis, constrained ordination by canonical correspondence analysis, and classification by two-way indicator species analysis — all confirmed an east/west geographical difference in caddisfly communities and pointed to elevation, extent of groundwater source, and summer temperature as environmental factors influencing, but not totally responsible for, east/west species distributions. Past and present barriers to migration both appear to be important. Riparian vegetation, current, substrate particle size, microhabitat diversity, and pH all have strong influences upon the composition of spring communities in both the east and the west. Springs in which caddisflies were primarily associated with detrital processing were dominated by Frenesia and Lepidostoma in the east but by Homophylax in the west. Scrapers and predators were abundant only in springs with relatively high microhabitat diversity, current speed, and PH.

The Neopsini encompasses two genera, both exclusively Neotropical: Neopsis Oman (5 species) and Nollia n. gen. (2 species). Neopsis amazonica n. sp., Neopsis tumidifrons n. sp., Neopsis magna n. sp. (Brazil), and Nollia rustica n. sp. (Chile) are described, and the genera and species of the Neopsini are keyed.The New-World Macropsini encompasses five genera: Pediopsis Burmeister (1 species), Pediopsoides Matsumura (2 species), Reticopsis Hamilton (2 species), Macropsis Lewis (55 species), and Oncopsis Burmeister (36 species). Biological and morphological data are used to define the species in this taxonomically difficult tribe, with the result that 45 new species are described: Macropsis acapulco, M. dimorpha, M. igniscutellata, M. mexicana, M. oncopsimilis, and M. zebra from Mexico; Macropsis aureocephala, M. californiensis, M. ferrax, M. inversalis, M. palustris, M. pulchra, Oncopsis arizona, O. aureostria, and Reticopsis udrobates from southern California and Arizona; Oncopsis insignifica, O. mica, and O. tangenta from Utah; Macropsis borealis, M. rufescens, Oncopsis albicollis, O. incidens, O. interior, O. juno, O. marilynae, O. monticola, and O. tenuifoliae from northwestern North America; Macropsis dixiensis and O. infumata from southeastern North America; Macropsis decisa, M. jocosa, M. microceps, M. tunicata, M. xena, Oncopsis citrella, O. concurrens, O. dentata, O. deluda, O. prolixa, O. quebecensis, and O. vartyi from northeastern North America; and Macropsis deviridis, Oncopsis citra, O. crispae, and O. prairiana from Canada. Five new subspecies are described: O. cinctifrons kootenensis, O. prairiana ferrosus, and O. prairiana occidentalis, all from southern British Columbia; Oncopsis nigrinasi florida from Florida; and Macropsis deviridis alberta from western Canada. Five new synonymies are created. Keys to all taxa, host associations, and distribution maps are provided and the colour phases of the various polymorphic species are analyzed.The morphology and significance of intersex individuals of Oncopsis spp. are discussed.

Entomophaga grylli (Fresenius) Batko (North American pathotype 1) is a fungal pathogen of the clearwinged grasshopper, Camnula pellucida (Scudder). We present results from a field experiment conducted in Arizona in 1984, designed to investigate factors associated with seasonal patterns of cadaver persistence and sporulation by E. grylli. Rangeland plots at two sites were monitored daily for 8 weeks for the appearance of new cadavers of diseased grasshoppers during a natural epizootic. Cadavers were individually marked and revisited on subsequent days, when it was noted whether or not conidial sporulation was underway. Environmental variables were recorded by electronic data loggers. Daily probabilities of cadaver disappearance and fungal sporulation were analysed in relation to site, date, and various measures of cadaver status, sporulation history, and environmental variables by logistic regression analysis. The average daily rate of cadaver disappearance was 0.22, yielding an expected time to 50% disappearance of 2.8 days. The environmental factor most significantly associated with cadaver disappearance was rainfall, and the most important host factor was age of the cadaver. The probability that conidia would be discharged from a cadaver over the next 24 h was most dependent on whether or not conidial sporulation was underway already. This probably reflects a state of readiness for sporulation on the part of the fungus. Although the probability of sporulation declined with increasing age of a cadaver, high rates of sporulation were predicted under conditions of prolonged leaf wetness and high humidity at night, regardless of age of the cadaver. These results, together with the observation that in some cadavers sequences of sporulation were interspersed with periods of no sporulation, suggest that E. grylli may undergo cycles of dehydration and rehydration, in which conidial production is interrupted and then resumes in response to changing environmental conditions.

