A rich fauna of water beetles, comprising 11 families and 485 species, occurs in Canadian peatlands and marshes. These beetles are diverse with respect to morphology, feeding habits, life-history patterns, and even in the degree to which they occur in water. Major adaptations to peatland and marsh habitats are described. Based on species composition, the following regional communities of marsh-inhabiting beetles are recognized: arctic, boreal, Cordilleran, grasslands, and eastern temperate. Peatlands possess a community of beetles similar to that of boreal marshes but contain enough unique elements to warrant separate recognition. However, based on water beetle distribution, it is not possible to subdivide peatlands into bog and fen communities because these habitats have many species in common. Future needs for research on wetland water beetles are identified.

The Sminthuridae, which comprises the largest of the two world-wide families in the suborder Symphypleona, contains 31 genera. Four of these, Collophora, Bothriovulsus, Vesicephalus, and Temeritas are described as new. This study was undertaken mainly to more accurately ascertain relationships within the family. As a result four subfamilies, the Sminthuridinae, the Katianninae, the Dicyrtominae, and the Sminthurinae, are recognized. Of these, the Sminthuridinae seems to have been the first group to become established and the Sminthurinae was relatively the more recent group. The material has been analyzed for indications as to probable age of the units that have been called genera and the place of origin. It seems likely that the generic units existed before the close of the Cretaceous and that the group originated in the north.

Presented, with comments, are 131 plates of illustrations of geometrid eggs representing five subfamilies of the Geometridae: one species of Oenochrominae, 72 species of Ennominae, four species of Geometrinae, nine species of Sterrhinae, and 45 species of Larentiinae. The illustrations are useful as identification aids, in demonstrating relationships between species, and in assessing the validity of species groupings based on taxonomic criteria from other life stages.

Entomopoxviruses (EPVs) are insect poxviruses that are often found infecting grasshoppers and locusts. Nearly 15 grasshopper and locust EPVs have been reported in the literature. This review describes our current knowledge of the biology of grasshopper and locust EPVs including virus ultrastructure, host range, production in cell culture, pathology, process of infection, epizootiology, and field evaluations of the viruses to assess their potential as biological control agents. The most extensively studied has been the Melanoplus sanguinipes EPV (MsEPV). Trypsin-like protease activity has been identified in association with MsEPV occlusion bodies but its importance in the infection process is not known. Mortality from MsEPV has been found to occur in two distinct time frames over 6 weeks or longer. MsEPV is also the only grasshopper EPV that has been grown in vitro and been shown to produce virus that is both infectious and virulent to M. sanguinipes. Horizontal transmission of grasshopper EPVs is apparently by consumption of infected cadavers. Field evaluations of MsEPV at an application rate of 1 × 1010 occlusion bodies per hectare resulted in a 23% prevalence after 13 days despite a considerable amount of dispersal of grasshoppers between plots. Epizootiological studies of EPVs will continue to be an area requiring additional research. Virus production and a limited host range are the two most critical issues affecting the development of EPVs as microbial control agents.

A total of 181 isolates of Metarhizium anisopliae (Metschnikoff) Sorokin, M. flavoviride Gams and Rozsypal, Beauveria bassiana (Balsamo) Vuillemin, and Sorosporella sp. was found in a survey of Orthoptera in West Africa, Madagascar, Oman, and Pakistan between 1990 and 1993. Prior to this survey, there were only 28 isolates of hyphomycete fungi from Orthoptera held in international culture collections. Seventeen of the recently acquired Metarhizium isolates have been determined to be highly virulent during screening tests as part of a research programme for the development of a microbial insecticide against locusts and grasshoppers in Africa. Ninety-five isolates came from Benin which was the country where survey activities were most concentrated, and 63 of these isolates were found in Malanville, northern Benin, between 1991 and 1992 during an epizootic of M. flavoviride. Recordings from Oman and Pakistan represent the first specimens from these countries to be deposited in international culture collections. No deductions can be made on the best method for survey; both incubation of live grasshoppers and field searches for cadavers yielded results. Soil baiting with Orthoptera was used with some success. Limited soil screening using selective agar media was not found to be particularly useful.

Peatlands were studied in temperate, boreal, subarctic, and arctic wetland regions of Quebec, mainly using pitfall traps. Altogether, 169 species of spiders, belonging to 14 families, were collected; 73 species were found only in the temperate-boreal region, 58 only in the subarctic-arctic region, and 38 in both regions. The most species-rich spider families were Linyphiidae (58.3% of all species), Lycosidae (12.4%), and Gnaphosidae (7.1%). Families occurring only, or mainly, in the temperate (and boreal) region were Hahniidae, Dictynidae, Salticidae, Liocranidae, and Theridiidae. Linyphiidae, especially Erigoninae, were typical of the subarctic region. Alopecosa aculeata (Clerck) and Pardosa hyperborea (Thorell) (Lycosidae), Theonoe stridula Crosby (Theridiidae), and Ceratinella brunnea Emerton (Linyphiidae) were found in six of the seven study areas. Seven of the eight opilionid species were found in the temperate region, but Mitopus morio (Fabricius) occurred only in the subarctic bogs. The only pseudoscorpion, Microbisium brunneum (Hagen), was caught in the temperate, boreal, and subarctic regions. The percentage of spiders collected in bogs of both Quebec and southern Ontario was 64% in the temperate region and only 27% in the subarctic region. Almost 50% of species from bogs in the Manitoba taiga were found also in Quebec. About a third of the Quebec bog spiders are Holarctic.

