Ecological status assessment of the Zasavica river based on algological parameters

Jedinstven vodeni ekosistem Zasavica, koji čini kičmu istoimenog Specijalnog rezervata prirode, u svojoj osnovi podrazumeva rečni ekosistem, a danas predstavlja napušteno rečno korito, odnosno vlažno stanište, uporedivo u ekološkom smislu sa plitkim jezerima, barskim i močvarnim ekosistemima. Postizanje i održavanje dobrog ekološkog statusa vlažnih staništa, gde je ekološki status odraz kvaliteta strukture i funcionalnosti tih ekosistema, predstavlja glavni cilj Direktive o vodama. U Srbiji procenu ekološkog statusa površinskih voda reguliše Pravilnik o parametrima ekološkog i hemijskog statusa površinskih voda i parametrima hemijskog i kvantitativnog statusa podzemnih voda. Predmet ove doktorske disertacije je detaljna analiza cijanobakterija i algi sa ciljem procene ekološkog statusa Zasavice na osnovu parametara fitoplanktona i fitobentosa kao relevantnih bioloških grupa. Dodatno je analizirana i zajednica metafitona, da bi se dobili dopunski podaci o stabilnosti ovog osetljivog ekosistema. Uzorci za analizu fizičkih, hemijskih i biohemijskih (koncentracija hlorofila a) parametara kvaliteta vode, kao i uzorci za kvalitativnu i kvantitativnu analizu fitoplanktona, fitobentosa (epilitskih silikatnih algi) i metafitona, prikupljani su jednom mesečno od decembra 2012. godine do novembra 2013. godine, na dva lokaliteta. Nakon prikupljanja uzoraka, usledila je laboratorijska analiza uzoraka standardnim metodama i izračunavanje potrebnih indeksa. Kvalitativnom analizom cijanobakterija i algi utvrđeno je prisustvo 503 taksona iz 8 razdela (Cyanobacteria, Bacillariophyta, Chlorophyta, Chrysophyta, Cryptophyta, Dinophyta, Euglenophyta i Xanthophyta). Razdeo Bacillariophyta se izdvaja sa 170 identifikovanih taksona. Od 50 prisutnih taksona cijanobakterija, 12 je novo za floru Srbije. Pored toga, 13 taksona cijanobakterija je potencijalno toksično, a među njima tri vrste su i invazivne na području Evrope (Cylindrospermopsis raciborskii, Raphidiopsis mediteranea i Sphaerospermopsis aphanizomenoides)...A unique ecosystem of Zasavica, the basis of the eponymous Special nature reserve, originated as river ecosystem. Nowadays, however, it represents an oxbow lake or wetland, in ecological terms comparable with shallow lakes, ponds and swamps. To achieve and maintain good ecological status of the wetlands is one of the main aims of Water Framework Directive, in which ecological status is defined as an expression of the quality of the structure and functioning of ecosystem. The ecological status assessment of Serbian waters is regulated through the Rulebook on parameters of ecological and chemical status of surface waters, and quantitative and chemical status of groundwaters. The aim of this PhD thesis was to conduct a comprehensive analysis of cyanobacteria and algae in order to assess the ecological status of Zasavica wetland, using phytoplankton and phytobenthos assemblages as relevant biological quality elements. In addition, metaphyton community was analyzed to support the data on stability of this vulnerable ecosystem. Samples for physical, chemical and biochemical (chlorophyll a concentration) analysis of water quality parameters, as well as samples for quantitative and qualitative analysis of phytoplankton, phytobenthos (epilithic diatoms) and metaphyton communities, were collected monthly from two localities, in the period from December 2012 to November 2013. Further, a standard laboratory methods and formulas for calculating selected indices were used to conduct the analysis. A total of 503 taxa belonging to 8 phyla (Cyanobacteria, Bacillariophyta, Chlorophyta, Chrysophyta, Cryptophyta, Dinophyta, Euglenophyta and Xanthophyta) were identified after the qualitative analysis. Bacillariophyta was the most diverse division, with 170 identified taxa. Regarding Cyanobacteria, out of 50 recorded taxa, 12 were new for the Serbian flora. However, there were 13 cyanobacterial species that are potentially toxic and, among them, three are regarded as invasive in Europe (Cylindrospermopsis raciborskii, Raphidiopsis mediteranea and Sphaerospermopsis aphanizomenoides)..

Susceptibility of dried berries to infestation by Plodia interpunctella (Lepidoptera: Pyralidae) in correlation with total sugar content: Poster