Three populations of the pea aphid, Acyrthosiphon pisum (Harris), from locations between 27 and 36°S in eastern Australia were studied at five constant temperatures from 10 to 28 °C. A three-parameter, nonlinear equation accurately described developmental rate as a function of temperature for each of the five lines from each population. Maximum adult weight was attained at 20 °C. Wingless aphids developed faster and were heavier than winged aphids. There were no significant differences in developmental times among populations, and adult weights among populations differed only at 25 °C. These weight differences and other nonsignificant differences among populations showed no trends with the long-term average temperatures at the collection sites. This finding indicates that developmental rate and adult weight have not been adapted to temperature in the 5 years since the aphids were introduced. The maximum rate of development, optimum temperature for rapid development, developmental threshold, and optimum temperature for high adult weight were higher for the Australian populations than for North American populations, but these differences do not reflect adaptation to different environmental temperatures. We conclude that Australian populations of A. pisum did not originate in North America.

The 33 species of Prosimulium Roubaud known from Canada and Alaska are reviewed. These are segregated into four subgenera: Distosimulium new subgenus, containing one species; Parahelodon new subgenus, containing three species; Helodon Enderlein, containing seven species of which clavatum, martini, and susanae are new, and one (known only from the larva) remains undescribed; Prosimulium s. str., containing 25 species of which approximatum, constrictistylum, impostor, mysticium, neomacropyga, and woodorum are new. Species of the last subgenus are segregated into three species groups. A lectotype is designated for P. ursinum (Edwards). Descriptions, distribution maps, keys, and 158 illustrations for the identification of the known adults, pupae, and larvae are provided.

The habitat preferences of each of the 663 species of aquatic Coleoptera known from Canada and Alaska were categorized as lentic, lotic, spring-inhabiting, other, or unknown. Most species were assigned to a single habitat type although some occur in more than one habitat. The distribution of species among these habitat types is as follows: lentic, 61%; lotic, 23%; springs, 8%; other, <1%, unknown, 8%. The 63 spring-inhabiting species are distributed among the families Dytiscidae (38 species), Hydrophilidae (nine), Hydraenidae (eight), Chrysomelidae (subfamily Donaciinae) (six), Haliplidae (one), and Dryopidae (one). The diversity of these families in springs only approximately parallels their diversity in the total fauna. Several relatively diverse families (Gyrinidae, Scirtidae, and Curculionidae) are absent from springs as are some predominantly lotic families (Amphizoidae, Elmidae, and Psephenidae). About half the spring species are western (occurring in Manitoba and west), about a quarter are eastern, and a quarter are transcontinental. Most of these spring species are known from the conterminous United States and it is suggested that spring habitats within Canada are being colonized slowly from southern refugia.The habitat affinities of spring-inhabiting Dytiscidae are examined in detail. Of the 260 species occurring in Canada, 38 species occur in springs and represent about 60% of all beetle species in Canadian springs. The spring fauna of dytiscids comprises four elements: nine (24%) inhabit springs only, 11 (29%) are lotic species that also occur in springs, 12 (31%) are species that use a broad range of habitats, and six (16%) are species known otherwise only from lentic habitats. The dytiscid fauna of springs is a heterogeneous assemblage derived from many separate phylogenetic elements.

