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The daggerfly, Tachypeza yinyang Papp & Földváry, 2002, originally described from Hungary is recorded for the first time in Croatia. Additional notes on its description and illustrations of habitus and male terminalia are provided.

The Wiedemannia zetterstedti species group is revised after examination of all available type specimens and includes one new species (W. ulrichi Ivković & Sinclair sp. nov.) and four redescribed species (W. czernyi (Bezzi), W. longipennis (Mik) stat. rev., W. rufipes (Oldenberg) stat. rev. and W. zetterstedti (Fallén)). The following new synonyms are proposed: W. (Roederella) ouedorum Vaillant, 1952 = W. czernyi (Bezzi, 1905); Paramesia riparia Robert, 1836 = W. zetterstedti (Fallén, 1826). Lectotypes are designated for the following species/subspecies: Atalanta hirtiloba Speiser, Brachystoma escheri Zetterstedt, Clinocera czernyi Bezzi, Clinocera longipennis Mik, Paramesia riparia Robert, and Roederia czernyi rufipes Oldenberg. In addition to morphological evidence, molecular species concepts were investigated using a molecular phylogenetic divergence-based species delimitation (bPTP) and results confirmed the morphological conclusions. A key to species is presented and geographic distributions are mapped.

Knowledge of the European aquatic dance flies (Clinocerinae, Hemerodromiinae) is updated. The following new synonyms are proposed: Chelifera pallida Vaillant, 1981 with Chelifera diversicauda Collin, 1927, syn. nov.; Chelifera giraudae Vaillant, 1981 and Chelifera berdeni Vaillant, 1978 (nomen nudum) with Chelifera subangusta Collin, 1961, syn. nov.; Hemerodromia slovenica Horvat & Wagner, 1989 with Hemerodromia laudatoria Collin, 1927, syn. nov.; Hemerodromia maculata Vaillant, 1968 with Hemerodromia unilineata Zetterstedt, 1842, syn. nov.; Wiedemannia aerea Vaillant, 1967 with Wiedemannia hastata (Mik, 1880), syn. nov.; Wiedemannia brevilamellata Wagner, 1985 with Wiedemannia debilis Collin, 1961, syn. nov.; Wiedemannia bilobata Oldenberg, 1910 with Wiedemannia oxystoma (Bezzi, 1905), syn. nov. Lectotypes are designated for Clinocera (Wiedemannia) oxystoma Bezzi, 1905, Wiedemannia aerea Vaillant, 1967, Wiedemannia bilobata Oldenberg, 1910, Philolutra erminea Mik, 1887, Wiedemannia hastata (Mik, 1880), Wiedemannia mirousei Vaillant, 1956 and Phaeobalia pokornyi Mik, 1886. A neotype is designated for Wiedemannia alpina Vaillant, 1953. Wiedemannia rudolfi Wagner & Ivković, sp. nov. and Phaeobalia remschakae Wagner sp. nov. are described and figures of male terminalia are provided.

All known records of aquatic dance flies (Empididae, Clinocerinae: 21 species; Hemerodromiinae: eight species) from the island of Corsica (France) are summarized, including previously unpublished data and data on the newly described species Chelipoda puschae Ivković, Perović & Grootaert, sp. nov. This species was collected during the “La Planète Revisitée Corsica 2019” survey and represents the first description of a new species in the genus Chelipoda from the European–Mediterranean region in more than 180 years. A key to European species of Chelipoda is provided. Including the new species, five species are recorded from Corsica for the first time: Dolichocephala malickyi Wagner, 1995, Dolichocephala oblongoguttata (Dale, 1878), Dolichocephala ocellata (Costa, 1854), Chelifera subangusta Collin, 1961, and Hemerodromia unilineata Zetterstedt, 1842. The new species is described and illustrated, and new records of aquatic dance flies from Corsica are given, with new data on 17 species in eight different genera. At present, 29 species of aquatic dance flies are known from Corsica, with 10 species endemic to the island.

