Plant substances and inert dusts – natural insecticide formulations in storage insect control

Cilj istraživanja bio je utvrditi učinkovitost botaničkih insekticida u obliku prašiva i ekstrakata, inertnih prašiva te kombinacije botaničkih insekticida i inertnih prašiva u suzbijanju triju vrsta skladišnih štetnih kukaca: Rhyzopertha dominica (Fab.), Sitophilus oryzae (L.) i Tribolium castaneum (Herbst). Istraživanje je provedeno u laboratorijskim uvjetima nizom pokusa u staklenim posudama s pšenicom te primjenom na različitim građevinskim površinama. Testirano je devet biljnih vrsta u obliku prašiva i ekstrakata te šest inertnih prašiva hrvatskoga porijekla i dijatomejska zemlja Celatom Mn-51®. Insekticidni učinak ovisio je o vrsti tretmana, dozi, ekspoziciji i vrsti kukca. Testiranjem biljnih prašiva na pšenici postignut je zadovoljavajući mortalitet (91,0%) samo kod R. dominica s prašivom lavandina pri dozi od 8 000 mg kg-1. Primjenom biljnih ekstrakta na staklenoj površini postignut je najviši mortalitet kod svih vrsta kukaca. Rezultati testiranih inertnih prašiva ukazuju da je najviši mortalitet (90,0%) kod R. dominica postignut s Celatom Mn-51®, kao i najviša inhibicija potomstva (99,19%), dok je najviši mortalitet (100,0%) kod S. oryzae postignut s inertnim prašivima D-01, MA-4 i Celatom Mn-51®, a potpuna inhibicija potomstva s Celatom Mn-51®. Maksimalni mortalitet T. castaneum postignut je s Celatom Mn-51®, a potpuna inhibicija potomstva s inertnim prašivima D-01, MA-4 i Celatom Mn-51®. Značajno smanjenje hektolitarske mase pšenice očitovalo se pri najvišim dozama (LD90) u tretmanima Celatom Mn-51®, te s inertnim prašivima PD-1 i MR-10. Rezultati testiranih mješavina prašiva ukazuju da je najviši mortalitet R. dominica (68,0%) postignut s kombinacijom Celatom Mn-51® i lavandinom pri omjeru 1:15 te je u istom tretmanu postignuta najviša inhibicija potomstva (93,83%). Testiranjem mješavina biljnih ekstrakata i inertnih prašiva nije postignut veći mortalitet kod T. castaneum u odnosu na samo inertno prašivo, osim u kombinaciji inertnog prašiva MA-4 i poljskog maka pri omjeru 1:10. Ovu je doktorsku disertaciju financirala Hrvatska zaklada za znanost projektom IP-11-2013-5570.The aim of the research was to determine the efficacy of botanical insecticides in form of powder and extract, inert dusts and combination of botanical insecticides and inert dusts in control of three stored-product insects: Rhyzopertha dominica (Fab.), Sitophilus oryzae (L.) i Tribolium castaneum (Herbst). The research was carried out in laboratory conditions through a series of experiments in glass containers filled with wheat and application on various surfaces. Nine plant species were tested as powders and extracts and also six inert dusts of Croatian origin as well as diatomaceous earth Celatom Mn-51®. The insecticidal effect depended on type of treatment, dose, exposure and insect species. Tested plant powders on wheat indicate that satisfactory mortality (91.0%) was achieved only against R. dominica with lavandin at a dose of 8,000 mg kg-1. Application of plant extracts on glass surface reached the highest mortality of all insect species. Results of tested inert dusts showed that the highest mortality (90.0%) of R. dominica was achieved with Celatom Mn-51® as well as the highest inhibition of progeny (99.19%), while maximum mortality of S. oryzae was achieved with inert dusts D-01, MA-4 and Celatom Mn-51®, which also achieved a complete progeny inhibition. Maximum mortality of T. castaneum was achieved with Celatom Mn-51® and a complete progeny inhibition was achieved with inert dusts D-01, MA-4 and Celatom Mn-51®. Significant reduction of test weight was observed at the highest LD90 doses in treatments Celatom Mn-51® and inert dusts PD-1 and MR-10. Results of tested mixture of plant powder and inert dust indicate that the highest mortality (68.0%) of R. dominica was achieved with combination of Celatom Mn-51® and lavandin at a 1:15 ratio and in the same treatment the highest progeny inhibition (93.83%) was also achieved. Testing of mixture of plant extracts and inert dusts indicate that only the combination of inert dust MA-4 and poppy at a 1:10 ratio has achieved a higher mortality of T. castaneum compared to inert dusts applied alone. This doctoral dissertation was funded by the Croatian Science Foundation under the project IP-11-2013-5570

