Jukka Salmela

Risk of local extinction of Odonata freshwater habitat generalists and specialists.

Understanding the risk of a local extinction in a single population relative to the habitat requirements of a species is important in both theoretical and applied ecology. Local extinction risk depends on several factors, such as habitat requirements, range size of species, and habitat quality. We studied the local extinctions among 31 dragonfly and damselfly species from 1930 to 1975 and from 1995 to 2003 in Central Finland. We tested whether habitat specialists had a higher local extinction rate than generalist species. Approximately 30% of the local dragonfly and damselfly populations were extirpated during the 2 study periods. The size of the geographical range of the species was negatively related to extinction rate of the local populations. In contrast to our prediction, the specialist species had lower local extinction rates than the generalist species, probably because generalist species occurred in both low- and high-quality habitat. Our results are consistent with source-sink theory.

High within- and between-trunk variation in the nematoceran (Diptera) community and its physical environment in decaying aspen trunks

Dead wood is a primary habitat for a large number of insects, including species from many nematoceran (Diptera) groups. The species living in dead wood must be adapted to the ephemeral and ever‐changing nature of their substrate. There is a growing body of knowledge about the effects of dead wood quality and the surrounding landscape on the saproxylic beetle community, but we know very little about the other saproxylic insects. Moreover, we know only very little about the variation in the insect community between different parts of decaying wood pieces. Using emergence traps, we studied the saproxylic nematoceran communities occupying different parts of decaying fallen aspen trunks in a boreal forest. To explain the variation in the detected assemblages, we also studied the variation in the physical environment in different parts of one of the studied trunks during the season. We found out that the overall variation in assemblages was very high and also the similarity between the base and top of the same trunk was usually low. Dissimilarity arose more from differences in species richness than from species turnover. The greatest contrasts in the physical conditions of the study trunk were between the inside and the upper and lower surface of the trunk base. Due to high variation within the trunks and especially between the trunks, the sampling effort in studies on the ecology of saproxylic insects should be high to have a reliable estimate of the local community.

The Semiaquatic Nematoceran Fly Assemblages of Three Wetland Habitats and Concordance with Plant Species Composition, a Case Study from Subalpine Fennoscandia

Abstract Semiaquatic flies (Diptera, Nematocera) are an ecologically important and species rich group of insects within the boreal and arctic biomes. Community structure, species richness and abundance of semiaquatic flies were studied in three habitat types (aapa mires, springs and headwater streams), totaling 19 study sites, within the subalpine ecoregion of northern boreal Finland. Concordance of semiaquatic fly species composition with plant assemblages (higher plants and mosses), and geographical and environmental distance matrices were also studied. The collected insect material consisted of 94 species and 9038 specimens. According to non-metric multidimensional scaling ordination (visual inspection), multi-response permutation procedure and analysis of similarity tests, fly assemblages of aapa mires were clearly different from those of springs and headwater streams, but no differences were found between spring and headwater stream assemblages. The cumulative number of species was highest in headwater streams. Alpha diversity varied within the habitat types but was generally highest among headwater streams. Semiaquatic fly communities of headwater streams were the most abundant (number of specimens) and their rank-abundance distributions were relatively skewed; assemblages of aapa mires were less abundant and rather even. Community composition of combined plant material (219 taxa), higher plants (116 taxa) and mosses (103 taxa) were all in concordance with the flies; the strongest matrix correlation was found between higher plants and flies (Mantel test). The influence of geographical distance of the study sites to species composition was statistically significant but rather weak; instead, much stronger concordance was noted with environmental variables (Mantel test). Plants, especially higher plants, may be potential surrogates for semiaquatic fly assemblage composition. However, more studies of community concordance in a larger geographic area and within one habitat type are needed.

Recent noteworthy findings of fungus gnats from Finland and northwestern Russia (Diptera: Ditomyiidae, Keroplatidae, Bolitophilidae and Mycetophilidae)

Abstract New faunistic data on fungus gnats (Diptera: Sciaroidea excluding Sciaridae) from Finland and NW Russia (Karelia and Murmansk Region) are presented. A total of 64 and 34 species are reported for the first time form Finland and Russian Karelia, respectively. Nine of the species are also new for the European fauna: Mycomya shewelli Väisänen, 1984, Mycomya thula Väisänen, 1984, Acnemia trifida Zaitzev, 1982, Coelosia gracilis Johannsen, 1912, Orfelia krivosheinae Zaitzev, 1994, Mycetophila biformis Maximova, 2002, Mycetophila monstera Maximova, 2002, Mycetophila uschaica Subbotina & Maximova, 2011 and Trichonta palustris Maximova, 2002.