Dixidae (Insecta, Diptera) are an interesting ecological component in freshwater ecosystems. They are merolimnic insects with larvae and pupae living in aquatic habitats while adults live in terrestrial habitats in close proximity to water. The goals of this study were to determine the phenology patterns of Dixidae and what influences them, to analyse their preference for microhabitats, and to determine the main ecological factors that have an influence on the composition of Dixidae. Adult Dixidae were collected monthly in the period from 2007 to 2008 at 10 sites, from 2009 to 2010 at four sites, and from 2011 to 2014 at three sites in the Plitvice Lakes National Park. Adult specimens were collected using pyramid-type emergence traps. A total of 1271 Dixidae were collected during eight years of study belonging to five species of the genus Dixa. Dixa submaculata was most abundant species at the spring and upper reach of Bijela rijeka Stream and the upper reach of Crna rijeka Stream. Dixa nebulosa was most numerous at the Kozjak-Milanovac tufa barrier site. Dixa puberula was the dominant species at the rest of the sites. Dixa puberula and Dixa submaculata were univoltine, bivoltine or trivoltine, depending on the site, while Dixa nebulosa was only univoltine. The highest diversity was recorded at the tufa barrier Kozjak-Milanovac, and the highest number of species, four species, was found at the upper reach of the Crna rijeka Stream. The greatest number of specimens was recorded at the Labudovac tufa barrier, 128 specimens in 2014. Water temperature is the main ecological factor that influences the phenology of Dixidae at the tufa barriers and lower streams. Discharge affected the abundance of Dixidae. Dixa puberula prefers moss as a substrate and a faster water velocity.

The subgenera of Wiedemannia are poorly defined and, as such, most recently described species are not assigned to a subgenus or have been assigned to a subgenus without explanation. In this study w ...

Freshwater biodiversity is facing a severe crisis due to many human impacts, yet the diversity dynamics of freshwater communities and possibilities of assessing these are vastly unexplored. We aimed at emphasizing different aspects of portraying diversity of a species-rich, aquatic insect group (caddisflies, Trichoptera) across four different habitats in an anthropogenically unimpacted, connected karst barrage lake/riverine system. To define diversity, we used common indices with pre-set sensitivity to species abundance/dominance, i.e., sensitivity parameter (species richness, Shannon, Simpson, Berger-Parker) and diversity profiles based on continuous gradients of this sensitivity parameter: the naïve and non-naïve diversity profiles developed by Leinster and Cobbold. The non-naïve diversity profiles show diversity profiles with regard to the similarity among species in terms of ecological traits and preferences, whereas the naïve diversity profile is called mathematically “naïve” as it assumes absolute dissimilarity between species that is almost never true. The commonly used indices and the naïve diversity profile both ranked the springs as least diverse and tufa barriers as most diverse. The non-naïve diversity profiles based on similarity matrices (using feeding behavior and stream zonation preferences of species), showed even greater differences between these habitats, while ranking stream habitats close together, regardless of their longitudinal position. We constructed the Climate Score index (CSI) in order to assess how diversity and species’ vulnerability project the community’s resistance and/or resilience to climate change. The CSI ranked the springs as most vulnerable, followed by all habitats longitudinally placed below them. We highlight the importance of integrating ecological information into biodiversity and vulnerability assessment of freshwater communities.

Chironomid identification for freshwater bioassessment purposes is rarely finer than family or subfamily level. This has led to their taxonomic neglect and a lack of knowledge about their characteristics and ecology at the genus or species level, which in turn makes their implementation in bioassessment models even less appealing. The aim of this study was to object against this practice and evaluate the possibility of using chironomid assemblages solely in assessing organic and nutrient enrichment levels of lentic habitats. For this purpose, the littoral zone of 28 lentic water bodies of the Dinaric western Balkan ecoregion was sampled. Due to the scarcity of natural lakes in this region, resulting from its specific karst geology, both natural and artificial water bodies were included in this survey. Chironomids, determined mostly to species and genus level, were tested in response to variables associated with organic enrichment (dissolved organic carbon and oxygen demand measures) and nitrate concentration. A metric (Lake chironomid metric, LCM) based on 107 chironomid taxa was developed and proven to reflect organic enrichment more precisely than standard metrics that respond to organic enrichment (BMWP and different Saprobic indices). We found that the LCM strongly supports the use of chironomids with high taxonomic resolution in lentic habitat assessment, as we have shown that chironomids have the ability to improve, or even replace, already existing models for organic nutrient enrichment. We have also shown that chironomids can be used in assessing even finer levels of nitrate pollution with changes in community occurring at as low as 0.07 mgNO3−/l. This allows earlier intervention and hopefully prevention of considerable damage to the environment. We can conclude that chironomids (especially determined to species level) have great potential in monitoring of lake ecosystems.