Pilot-istraživanje djelotvornosti prirodne formulacije u zaštiti uskladištene pšenice i ječma protiv skladišnih kukaca

The stored-product insects are one of the major causes of losses in the stored cereals. Most of control measures still rely on a synthetic pesticide usage, but due to its negative side effects on the goods, human health, and the environment, there is an urgent need for an alternative control. A natural formulation based on the diatomaceous earth (DE) SilicoSec®, enhanced with the botanicals (essential oil lavender, corn oil, and bay leaves dust) and the silica gel was developed. The aim of the study was to test the activity of the developed formulation as a postharvest protectant of seed wheat and barley in the suppression Sitophilus oryzae (L.), Rhyzopertha dominica (F.) and Tribolium castaneum (Herbst). As a reference comparative value, the DE SilicoSec® was applied. Subsequent to the six months of storage under the simulated warehouse conditions, the formulation has completely suppressed the initial population development of all three tested insect species, both in wheat and barley. In wheat, a complete suppression was detected at the dose of 500 ppm against T. castaneum and 600 ppm against both R. dominica and S. oryzae. In barley, a complete suppression was detected at the doses of 500 ppm, 400 ppm, and 600 ppm against R. dominica, T. castaneum and S. oryzae, respectively. Conclusively, the results of this study indicate that the developed natural formulation based on the DE, botanicals, and silica gel was highly effective against the three major stored‐product insect species, providing a long-term safe storage of wheat and barley seeds.Skladišni kukci jedan su od glavnih uzroka nastanka gubitka uskladištenih žitarica. Većina mjera zaštite i dalje se oslanja na primjenu sintetičkih pesticida, ali zbog njihova negativnoga utjecaja na robu, ljudsko zdravlje i okoliš, velika je potreba za alternativnim mjerama zaštite. Razvijena je prirodna formulacija na bazi dijatomejske zemlje (DZ) SilicoSec®, obogaćena botaničkim komponentama (eteričnim uljem lavandina, kukuruznim uljem i prahom lovorova lišća) te silikagelom. Cilj istraživanja bio je testirati djelotvornost razvijene formulacije kao zaštitnoga sredstva uskladištenoga zrna pšenice i ječma u suzbijanju Sitophilus oryzae (L.), Rhyzopertha dominica (F.) i Tribolium castaneum (Herbst). Kao referentna usporedna vrijednost korištena je DZ SilicoSec®. Nakon šest mjeseci čuvanja u simuliranim skladišnim uvjetima, formulacija je u potpunosti suzbila razvoj početne populacije svih triju testiranih vrsta kukaca u pšenici i u ječmu. U pšenici je potpuna inhibicija postignuta pri dozi od 500 ppm kod T. castaneum te pri dozi od 600 ppm kod R. dominica i S. oryzae. U ječmu je potpuna inhibicija postignuta pri dozama od 500 ppm, 400 ppm i 600 ppm kod R. dominica T. castaneum i S. oryzae. Zaključno, rezultati ovoga istraživanja ukazuju na vrlo visoku učinkovitost razvijene prirodne formulacije na bazi dijatomejske zemlje, botaničkih komponenata i silikagela protiv triju glavnih vrtsa skladišnih kukaca, osiguravajući dugotrajnu zaštitu uskladištenoga zrna pšenice i ječma

Značaj suzbijanja korova i roka sjetve u proizvodnji kivana (Cucumis metuliferus E. Meyer Ex. Naudin) na području istočne Slavonije

