Statistical interpretation of geometrical characteristics of discontinuities in rock masses : master’s thesis

Pukotine su uz monolite sastavni dio stijenske mase. Statističkom analizom značajki pukotina (diskontinuiteta) može se postići bolje razumijevanje geološke prošlosti i ponašanje stijenske mase pod različitim uvjetima. Određivanjem razdioba vrijednosti za orijentacije, razmake i postojanosti diskontinuiteta stvara se slika o potencijalnom izgledu blokova unutar stijene što bitno utječe na stabilnost kosina i podzemnih prostorija. Kroz ovaj rad su prikazane metode prikupljanja podataka i metode određivanja teoretskih razdioba koje bi najbolje opisivale navedene značajke. Provođenje statističke analize orijentacija, razmaka i postojanosti diskontinuiteta je napravljeno prema podacima prikupljenih sa kamenoloma „Ivanec“.Abstract: Discontinuities and monolithes form a rock mass. Better understanding of geological history and rock mass behavior under different conditions could be achievable through statistical analysis of discontinuity characteristics. By defining distribution of values for orientations, spacing and persistence of discontinuities, it is possible to form image of blocks inside a rock that is crucial for defining rock slope and underground spaces stability. Methods of sampling and statistical describing of mentioned discontinuity characteristics had been elaborated by this thesis. Statistical analysis of orientation, spacing and persistence had been conducted based on data collected from „Ivanec“ quarry

Statistical interpretation of geometrical characteristics of discontinuities in rock masses : master’s thesis

Pukotine su uz monolite sastavni dio stijenske mase. Statističkom analizom značajki pukotina (diskontinuiteta) može se postići bolje razumijevanje geološke prošlosti i ponašanje stijenske mase pod različitim uvjetima. Određivanjem razdioba vrijednosti za orijentacije, razmake i postojanosti diskontinuiteta stvara se slika o potencijalnom izgledu blokova unutar stijene što bitno utječe na stabilnost kosina i podzemnih prostorija. Kroz ovaj rad su prikazane metode prikupljanja podataka i metode određivanja teoretskih razdioba koje bi najbolje opisivale navedene značajke. Provođenje statističke analize orijentacija, razmaka i postojanosti diskontinuiteta je napravljeno prema podacima prikupljenih sa kamenoloma „Ivanec“.Abstract: Discontinuities and monolithes form a rock mass. Better understanding of geological history and rock mass behavior under different conditions could be achievable through statistical analysis of discontinuity characteristics. By defining distribution of values for orientations, spacing and persistence of discontinuities, it is possible to form image of blocks inside a rock that is crucial for defining rock slope and underground spaces stability. Methods of sampling and statistical describing of mentioned discontinuity characteristics had been elaborated by this thesis. Statistical analysis of orientation, spacing and persistence had been conducted based on data collected from „Ivanec“ quarry

Residual efficacy of deltamethrin applied on porous and non-porous surfaces against Sitophilus granarius (L.), Plodia interpunctella (Hübner) and Blattella germanica (L.): Poster