The Empididae fauna of Serbia is summarised including currently 50 confirmed species belonging to nine genera: Clinocerinae—Kowarzia Mik (1), Phaeobalia Mik (2), Wiedemannia Zetterstedt (4); Empidinae—Empis Linnaeus (16), Hilara Meigen (11), Rhamphomyia Meigen (6); Hemerodromiinae—Chelifera Macquart (7), Hemerodromia Meigen (2), Phyllodromia Zetterstedt (1). A checklist of species is provided. Empis (Empis) serbica sp. nov. is described.

The daggerfly, Tachypeza yinyang Papp & Földváry, 2002, originally described from Hungary is recorded for the first time in Croatia. Additional notes on its description and illustrations of habitus and male terminalia are provided., Muha bodežica Tachypeza yinyang Papp & Földváry, 2002 koja je opisana iz Mađarske po prvi put je zabilježena u Hrvatskoj. Dodatni podaci o njenom opisu te crteži habitusa i genitalija mužjaka su također priloženi.

Mayfly assemblage structure, microhabitat preference and emergence patterns were studied over a decade in two types of karst freshwater habitats, namely, a spring and two tufa barriers. Mayfly adults were collected using pyramidal emergence traps. A total of nine species was recorded. Tufa barriers had a higher species richness but a lower abundance than did the spring. All sites were dominated by species typical of the rhithral zone. The spring had the highest share of grazers, whereas gatherers (collectors and filter feeders) dominated at tufa barriers, with minimal changes through the years. Mayfly abundance at the spring was higher in years with a higher discharge. The opposite was recorded for tufa barriers, which could be related to drift and food availability. Mayflies emerged from the spring between March and November, most probably being triggered by the photoperiod. Emergence from tufa barriers was seasonal and related to changes in water temperature. Some species exhibited typical central European emergence patterns, whereas, in some others, certain discrepancies were recorded. Several taxa showed preference towards emergence from a particular microhabitat. The present study showed that for fine ecological data on aquatic insects, long-term studies are essential.

Flood forecasting relies on good quality of observed and forecasted rainfall. In Serbia, the recording rain gauge network is sparse and rainfall data mainly come from dense non-recording rain gauges. This is not beneficial for flood forecasting in smaller catchments and short-duration events, when hydrologic models operating on subdaily scale are applied. Moreover, differences in rainfall amounts from two types of gauges can be considerable, which is common in operational hydrological practice. This paper examines the possibility of including daily rainfall data from dense observation networks in flood forecasting based on subdaily data, using the extreme flood event in the Kolubara catchment in May 2014 as a case study. Daily rainfall from a dense observation network is disaggregated to hourly scale using the MuDRain multivariate disaggregation software. The disaggregation procedure results in well-reproduced rainfall dynamics and adjusts rainfall volume to the values from the non-recording gauges. The fully distributed wflow_hbv model, which is under development as a forecasting tool for the Kolubara catchment, is used for flood simulations with two alternative hourly rainfall data. The results show an improvement when the disaggregated rainfall from denser network is used, thus indicating the significance of better representation of rainfall temporal and spatial variability for flood forecasting.

The hunter-fly genus Limnophora (Muscidae: Coenosiinae) is an important component of running water assemblages. Both adults and larvae are predators, the adults mostly feeding on blackflies (Simuliidae) and other small aquatic insects. This study was conducted at two tufa barriers in Plitvice Lakes National Park (NP) (tufa barrier Labudovac and tufa barrier Kozjak-Milanovac) and at two tufa barriers in Krka National Park (NP) (tufa barrier Roski slap and tufa barrier Skradinski buk). Adults were collected monthly from February 2007 until December 2013 at Plitvice Lakes NP and from September 2013 to October 2014 at Krka NP, using pyramid-type emergence traps. Over the 7-year study period at the Plitvice Lakes tufa barriers, a total of 193 specimens belonging to 6 species were collected, while during the 1-year study period at the Krka tufa barriers a total of 848 specimens belonging to 4 species were collected. Abundance of Limnophora specimens at the Krka NP sites was up to 30 times higher than at the Plitvice Lakes NP sites, which could be attributed to higher levels of potential food and higher water temperatures. The dominant species at the Plitvice Lakes sites were Limnophora pulchriceps and Limnophora riparia. At the Krka tufa barriers, the dominant species at site Roski slap was Limnophora croatica and at site Skradinski buk Limnophora riparia. The highest numbers of emerging specimens at all sites were present in the summer months. At the Plitvice Lakes sites most species were univoltine or bivoltine, while at the Krka sites most species were multivoltine. Water temperature was the main factor influencing the timing of emergence and the duration of the flight period. The highest abundance of Limnophora species was recorded over moss substrate. A significant positive correlation emerged between the numbers of emerging prey and the numbers of emerging specimens of Limnophora. These results give a new insight into the microhabitat preferences and prey-predator relationships of Limnophora.