By assessing the degree of resistance of stored products to infestation by insect pests and correlating it with physical, chemical and nutritional characteristics of products, we could gain a real insight in these pests feeding preferences, and consequently in their biology and ecology. The aim of this study was to assess the degree of resistance of five dried berry species (strawberry, raspberry, blackberry, black chokeberry and cranberry) to infestation caused by the major pest of dried berries, Plodia interpunctella. Susceptibility was rated based on the Index of susceptibility (IS) for insect development and the Susceptibility rating. Dried cranberries were absolutely resistant to infestation by P. interpunctella (IS = 0) - no larvae reached the adult stage. Four other dried berry species were also resistant (IS ranged 2.01 – 2.44). In other words, dried cranberries are very unsuitable food for P. interpunctella, while other four tested species were slightly more suitable. The content of total sugars in dried berries varied from 24.2% (black chokeberry) to 72.8% (strawberry), but important correlation between IS and total sugar content was not found. By analysing feeding preferences of P. interpunctella, we can undertake different pest-management strategies for protection of stored dried fruits.By assessing the degree of resistance of stored products to infestation by insect pests and correlating it with physical, chemical and nutritional characteristics of products, we could gain a real insight in these pests feeding preferences, and consequently in their biology and ecology. The aim of this study was to assess the degree of resistance of five dried berry species (strawberry, raspberry, blackberry, black chokeberry and cranberry) to infestation caused by the major pest of dried berries, Plodia interpunctella. Susceptibility was rated based on the Index of susceptibility (IS) for insect development and the Susceptibility rating. Dried cranberries were absolutely resistant to infestation by P. interpunctella (IS = 0) - no larvae reached the adult stage. Four other dried berry species were also resistant (IS ranged 2.01 – 2.44). In other words, dried cranberries are very unsuitable food for P. interpunctella, while other four tested species were slightly more suitable. The content of total sugars in dried berries varied from 24.2% (black chokeberry) to 72.8% (strawberry), but important correlation between IS and total sugar content was not found. By analysing feeding preferences of P. interpunctella, we can undertake different pest-management strategies for protection of stored dried fruits

Rediscovery of Chara canescens Loiseleur in Serbia

Chara canescens is the only charophyte performing parthenogenetic reproduction. Although most recently found populations consist solely of parthenogenetically reproducing females, bisexual populations exist as well, making the species a unique example of the sympatric occurrence of both reproductive modes. In Serbia, C. canescens was found only once for certain, near Prokuplje in 2005. The purpose of the present study is to report a reliable new finding of C. canescens in Serbia, in a stable parthenogenetic female population. Sampling was conducted on 7 July 2018 from the Plava Banja pond near the city of Kikinda. Results of water analyses revealed high concentrations of almost all measured parameters, but especially high levels of salinity and alkalinity markers. Very high concentrations of sulphates and chlorides in the Plava Banja pond pointed to extreme ion anomalies. On the basis of the concentration of nutrients in it, the Plava Banja pond can be characterised as a eutrophic water body. Chara specimens collected from this pond were identified as C. canescens, and only females in the reproductive phase were detected. The environmental features of this habitat are typical in relation to preferences of the given species for light and salinity (ion concentration). This record is of great importance because C. canescens has been declared to be probably extinct in the wild in Serbia

Efficacy of Echium spp. water extracts as post-harvest grain protectants against Plodia interpunctella

Water extracts of three plant species of the genus Echium (E. italicum L., E. vulgare L. and E. rubrum Jacq.) were tested under laboratory conditions for their activity as potential post-harvest grain protectants against Plodia interpunctella (Hubner, 1813) (Lepidoptera: Pyralidae) larvae. Antioxidative activity and total phenolic, flavonoid and tannin contents in plant extracts were determined. The larvicidal assays were conducted with the local population of P. interpunctella from Central Serbia on kernels of Takovoanka winter wheat cultivar. The experiment was set as factorial 3x3x3x3 block design type. Three groups of larvae of different maturity were used. The larvae were exposed to three different concentrations of water extracts (1%, 2% and 5%) of three listed plant species. Mortality was registered daily during 96 hours and the efficacy was calculated using Schneider-Orelli's formula. The largest number of dead larvae was recorded in the treatment of 1% extract of E. italicum on youngest group, after 72 and 96 h. Extracts of E. vulgare and E. rubrum did not show high larvicidal effect

Larvicidal efficacy of Verbascum spp. methanol extracts against Plodia interpunctella (Hübner, 1813) (Lepidoptera: Pyralidae)

Verbascum species (fam. Scrophulariaceae) contain a high concentration of rotenone and verbascoside and traditionally have long been used as insecticides. This study is aimed to investigate the larvicidal efficacy of Verbascum thapsus L. and V. phlomoides L. methanolic extracts in the suppression of the Plodia interpunctella (Hübner, 1813), under laboratory conditions. The experiment was set up in two separate blocks (for two different extracts), each as 3˟3˟3 factorial trial: three concentrations of extracts (1, 2 and 5%) were tested against the three larval age groups (14, 14-28 and 28 days old) and each treatment was repeated three times. Mortality was recorded after 24, 48, 72, and 96 h. Both tested extracts were the most effective 96 h after the exposure in 5% concentration applied on the youngest larvae. Extract of V. thapsus caused the mortality of 64.00%, while in treatment with V. phlomoides extract mortality was 48.00%. Tested Verbascum extracts have shown moderate potential for application as botanical larvicides.Publishe