Residual efficacy of the insecticide deltamethrin, EC formulation with 25 g/L AI + 225 g/L PBO (synergist piperonyl butoxide), against lab populations of S. granarius and P. interpunctella by applying product water solutions (12.5 mg AI/m2) to porous surface, and against B. germanica by applying them to non-porous surface, was investigated in laboratory (at 25±1°C and 55-60% r.h.). The mortality of cockroach adults on deposits aged 0, 14, 30 and 45 days was estimated after 30 minutes of their contact with the treated surfaces, and additional 24 h and 48 h of recovery, while the mortality of stored-product insects (adults or larvae) on 0, 7, 14 and 30 days old deposits was estimated after 2, 7 and 14 days of exposure to treated surfaces and additional 7 days of recovery. Mortality of cockroaches in all variants was 100%, except on 45 days old deposit and after 24 h of recovery, when it was 97%. Deltamethrin caused 0% weevil mortality after 2 days of exposure to deposits of all ages (0-30 days), while P. interpunctella larval mortality was 87-93%. However, mortality was 100% after 7 and 14 days of weevil/moth exposure in all variants of deposit ages and/or additional 7 days of recovery. The results show that deltamethrin applied to porous and non-porous surfaces is a highly effective insecticide for weevil/moth and cockroach control, and it showed a good residual activity for up to 30 and 45 days, respectively.Residual efficacy of the insecticide deltamethrin, EC formulation with 25 g/L AI + 225 g/L PBO (synergist piperonyl butoxide), against lab populations of S. granarius and P. interpunctella by applying product water solutions (12.5 mg AI/m2) to porous surface, and against B. germanica by applying them to non-porous surface, was investigated in laboratory (at 25±1°C and 55-60% r.h.). The mortality of cockroach adults on deposits aged 0, 14, 30 and 45 days was estimated after 30 minutes of their contact with the treated surfaces, and additional 24 h and 48 h of recovery, while the mortality of stored-product insects (adults or larvae) on 0, 7, 14 and 30 days old deposits was estimated after 2, 7 and 14 days of exposure to treated surfaces and additional 7 days of recovery. Mortality of cockroaches in all variants was 100%, except on 45 days old deposit and after 24 h of recovery, when it was 97%. Deltamethrin caused 0% weevil mortality after 2 days of exposure to deposits of all ages (0-30 days), while P. interpunctella larval mortality was 87-93%. However, mortality was 100% after 7 and 14 days of weevil/moth exposure in all variants of deposit ages and/or additional 7 days of recovery. The results show that deltamethrin applied to porous and non-porous surfaces is a highly effective insecticide for weevil/moth and cockroach control, and it showed a good residual activity for up to 30 and 45 days, respectively

Suzbijanje kukuruzove zlatice Diabrotica virgifera virgifera

Western corn rootworm (WCR) was registered for the first time in Europe near the Surčin international airport in Serbia in 1992. The spread of WCR on the territory of Serbia and its population density increased fast. The Serbian territory was entirely populated in the following few years, while major damages occurred on corn grown for two or more years in the same field. Data on damages caused to over 140,000 ha under corn until 1999 were collected by organized monitoring. After 2000 and 2003, population abundance of D.v. virgifera, as well as the number of damaged corn fields, significantly decreased due to drought and application of crop rotation. Corn rootworm has one generation per year. It overwinters in the egg stage. Under the climatic conditions of Serbia larvae hatching starts around May 15th. The highest number of larvae on root is observed around June 20th when feeding is most intensive and plants become lodged as they lose roots. First adults emerge by the end of June. Their abundance increases during July and reaches maximum by the end of the month. From the second decade of August the abundance decreases. Adults are present in the field until the first frosts. Larvae are much more harmful and significant than adults. Larvae feed on roots or into roots by boring. Roots can be entirely destroyed under heavy attack and the host plants lodged already at the end of June. Under our climatic and agrotechnical conditions, adults are sporadic pests. Adults are a threat only when sowing is done after the optimal sowing date or in case of stubble corn sowing. Crop rotation is an efficient and most widespread means of WCR control. No damage on corn grown in crop rotation has been registered in Serbia for now. In the first year of production corn does not require protection from Diabrotica virgifera virgifera LeConte larvae. Several insecticides have performed high efficacy by application at sowing and have been registered for commercial use. On the other hand, soil insecticides have never been applied on a significant area in Serbia.Kukuruzova zlatica je prvi put registrovana 1992. godine pored međunarodnog aerodroma Surčin. Širenje zlatice po teritoriji Srbije i porast gustine njene populacije je bilo brzo. Celokupna teritorija Srbije je naseljena u narednih nekoliko godina, pri čemu su se značajne štete javile na kukuruzu u ponovljenoj setvi. Sakupljeni su podaci o štetama na preko 140.000 ha kukuruza u periodu do 1999. godine. Posle 2000. i 2003. godine brojnost popualcije D.v. virgifera kao i broj oštećenih kukuruzovih polja je značajno smanjen zbog suše i masovne primene plodoreda. Kukuruzova zlatica ima jednu generaciju godišnje. Prezimljava u stadijumu jajeta. U klimatskim uslovima Srbije piljenje larvi počinje oko 15. maja. Najveći broj larvi se nalazi na korenu kukuruza oko 20. juna kada je ishrana larvi najintenzivnija. Zbog gubitka korena dolazi do poleganja biljaka. Odrasli insekti se javljaju krajem juna. Njihova brojnost raste tokom jula i dostiže maksimum krajem tog meseca. Od druge dekade avgusta brojnost imaga opada. Odrasli insekti se mogu naći u polju sve do prvih mrazeva. Larve se hrane na korenu ili se ubušuju u njega. U slučaju velikog napada koren može biti potpuno uništen i takve biljke već krajem juna poležu. U našim klimatskim i agrotehničkim uslovima odrasli insekti su sporadične štetočine. Oni mogu biti štetni u slučajevima kasnije setve ili postrne setve. Plodored je efikasan i najrasprostranjeniji način suzbijanja kukuruzove zlatice. Do sada se u Srbiji nisu javile štete na kukuruzu u plodoredu. Stoga se u kukuruzu u plodoredu ne primenjuju zaštitne mere. Više insekticida pokazuje dobre rezultate u suzbijanju kukuruzove zlatice kada se primenjuju sa setvom i imaju dozvolu za primenu u Srbiji. Međutim, zemljišni insekticidi nisu nikada do sada primenjeni na većim površinama za suzbijanje kukuruzove zlatice