Seed germination, growth, flowering and yields of kiwano (Cucumis metuliferus E. Meyer Ex. Naudin) were examined in eastern Slavonia during 2021 growing season. The objective of this study was to determine agro-morphological diversity within kiwano growing under different weed management practices and sowing time. The experiment was arranged as a 3 x 3 factorial design with three replications. Factors included three weed management options (wheat straw mulch, cultivation and un-weeded control) and three planting dates (early, mid and late May). A typical summer weed community that develops during experiment dominated with bristly foxtail (Setaria verticilata (L.) P. Beauv.) and redroot pigweed (Amaranthus retroflexus L.) while the others were with lower relative density and frequency per unit area and with the lower impact on the crop. Weed control was very effective compared to weedy check. However, sowing date appears as a critical factor in kiwano production, influencing not only emergence, growth and flowering, but also fruit number and size. This study concluded that mid sowing time and cultivation as a weed control measure has a highest agronomic potential for a kiwano production following by mid and early sowing time with mulch as a weed control measure.U pokusu provedenom u istočnoj Slavoniji tijekom 2021. godine analizirano je nicanje, rast, cvatnja i prinos kivana (Cucumis metuliferus E. Meyer Ex. Naudin). Cilj istraživanja bio je utvrditi agromorfološke razlike pri proizvodnji kivana uzgajanog s različitim sustavima kontrole korova te različitim rokovima sjetve. Pokus je postavljem kao 3 x 3 faktorski plan s tri ponavljanja. Faktori su uključivali tri varijante suzbijanja korova (primjena slame kao malča, kultivacija i kontrolna zakorovljena varijanta) te tri roka sjetve (rani, srednji i kasni). Tijekom pokusa se razvila tipična zajednica ljetnih korova u kojoj su dominirali pršljenasti muhar (Setaria verticilata (L.) P. Beauv.) i oštrodlakavi šćir (Amaranthus retroflexus L.), dok su ostali korovi bili niske relativne gustoće i frekvencije po jedinici površine i slabog utjecaja na uzgajane biljke. Tretmani suzbijanja korova bili su vrlo učinkoviti u usporedbi sa zakorovljenom kontrolom. Međutim, vrijeme sjetve pokazalo se kao kritičan faktor u proizvodnji kivana, i imalo je utjecaja ne samo na nicanje, rast i cvatnju, već i na broj i veličinu plodova. Zaključno, srednji rok sjetve i kultivacija kao mjera suzbijanja korova pokazali su najveći agronomski potencijal za proizvodnju kivana, a slijede srednji i rani rok sjetve uz primjenu malča za suzbijanje korova

Širenje pajasena (Ailanthus altissima (Mill.) Swingle) u urbanom području: primjer grada Osijeka (Republika Hrvatska)

Three-of-heaven (Ailanthus altissima (Mill.) Swingle) is considered as one of the most invasive plant species worldwide in rural and urban environment. Although tree-of-heaven is commonly observed throughout the city of Osijek (Croatia), its prevalence and frequency has not been documented. This study has been conducted from May to September 2022 in the streets of Osijek to determine the distribution, abundance and competitive advantage of this species. A survey was performed by sampling randomly selected 20 quadrats in each city district, having together 140 phytocoenological records, and presence-absence of tree-of heaven was recorded in each plot. Where present at urban habitats, the number of threes were recorded and categorized approximately by the diameter at breast height (dbh). Habitats were distinguished as follows: alleys, abandoned private areas, public areas, ruderal sites, cracked walls and road edges. Risk assessment analysis were prepared by combining quantitative (number of trees per plots) and qualitative (four categories: biological characteristics and dispersal abilities, ecological amplitude and distribution, ecological impact, and difficulty to control) data. There was e recorded a total of 189 tree-of-heaven, occurring both as solitary plants or in developed stands. The habitat types with the highest rate of tree-of-heaven are abandoned private areas (34%) followed by public areas (31%). Out of the total, 55% of the recorded tree-of heaven are young individuals belonging to the very small and small diameter classes, and are mainly present on abandoned private and public areas. Ecological impact and biological characteristics are primary course of its landscape spread.Pajasen (Ailanthus altissima (Mill.) Swingle) je jedna od najinvazivnijih biljnih vrsta širom svijeta kako u ruralnim, tako i u urbanim područjima. Premda je pajasen široko rasprostranjen na području grada Osijeka (Hrvatska), njegova prevalencija i frekvencija još do sada nije zabilježena. Istraživanje je sprovedeno od svibnja do rujna 2022. na osječkim ulicama kako bi se utvrdila njegova distribucija, abundacija i kompetitivna sposobnost. Istraživanje je obavljeno metodom slučajno odabranih kvadrata unutar svakog gradskog kvarta, što je ukupno iznosilo 140 fitocenoloških snimaka. Na plohama gdje je utvrđen pajasen, pobrojane su sve individue i kategorizirane su prema obujmu prsnog promjera stabla. Plohe su razvrstane kao: ulice, napušteni privatni posjedi, javne površine, ruderalna staništa, napuknuti zidovi i rubovi puteva. Procjena rizika pripremljena je kombinacijom kvantitativnih (broj individua po plohi) i kvalitativnih kategorija (biološka obilježja i sposobnost širenja, ekološke amplitude i rasprostranjenost, ekološki utjecaj i poteškoće u suzbijanju). Utvrdili smo ukupno 189 stabala pajesena, koji su bili prisutni i kao solitarna drva a također i oblikujući nakupine. Od urbanih staništa, s najvećim postotkom (34 %) pajasen je utvrđen na napuštenim privatnim posjedima a zatim slijede javne površine (31 %). Od ukupno zabilježenih vrsta, 55 % pajasena su mladice koje pripadaju kategoriji stabala s vrlo malim ili malim promjerom debla i uglavnom su rašireni na napuštenim privatnim posjedima i javnim površinama. Ekološka i biološka obilježja pajasena primarno su zaslužna za njegovo širenje urbanim prostorima grada Osijeka