Invertebrate surveys in Croatia conducted between 2005 and 2018 included 39 sampling sites yielding bycatch samples of Dixidae (Diptera). All records of this family from the territory of Croatia are summarized, including previously unpublished data. Collections contained six species of Dixa Meigen – D. dilatata Strobl, D. maculata Meigen, D. nebulosa Meigen, D. nubilipennis Curtis, D. puberula Loew, and D. submaculata Edwards, with Dixa dilatata reported from Croatia for the first time. Information relating to the ecoregions in which species were found and specific species traits are provided. Compared to neighbouring countries, the Croatian species assemblage is most similar to the fauna of Italy and least similar to that of Serbia and Montenegro.

The influences of river regulations on aquatic biota are insufficiently investigated. We assessed the level of ecological disturbance of the mayfly assemblages through the damming and flow alterations at two highly regulated Mediterranean rivers in Croatia: the Cetina River and its tributary, the Ruda. Contrary to our hypotheses, species richness, abundance and diversity of mayflies increased along the river’s course. At the sites directly influenced by the river regulations, mayfly assemblage changed: it was less diverse and less abundant. However, no obvious influence of the river regulation on the mayfly assemblages was detected for the sites that were indirectly influenced by these alterations. This was most likely due to specific karst hydrology, i.e., the presence of lateral springs along the course of the river. Multidimensional scaling analysis (MDS) revealed grouping of sites according to the similarity in physico-chemical water properties. The pH and water temperature were the most important environmental variables influencing mayfly assemblages. The data on ecology and distribution of mayflies presented in the current study represent a valuable background for further research and conservation practices in the Mediterranean region.

Pericoma miljenkoi sp. nov. is described based on adult males from the Plitvička jezera National Park, Croatia. Pericoma trifasciata is recorded from Croatia for the first time, and COI DNA barcodes are given from specimens collected in Germany. An emended key to adult Pericoma of the trifasciata group is presented. The Croatian Psychodidae fauna now stands at 35 species.

Several invertebrate surveys in Croatia conducted between 2005 and 2014 and including; e.g., Plitvice Lakes, produced 123 bycatch samples of Dolichopodidae (Diptera) from 68 sampling sites collected at 36 localities in seven counties. Seventy-seven were retrieved from emergence traps, six from pan traps and 40 were collected with sweep net and/or aspirator. They contained 420 dolichopodid flies that belonged to 64 species in 22 genera. Four species, Campsicnemus umbripennis, Hercostomus chetifer, Liancalus virens and Syntormon pallipes, accounted for over half of the yields. Contrary to most species that were found in largest numbers in rivers, and their beds in particular, S. pallipes and Hercostomus gracilis were considerably more abundant at springs. Fifty-five species could be added to the national checklist which raises the total number to 94 species. All species records are given, the habitat of each species is described, if possible, and taxonomic notes are provided for some dubious species. Finally, elements are presented to support the assumption that the extant dolichopodid species richness of Croatia is at least three- to fourfold of the current number.

Stoneflies are among the most sensitive aquatic insect taxa and therefore arguably the best indicator of the excellent, i.e. pristine, ecological status of surface streams. Karst habitats are one of the most exciting freshwater habitats in terms of biological-geological interplay. They, in turn, support a biodiversity far superior to surrounding freshwater habitats and hence these habitats are designated as biodiversity hotspots. Our study deals with both of these crucial ecological players. We studied stonefly assemblages, their microhabitat preferences and emergence patterns along a karst oligotrophic hydrosystem. The sampling was conducted monthly from March 2007 to December 2008 using pyramid-type emergence traps set in various habitats and associated microhabitats (e.g. springs, rivers, streams, tufa barriers × moss, angiosperm, cobble, sand, silt substrates). Favorable environmental conditions, such as a wide range of karst habitat types with low water temperature and high oxygen concentration, resulted in high stonefly species richness (31 recorded species). Water temperature and pH had the highest influence on stonefly assemblages. Species richness and diversity decreased in a downstream direction. We recorded a longitudinal shift from crenal-epirhithral to epirhithral-metarhithral assemblages with some hyporhithral and potamal elements. Upstream sites were dominated by shredders, while downstream sites had a higher proportion of gatherers-collectors. Several species showed a significant preference for a specific microhabitat type in accordance with their feeding strategies and food availability. The majority of recorded species exhibited univoltine life cycles slow or fast.