The insect fauna of the Pacific Northwest Coast is diverse and rich in endemic forms. Nine different elements are recognized in the fauna, including (1) restricted coastal, (2) coast-centred, (3) Great Basin, (4) Rocky Mountain, (5) trans-American, (6) Holarctic, (7) trans-Beringian, (8) Alaskan, and (9) introduced elements. Elements (6), (7), and (8) are generally restricted to the northwestern portion of the coast; and representation of Rocky Mountain elements (4) increases in three major steps from south to north along the coast—at the Puget Lowland/Fraser River valley, the Prince Rupert area, and the Kenai Peninsula, respectively. Patterns of vicariance among sister taxa in the carabid beetle genus Nebria demonstrate relationships which, together with analyses of other faunal elements, show that the fauna of glaciated portions of the Coastal region has greatest affinity with faunas of southern coastal areas, less affinity with those of southern interior areas, and least affinity with faunas of northern areas. Areas of local endemism within the region include the Aleutian Archipelago, the southeastern Alaskan Panhandle, the Queen Charlotte Archipelago, the Olympic Peninsula/Vancouver Island, the northern Cascade Range, the Klamath Mountains system, and the Sierra Nevada. The extant coastal insect fauna has evolved from a widespread northern Tertiary fauna, elements of which were isolated in several separate refugia during Pleistocene glaciations. The northern two-thirds of the region has been recolonized in postglacial time from both coastal and interior refugia south of the Cordilleran and Laurentide ice sheets. Local endemism in the region reflects survival and differentiation of a few forms in small coastal refugia; but survivors from these refugia, as well as those from the Yukon/Beringian refugium, have generally been unable to extend their ranges to other parts of the Coastal region following deglaciation.

Characteristics of the cocoons, cephalic structures, spiracles, and skins of 97 species and 19 genera of the tribe Campoplegini (Hymenoptera: Ichneumonidae: Campopleginae) are described and illustrated and keys are given for identification of the genera and species. An additional five species and two genera that were described and illustrated in earlier papers (Finlayson 1967, 1969) are included in the keys, for a total of 102 species and 21 genera. Characteristics of final-instar larvae were found that support most of the generic entities defined on the basis of adult characteristics, and new relationships were revealed that may assist with taxonomic problems in the group.

Saskatchewan had periodic outbreaks of grasshoppers long before the arrival of settlers. With the advent of agriculture these insects threatened the production of cereal and forage crops and necessitated the implementation of extensive control procedures. The effectiveness of control could be enhanced if farmers and government agencies were alerted and informed of the probable intensity and area of outbreak in the coming year. This lead to the initiation of forecasting the expected outbreaks, first, by questioning local persons as to the density, egg laying activities, and damage caused by local grasshopper populations and, secondly, by the inauguration of a special survey system of assessing abundance. Current populations of grasshopper adults or eggs were counted in all arable land areas of the province and rated in four categories of potential outbreak or hazard. The mapping of such ratings in their respective locations resulted in the production of a forecast map which indicated areas of probable light, moderate, severe, or very severe outbreak the following year. In Saskatchewan such maps have been produced annually since 1931 and are reproduced here. They represent the changing scene of grasshopper abundance in the past 36 years and have been accepted by agriculturists as a standard reference to be considered for sound agricultural production in the province.

Presented here, with notes, are 55 plates of illustrations: 48 are larval sketches representing 48 species in 18 families of Microlepidoptera; the remaining seven are scanning electron micrographs of larvae of three of the families, Lyonetiidae, Bucculatrigidae, and Stigmellidae. The illustrations suggest interesting affinities in some instances, are useful as identification aids, and show structural details not hitherto observed or recognized as important taxonomically.

The peatlands of the northern Cordillera of North America (consisting of the mountain ranges and intermontane lowlands and plateaus of British Columbia, Alberta, the Northwest Territories, the Yukon, and Alaska) support a distinctive Odonata fauna. Forty species in six families and 12 genera are typical of northwestern peatlands and another 12 species are occasional inhabitants of these environments. Of the 40 species, eight (20%) are peatland obligates and four (10%) almost always occur in such habitats. The remaining 28 (70%) are generalists and live in a wide range of aquatic habitats; nevertheless, they often are common inhabitants of, or are even dominant in, peatland environments. The fauna is dominated by the genera Aeshna Fabricius and Somatochlora Selys, with 11 and 10 species, respectively. It is also dominated by species restricted to Boreal regions (25 species, 62.5%), six (15%) of which have Holarctic distributions. The remainder of the fauna consists of eight species (20%) ranging transcontinentally in Transition Zone forests south of the Boreal Forest, five (12.5%) restricted to the Cordillera, and two (5%) with wide distributions in North America. Notes and maps summarize our knowledge of biogeographical information and previously unpublished records are listed. Significant southerly range extensions for species such as Coenagrion interrogatum (Hagen), Aeshna septentrionalis Burmeister, A. sitchensis Hagen, A. subarctica Walker, Somatochlora septentrionalis (Hagen), and Leucorrhinia patricia Walker are reported. Ecological and natural history data are outlined for each species. There do not appear to be any clear differences between the faunas of bogs and fens; dragonflies seem to respond to the habitat's form and structure rather than to its acidity or nutrient levels. Distinctive species associations result. A better understanding of the preferences of these dragonflies for different peatland microhabitats must await detailed research on oviposition behaviour and larval ecology.