Advances of stored insect detection and monitoring

Skladišni kukci predstavljaju značajan segment upravljanja uskladištenim poljoprivrednim proizvodima. Često su uzrok velikih gubitaka koji nastaju direktnim konzumiranjem uskladištenog proizvoda, kontaminacijom svojim prisustvom, fekalijama, dijelovima tijela, te mogu biti prijenosnici različitih alergijskih reakcija za ljude i stoku. Kao posljedica njihove životne aktivnosti, javlja se porast temperature i vlage uskladištenih proizvoda čime se dodatno ubrzava narušavanje kvalitete i kvantitete proizvoda. Za uspješno čuvanje proizvoda od iznimne je važnosti pravovremena detekcija skladišnih štetnika kako bi se na vrijeme uočila početna populacija i izbjegao nastanak značajnijih gubitaka. U preglednom radu prikazani su noviji pristupi u detekciji i monitoringu skladišnih kukaca s naglaskom na automatsku detekciju i detekciju skrivene zaraze zrnate uskladištene robe.Stored product insects represent a significant parametar for stored product management. Frequently, they cause considerable losses of stored products due to direct consummation of product, stock contamination with their presence, faeces and body parts, and also can be agent of different allergic reaction on human and livestock. As a consequence of life activity, they impact on grain temperature and moisture increase which is additionally speeding up the product quality and quantity deterioration. For successful product storing timely detection of stored product pest is of utmost importance in order to detect an initial population and to avoid huge losses. The advances in stored insect detection and monitoring are shown in this review form, with the emphasis on automatic detection and detection of hidden contagion on stored goods

Allelopathic effect of Aloe vera (L.) Burm. F. on seed germination and seedlings growth of cereals, industrial crops and vegetables

U radu je istražen alelopatski utjecaj vrste Aloe vera (L.) Burm.f. na klijavost sjemena i rast klijanaca sedam biljnih vrsta. Pokus je proveden u Petrijevim zdjelicama, gdje su procijenjeni ekstrakti svježih listova vrste A. vera u različitim koncentracijama (2, 4, 6, 8 i 10%) na klijavost, duljinu klijanaca te svježu i suhu masu klijanaca ječma, pšenice, soje, uljne bundeve, radiča, rukole i salate. Djelovanje vodenih ekstrakata ovisilo je o koncentraciji ekstrakata i test vrsti. Ekstrakti koncentracije iznad 2% smanjili su klijavost sjemena ječma i salate, dok je pozitivan utjecaj zabilježen kod uljne bundeve. Najveće smanjenje duljine korijena bilo je kod salate i to za 41,6%, dok je duljina korijena uljne bundeve bila povećana do 49,9%. Vodeni ekstrakti povećali su značajno duljinu izdanka kod pšenice, soje i uljne bundeve. Pozitivan i negativan utjecaj utvrđen je na svježu masu klijanaca test vrsta, dok je suha masa klijanaca bila snižena samo kod ječma u svim tretmanima te salate u tretmanu s ekstraktom koncentracije 4%. Među test vrstama, kao najosjetljivija se pokazao ječam kod svih mjerenih parametara, izuzev kod duljine korijena.Allelopathic effect of Aloe vera (L.) Burm.f. on seed germination and seedlings growth of seven plant species was investigated. The experiment was conducted out in Petri dishes and extracts from fresh leaves of A. vera at various concentrations (2, 4, 6, 8, and 10%) were evaluated on germination, seedlings length and fresh and dry weight of seedlings of barley, wheat, soybean, oil pumpkin, radicchio, rocket and lettuce. The effect of water extracts depended on the extract concentration and test species. Extract with concentrations above 2% reduced germination of barley and lettuce seeds, while positive effect was observed on oil pumpkin. The highest decrease of root length was recorded for lettuce by 41.6%, while the root length of oil pumpkin was increased up to 49.9%. Water extracts significantly increased shoot length of wheat, soybean and oil pumpkin. Both positive and negative effects were observed on the fresh weight of test species seedlings, while the dry weight of seedlings was reduced only for barley in all treatments, and for lettuce in the treatment with extract concentration of 4%. Among the test species barley proved to be the most sensitive in all measured parameters, except in root length