We identify local hotspots of elevated species richness and endemicity of aquatic insects in the Dinarides (Balkans) using aquatic Empididae (Diptera) as models and compared observed patterns with historical geological and hydrological changes in the region. We analysed species richness and reciprocal weighted endemicity. Parsimony analysis of endemism was used to generate an historical hypothesis of the relationships between the aquatic Empididae biotas of different regions of local endemism within the Dinarides and the results reconciled with the geological and hydrological history of the region. Hotspots of high endemicity were coincident with areas of elevated species richness and were located primarily in the northwest Dinarides, central Bosnia & Herzegovina, and southeast Montenegro. Parsimony analysis of endemism retrieved three weakly supported area clades comprising areas of southeast Dinarides together with disjunct areas at the western Dinarides, and central Bosnia & Herzegovina together with the disjunct northwest Dinarides. The aquatic Empididae fauna of the northwest Dinarides has been strongly influenced by dispersal from the European Alps, whereas that at the southern end of the range may have been shaped by immigration from ranges further south. In the central Dinarides, progressive fragmentation of the hydrological network through orogenesis, karstification, redistribution of flysch deposits, and saline ingressions may underlie current diversity patterns with populations becoming increasingly isolated and focused within refugia. Hotspots of endemism and diversity are not necessarily coincident with protected areas and further work will be needed if they are to be reconciled with future planning of conservation priorities.

Rad se bavi modeliranjem hidroloških procesa u slivu Skadarskog jezera koji pripada prostoru Crne Gore. Ovo jezero i njegov sliv predstavljaju jedan od najznačajnijih prirodnih resursa u Crnoj Gori. Korišćen je postojeći model (MIKE SHE (DHI)) za simulaciju hidroloških procesa na slivu. Njegova primjena je pokazala neke limite koji se primarno odnose na nedostatak dovoljnog fonda raspoloživih ulaznih podataka. Poseban problem koji se pokazao jeste nedostatak podataka o režimu podzemnih voda kao jednog od ključnih faktora u modeliranju ukupnog vodnog bilansa na slivu. Ipak kalibracija modela je pokazala zadovoljavajuće rezultate i dovoljnu prihvatljivost modela tako da on može biti dobra osnova za buduće prognoze hidroloških veličina na slivnom području. Također, model je moguće i dalje nadograđivati s novim podacima i rezultatima, čim se za to steknu uvjeti., Paper deals with the modelling of hydrological processes in the catchment area of Lake Skadar in Montenegro. This lake and its catchment area is one of the most important natural resources of Montenegro. We used an existing model (Mike SHE (DHI)) to simulate the hydrological processes. Its implementation has shown some limitations that are primarily related to insufficient funds of available input data. A particular problem is the lack of data on groundwater regime as one of the key model and water balance factors. However, calibration of the model showed that the results obtained were sufficiently acceptable and that the model can be a good basis for future hydrological forecasts of the basin size. Also, the model can still be upgraded with the new data and results, as soon as the conditions call for it.