Thirteen families containing 138 species of aquatic and semiaquatic Hemiptera have so far been recorded from Canada. The identification of these presents few real difficulties and so the general occurrence of the taxa across the country is fairly well known. Although there has been no intensive study of the Hemipterous insects in peatlands and marshes, the 61 species so far reported from marshes, 32 from fens, and the 33 from bogs appear to be facultative rather than obligatory inhabitants of these habitats. All have been found in other habitats and probably most lentic species occur in marsh habitats. All aquatic and semiaquatic bugs are predators, and most overwinter as adults. Environmental–physiological study of species occurring in bogs has just begun, but evidence suggests that many species have the ability to regulate their internal milieu in water with pH below 4.6–4.7. However, further experiments are needed to determine the physiological limits of tolerance of these insects, the details of osmotic and ionic regulation, and acid–base balance in low-pH water. More collecting is needed in bogs, fens, and marshes, and the life cycle and biology of the Hemiptera occurring in peat-lands still require intensive study.

The world species of Limotettix Sahlberg are reviewed, and 13 new Nearctic species are described: in the typical subgenus — L. conservatus; in the new subgenus Dryola — L. elegans, L. minuendus; in subgenus Neodrylix — L. urnura; in subgenus Ophiolix — L. nigristriatus, L. pseudosphagneticus, L. xanthus; and in subgenus Scleroracus — L. brooksi, L. medleri, L. obesura, L. scudderi, L. strictus, and L. zacki. Limotettix (L.) emeljanovi is proposed to replace L. luteolus Emel'janov, 1962, nec L. (Scleroracus) luteolus (Sleesman, 1930). The 80 known world species are arranged phylogenetically. From this analysis the genus evidently evolved in the New World from swale and fen inhabiting ancestors that fed on spike-rush. Their bog-inhabiting descendents fed on various rushes and sedges, but apomorphic lineages transferred to ericaceous plants. Adaptation to ericaceous plants permitted invasion of drier habitats, with subsequent radiation on other semiwoody plants, principally Asteraceae and Symphoricarpos.

The ability of the egg parasitoid, Trichogramma minutum Riley, to suppress outbreak populations of the spruce budworm, Choristoneura fumiferana (Clemens), was studied annually near Hearst, Ont., from 1982 through 1986. Timing of broadcast parasitoid-releases was linked to spruce budworm moth emergence and oviposition. These phenological relationships were predicted from a regression based on larval development at least 2 weeks before expected emergence; this allowed sufficient time to regulate (program) parasitoid emergence during mass-rearing. Emergence of caged spruce budworm adults was used to monitor moth eclosion in the field. Pheromone traps provided daily information on the activity of male moths and helped to synchronize the parasitoid releases with spruce budworm oviposition. Information on parasitoid activity was obtained from sentinel (laboratory-reared) and naturally occurring spruce budworm egg masses. A curvilinear relationship between the rate of parasitoid release and parasitism of sentinel egg masses was developed. Two parasitoid releases, 1 week apart, early in the oviposition period of spruce budworm, significantly increased parasitism of host eggs by 14–83% and reduced larval populations correspondingly from 42 to 82%. Single releases were less effective and increased parasitism by 0.3–52% (single ground release, 1986). Two parasitoid releases, combined with a spring application of Bacillus thuringiensis Berliner to larval populations, was the most effective strategy and resulted in 83% egg parasitism and 93% larval reduction. Release rates greater than 12–16 × 106 ♀ ♀ T. minutum per hectare were not warranted based on impact and costs. The effects of release timing, weather, host density, and parasitoid quality on the future successful use of T. minutum are discussed.

Relative abundance of Nicrophorus species sampled with pitfall traps varies between habitats and seasons in the Mer Bleue bog area near Ottawa, Canada. Baited pitfall trapping is useful in studying habitat associations but does not accurately sample reproductively active species. Nicrophorus sayi Laporte is a spring breeding species associated with stands of mature forest. Nicrophorus orbicollis Say and N. tomentosus Weber were taken at baited pitfall traps in all habitats. Nicrophorus defodiens Mannerheim and N. vespilloides Herbst were found primarily in forest and bog habitats, respectively, and did not reproduce outside of these habitats.