LABORATORY TESTS ON INSECTICIDAL EFFECTIVENESS OF DISODIUM OCTABORATE TETRAHYDRATE, DIATOMACEOUS EARTH AND AMORPHOUS SILICA GEL AGAINST Sitophilus oryzae (L.) AND THEIR EFFECT ON WHEAT BULK DENSITY

Istraživali smo insekticidnu učinkovitost tri različita inertna prašiva: dinatrijev oktaborat tetrahidrat (DOT) i dijatomejsku zemlju (DZ) Celatom® Mn 51 primijenjenih kao prašivo i suspenzija i silika gel Sipernat® 50 S u obliku prašiva na Sitophilus oryzae (L.) te njihov utjecaj na smanjenje hektolitarske mase. Sipernat® 50 S bio najučinkovitije je prašivo s vrlo brzim inicijalnim djelovanjem. DZ i DOT imaju sličnu učinkovitost na S. oryzae. DOT je imao nisko inicijalno djelovanje, no nakon produženog izlaganja od 8., a osobito 21. dana, mortalitet je vrlo visok (100%), slično djelovanju DZ-a. Sličan slijed prašiva zabilježen je i kod utjecaja na smanjenje hektolitarske mase. Pri dozama od 200 i 500 ppm, najmanju razliku u hektolitarskoj masi u odnosu na hektolitarsku masu netretirane pšenice imao je DOT (-1,1 i -1,9 kg hl-1, kako slijedi), potom Celatom® MN 51 (-3,5 i -4,3 kg hl-1, kako slijedi) te Sipernat® 50 S (-5.2 i -5.5 kg hl-1, kako slijedi). Zbog takvog učinka na hektolitarsku masu pšenice, DOT pripada u skupinu s najslabijim negativnim učinkom na hektolitarsku masu i stoga je obećavajuće prašivo u suzbijanju štetnika na uskladištenoj pšeniciWe examined insecticide effectiveness of three different inert dusts: disodium octaborate tetrahydrate (DOT) and diatomaceous earth (DE) Celatom® Mn 51 applied as powder and suspension, and silica gel Sipernat® 50 S applied as powder against Sitophilus oryzae (L.) and their reduction of grain bulk density. Sipernat® 50 S was the most effective dust with a very fast initial effectiveness. DE and DOT generated similar effectiveness against S. oryzae. DOT generated low initial effectiveness but after prolonged exposure time of 8 and especially after 21 days, the mortality was very high (100%), similar to the effectiveness of DE. The similar order of dusts was obtained in the reduction of wheat bulk density. Applied at dose of 200 and 500 ppm, the lowest bulk density difference in regard to bulk density of untreated wheat had DOT (-1.1 and -1.9 kg hl-1, respectively), followed by Celatom® Mn 51 (-3.5 and -4.3 kg hl-1, respectively) and Sipernat® 50 S (-5.2 and -5.5 kg hl-1, respectively). Due to the effect on wheat bulk density DOT belongs to the group with the least negative effect on bulk density and therefore, it is a promising dust to control stored grain insect pests

APPLICATION OF INERT DUST DIATOMACEOUS EARTH IN CONTROL OF LESSER GRAIN BORER RHYZOPERTHA DOMINICA FAB. (COLEOPTERA: BOSTRICHIDAE) ON VARIETIES OF WHEAT, RYE AND OATS

