Susceptibility of red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) populations to synthetic and natural insecticides in interaction with effects of extreme temperature

Ispitivana je toksičnost sintetisanih (kontaktnih) insekticida za adulte laboratorijske populacije Tribolium castaneum i osetljivost/rezistentnost populacija iz različitih skladišnih objekata. Parametri toksičnosti (LD parametri i ld-p linije) su utvrđivani posle mikroaplikacije insekticida: dihlorvosa, malationa, pirimifos-metila, hlorpirifos-metila, deltametrina i bifentrina i posle aplikacije insekticidnih preparata: malationa, pirimifos-metila, hlorpirifos-metila, deltametrina sa piperonil butoksidom, bifentrina, tiametoksama, spinosada i abamektina na pšenici u zrnu. Utvrđivani su efekti prirodnih insekticida (inertnih prašiva) na bazi zeolita (Prirodni zeolit, Prirodni zeolit fine granulacije, Modifikovani prirodni zeolit) i diatomejske zemlje (DZ S-1, DZ S-2, Protect-It) pri različitm vlažnostima vazduha na adulte T. castaneum iz laboratorijske i populacija sa promenjenom osetljivošću na insekticide. Utvrđivani su efekti ekstremene temperature od 50°C izlaganjem adulta T. castaneum iz laboratorijske populacije i rezistentnih populacija u brašnu i pšenici u zrnu. U interakciji sa subletalnim ekspozicijama (LT25 i LT50) na 50°C u pšenici u zrnu, utvrđivani su efekti LD50 sintetisanih insekticida i inertnih prašiva (0,25 i 0,5 g/kg). Mikroaplikacijom je utvrđeno da je deltametrin najtoksičniji insekticid za laboratorijsku populaciju, te populacije Nikinci i Jakovo. Za T. castaneum iz Nikinaca selekcionisane pirimifosmetilom najtoksičniji insekticid je hlorpirifos-metil, a za selekcionisane deltametrinom, pirimifosmetil. Malation je kod svih populacija ispoljio najslabiju toksičnost, a kod sedam od 12 populacija diskriminativna doza ovog insekticida je prouzrokovala smrtnost <85%. U pšenici u zrnu za adulte iz laboratorijske populacije, Jakova i Nikinaca selekcionisanih deltametrinom najtoksičniji insekticid je tiametoksam, a za adulte iz Nikinaca i Nikinaca selekcionisanih pirimifos-metilom, deltametrin sa piperonil butoksidom. Populacija Jakovo je razvila rezistentnost na malation, a populacija iz Nikinaca pored malationa ispoljava i rezistentnost na tiametoksam i abamektin. Efikasnost inertnih prašiva zavisi od relativne vlažnosti vazduha i osobina prašiva (sadržaja SiO2 i veličine čestica). Utvrđen je značajan insekticidni potencijal prašiva DZ S-1, DZ S-2 i Prirodni zeolit, dok je preparat Protect-It značajno efikasniji. Visoku efikasnost i redukciju potomstva prašiva su postigla posle 21 dana izlaganja. Nisu utvrđene statistički značajne razlike u osetljivosti na diatomejsku zemlju između laboratorijske populacije i populacija iz Nikinaca i Kikinde koje ispoljavaju promenjenu osetljivost na malation. Nisu utvrđene značajne razlike u delovanju ekstremne temperature 50°C u brašnu i pšenici u zrnu za brašnare iz testiranih populacija. Sintetisani insekticidi značajno povećavaju efikasnost u interakciji sa 50°C, a najveći uticaj interakcije je utvrđen kod bifentrina, dok je kod tiametoksama i abamektina utvrđen najmanji uticaj. Preparat diatomejske zemlje značajno povećava efikasnost u interakciji sa 50°C, dok je kod drugih prašiva utvrđen slab uticaj interakcije na efikasnost.Toxicity of synthetic (contact) insecticides against adults of laboratory population of Tribolium castaneum and susceptibility/resistance of the populations from different storage facilities was studied. Toxicity parameters (LD parameters and ld-p lines) were determined after microapplication of the following insecticides: dichlorvos, malathion, pirimiphos-methyl, chlorpyrifos-methyl, deltamethrin and bifenthrin and after application of insecticide products: malathion, pirimiphos-methyl, chlorpyrifos-methyl, deltamethrin with piperonyl butoxide, bifenthrin, thiamethoxam, spinosad and abamectin on wheat grain. Effects of natural insecticides (inert dust) based on zeolites (Natural zeolite, Fine granulated natural zeolite, Modified natural zeolite) and diatomaceous earth (DE S-1, DE S-2, Protect-It) against T. castaneum adults from laboratory population and populations with altered susceptibility to contact insecticides at different air humidity, were also determined. Effects of extreme temperature of 50°C were evaluated by exposure of T. castaneum from laboratory population and resistant populations in flour and wheat grain. In interaction with sublethal exposures (LT25 and LT50) at 50°C in wheat grain, effects of LD50 of synthetic insecticides and inert dusts (0,25 and 0,5 g/kg) were established. Using microapplication, it was found that deltamethrin is the most toxic insecticide to laboratory population, and populations from Nikinci and Jakovo. The most toxic insecticide to T. castaneum populations from Nikinci selected with pirimiphos-methyl, was chlorpyrifos-methyl and to populations selected with deltamethrin, it was pirimiphos-methyl. In all populations, malathion expressed the lowest toxicity, and in seven out of 12 populations, discriminative dose of this insecticide caused mortality <85%. The most toxic insecticide in wheat grain to adults from laboratory and populations from Jakovo and Nikinci selected with deltamethrin was thiamethoxam, and to adults from Nikinci and adults from Nikinci selected with pirimiphos-methyl, it was deltamethrin with piperonyl butoxide. Population from Jakovo developed resistance to malathion while population from Nikinci, besides to malathion, showed resistance to thiamethoxam and abamectin. Efficacy of inert dusts depends on relative air humidity and dust properties (SiO2 content and particle size). A notable insecticidal potential of the dusts DE S-1, DE S-2 and Natural zeolite was found, while the product Protect-It had significantly higher efficacy. High efficacy and progeny reduction were obtained after 21-day exposure to inert dusts. No statistically significant differences in susceptibility to diatomaceous earth were found between laboratory population and populations from Nikinci and Kikinda which expressed altered susceptibility to malathion. No statistically significant differences were found for effect of extreme temperature of 50°C in flour and wheat grain on T. castaneum from tested populations. Efficacy of synthetic insecticides was significantly increased in interaction with 50°C, and the strongest effect of interaction was established for bifenthrin, while for thiamethoxam and abamectin the effect was the weakest. Efficacy of diatomaceus earth product was significantly increased in interaction with 50°C, while weak impact of interaction on efficacy of other dusts was observed

