Effects of pollution-induced changes in oxygen conditions scaling up from individuals to ecosystems in a tropical river network.

Anthropogenic inputs of nutrients and organic matter are common in tropical lowland rivers while little is known about the pollution-induced changes in oxygen availability and respiratory performance of ectotherms in these high temperature systems. We investigated the effects of agriculture and urban land-use on river water oxygen levels (diel measurements), decomposition rates (Wettex) and macroinvertebrate assemblages (field studies), as well as the oxy-regulatory capacity of eight riverine macroinvertebrate taxa (laboratory study) from a tropical lowland river network in Myanmar. The highest decomposition rates (0.1-5.5 mg Wettex degree day-1) and oxygen stress (≤91% saturation deficits) were found in reaches draining degraded catchments with elevated concentrations of nutrients. All individual macroinvertebrate taxa investigated were to some extent able to regulate their respiration when placed under oxygen stress in the laboratory (regulation value of 0.74-0.89). The oxy-regulation capacity of macroinvertebrate assemblages in the river network were, as predicted, inversely related to diel oxygen stress (maximum deficit; lm, R2 = 0.69), where taxonomic richness and pollution sensitivity (ASPT metric) also declined sharply (lm, R2 ≥ 0.79). Our study shows that eutrophication and organic pollution induce oxygen deficits in tropical rivers but stimulate decomposition rates, which may further deplete oxygen levels. Furthermore, macroinvertebrate oxy-regulatory capacity predicts assemblage composition along gradients in oxygen stress at the ecosystem level. Our findings suggest that tropical lowland river systems could be highly sensitive to pollution by nutrients and organic matter leading to substantial impacts on ectotherm community composition and ecosystem functioning.

Revision of the Exechiaparva group (Diptera: Mycetophilidae).

BACKGROUND: Exechia is a diverse genus of small fungus gnats, widespread in the Holarctic Region, while the fauna is largely unknown elsewhere, such as in the Afrotropical and Oriental Region. Members of Exechia can be arranged into several species groups, based on homologies in the male and female terminalia. The Exechiaparva group is delimited, based on male terminalia possessing a pair of gonocoxal lobes on the apicoventral gonocoxal margin. Eight previously-described species can be placed in this group, of which six are from the Holarctic Region, while one is recorded each from the Oriental and the Afrotropical Regions. NEW INFORMATION: The Exechiaparva group was reviewed and found to include 33 species, of which 24 were described as new to science and six were re-described. Identification keys to 32 species for males and nine species for females are provided together with illustrations and photos of male and female terminalia. Species delimitations were based on morphological examination of 94 male and female specimens, as well as DNA barcodes obtained from 124 specimens. Molecular and morphological species delimitations were mostly congruent, except in two cases where two species were delimited within a single Barcode Index Number (BIN). We found that each species is only known from a single zoogeographical region and that several species complexes are largely congruent with zoogeographical divisions, indicating that intercontinental barriers may have a strong impact on the species diversity of the group.

New data on the genus Manota Williston (Diptera: Mycetophilidae) from Africa, with an updated key to the species.