Laboratorijski je ispitan insekticidni učinak dijatomejske zemlje na skladišnog štetnika, žitnog kukuljičara Rhyzopertha dominica Fab. zaprašivanjem tri različite sorte pšenice (Divana, Kraljica i Vulkan), zobi (BC Marta, Winnipeg i Winsent) i raži (Albedo, Marcelo i Picasso). Cilj je bio utvrditi ima li dijatomejska zemlja jednaku djelotvornost kod različitih sorti žitarica, te utvrditi utjecaj prašiva na fizikalna svojstva sorata. Pri dozi od 500 ppm nakon 7 dana ekspozicije, najviši prosječni mortalitet kukuljičara je postignut kod raži (98,5%), zatim kod pšenice (95,9%), te najniži kod zobi (84,2%). Značajna razlika u djelotvornosti uočena je jedino kod zobi; između sorti Winsent i BC Marta, te u vremenu ekspozicije (između 7 i 21 dan kod sorata BC Marta i Winnipeg, te između 7 i 14 dana kod sorte Winsent). Dijatomejska zemlja je kod svih ispitivanih sorti žitarica djelovala na sniženje hektolitarske mase, posebice kod sorti pšenice (za 4,3-5,0 kg hl-1). Najmanje sniženje hektolitarske mase uočeno je kod raži, kod sorte Marcelo (za 0,3 kg hl-1). Također je kod tretiranih sorti žitarica (osim kod sorte zobi Winsent) zabilježeno blago sniženje vlage zrna (za 0,2 do 1,0%), kao i promjena temperature zrna od ± 0,1 do 0,4 °C. Temeljem dobivenih rezultata, vidljivo je da djelotvornost dijatomejske zemlje značajno varira ovisno o sorti žitarica.Insecticidal effect of the commercial inert dust based on diatomaceous earth was tested in laboratory conditions against stored product pest, lesser grain borer Rhyzopertha dominica Fab. on three different varieties of wheat (Divana, Kraljica i Vulkan), oats (BC Marta, Winnipeg i Winsent) and rye (Albedo, Marcelo i Picasso). The aim of this study was to determine whether diatomaceous earth has the same efficacy at different varieties of cereals, and to determine the impact of dust on physical properties of varieties. At dose of 500 ppm after 7 days of exposure, the highest average mortality of lesser grain borer was achieved in rye (98.5%), followed by wheat (95.9%), and oats (84.2%). A significant difference in efficacy was observed only in oats; between varieties Winsent and BC Marta, and in the exposure time (between 7 and 21 days in BC Martha and Winnipeg, and between 7 and 14 days at variety Winsent). Diatomaceous earth reduced test weight of all tested varieties of cereals, especially of wheat varieties (by 4.3 to 5.0 kg hl-1). A minimum test weight reduction was observed in rye, at Marcelo variety (by 0.3 kg hl-1). Further, reduction in grain moisture (0.2 to 1.0%) and oscillation in grain temperature (± 0.1 to 0.4 °C) was noticed in all treated varieties of cereals (except for varieties Winsent). Results of this study showed that the efficiency of ditomaceous earth significantly depend on variety of cereals which is treated

Evaluation of the potential value of the F1H and F2H Diatomaceous earth formulations as grain protectants against Rhyzopertha dominica (Fabricius) (Coleoptera: Bostrichidae): Poster