Mayfly emergence was studied in the Plitvice Lakes National Park (Croatia) monthly over a 2- year period in four habitats (springs, streams, mountainous rivers, tufa barriers) using monthly collections of emergence traps. A total of 12 mayfly taxa were recorded. Almost half of the collected specimens belonged to the genus Baetis Leach, 1815, which was recorded at every site, but we were unable to distinguish between two included species (B. rhodani and B. cf. nubecularis). Other abundant species were Centroptilum luteolum (Müller, 1776), Alainites muticus (Linnaeus, 1758), Habrophlebia lauta Eaton 1884, Paraleptophlebia submarginata (Stephens, 1835), Serratella ignita (Poda, 1761), Ephemera danica Müller, 1764 and Rhithrogena braaschi Jacob, 1974. The mayfly assemblages at all sites were dominated by species typical of the rhithral zone, but there was a shift in species composition along a longitudinal gradient (from 720 to 390 m a.s.l.) from dominance of eucrenal–epirhithral to metarhithral–hyporhithral elements and finally to appearance of metapotamal and littoral elements. Two environmental factors, maximum water temperature and mean pH, had the highest influence on the mayfly assemblages. Emergence mainly occurred between March and November and was related to the elevated water temperature. Emergence patterns of some species were in accordance with their typical Central European emergence patterns (e.g. S. ignita, H. lauta) while some others showed certain discrepancies (e.g. longer emergence period in Rh. braaschi and P. submarginata, one generation emergence in A. muticus and variable emergence patterns between the sites and between the two studied years in C. luteolum). The current study provides a significant contribution to the knowledge of mayfly ecology in karst freshwater habitats which forms a basis for further investigation and monitoring of mayflies in this area.

This study presents the first comprehensive investigation of population aspects and ecological traits of water beetles in oligotrophic hydrosystems with tufa formation in southeastern Europe. Diverse lotic habitats (springs, rivers and tufa barriers) were investigated monthly for one year in Plitvice Lakes National Park in Croatia. Elmidae were the most diverse and abundant family, followed by Scirtidae and Hydraenidae. The ecological traits of water beetles were primarily defined by nutrients and water depth.Elmis bosnicaZaitzev, 1908, about which little has been published, was found to be bryophilous and to prefer low water temperatures. Biogeographical analysis revealed the dominance of typical southeastern and Mediterranean species. Species population dynamics could be attributed to differences in flow permanence, current velocity and canopy coverage. Both current velocity and water depth significantly influenced the occurrence of larval stages, while abundance of adults correlated with water depth. Our results highlight tufa barriers as preferred habitats for species of the genusRiolusand the family Scirtidae. The results of this study, many of which are the first to be reported for water beetles, provide a basis for further investigations of these animals and their ecology in oligotrophic hydrosystems with tufa. In particular, our study demonstrates the potential of Elmidae as water quality indicators, which should be considered in future conservation and protection management efforts.

Emergence patterns of blackflies (Diptera: Simuliidae) were investigated for 2 years at nine sites in the Plitvice Lakes area of Croatia, using pyramid-type traps. A total of 38 012 specimens representing 10 haematophagous species were collected. The dominant species was Simulium angustipes Edwards, 1915, a vector transmitting avian trypanosomes. Water temperature, alkalinity, conductivity and habitat type represented the factors with the greatest degree of influence on blackfly species composition, structure and distribution along a longitudinal gradient of this oligotrophic karstic hydrosystem. Simulium angustipes was highly associated with lake outlets. The blackfly communities at all sites were dominated by species typical of the rhithral zone, but there was a shift in species composition along a longitudinal gradient from the hypocrenal-epirhithral to the epirhithral-metarhithral zone. Multiple generations per year were detected in S. angustipes, whereas in Simulium costatum Friederichs, 1920, the number of generations differed between sites with constant and those with variable water temperature.

The aim of this study was to determine which environmental factors influence emergence of insects at two contrasting habitats: one with constant and one with variable water temperature. We hypothesized that emergence of holometabolous insects is triggered by water temperature where temperature variations occur, while light is the main stimulus for emergence at site with constant water temperature. We expected that for the emergence of hemimetabolous insects, some additional environmental stimuli might be required. We also expected weather conditions to be more important at sites that lack variations in water temperature. To test our hypotheses we placed six pyramid-type emergence traps at the two sites. Emergent aquatic insects were collected at 8-hour intervals over a 13-day period, during peak emergence for most of the target species. Most taxa emerged during the afternoon at both sites. Only Hydropsyche saxonica/instabilis emerged nocturnally. At the site with constant water temperature, emergence of Drusus croaticus was stimulated by length of sunlight period. Emergence of Protonemura auberti was promoted by higher air temperature and humidity of the day before. Brachyptera tristis emerged in higher numbers when humidity and cloudiness were high the preceding day. At site with variable water temperature, an increase in water temperature, with a threshold at 16 °C, was a significant factor for the emergence of Hemerodromia unilineata. This study gives new insight into the complexity of relationships between aquatic insect emergence patterns and environmental drivers, and show that light and weather conditions trigger emergence of most insects under constant water temperature conditions, while temperature is a dominant trigger at variable water temperature habitat.