A total of 346 male specimens of Manota collected from 13 countries in Africa are studied. They belong to 40 different species including 12 new to science. The new species are: M. burundiensis (Burundi), M. cornuta (Ghana), M. fuscinula (Ghana), M. geniculata (Gabon), M. kirkspriggsi (Madagascar), M. kjaerandseni (Ghana, Côte d'Ivoire), M. leptochaeta (Madagascar), M. limai (São Tomé and Principe), M. oronnai (Nigeria), M. platychaeta (Madagascar), M. polylobata (Nigeria) and M. triseta (Ghana, Guinea). New records of the following 28 species are presented: M. aculifera Hippa Kurina, 2012 (Ghana), M. afra Hippa Kurina, 2012 (Ghana, Democratic Republic of Congo), M. clinochaeta Hippa, 2008 (Madagascar), M. clurina Hippa Kurina, 2012 (Côte d'Ivoire), M. comata Hippa Kurina, 2012 (Ghana, Guinea, Democratic Republic of Congo, Uganda), M. cultigera Hippa, 2008 (Madagascar), M. dissidens Hippa Kurina, 2012 (Ghana, Côte d'Ivoire), M. foliolata Hippa Kurina, 2012 (Cameroon), M. ghanaensis Hippa Kurina, 2012 (Ghana), M. grootaerti Kurina Hippa, 2014 (Democratic Republic of Congo), M. katusabei Hippa Kurina, 2012 (Ghana, Guinea, Uganda), M. lachaisei Matile, 1972 (Democratic Republic of Congo), M. mabokeensis Matile, 1972 (Democratic Republic of Congo, Uganda), M. macrodon Hippa, 2008 (Madagascar), M. mazumbaiensis Søli, 1993 (Ghana, Guinea, Uganda), M. natalensis Jaschhof Mostovski, 2006 (Republic of South Africa), M. peltata Kurina Hippa, 2014 (Ghana), M. peltigera Kurina Hippa, 2014 (Ghana, Uganda), M. petiolata Hippa Kurina, 2012 (Ghana), M. phyllochaeta Hippa, 2008 (Madagascar), M. pilosa Hippa Kurina, 2012 (Ghana, Guinea, Côte d'Ivoire, Nigeria), M. pinnata Hippa Kurina, 2012 (Democratic Republic of Congo), M. pinnulata Hippa Kurina, 2012 (Ghana), M. reclinata Kurina Hippa, 2014 (Ghana, Guinea, Côte d'Ivoire), M. relicina Hippa Kurina, 2012 (Uganda), M. senticosa Hippa Kurina, 2012 (Ghana, Gabon, Guinea, Central African Republic), M. uncinata Hippa, 2008 (Madagascar) and M. whiteleyi Jaschhof Mostovski, 2006 (Ghana, Cameroon). An updated key to the Afrotropical Manota species is provided and their distribution briefly discussed. Altogether 68 species of Manota are now known from the Afrotropical region, while the genus holds 314 described species worldwide.

Allodia Winnertz from the Himalayas, with nine species new to science (Diptera, Mycetophilidae).

An extensive collection of fungus gnats from Nepal and Bhutan, deposited at Kyushu University Museum in Japan, has been examined and revealed nine species of Allodia Winnertz, 1864 new to science: Allodiacaligata Magnussen, sp. n., A.dibolia Magnussen, sp. n., A.shimai Magnussen, sp. n., A.spathulata Magnussen, sp. n., A.horologia Magnussen, sp. n., A.himalayensis Magnussen, sp. n., A.nepalensis Magnussen, sp. n., A.thudamensis Magnussen, sp. n., and A.scalprata Magnussen, sp. n. All specimens were collected at high altitudes in the central and eastern Himalayas. The species all belong to the subgenusAllodia s. str. and constitute the first records of the genus Allodia in Nepal and Bhutan. Brevicornunigrofasciatum (Brunetti, 1912) comb. n., originally described from northern India, is transferred from Allodia based on the original description. A key for the identification of the new species is provided.

Six new species of Afrotropical Allodia (Diptera: Mycetophilidae): DNA barcodes indicate recent diversification with a single origin.

Only one species of the genus Allodia has been previously recorded from the Afrotropical region, Allodia (Brachycampta) flavorufa Matile, 1978. Six new species are described here, all representing the nominotypical subgenus, Allodia s.s. The new species are described from material collected in different mountainous areas in south and east Africa; A. jaschhofi sp. nov., A. karkloofensis sp. nov., A. drakensbergensis sp. nov., A. nyeriensis sp. nov., A. mazumbaiensis sp. nov. and A. keurbosensis sp. nov. The species are morphologically very similar, and can only be separated based on minor differences in wing venation and characters of the male terminalia. The genetic differences between the species in the DNA barcode region (CO1), however, support delimitation. The origin and distribution of these Afrotropical taxa, in relation to each other and to their Holarctic relatives, is discussed.