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

Cardiovascular diseases, risk factors and barriers in their prevention in Croatia [Kardiovaskularne bolesti, rizični faktori i zapreke za prevenciju u Hrvatskoj]

Cardiovascular diseases are the leading cause of death in Croatia, with significant regional differences. Despite high mortality rates, high prevalence of various cardiovascular risk factors and well organized public health network, comprehensive system for cardiovascular disease monitoring and interventions does not exist. In this study we analyzed legislation framework and responsibilities of stakeholders relevant for cardiovascular disease surveillance and prevention. According to the international experiences we analyzed characteristics of cardiovascular disease prevention in Croatia and causes of the problems appeared in the preventive programs in Croatia. Analysis showed that primary problem is not inefficiency, but the existence of barriers in preventive activities definition, responsibilities distribution and task implementation. Main cause for such situation is incompatibility of the existing practices in clinical medicine and public health with recommendations from other countries. For the successful prevention of cardiovascular disease in Croatia at least three changes need to be made--define new terms and contents of prevention, define new responsibilities distribution and provide equity in health as basic criterion for successful preventive programs

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

Application of Hybrid Density Functional Theory in Calculation of Edge-to-Face Interactions of Receptor-Ligand System

Our previously described research on docking analysis of a series of isosteric N4-arylpiperazines on a model of 5-HT1A receptor was used earlier to investigate interactions of different ligands with the receptor binding site. Due to the limitations of molecular mechanics (MM) methods, docking analysis failed to give precise results about interactions that influence binding affinity of the ligands, but we presumed that aromatic-aromatic interactions, or edge-to-face, to be more precise, play an important role in the binding process. In order to further elaborate on this hypothesis, ab initio approach was used to calculate possible edge-to-face interactions on a model system and correlate them to ligand affinity. Obtained results indicate that those dispersive interactions can show notable influence on the binding of the ligands to 5-HT1A receptor. Stabilization energies of modeled receptor-ligand complex, calculated using Becke's "half-and-half" hybrid DFT method showed strong correlation with the affinity of investigated ligands towards 5-HT1A receptor