Rezidualna efikasnost deltametrina u suzbijanju Sitophilus oryzae (L.), Rhyzopertha dominica (F.), Tribolium castaneum (Herbst) i Sitotroga cerealella (Oliv.) u tretiranoj pšenici

Residual efficacy of the insecticide deltamethrin, an EC formulation containing 25 g/L AI + 225 g/L PBO (piperonyl butoxide synergist), against lab populations of Sitophilus oryzae, Rhyzopertha dominica, Tribolium castaneum and Sitotroga cerealella was investigated in the laboratory by applying product water solutions (0.25 mg AI/kg) to wheat grain (at 25±1°C and 60±5% r.h.). Adult mortality on 0, 7, 14 and 30 days old deposits was estimated after 2, 7 and 14 days of exposure to treated wheat grain and additional 7 days of recovery. Progeny reduction (PR, %) was also assessed. After 2 days of exposure to deposits of all ages, deltamethrin caused only 0-10% mortality of coleopterans (up to 37% after the recovery period) and 23-30% of S. cerealella, while mortality before and after recovery from 14 days of exposure was 95-50% for S. oryzae, 97-100% for R. dominica, 99-100% for T. castaneum and 100% for S. cerealella. Progeny production of S. oryzae was highest after parents contacted with 14 days old deposit of deltamethrin (PR, 76%), and lowest after contact with fresh deposit (PR, 95%), while R. dominica and T. castaneum had no progeny on any deltamethrin deposit age in wheat (PR, 100%), and S. cerealella had only a very low progeny (PR, 99%). The results showed that the synergised deltamethrin, applied at 0.25 mg/kg in wheat grain, is a highly effective insecticide for stored-product insect control, while a higher dose is required for successful residual control of S. oryzae.Ispitivana je rezidualna efikasnost deltametrina, EC formulacije sa 25 g/L a.s. + 225 g/L PBO (piperonil butoksid) u suzbijanju laboratorijskih populacija Sitophilus oryzae, Rhyzopertha dominica, Tribolium castaneum i Sitotroga cerealella nanošenjem vodenog rastvora insekticida (0.25 mg a.s./kg) na pšenicu u zrnu u laboratorijskim uslovima (25±1°C i 60±5 % r.v.v). Smrtnost adulta na depozitima starosti 0, 7, 14 i 30 dana je utvrđivana posle 2, 7 i 14 dana izlaganja u tretiranoj pšenici i 7 dana oporavka adulta (izuzev S. cerealella) u netretiraoj pšenici. Takođe je utvrđivana i produkcija potomstva izlaganih roditelja (PR, %). Posle 2 dana izlaganja bez obzira na starost depozita, deltametrin je prouzrokovao 0-10% smrtnosti tvrdokrilaca (posle oporavka do 37%) i 23-30% smrtnosti S. cerealella, dok je posle 14 dana izlaganja smrtnost S. oryzae pre i posle perioda oporavka bila 95-50%, R. dominica 97-100%, T. castaneum 99-100% i S. cerealella 100%. Najveći broj potomaka S. oryzae je utvrđen posle kontakta roditelja sa 14 dana starim depozitom deltametrina (PR, 76%), a najmanji posle kontakta sa svežim depozitom (PR, 95%), dok u tretiranoj pšenici, bez obzira na starost depozita, nije bilo potomaka R. dominica i T. castaneum (PR, 100%), dok je kod S. cerealella zabeležen mali broj potomaka (PR, 99%). Na osnovu dobijenih rezultata može se zaključiti da je sinergizovani deltametrin primenjen u količini 0,25 mg/kg pšenice visoko efektivan u suzbijanju skladišnih insekata, dok je za dužu zaštitu pšenice od S. oryzae potrebno primeniti veću dozu ovog insekticida