Abandoned artificial saline pond – safe place for rare/endangered species

Inland saline ecosystems are characterized by very specific and unique biodiversity Still, biodiversity studies of saline habitats are mostly focused on lakes and ponds of natural origin We investigated the biodiversity of submerged macrophytes, phytoplankton and phytobenthos in the saline pond near Kikinda city (in Vojvodina, the northern province of Serbia) that was artificially made by commercial clay digging and abandoned in the landscape of the city suburban over time Collecting samples and field measurements were conducted in July 2018 The dense cover of macrophytes in the litoral area consisted of a carpet of Chara canescens with sparse specimens of Zannichellia palustris This is the second currently known locality of C canescens in Serbia which was recently rediscovered Despite the relatively wide range of this typically brackish species, populations of C canescens are isolated, and it is worldwide considered threatened/endangered and rare A total number of 27 algal taxa were detected in phytoplankton A few taxa characteristic for saline or brackish water were detected Oocystis submarina Merismopedia warmingiana Euglena proxima However, the majority of detected taxa can be characterized as halotolerant In the phytobenthic community 15 diatom taxa were recorded The most dominant genus was Nitzschia 4 species) Brackish water species were also recorded (e g Tryblionella hungarica T apiculata Navicymbula pusilla first recorded in Serbian flora in 2018 was also discovered here Generally low diversity, typical for saline habitats, was observed in relation to all communities, however typically brackish, rare/endangered species were recorded Since our preliminary results (obtained after one sampling occasion) indicate the potential for detecting specific biodiversity in macrophyte, phytoplankton, and phytobenthic communities in one artificial saline pond, we propose conducting a detailed study of this and other ponds of similar origin.10th International Shallow Lakes Conference, Towards a landscape ecology of shallow lakes, virtual format, March 1st to 5th 2021

Comparative analysis of life span of imago Plodia interpunctella (Hübner) grown on three different types of nuts

Bakrenasti plamenac brašna (Plodia interpunctella, Lepidoptera, Pyralidae) predstavlja ekonomski najznačajniju štetočinu uskladištenih prehrambenih proizvoda. Cilj istraživanja bio je da se utvrdi da li postoje razlike u dužini života imaga P. interpunctella gajenog na izlomljenim jezgrama oraha, lešnika i badema. Najduži životni vek od 7,69 dana imala su imaga gajena na orahu. Na bademu i lešniku ova vrednost se statistički značajno ne razlikuje, i iznosi 7,07 i 6,73 dana, po podlogama. Na osnovu rezultata možemo zaključiti da je orah najpogodniji supstrat za razviće P. interpunctella.Indian Meal Moth (Plodia interpunctella, Lepidoptera, Pyralidae) is one of the most important pests of stored food products. The aim of this study was to determine the influence of different nutrient medium (broken kernels of walnuts, hazelnuts and almonds) on life span of imago P. interpunctella. The longest life span (7,69 days) was recorded on walnut. On hazelnut and almond, this value was statistically not significantly different, amounting to 7,07 and 6,73 days, respectively. According to obtained results, it can be concluded that the walnut is the most suitable nutrient medium for the development P. interpunctella

The application of diatom indices for water quality assessment – case study of Jovac and Ročnjak streams

U ovom istraživanju predstavljeni su rezultati analize epilitskih zajednica silikatnih algi iz potoka Jovac i Ročnjak, dve pritoke akumulacije Vrutci. Uzorci su sakupljani mesečno u periodu od decembra 2014. do oktobra 2015. godine. Identifikovano je ukupno 118 taksona silikatnih algi. Najbrojnije populacije u okviru epilitske zajednice silikatnih algi, u oba potoka, grade Achnanthidium minutissimum var. minutissimum i Cocconeis placentula var. lineata. Rezultati izračunavanja dijatomnih indeksa, uz pomoć softverskog paketa OMNIDIA, ukazuju da je ekološki status vode oba potoka u ispitivanom periodu dobar, sa veoma niskim organskim opterećenjem i uz odsustvo antropogene eutrofikacije.Faculty of Agriculture, Belgrade-Zemun, Serbia, June, 13 – 15. 2018

Expansion of invasive diatom species Didymosphenia geminata (Lyngb.) M.Schmidt and Diadesmis confervacea (Grun.) Hustedt in the waters of Serbia

For the first time in Serbia, the presence of Didymosphenia geminata was recorded in lakes of the Šar Planina mountain (Urošević, 1994). Subsequently, it was observed in the rivers Danube, Tisa, Sava. Detailed range of D. geminata spreading in the waters of Serbia was given by Subakov-Simić et al. (2006). Throughout monitiring rivers and channels in Serbia we recorded expand of this species in norther part of Serbia, Vojvodina, in the channel Novi Sad-Savino Selo. Diadesmis confervacea is diatom with a mainly tropical distribution. Majority of the findings in Europe originate from quiescent waters of botanical gardens and it is common in power plant discharges (Coste and Ector, 2000). They suggest it is invasive species that may spread further if global warming persists. While monitoring rivers and channels of Serbia from 2002 till 2013 we noticed the rapid expansion of distribution of D. confervacea. It occupied new habitats and nowadays can be found in the rivers Jegrička and Zasavica, as well in the channals Bački Petrovac-Karavukovo, Bečej-Bogojevo and Kikindski kanal in Vojvodina.6th Balkan Botanical Congress, Rijeka, September 14-18, 201