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Alaska Wild Rhubarb (Koenigia alaskana var. glabrescens; Polygonaceae) is a native Arctic, subarctic, and alpine plant of northwestern North America. Although the plant has some economic and ecological importance, its biology is poorly known. At 11 sites in the northeast corner of its range in Northwest Territories, we found that 87% of its floral visitors were flies, mostly Syrphidae, a diverse family known to be important pollinators. Insects visiting consecutive flowers on different plants and, thus, likely effecting pollination were also flies (78.6%) and also mostly Syrphidae (72.7%) followed by Hymenoptera (20%). Although syrphids were the dominant potential pollinators at most sites, there was some variation among sites. Our results provide quantitative support for pollinator diversity and the major role of Syrphidae in pollination of Alaska Wild Rhubarb. We suggest that pollination is not a limiting factor in this plant's spread, nor its rare and local occurrence and restricted distribution, because the majority of its pollinators are widespread. [ABSTRACT FROM AUTHOR]

Azalea Sawfly (Euura lipovskyi) larvae found feeding on foliage and flowers of cultivated Flame Azalea (Rhododendron calendulaceum) in Ottawa, Ontario, in late May 2021 are the first records of this sawfly in Canada. The native range of Azalea Sawfly includes the eastern United States, but the species has extended its distribution recently to the Pacific northwest of North America and Europe. Recorded foodplants include Rhododendron calendulaceum, Rhododendron luteum, Rhododendron obtrusum, Rhododendron occidentale, Rhododendron molle, Rhododendron viscosum, and possibly Early Azalea (Rhododendron prinophyllum), all in Rhododendron section Pentanthera. The new combinations Euura lipovskyi and Euura azaleae are proposed. [ABSTRACT FROM AUTHOR]

Disjunctions are reported for Needle-leaved Sedge (Carex duriuscula) and Thread-leaved Sedge (Carex filifolia) into the Arctic region of Northwest Territories at the Husky Lakes south of Tuktoyaktuk. These are significant additions to the Canadian Arctic flora and may be part of a group of relicts of the Arctic vegetation of the Pleistocene, specifically the Tundrasteppe. The occurrence of relict vegetation east of the Mackenzie Delta is east of its frequently cited eastern limit in North America. [ABSTRACT FROM AUTHOR]

We provide information on two additions to the fauna of Northwest Territories, Canada: Two-striped Grasshopper (Melanoplus bivittatus) and Huron Short-winged Locust (Melanoplus huroni). We suspect that both are long established but were overlooked in the past as a consequence of general rarity. [ABSTRACT FROM AUTHOR]

The introduced Wormslug (Boettgerilla pallens Simroth, 1912) is reported from Quebec, Canada, for the first time, from two closely situated localities in Gatineau Park. It was previously reported from the Vancouver area of British Columbia and, very recently, from Newfoundland. Within the Americas, the species has been reported from northern California, Mexico, and Colombia, and, because it is easily overlooked, likely occurs elsewhere in North America, especially in the eastern United States. In Quebec, it was found in a natural Sugar Maple (Acer saccharum Marshall) woodland and an ornamental garden. Wormslug likely reached both sites with shrub plantings from commercial nurseries, probably quite recently, because the invasive spread of the species, worldwide, has occurred mostly during the last few decades. Although the woodland where it occurred is dominated by native plants, the gastropod fauna there is mainly introduced. Identification, characteristics, and ecology of Wormslug are discussed. The potential for impact on native soil and soil surface organisms, including native terrestrial slugs and snails, is noted. [ABSTRACT FROM AUTHOR]

A Red Pine (Pinus resinosa Aiton) plantation and adjacent Northern Red Oak (Quercus rubra L.) - Large-toothed Aspen (Populus grandidentata Michx.) woods, both of which developed from a savannah scrub beginning approximately 60 years ago, were compared with regard to terrestrial snail diversity and abundance. The comparison involved a 30-minute search of ten 1-m2 quadrats at ten sites in each habitat. In the Northern Red Oak - Large-toothed Aspen woodland, 13 species and 661 individuals were recorded, whereas, in the Red Pine plantation, six species and 24 individuals were recorded. In the Northern Red Oak - Large-toothed Aspen woodland, the most characteristic and abundant species was Novisuccinea ovalis (Say, 1817), which was present in 74 of the 100 quadrats and was represented by 460 individuals. In the pine plantation, the most common species was Zonitoides arboreus (Say, 1816), which was present in 16 quadrats and was represented by 17 individuals. This species was the second most common in the Northern Red Oak - Large-toothed Aspen woodland where 70 individuals were found in 34 quadrats. In both habitats, Z. arboreus was associated with downed wood. Other species occurring in more than 15% of quadrats in the NorthernRedOak-Large-toothed Aspen woodland were Strobilops labyrinthicus (Say, 1817), Glyphyalinia indentata (Say, 1823), and Euche motrema fraternum (Say, 1824). Although a lower number and diversity of terrestrial snails in the conifer plantation was expected, the contrast was greater than anticipated. The estimated abundance of 46 000 N. ovalis per hectare suggests the potential importance of these medium-sized snails in the relatively dry Northern Red Oak - Large-toothed Aspen ecosystem. [ABSTRACT FROM AUTHOR]

The article presents information related Alvar plant communities.