Biogeographic Patterns of Finnish Crane Flies (Diptera, Tipuloidea)

Species richness of terrestrial and freshwater biota generally decreases with increasing latitude. Some taxa, however, show an anomalous species richness pattern in a regional or global scale. The aim of this study was to examine (i) regional variation in species richness, (ii) faunistic composition, (iii) occupancy, and (iv) proportions of different distribution types of Finnish crane flies. Analyses were based on incidence data pooled into 20 biogeographical provinces. Finnish crane fly fauna consists of 335 species; the provincial richness varies from 91 to 237. The species richness of all species and saproxylic/fungivorous species decreased with increasing latitude; mire-dwelling crane flies displayed a reversed pattern (Spearmans correlations). Thirty-one species occupied a single province and 11 species were present in all provinces. Provincial assemblages showed a strong latitudinal gradient (NMS ordination) and faunistic distance increased with increasing geographical distance (Mantel test). Nearly half (48%) of the Finnish crane flies are Trans-Palaearctic, roughly one-third (34%) are West Palaearctic, and only 16 and 2% are Holarctic and Fennoscandian, respectively. Endemic Fennoscandian species are discussed in detail; most likely there are no true endemic crane flies in this region.

New and poorly known Holarctic species of Boletina Staeger, 1840 (Diptera, Mycetophilidae)

Abstract Background The genus Boletina is a species rich group of fungus gnats. Members of the genus are mainly known from temperate, boreal and arctic biomes. Phylogeny of the genus is still poorly resolved, dozens of species are insufficiently described and undescribed species are often discovered, especially from samples taken from the boreal zone. New information Four new species are described. Boletina valteri Salmela sp.n. (Finland), Boletina kullervoi Salmela sp.n. (Finland), B. hyperborea Salmela sp.n. (Finland, Norway, Sweden, Canada) and B. nuortti Salmela sp.n. (Finland). Boletina arctica Holmgren is redescribed and reported for the first time from the Canadian high arctic zone. Boletina borealis Zetterstedt and B. birulai Lundström are reported for the first time from Canada. Boletina subnitidula Sasakawa (syn. n.) is proposed as a junior synonym of B. pallidula Edwards.

New data on poorly known species of the genus Leia Meigen (Diptera, Mycetophilidae) from the Palaearctic region

New data on four poorly known species of the genus Leia Meigen (L. nigricornis van Duzee, L. flavipennis Laštovka & Matile, L. iturupensis Zaitzev and L. rufiptera Ostroverkhova) are presented. Detailed redescriptions and terminalia figures are provided. Leia nigricornis is reported for the first time from the Palaearctic region and L. automnala Ostroverkhova & Grishina is found to be a junior synonym of L. flavipennis. A variation in the male terminalia of L. bimaculata Meigen is illustrated, based on specimens from several European countries.

New taxonomic and faunistic records of fungus gnats (Insecta, Diptera) from Montenegro, Romania, and Serbia

A total of 95 fungus gnats species were identified from sweep net samples collected from Montenegro, Romania and Serbia during 2010–2017. A mycetophilid species, Trichonta comis Gagné, 1981, is redescribed and a key is provided for the separation of European Boletina trivittata (Meigen, 1818)-group species. Ten species from Montenegro, 27 from Romania and 1 species from Serbia are reported for the first time. The presence of Stigmatomeria crassicornis (Stannius, 1831) in Romania is verified.

New and poorly known Palaearctic fungus gnats (Diptera, Sciaroidea)

Abstract Background Fungus gnats (Sciaroidea) are a globally species rich group of lower Diptera. In Europe, Fennoscandian peninsula in particular holds a notable diversity, ca. 1000 species, of which 10 % are still unnamed. Fungus gnats are predominantly terrestrial insects, but some species dwell in wetland habitats. New information Eight new fungus gnat species, belonging to the families Keroplatidae (Orfelia boreoalpina Salmela sp.n.) and Mycetophilidae (Sciophila holopaineni Salmela sp.n., S. curvata Salmela sp.n., Boletina sasakawai Salmela & Kolcsár sp.n., B. norokorpii Salmela & Kolcsár sp.n., Phronia sompio Salmela sp.n., P. reducta Salmela sp.n., P. prolongata Salmela sp.n.), are described. Four of the species are known from Fennoscandia only whilst two are supposed to have boreo-alpine disjunct ranges, i.e. having populations in Fennoscandia and the Central European Alps. One of the species probably has a boreal range (Finnish Lapland and Central Siberia). Type material of Boletina curta Sasakawa & Kimura from Japan was found to consist of two species, and a further species close to these taxa is described from Finland. Phronia elegantula Hackman is redescribed and reported for the first time from Norway. DNA barcodes are provided for the first time for five species.

Pachyneuridae (Diptera): new data on the geographic range and designation of the lectotype of Pachyneura fasciata Zetterstedt, 1838.

All available records of two nematoceran flies Pachyneura fasciata and P. oculata were gathered and mapped. P. fasciata is a wide-ranging Palaearctic species, and is here reported for the first time for some regions of the Russian Federation, including the European part of Russia (Leningrad Oblast), Western Siberia (Tomsk Oblast, Altay Republic), Eastern Siberia (Krasnoyarsk Krai, Irkutsk Oblast, Chita Oblast), the Far East of Russia (Kuril islands, Kunashir and Paramushir Islands), and for continental China. Pachyneura oculata has a restricted eastern Palaearctic range. The lectotype of P. fasciata has been designated and a key for the identification of Pachyneura species is provided.