Larval and adult material collected from July 2012 to July 2013 and previously collected larval material were evaluated taxonomically to determine the Chironomidae (Diptera) fauna of Kırklareli Province. Accordingly, a total of 64 species belonging to the subfamilies Tanypodinae, Prodiamesinae, Orthocladinae, and Chironominae of the family Chironomidae were determined, of which

Recent taxonomic studies suggest that findings of larval chironomids should be supported also by adult findings in order to obtain more robust and reliable results on the studied group. Moreover identifications of larvae of some species can be made to genus level only due to similarities of some larval characteristics in different species. In such cases, species level identifications can be achieved by the growth of larvae in laboratory conditions. Also, larval culturing under optimum growth conditions will not only make it easy to provide materials for experimental studies and but also achievement of larvae with a higher biomass value to be used as food in the sector. In this study, Tanypus punctipennis Meigen (Diptera, Chironomidae), a very common species in Turkish Thrace, was used as the model organism for culture studies. Individual larvae were cultured from third instar stage to adult form under laboratory conditions. A simple and cheap method is offered for experimental studies on larval growths of chironomids and the effects of water temperature and pH, both with very important roles in larval culturing, were determined. The overall results of laboratory tests showed that the temperature value of 25°C and 7-8 pH interval were the optimal laboratory conditions for culture of T. punctipennis larvae.

Benthic macroinvertebrates are very important components of aquatic environments, and monitoring their population dynamics helps us understand the effects of environmental factors on ecosystems. This study aimed to determine the dynamics of benthic macroinvertebrate fauna in paddy fields in the Meriç–Ergene River Basin (Turkish Thrace region) by investigating some physicochemical environmental parameters that may affect its distribution. For this purpose, water and sediment samples were collected from paddy fields in the study area during the cultivation season, including spring, summer and autumn of 2016, taking into account the water resources that supply the rice fields (artesian water, the Meriç River, the Ergene River and Meriç–Ergene mixed water). A total of 47 taxa (on average 8953 individuals per m2 ) were identified at the study sites. Water samples were analyzed to determine water temperature, pH, conductivity, salinity, total dissolved solids, calcium, magnesium, total hardness, nitrite nitrogen, nitrate nitrogen, phosphate, sulfate, dissolved oxygen and pesticides, and sediment samples were analyzed to determine the content of some heavy metals, including Cd, Ni, Cu, and Mn. The biological risk index (mERM-Q) and the potential ecological risk index (RI) were applied to the data and a hypothetical ecological risk analysis was conducted using our data and data available in the literature to assess the ecological risk profile of the ecosystem based on benthic macroinvertebrates. To this end, environmental factors were grouped based on the literature as heavy metals (S1), nutrients (S2), other physicochemical parameters (S3) and pesticides (S4), while organisms were grouped as Oligochaeta, Chironomidae, Insecta and others based on the dynamics of benthic macroinvertebrates to assess pressure factors. As a result, pesticides (S4) were found to exert the strongest ecological pressure on benthic macroinvertebrate fauna in paddy fields in the Meriç–Ergene River Basin.

The roles of larval chironomids in the food chain of both the lotic and the lentic ecosystems are very important. On the one hand, chironomid larvae feeding on algae, diatoms, rotting organic matter, plant, and animal residues also play an important role in these systems as a source of food for other carnivores and omnivorous organisms. In this study, the gut contents of Cryptochironomus defectus (Kieffer, 1913), Cladotanytarsus mancus (Walker, 1856), Polypedilum scalaenum (Schrank, 1803), Tanypus kraatzi (Kieffer, 1912) collected from the freshwater ecosystems located in the northern parts of the Thrace region of Turkey were analyzed to compare their feeding habits. As a result of the analysis, it was determined that while plant fragments were dominant in C. defectus species in the gut content (44.3%), algae were dominant for C. mancus (44.7%), P. scalaenum (63.5%), T. kraatzi (65%). According to the results of the Shannon-Wiener (H') index species, diversity of the P. scalaenum was found to be the highest among the larvae (H'= 1.345). Also, according to the Bray-Curtis similarity index, the most similar types of gut contents were P. scalaenum and C. defectus (38%). This low rate indicated that the species have different food preferences.

Larval chironomids feed on algae, diatomae, detritus, decaying plant and animal fragments. The larvae in turn are food for other carnivore and omnivore animals. Thus, larval chironomids have a very important role in the aquatic food cycle. In this study, the algal flora in the stomachs of Tanypus punctipennis, which is known as a very common species in Turkish Thrace, was examined in terms of qualitative and quantitative factors. It was found that Bacillariophyta was the dominant group with 42 taxa in the stomach of T. punctipennis. It was followed by Cyanophyta with 3 taxa, Euglenophyta with 6 taxa, Chlorophyta with 4 taxa, Carophyta with 2 taxa, and Rhodophyta with 1 taxa.