The wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), is historically one of the most important economic insect pests in the northern Great Plains of North America. Within this geographical region, the areas subjected to greatest attack are southern Alberta and Saskatchewan, southwestern Manitoba, eastern and northern Montana, North Dakota, northern South Dakota, and western Minnesota. Cumulative grain-yield losses and annual economic losses associated with this pest can exceed 30% and $350 million, respectively. Solid-stemmed cultivars of common wheat, Triticum aestivum L. (Poaceae), tolerant of infestation, are critical for C. cinctus management, but outbreaks of this pest continue to occur even after six decades of cultivar development. Furthermore, chemical control (a primary control option for other cereal (Poaceae) insect pests) has proven ineffective; this underscores the need to integrate resistant cultivars into a comprehensive integrated pest management program. We provide overviews of wheat stem sawfly biology, recent advances in applied research, the efficacy and integration of cultural and biological management strategies, and future directions for global research activities to manage wheat stem sawfly.

Laboratory experiments were conducted with the millipede Harpaphe haydeniana haydeniana Wood (Polydesmida: Xystodesmidae) to determine (i) its litter feeding preferences, (ii) rates of leaf litter consumption, (iii) feeding effects on available nitrogen, and (iv) functional microbial diversity. The millipede exhibited a preference for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and, to a lesser extent, Sitka spruce (Picea sitchensis (Bong.) Carrière) litter compared with western hemlock (Tsuga heterophylla (Raf.) Sarg.) and western redcedar (Thuja plicata Donn ex D. Don) litter when given a choice. When only one litter type was provided, millipedes consumed considerably more western redcedar than Douglas-fir, Sitka spruce, or western hemlock. Among the six broadleaf species tested, paper birch (Betula papyrifera Marsh.), bigleaf maple (Acer macrophyllum Pursh), vine maple (Acer circinatum Pursh), and red alder (Alnus rubra Bong.) were consumed at much higher rates than swordfern (Polystichum munitum (Kaulf.) Presl.) or salal (Gaultheria shallon Pursh). Daily rates of conifer litter consumption ranged between 10 and 20% of the millipede's fresh biomass and may translate to 36% of the annual litter fall. Our results suggest that transformation of conifer litter into millipede frass can increase rates of litter decomposition and N mineralization, as well as influence microbial activity and diversity in coastal forests.Résumé : Des expériences en laboratoire ont été réalisées avec des millipèdes (Harpaphe haydeniana haydeniana Wood, Polydesmida : Xystodesmidae) en vue de déterminer (i) la litière qu'ils préfèrent comme source de nourriture, (ii) leur taux de consommation de litière de feuilles, (iii) les effets de leur consommation sur l'azote disponible et (iv) la diversité microbienne fonctionnelle. Lorsqu'ils avaient le choix, les millipèdes ont manifesté une préférence pour la litière du douglas de Menzies (Pseudotsuga menziesii (Mirb.) Franco) et, dans une moindre mesure, pour celle de l'épinette de Sitka (Picea sitchensis (Bong.) Carrière), comparativement à la litière de la pruche de l'Ouest (Tsuga heterophylla (Raf.) Sarg.) et du thuya géant (Thuja plicata Donn ex D. Don). Lorsqu'on leur fournissait seulement un type de litière, les millipèdes consommaient beaucoup plus de thuya géant que de douglas de Menzies, d'épinette de Sitka ou de pruche de l'Ouest. Parmi les six espèces feuillues testées, le bouleau blanc (Betula papyrifera Marsh.), l'érable à grandes feuilles (Acer macrophyllum Pursh), l'érable circiné (Acer circinatum Pursh) et l'aulne rouge (Alnus rubra Bong.) étaient consommés à un taux beaucoup plus élevé que le polystic épée (Polystichum munitum (Kaulf.) Presl) ou la gaulthérie salal (Gaultheria shallon Pursh). Les taux journaliers de consommation de litière de conifères se situaient entre 10 et 20% de la biomasse fraîche des millipèdes et pouvaient représenter 36% de la chute annuelle de litière. Les résultats obtenus suggèrent que, dans les forêts côtières, la transformation de la litièr...

We studied the effects of agricultural practice on ground beetles, using pitfall traps in field plots and in an uncultivated meadow near Edmonton, Alberta. Ground beetle abundance and species richness were higher in plots operated under an organic farming regime than in those under a chemical regime, but neither crop type [barley (Hordeum vulgare L.), faba bean (Vicia faba L.), barley-pea (Pisum sativum L.) intercrop] nor crop rotation had an effect. Reduced tillage did not significantly change overall carabid activity or species richness but species differed in their response to tillage treatments. The carabid assemblage from an uncultivated field differed conspicuously from assemblages in the crops and fescue. Carabid abundance was highest in the meadow and the fauna was dominated by the exotic species Pterostichus melanarius Illiger. Effects of agronomic practice on carabid assemblages are complex, reflecting the interaction of biological traits of particular species and the combination of agronomic treatments applied.

The wheat stem sawfly [Cephus cinctus Norton (Hymenoptera: Cephidae)] (WSS) has been a serious pest of wheat (Triticum aestivum L.) since the late 19th century. Adoption of solid‐stemmed cultivars, which are available only in the spring bread wheat class in Canada, can mitigate damage but the trait that confers resistance tends to be variable. Five other classes of wheat are grown within the geographical range of C. cinctus and are vulnerable to WSS infestation, and the entire production area for durum (T. turgidum L.) in western Canada, Montana, and western North Dakota lies within the geographic range of C. cinctus. Our objective was to test the hypothesis that the response of hollow‐ and solid‐stemmed cultivars to sowing density (150, 250, 350, or 450 seeds m−2) would differ and subsequently affect infestation patterns of WSS and an endemic parasitoids. The lowest rates of infestation occurred in the hollow‐stemmed durum cultivar AC Avonlea and declined with increased sowing density. Wheat pith expression was optimized at the lowest sowing density but the same level produced low and variable grain yield. In the solid‐stemmed cultivar Lillian, pith expression was most stable at 250 or 350 seeds m−2. For all cultivars, grain yield was optimized at the higher seeding rates of 350 and 450 seeds m−2. Solid‐stemmed wheat should be seeded at low to moderate density to maximize resistance to WSS, but hollow‐stemmed cultivars should be seeded at higher seeding rates to optimize yield, lower WSS infestation, and to increase overall crop competitiveness.

The pea leaf weevil, Sitona lineatus L. (Coleoptera, Curculionidae), is a significant pest of field pea (Pisum sativum L.) and broad bean (Vicia faba L.) crops throughout Europe, Asia, Africa and North America and it has recently become an established pest in the Canadian prairies. The geographical expansion and current distribution of S. lineatus, its life history, economic impact and control strategies are reviewed. Primary hosts of the pea leaf weevil, on which pre-imaginal development can occur, are identified, in addition to its secondary hosts, which provide nourishment for adults when not in their reproductive phase. The importance of pheromones and host plant volatile compounds for mate finding and host plant location is reviewed. Research on control strategies for S. lineatus is summarized, but to date surprisingly little effort has been expended to develop and implement integrated pest management (IPM) programmes, even though combining insecticide use with host plant resistance, cultural and biological control strategies promises to enhance its management. The development of an effective population monitoring system for pea leaf weevil, scientifically derived economic threshold values, and designing an IPM programme for S. lineatus comprise the most critical research needs for improving the sustainable management of this insect.