Atraktivnost mirisa infestirane i neinfestirane pšenice u zrnu i prekrupe za skladišne tvrdokrilce

Using a two-way olfactometer, the effects of the whole wheat grains and coarse wheat meal odors on the primary Sitophilus granarius (L.), S. oryzae (L.) and S. zeamais (Motch.) and secondary Tribolium castaneum (Herbst) and T. confusum (Du Val) stored-product pests behavior were examined. Whole wheat grains and coarse wheat meal were used in uninfested and infested form. Whole wheat grains were infested with S. oryzae adults and coarse wheat meal with T. castaneum adults. The odors of infested wheat grains depending on the insect species were 1.9 to 3 times more attractive than the uninfested wheat grains odors, except for the T. castaneum for whome the odors of infested and uninfested grains were equally attractive (p = 0.641). The greatest difference in the attractiveness of the infested and uninfested wheat grains odors was found for T. confusum (3 times longer in the arm with the odors of infested grain), and the smallest for S. granarius (1.9 times). We found that all primary and secondary stored-product pests, depending on the species, were 1.4 - 2.4 times more attracted to the odors of infested compared to the odors of uninfested wheat meal. The greatest difference in the atraction of infested and uninfested coarse wheat meal odors was recorded for the T. confusum, whose adults were 2.4 times longer in the arm with the odors of infested coarse wheat meal than in the arm with odors of uninfested wheat meal, while the smallest difference (1.4 times) was recorded for S. oryzae. The results of this study give a significant contribution to a better understanding of the storage insects behavior, which could be used in the design of new methods of monitoring of their presence in stored products.Pomoću dvokrakog olfaktometra ispitivan je uticaj mirisa pšenice u zrnu i pšenične prekrupe na ponašanje primarnih štetočina Sitophilus granarius (L.), Sitophilus oryzae (L.) i Sitophilus zeamais (Motch) i sekundarnih štetočina Tribolium castaneum (Herbst) i Tribolium confusum (Du Val). Pšenica u zrnu i pšenična prekrupa korišćeni su u neinfestiranom i infestiranom obliku, s tim da su zrna pšenice bila infestirana adultima S.oryzae a prekrupa adultima T. castaneum. Miris infestirane pšenice u zrnu je bio u zavisnosti od insekatske vrste od 1,9 do 3,0 puta atraktivniji od mirisa neinfestirane pšenice, osim za adulte T. castaneum za koje je bio podjednako privlačan (p=0,641). Najveća razlika u atraktivnosti mirisa infestirane i neinfestirane pšenice je zabeležena kod T. confusum (3 puta više vremena u kraku sa mirisom infestiranog zrna), a najmanja kod S. granarius (1,9 puta). Sve primarne i sekundarne štetočine su u zavisnosti od vrste bile od 1,4 - 2,4 puta više privučene mirisom infestirane, nego mirisom neinfestirane pšenične prekrupe. Najveća razlika u atraktivnosti mirisa infestirane i neinfestirane prekrupe, utvrđena je kod T. confusum, čiji su adulti proveli 2,4 puta više vremena u kraku sa mirisom infestirane prekrupe nego u kraku sa mirisom neinfestirane, a najmanja razlika (1,4 puta) zabeležena je kod S.oryzae. Rezultati ovih istraživanja daju značajan doprinos boljem poznavanju ponašanja skladišnih insekata, što bi moglo da se upotrebi u osmišljavanju novog načina praćenja njihovog prisustva u uskladištenim proizvodima