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

Uticaj osobina N-1 supstituenta na afinitet arilpiperazina prema vezivnom mestu 5-HT1A receptora

Scrotonin receptors (5-HTRs), especially the 5-HT1A subtype, have been the subject of intensive research for the past decade, due to their function in human physiology. Several structurally different classes of ligands are known to bind to the 5-HT1A receptor, but arylpiperazine derivatives are among the most important ligands. In the work, docking analyses were used to explain the binding affinities of a series of ligands with different N-1 substituent. All ligands had ill common the arylpiperazine structure, while the N-1 substituent was modified to investigate the influence of ligand structure on its binding affinity. The shape and size, as well as the rigidity of the substituents were altered to investigate the possible effects on the formation of the receptor - ligand complex.Serotoninski receptori su, a naročito 5-HT 1A pod tip, zbog značajne uloge u fiziologiji ljudskog organizma, predmet intenzivnog izučavanja tokom protekle decenije. Poznato je da se za 5-HT 1A receptor vezuje nekoliko strukturno različitih klasa liganada, ali su arilpiperazinski derivati među najznačajnijim. Da bi objasnili vezivanje serije liganada sa različitim N-1 supstituentima za receptor koristili smo analizu vezivanja (docking analizu). Svi ligandi su imali zajedničku arilpiperazinsku strukturu dok su im N-1 supstituenti modifikovani tako što je menjan oblik, veličina kao i krutost supstituenta da bi se istražio njihov eventualni uticaj na formiranje kompleksa receptor - ligand

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

Uticaj disperzivnih interakcija na afinitet vezivanja liganada sa arilpiperazinskom funkcijom za dopaminski D2 receptor

Several isosteric 1,3-dihydro-5-[2-(4-aryl-l-piperazinyl)ethyl]-2H-benzinlidazole-2-thiones were used to investigate the interactions of different ligands with the binding site of the D2 receptor. Due to limitations of the simulation methods, docking analysis failed to show precisely the interactions that influence the binding affinity of the ligands. It is presumed that dispersive forces or more precisely edge-to-face interactions play an important role in the binding process, especially for the lipophilic part of the ligands. In order to confirm this hypothesis, ab initio calculations were applied on a model system in order to find the stabilization energies of potential edge-to-face interactions and then to correlate them with the ligand affinity. The obtained results indicate that there is a significant correlation between the strength of dispersive interactions and ligand affinity. It was shown that for the calculation of stabilization energies of modeled receptor-ligand complexes the Becke "half-and-half" hybrid DFT method can be used, thus speeding up the usually long calculation time and reducing the required computer strength.Nekoliko izosternih 1,3-dihidro-5-[2-(4-aril-1-piperazinil)etil]-2H-benzimidazol-2-tiona je korišćeno da bi se ispitale interakcije različitih liganada sa vezivnim mestom dopaminskog D2 receptora. Zbog ograničenja metoda korišćenih za simulaciju vezivanja, analiza ovih rezultata nije mogla da pokaže preciznije koje interakcije utiču na afinitet vezivanja liganada. Pretpostavljeno je da disperzivne sile, ili preciznije, tzv. edge-to-face interakcije, igraju značajnu ulogu u procesu vezivanja, naročito u lipofilnom delu liganda. Da bi se potvrdila ova hipoteza primenom ab initio izračunavanja na model sistem, pokušano je izračunavanje stabilizacione energije ovih interakcija i njeno dovođenje u vezu sa afinitetom liganada. Dobijeni rezultati ukazuju da postoji značajna korelacija između jačine disperzivnih interakcija i afiniteta liganda. Pokazano je da se pri izračunavanju stabilizacionih energija modelovanih kompleksa ligand-receptor može upotrebiti Beckeova 'half-and-half' hibridna DFT metoda, što značajno smanjuje vreme potrebno za izračunavanja i potrebne računarske resurse

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