This paper includes illustrations, descriptions, and keys to the following eight genera and 42 species: Atheroides serrulatus Haliday, Caricosipha paniculatae BÖrner, Chaetosiphella berlesei (del Guercio), Chaitophorus abditus (Hottes), Chaitophorus albicentrus new species, Chaitophorus canens Richards, Chaitophorus crucis (Essig), Chaitophorus delicatus Patch, Chaitophorus longipes Tissot, Chaitophorus knowltoni Hille Ris Lambers, Chaitophorus macgillivrayae new species, Chaitophorus macrostachyae (Essig), Chaitophorus minutus (Tissot), Chaitophorus monelli (Essig), Chaitophorus neglectus Hottes and Frison, Chaitophorus nigrae Oestlund, Chaitophorus nigricentrus new species, Chaitophorus nodulosus Richards, Chaitophorus nudus Richards, Chaitophorus pallipes new species, Chaitophorus populialbae (Boyer de Fonscolombe), Chaitophorus populicola Thomas, Chaitophorus populifolii (Essig), Chaitophorus pusillus Hottes and Frison, Chaitophorus pustulatus Hille Ris Lambers, Chaitophorus saliciniger (Knowlton), Chaitophorus versicolor (Koch), Chaitophorus viminalis Monell, Chaitophorus viminicola Hille Ris Lambers, Laingia psammae Theobald, Periphyllus americanus (Baker), Periphyllus brevispinosus Gillette and Palmer, Periphyllus californiensis (Shinji), Periphyllus lyropictus (Kessler), Periphyllus negundinis (Thomas), Periphyllus testudinacea (Fernie), Pseudopterocomma canadensis Richards, Pseudopterocomma hughi (MacGillivray), Sipha agropyrensis (Gillette), Sipha flava (Forbes), Sipha glyceriae (Kaltenbach), Sipha kurdjumovi Mordwilko. A host index has been compiled from the material studied and the literature cited.

Since the first observation that plants contained protease inhibitors, as identified by their ability to inhibit vertebrate enzymes, it has been postulated that the presence of these substances was related to their phytoprotective abilities. However the following assumptions (1) that phytophagous insects use trypsin, and (2) that ingested inhibitors disrupt digestive proteolysis in insects, have not been adequately tested. Identification of non-tryptic enzymes, cathepsin B, D, and H in phytophagous Coleoptera and unique trypsin-like enzymes in Lepidoptera, indicates insect proteases may differ from their vertebrate counterparts. Putative inhibitor proteins inhibited vertebrate trypsin and chymotrypsin in vitro but had no effect on the trypsin- or chymotrypsin-like activity from the insect midgut. Feeding experiments with the European corn borer, Ostrinia nubilalis (Hübner), indicate that ingestion of inhibitors may not disrupt digestive proteolysis in vivo and the vertebrate trypsin inhibitor in corn may be ineffective as a phytoprotective strategy for this insect. Limitations and implications of ingested inhibitors for future pest control may depend on the origin of the inhibitor, as well as the insect's response.

Bacteria have been implicated in disease epizootics observed in field populations and laboratory-reared locusts and grasshoppers. Two species [Serratia marcescens Bizio and Pseudomonas aeruginosa (Schroeter) Migula] consistently infect locusts when ingested with food and can spread in laboratory populations. However, research on developing these organisms for microbial control of locusts and grasshoppers begun in the 1950s has not been continued. In recent years strains of Bacillus thuringiensis Berliner have been studied for activity against locusts and grasshoppers. Results of additional trials by the authors are reported. Among 393 B. thuringiensis isolates and 93 preparations of other sporeforming bacteria fed to nymphs of Locusta migratoria (L.) and/or Schistocerca gregaria Forsk., none has shown any pathogenicity to the insects. The recent discovery of novel B. thuringiensis strains active against various diverse pests and the many properties of a sporeforming bacterium that satisfy the requirements for a microbial control agent, and the development of Serratia entomophila as a promising agent for control of grass grubs, provide incentive to continue the search for an orthopteran-active sporeforming bacterium and to re-investigate the potential of non-sporeforming bacterial pathogens as microbial control agents of grasshoppers and locusts.

This memoir is the fourth of a series dealing with the fauna of the Trichoptera of Canada and the adjacent States. It deals with the families Hyalopsychidae, Psychomyiidae, Goeridae, Brachycentridae, Sericostomatidae, Helicopsychidae, Beraeidae, Odontoceridae, Calamoceratidae and Molannidae. These families have been arbitrarily gathered here because of their small size and in spite of the fact that they are not all taxonomically related. In the following pages, one will find familial, subfamilial, generic and specific diagnosis of all the taxa constituting these families. Dichotomic keys are included and distributional records for each species are mapped. Ecological characters are given when possible.