Efikasnost različitih insekticida u poljskim uslovima u suzbijanju repičinog sjajnika (Meligethes aeneus F.) u usevima ozime uljane repice

Since pollen beetle, M. aeneus, is usually controlled by insecticides, the efficacy of several compounds with different modes of action against adult beetles was studied in a threeyear field study. The selected insecticides were: three pyrethroids (lambda-cyhalothrin, alpha-cypermethrin and bifenthrin), an oganophosphate (pirimiphos-methyl), a combination of an organophosphate and a pyrethroid (chlorpyrifos + cypermethrin) and a neonicotinoid (thiacloprid). The insecticides were applied at label rates to winter rapeseed crops at the moment of visible but still closed flower buds (BBCH 55-57). In all experiments, the efficacy of pyrethroids and the organophosphate ranged from 90-100%, while the efficacy of the neonicotinoid was 85-95%. Therefore, they can be recommended for control of pollen beetle in Serbia.S obzirom da gajenje uljane repice za sobom povlači i primenu insekticida za suzbijanje repičinog sjajnika kao najštetnije insekatske vrste, u radu je tokom trogodišnjih poljskih ogleda (2008-2010. godina) na tri lokaliteta (Kovin, Smederevo i Požarevac) ispitana efikasnost insekticida različitih mehanizama delovanja: piretroida (lambda-cihalotrin, alfa-cipermetrin, bifentrin), organofosfata (pirimifos-metil), kombinacije organofosfata i piretroida (hlorpirifos + cipermetrin) i neonikotinoida (tiakloprid) za imaga M. aeneus. Komercijalne formulacije insekticida su primenjivane u preporučenim dozama u usevima ozime uljane repice u vreme vidljivih cvetnih pupoljaka, ali još zatvorenih (BBCH 55-57). Efikasnost piretroida i organofosfata je tokom svih ogleda bila 90-100%, a neonikotinoida 85-95%, pa se zbog ispoljene visoke efikasnosti može preporučiti njihova primena u Srbiji

Efektivnost prašiva diatomejske zemlje za žitnog moljca i kukuruznog žiška u kukuruzu u zrnu