It has been suggested that European Skipper butterflies (Thymelicus lineola) trapped in the lips of the Showy Lady's-slipper orchid (Cypripedium reginae) may interfere with pollination. This could occur through blockage of the pollinator pathway, facilitation of pollinator escape without pollination, and/or disturbance of the normal pollinators. A large population of the orchid at an Ottawa Valley site provided an opportunity to test the interference hypothesis. The number of trapped skippers was compared in 475 post-blooming flowers with regard to capsule development and thus seed development. The presence of any skippers within flowers was associated with reduced capsule development (P = 0.0075), and the probability of capsule development was found to decrease with increasing numbers of skippers (P = 0.0271). The extent of a negative effect will depend on the abundance of the butterflies and the coincidence of flowering time and other factors. Counts of skippers trapped in flowers were found to follow closely a negative binomial distribution (P = 0.8656). [ABSTRACT FROM AUTHOR]

Climate warming is accepted as an explanation for the recent appearance of Blue Dasher, Pachydiplax longipennis (Burmeister, 1839), and Eastern Amberwing, Perithemis tenera (Say, 1839), in the Ottawa region, as this range expansion meets 6 criteria; (1) the climate in the newly occupied territory has warmed sufficiently to allow colonization; (2) a new range expectation based on the amount of climate wanning is met; (3) other factors potentially promoting spread are excluded; (4) the possibility that range extension is a result of difficulty of observation and/or insufficient fieldwork in earlier times is excluded; (5) there is ample evidence for establishment; and (6) spread has been in the direction of the wanner territory or within it. By 2000, the mean daily temperature in the Ottawa region had increased by about 2°C since 1880 and about 1.1 °C since 1960. This would allow new zonal boundaries and the prediction of expansion from a well-defined and long-occupied area into the Ottawa Valley. The two species entered this region in 2008-2012 and, subsequently, became well established. [ABSTRACT FROM AUTHOR]

The pollinator-non-rewarding Large Yellow Lady's-slipper (Cypripedium parviflorum var. pubescens [Willdenow] Knight) and the rewarding Balsam Ragwort (Packera paupercula [Michaux] A. Löve & D. Love) exist together in some eastern Ontario alvars where they share a group of medium-sized, dark blue metallic pollinators in the bee genus Osmia (Mason Bees, Megachilidae). I provide evidence of floral mimicry of the ragwort by the orchid based on several observations: (1) Osmia visiting P. paupercula also visit C. parviflorum var. pubescens; (2) Osmia are more frequent visitors to P. paupercula than to other coblooming plants; (3) Osmia are the primary pollinators of C. parviflorum var. pubescens; (4) the behaviour of Osmia on the flower of C. parviflorum var. pubescens involving landing on the staminode suggests mimicry; and (5) the largest populations of C. parviflorum var. pubescens in Ontario are in alvar landscapes where P. paupercula is abundant. Pollination in Large Yellow Lady's-slipper may vary geographically from non-model to species-specific Batesian mimicry, which is rare in orchids. This latter pollination mechanism may have evolved in ice-front environments during the Pleistocene, but then became isolated to unusual partial analogues of ice-front habitat during the Holocene with pollination in most of the current range appearing to be a generalist strategy. [ABSTRACT FROM AUTHOR]

Vascular plant biodiversity was evaluated in two adjacent sections of a continuous prairie glade. One section has been subject to moderate grazing by feral horses (Equus ferus caballus) in late summer and fall for the past 25 years, while the other has been protected. From 28 June to 2 July 2009, we recorded cover for all vascular plants present in ten 1-m² quadrats along five transects in each section. We calculated biodiversity measures, including species richness, evenness, and Shannon- Wiener and Simpson's diversity indexes. Horse grazing did not affect richness but significantly increased evenness. Grazing increased the Shannon-Wiener index, but did not affect the Simpson's index. Cover and frequency values for most species differed significantly between the two sites. Mountain Rough Fescue (Festuca campestris Rydberg) dominated the nongrazed site but several shorter grasses and different forbs dominated the grazed site. The plant community in the grazed areas can be seen as an earlier serai stage of the fescue community with a different contingent of plant species. Light grazing in part of the prairie glade increased overall plant diversity so that it provided more diverse animal habitat. [ABSTRACT FROM AUTHOR]