Gastropods commonly show enormous variation in growth rate, even among identically reared siblings. This was investigated using a small isolated population of Deroceras laeve (Müller) — a species with low genetic variability. A high degree of variation in growth rate was evident, even among offspring from unmated mothers. This confirmed our hypothesis that this variation does not require high genetic polymorphism. Four additional hypotheses concerning the causal mechanism(s) for this variation were investigated: (1) Maternal influence through variation of egg quality was rejected as a possible cause for the variation since animals from mothers raised on either high- or low-quality diets did not differ significantly in growth or maturation rates (when egg size was controlled). (2) The possibility that animals might have their growth trajectory fixed by early nutritional experience was tested by initially rearing slugs on either high- or low-quality diets, and then reversing their food. Such "nutritional imprinting" was not supported. (3) Intraspecific interaction among individuals was not supported as a cause of variation either since stunted slugs did not show improved growth when isolated from conspecifics, and there was equal variation among individuals reared from the egg in isolation. (4) Variation in the egg size was the only characteristic investigated that significantly changed rates of juvenile growth and the timing of maturation. Larger eggs produced slower-growing slugs that matured later, and egg size seemed to account for the full range of observed variation. The ultimate function of the mechanism remains to be determined, but possibilities include adjusting the performance of offspring to resource supply, ensuring availability of mature individuals to breed during favourable microclimates, reducing competition among members of a cohort, or ensuring sexual heterogeneity for hermaphroditic breeding.

In North America the genus Cephalcia Panzer includes 10 species. The californica group, californica Middlekauff, frontalis (Westwood), fulviceps (Rohwer), and probably hopkinsi (Rohwer), has large species with gregarious larvae which build frass nests on Pinus. The provancheri group, distincta (MacGillivray), provancheri (Huard), semidea (Cresson), and probably nigra Middlekauff, has smaller species with solitary larvae that build silk-tube shelters on Picea, Abies, or Tsuga. Two species fit in neither group: fascipennis (Cresson), a large species with weakly gregarious larvae that build frass nests on Picea, and marginata Middlekauff, a small species quite unlike those of the californica group, with gregarious larvae that build frass nests on Pinus. Californica and hopkinsi are western species, provancheri and fascipennis are transcontinental, and the others are eastern. Keys are given for larvae and adults.The immature forms are described; the larva of fascipennis in detail. Females have one more instar than males.The eggs of all species are laid on needles of the host tree with a small knob-like part inserted into the host tissue. The larvae, which eat previous years' foliage, develop rapidly and drop to the ground when through feeding. Larvae do not construct cocoons but overwinter in a cell formed in the soil. Pupation and emergence may occur the next spring, or after two or more winters in the soil.Sex is determined by whether or not the egg is fertilized, thus parthenogenesis is facultative and arrhenotokous. An exception is semidea, having thelyotokous parthenogenesis and no known males.

The genera Haida Keen and Pseudohaida Hatch are revised and transferred from the tribe Coryphiini to the Anthophagini; the Palearctic genus Eudectus Redten bacher is also placed in the Anthophagini. Eudectus crassicornis LeConte is transferred to the new gents Eudectoides. Two new species are described, Haida bisulcata from the Sierra Nevada in California and H. insulcata from Oregon. Pseudohaida ingrata Hatch is transferred to Subhaida Hatch, a member of the tribe Coryphiini.

The mouthparts and antenna are illustrated for each genus and the male aedeagus for each species. A key is included to aid in the identification of all the included taxa.