Žitni moljac, Sitotroga cerealella (Olivier) i kukuruzni žižak, Sitophilus zeamais (Motschulsky) su ekonomski najznačajniji štetni insekti na uskladištenom kukuruzu, koji mogu da ostvare infestaciju i tokom vegetacije. Prašiva na bazi diatomejske zemlje (DZ) su sve više zastupljena u programima suzbijanja skladišnih insekata, jer za razliku od sintetisanih insekticida nema štetnih ostataka i doprinose očuvanju kvaliteta uskladištenih proizvoda. Insekticidni potencijal prašiva i mogućnost komercijalne primene zavise od sadržaja amorfnog silicijum dioksida (SiO2), veličine čestica i geografskog porekla. Namera u ovom istraživanju je bila da se ispita efektivnost tri prašiva DZ za imaga S. cerealella i S. zeamais u tretiranom kukuruzu u zrnu. Prašiva DZ S1, S2 i S3 koja su korišćena u istraživanju su iz depozita diatomita u Srbiji sa 78,8%, 63,1% i 46,5% amorfnog SiO2 i najzastupljenijom veličinom čestica do 20 μm. Ispitivanja su realizovana prema OEPP/EPPO protokolima za testiranje kontaktne/rezidualne aktivnosti insekticida. Imaga S. cerealella i S. zeamais su izlagana u kukuruzu tretiranom prašivima u količinama 0,5, 1 i 1,5 g/kg. Smrtnost imaga obe vrste je utvrđena posle sedam i 14 dana izlaganja i sedam dana oporavka samo imaga S. zeamais u netretiranom kukuruzu. Uticaj prašiva na redukciju potomstva je utvrđen posle sedam nedelja za S. cerealella i posle osam nedelja za S. zeamais. Posle sedam dana izlaganja, utvrđena je smrtnost svih izlaganih imaga (100%) S. cerealella u kukuruzu tretiranom sa 0,5-1,5 g/kg prašiva S1, i 1 i 1,5 g/kg prašiva S2 i S3, dok je efikasnost prašiva S2 i S3 u količini od 0,5 g/kg bila 90% i 70%, respektivno. U istom periodu najveća utvrđena smrtnost, 19%, izlaganih imaga S. zeamais je bila u kukuruzu tretiranom sa 1,5 g/kg prašiva S1, dok je posle oporavka žižaka izlaganih ovoj količini efikasnost bila 32%. Posle 14 dana sva prašiva su bila maksimalno efikasna za imaga S. cerealella, dok je za imaga S. zeamais, najveća efikasnost (84%) utvrđena posle 14 dana kontakta sa 1,5 g/kg prašiva S1 i sedam dana oporavka. Visoka redukcija (≥90%) potomstva kod S. cerealella je utvrđena posle sedam dana u kukuruzu tretiranom sa 1 i 1,5 g/kg prašiva S1 i 1,5 g/kg prašiva S2 i, posle 14 dana u kukuruzu tretiranom sa sve tri količine prašiva S1 i S2 i sa 1,5 g/kg prašiva S3. Najveću redukciju potomstva kod S. zeamais 71% i 54% posle sedam dana i 86% i 67% posle 14 dana su prouzrokovala prašiva S1 i S2 sa količinom 1,5 g/kg. Dužina izlaganja, oporavak, kao i sadržaj SiO2 su značajno uticali na ukupnu efektivnost testiranih prašiva. Diatomejska zemlja S1 je pokazala najveću insekticidnu aktivnost i mogućnost uključivanja u programe zaštite uskladištenog kukuruza u zrnu od S. cerealella i S. zeamais

Adenotonsillectomy in a two-year-old boy with extremely severe obstructive sleep apnea

Postoje razne kirurške i ne-kirurške mogućnosti liječenja opstruktivne apneje u snu (OSA) kod odraslih, dok je kod djece kirurško liječenje jedina mogućnost zbog činjenice da je više od 90% slučajeva OSA u djetinjstvu povezano s hipertrofi jom adenoida i tonzila. Dob ispod tri godine često se opisuje kao jedan o najčešćih čimbenika rizika za razvoj poslijeoperacijskih komplikacija. Najvažniji dodatni rizični čimbenik je težina bolesti mjerena polisomnografi jom (PSG). Opisuje se slučaj 20-mjesečnog dječaka s iznimno teškom OSA i anamnezom opetovanog prestanka disanja u snu u trajanju do 30 sekunda i najnižom zabilježenom zasićenošću tijekom PSG od 67%, uz indeks AHI od 58,43/h. Kako se zbog niskog cirkulirajućeg volumena krvi klasična adenotonzilektomija preporuča tek nakon što dijete navrši tri godine, razmatrali su se različiti pristupi, no na koncu je izvedena klasična adenotonzilektomija tehnikom “cold steel” kad je dijete navršilo dvije godine. Ovaj slučaj ukazuje na važnost kirurškog liječenja teških slučajeva OSA-e čak i kod vrlo male djece usprkos preporukama, i to zbog povećanih rizika za neurokognitivni razvoj i smetnje ponašanja.While there is a variety of surgical and non-surgical treatment options for obstructive sleep apnoea (OSA) in adults, surgery remains the option of choice in paediatric patients due to the fact that more than 90% of childhood OSA is associated with adenotonsillar hypertrophy. Age under three years is often described as one of the most common risk factors for developing postoperative complications. The most important additional risk factor is severity of the disease as measured by polysomnography (PSG). The authors report a case of a 20-month-old boy with extremely severe OSA and a history of repeated respiratory cessation during sleep lasting for up to 30 seconds and lowest recorded saturation during PSG of 67% with the apnoea-hypopnoea index 58.43/h. As classical adenotonsillectomy is recommended only after the child has reached three years, due to the small circulating volume of the blood, several solutions were considered but, ultimately, classical ‘cold steel’ adenotonsillectomy was performed when the child reached two years. This case shows the importance of surgical treatment in severe cases of OSA even in very small children, despite the recommendations, due to the increased risks in neurocognitive and behavioural development

