Life history of the northern mayfly Baetis bundyae in Rankin Inlet, Nunavut, Canada, with updates to the list of mayflies of Nunavut

Abstract

Mayflies (Ephemeroptera) were collected from 35 sites (streams and tundra ponds) across southern Nunavut in 2002-2005. Nine mayfly species were previously reported for Nunavut: Acentrella feropagus Alba-Tercedor and McCafferty, Acerpenna pygmaea (Hagen), Baetis bundyae Lehmkuhl, B. flavistriga McDunnough, B. foemina McDunnough, Diphetor hageni (Eaton) (Baetidae), Ephemerella aurivillii (Bengtsson) (Ephemerellidae), Leptophlebia nebulosa (Walker) (Leptophlebiidae), and Metretopus borealis (Eaton) (Metrotopidae). We add 7 species to this list, bringing the total to 16: Ameletus inopinatus Eaton (Ameletidae), Acentrella lapponica Bengtsson, Baetis hudsonicus Ide, B. tricaudatus Dodds, Heptagenia solitaria McDunnough (Heptageniidae), Rhithrogena jejuna Eaton (Heptageniidae), and Parameletus chelifer Bengtsson (Siphlonuridae). Based on numbers collected, the dominant mayfly family was Baetidae.Baetis bundyae was the most common mayfly collected, particularly in coastal areas, where larvae were found in permanent and temporary streams and in small or shallow tundra ponds. Larvae hatched 2-3 weeks after ice-out and developed rapidly in 2.5-4 weeks, emerging as adults by early August. All populations containing larvae that were large enough to sex showed female-biased sex ratios, suggesting parthenogenesis. A combination of freeze-tolerant eggs, good dispersal ability, and probable parthenogenesis is probably responsible for the success of Baetidae across the Arctic. 642 Résumé-Nous avons récolté des éphémères (Ephemeroptera) à 35 sites (étangs et cours d'eau de la toundra) dans tout le sud du Nunavut en 2002-2005. Neuf espèces d'éphémères étaient déjà connues du Nunavut : Acentrella feropagus Alba-Tercedor et McCafferty, Acerpenna pygmaea (Hagen), Baetis bundyae Lehmkuhl, B. flavistriga McDunnough, B. foemina McDunnough, Diphetor hageni (Eaton) (Baetidae), Ephemerella aurivillii (Bengtsson) (Ephemerellidae), Leptophlebia nebulosa (Walker) (Leptophlebiidae) et Metretopus borealis (Eaton) (Metrotopidae). Nous en ajoutons 7 autres pour un total de 16 : Ameletus inopinatus Eaton (Ameletidae), Acentrella lapponica Bengtsson, Baetis hudsonicus Ide, B. tricaudatus Dodds, Heptagenia solitaria McDunnough (Heptageniidae), Rhithrogena jejuna Eaton (Heptageniidae) et Parameletus chelifer Bengtsson (Siphlonuridae). D'après le nombre de spécimens récoltés, la famille dominante est celle des Baetidae. Baetis bundyae est l'éphémère le plus couramment récolté, particulièrement dans les régions côtières où les larves vivent dans les cours d'eau permanents et temporaires et dans les étangs petits ou peu profonds de la toundra.Les larves éclosent 2-3 semaines après la fonte des glaces et se développent rapidement en 2,5-4 semaines, alors que les adultes émergent au début d'août. Dans toutes les populations où les larves étaient assez grandes pour permettre la détermination du sexe, il y a un surplus de femelles, ce qui laisse croire à la parthénogenèse. Le succès des Baetidae dans toute la région Can. Entomol. 139: 628-642 (2007)

How valid are old species lists? How archived samples can be used to update Ephemeroptera biodiversity information for northern Canada

“…Hepagenia pulla shows two morphological forms in northern Canada, and the one in the study area covered by the pipeline study is the "western form", in which the asymmetrical mandibles are reversed compared with the eastern form; this may actually be a synonym of the Palaearctic species H. dalecarlica Bengtsson . Based on samples examined from across Nunavut and the Northwest Territories (Giberson et al 2007 and this study), there does not appear to be an overlap in distribution for the two H. pulla forms, so the eastern and western forms may represent different species. The similar Heptagenia solitaria may also be confused in the west with the eastern form of H. pulla suggesting that the distribution of the two species should be investigated more thoroughly.…”

<i>Baetis jaervii</i> sp. n. (Ephemeroptera: Baetidae) from northern Europe

“…B. bundyae has been found in flowing water in arctic Canada (e.g. Cobb & Flannagan 1980, Harper & Harper 1997, Giberson et al 2007; it has an extensive distribution extending south along the Rocky Mountains. Morihara & Mc-Cafferty (1979) pointed out that the morphological characters of B. bundyae Lehmkuhl overlapped with the ones of B. macani Kimmins and placed it as a subspecies of B. macani Kimmins.…”

New records of Paraleptophlebia werneri Ulmer, 1920 and P. strandii (Eaton, 1901) from Finland (Ephemeroptera, Leptophlebiidae)

“…Due to flowing of groundwater and thick snow cover, the flarks and pools in aapamires may retain some free water during snow covered periods (Koutaniemi and Seppälä 1986, Seppälä and Koutaniemi 1985), thus enabling the survival of the eggs. On the other hand, it has been noted that eggs of other mayfly species such as Baetis macani and Baetis bundyae may tolerate freezing (Giberson et al 2007, Drotz et al 2012). …”