An insecticidal efficacy of two newly developed grain protectant formulations were assessed against lesser grain borer Rhyzopertha dominica (Fabricius) (Coleoptera: Bostrichidae) on wheat and corn after 6 months period of. Tested formulations, marked as F1H and F2H, based on inert dust, laurel leaves, lavender essential oil, corn oil, silica gel (both F1H and F2H) and pyrethrin (only F2H) were tested at six doses (from 100 ppm to 600 ppm) depending on formulation and type of grain. The appropriate weights of each formulation, were added seperately to plastic containers containing 10 kg of wheat or corn. An initial population of 200 adults of R. dominica were added into each container and left under natural environmental conditions for up to 6 months. A commercial diatomaceous earth (DE) insecticide, Celatom® Mn 51, was used for the comparison of the results, in addition to the untreated control. After six months, both formulations showed higher insecticidal effect than DE Mn 51 in corn and in wheat. Furthermore, the initial population of R. dominica, introduced in wheat was suppressed almost completely, with only 0.7%-5.3% live adults found, depending on formulations and dose. The order of efficacy was F1H>F2H>DE Mn 51. Similar suppression of the initial population was recorded in corn, where F2H was slightly more effective than F1H with 2.0%-10.6% and 4.1%-9.5% live adults found, respectively. At the same time, in the treatments with DE Mn 51 there were 4.7%-74.7% and 33.4%-56.1% live adults in wheat and corn, respectively.An insecticidal efficacy of two newly developed grain protectant formulations were assessed against lesser grain borer Rhyzopertha dominica (Fabricius) (Coleoptera: Bostrichidae) on wheat and corn after 6 months period of. Tested formulations, marked as F1H and F2H, based on inert dust, laurel leaves, lavender essential oil, corn oil, silica gel (both F1H and F2H) and pyrethrin (only F2H) were tested at six doses (from 100 ppm to 600 ppm) depending on formulation and type of grain. The appropriate weights of each formulation, were added seperately to plastic containers containing 10 kg of wheat or corn. An initial population of 200 adults of R. dominica were added into each container and left under natural environmental conditions for up to 6 months. A commercial diatomaceous earth (DE) insecticide, Celatom® Mn 51, was used for the comparison of the results, in addition to the untreated control. After six months, both formulations showed higher insecticidal effect than DE Mn 51 in corn and in wheat. Furthermore, the initial population of R. dominica, introduced in wheat was suppressed almost completely, with only 0.7%-5.3% live adults found, depending on formulations and dose. The order of efficacy was F1H>F2H>DE Mn 51. Similar suppression of the initial population was recorded in corn, where F2H was slightly more effective than F1H with 2.0%-10.6% and 4.1%-9.5% live adults found, respectively. At the same time, in the treatments with DE Mn 51 there were 4.7%-74.7% and 33.4%-56.1% live adults in wheat and corn, respectively

Osvrt na prirodne insekticide na bazi dijatomejske zemlje

The efficacy of diatomaceous earth (DE) formulations against insect pests is greatly influenced by environmental conditions. It is effective only under dry conditions and becomes wholly ineffective if it is wet. High air relative humidity and especially rain greatly reduce or completely destroy the efficacy of DE when used outdoors. Furthermore, depending on the insect species and commodity treated, DE takes from one to several days to kill insects, even in a dry environment. Because of these factors, DE is in limited use outdoors, especially in regions with a high precipitation. The main uses of DE are for the protection of stored agricultural products against insect infestation, in food industry for structural treatment and for indoor use against some household insects living in a dry environment. The mode of DEs action against insects, the effect of humidity and moisture on DE efficacy, brief overview of the research of DE use in stored grain protection and attempts to overcome DE limitations with combined use of DE and other reduced-risk methods with the insecticide activity for direct mixing with grains are discussed in this article.Klimatski uvjeti imaju značajan utjecaj na djelotvornost dijatomejske zemlje (DZ). DZ je djelotvorna u suhim uvjetima i postaje praktično nedjelotvorna na štetne kukce u vlažnoj okolini. Visoka relativna vlaga zraka i oborine na otvorenome, kao i visoka vlaga zrnate poljoprivredne robe, smanjuju ili u potpunosti eliminiraju djelotvornost DZ-a na štetne kukce. Također, ovisno o vrsti kukaca, kao i o vrsti tretirane zrnate robe, početna je djelotvornost spora i niska te, da bi se ostvarila zadovoljavajuća djelotvornost, izloženost štetnih kukaca na tretiranoj robi trebala bi biti tijekom više dana. Uporaba DZ-a u vanjskome prostoru, naročito u područjima s obilnim oborinama, ne daje zadovoljavajuće rezultate. Stoga, glavna je uporaba DZ-a u zaštiti uskladištenih poljoprivrednih proizvoda, u industriji hrane, za obradu raznih površina i za suzbijanje štetnika u zatvorenome prostoru. Način djelovanja DZ-a na štetne kukce, utjecaj relativne vlage zraka i vlage robe na djelotvornost, sažeti pregled istraživanja djelovanja DZ-a u zaštiti uskladištenih žitarica, kao i istraživanja o mogućnosti smanjenja negativnog utjecaja na tretiranu robu, s kombiniranom primjenom DZ-a i drugih insekticidnih metoda smanjenoga rizika razmatraju se u ovome članku