Uticaj etarskih uija iz tri vrste biljaka roda Cymbopogon na ponašanje kestenjastog brašnara (Tribolium castaneum Herbst)

Behavior bioassays were conducted in the laboratory (23 ± 1°C and 50 ± 5% r.h.) using the olfactometer to determine the effects of essential oils of three plant species in the Cymbopogon genus (Lemongrass), Cymbopogon nervatus, C. proximus and C. schoenanthus, on adults of Tribolium castaneum. The effect of essential oils was compared to a commercial biopesticide based on azadirachtin at three concentrations (0.0001, 0.001 and 0.01%). The results showed that all essential oils and the azadirachtin-based biopesticide had significant (p lt 0.05) repellent effects on T. castaneum adults at all tested concentrations, except C. proximus essential oil which showed a neutral effect at the lowest concentration. The highest concentrations of the essential oils of C. nervatus and C. proximus had significantly stronger repellent effects (p lt 0.05) than the lowest concentration. At the concentrations of 0.0001 and 0.001% all tested essential oils and azadirachtin showed a similar repellent effect without statistically significant difference, whereas the oil of C. nervatus had the highest repellent effect on adults of T. castaneum at the 0.01% concentration. Considering all tested variations, the essential oils of plants of the genus Cymbopogon showed similar or stronger repellent effects on T. castaneum adults than the biopesticide based on azadirachtin.U laboratorijskim uslovima (24±1°C i 50±5% r.v.v.) je pomoću olfaktometra ispitivan uticaj etarskih ulja iz tri biljne vrste roda limunovih trava (Cymbopogon nervatus, Cymbopogon proximus i Cymbopogon schoenanthus) na ponašanje (atraktivnost/repelentnost) adulta T. castaneum. Uticaj etarskih ulja na ponašanje kestenjastog brašnara, poređen je sa uticajem biopesticida na bazi azadirahtina u tri koncentracije: 0.0001, 0.001 i 0.01%. Rezultati testiranja pokazali su da sva etarska ulja i biopesticid na bazi azadirahtina u svim ispitivanim koncentracijama ispoljavaju statistički značajan odbijajući uticaj - repelentni efekat na adulte kestenjastog brašnara, osim najniže koncentracije ulja iz biljke C. proximus koja je ispoljila neutralan efekat na brašnara. Najviša koncentracija ulja iz biljaka C. nervatus i C. proximus je ispoljila statistički značajno jači repelentni efekat u odnosu na najnižu koncentraciju. Sva ispitivana etarska ulja i azadirahtin su u koncentracijama 0.0001 i 0.001% ispoljila sličan repelentni efekat bez statistički značajne razlike, dok je ulje iz biljke C. nervatus u koncentraciji 0.01% prouzrokovalo statistički značajno jači repelentni efekat na adulte kestenjastog brašnara u odnosu na ostale ispitivane supstance. Na osnovu rezultata istraživanja sa adultima kestenjastog brašnara može se zaključiti da su etarska ulja iz tri vrste biljaka iz roda Cymbopogon ispoljila sličan i/ili jači repelentni efekat od biopesticida na bazi azadirahtina. Takođe, dobijeni rezultati pokazuju značajan potencijal upotrebe ulja ovih biljaka kao prirodnog sredstva za zaštitu uskladištenih biljnih proizvoda