INSECTICIDAL TOXICITY OF 1,8-CINEOLE, CAMPHOR AND EUGENOL ON TRIBOLIUM CASTANEUM (HERBST)

Contact and fumigant activity of 1,8-cineole, camphor and eugenol compounds were tested In laboratory conditions on adult, larvae and pupae of the red flour beetle Tribolium castaneum (Herbst), as well as their effect on progeny emergence. Positive results were obtained with contact application for all three tested compounds and on all three stages of development of T. castaneum, with the highest activity of 1,8-cineole, followed by eugenol and camphor. Ingeneral, fumigant activity of all three compounds was lower in comparison to contact application, with the best activity of 1,8-cineole, followed by camphor and eugenol on all three developmental stages of T. castaneum. However, lower activity was recorded for fumigation of the space 50% filled with wheat grain for all three tested compounds on all three stages, with the best activity of 1,8-cineole, followed by camphor and eugenol, whereas eugenol showed no toxicity to the adult stage. The activity of 1,8-cineole and eugenol in the space 50% filled with wheat grain decreased by 3.5 and 32 times, respectively, whereas the activity of camphor had no significant difference on the larvae. Toxicity of the tested compounds on pupae T. castaneum was either lethal or directly affected to metamorphosis pupae. There were significant differences observed in the efficacy of the tested compounds on the gender of the pupae, with the most markedly differences for 1,8-cineole, followed by camphor and the minimal for eugenol. Males were more sensitive to the applied compounds, whereas females had more deformed units, especially in the fumigation treatment with camphor. The most tolerant stage on the contact and fumigant application of all compounds was the pupae stage. Eugenol and 1,8-cineole had influence on the reduction of T. castaneum progeny emergence, whereas camphor had no such effect. Due to a high potential of 1,8-cineole for the control of the red flour beetle Tribolium castaneum (Herbst) (at all treatments, for all the tested stages of development), camphor for the fumigant control of adult (in the empty storages), as well as of eugenol for contact control (all developmental stages) and for fumigant application (for the reduction of progeny), these compounds represent a valuable basis for creating new active substances as an alternative to the conventional pest control products

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

Development of stored pests resistance to fumigants

Učestala uporaba fumiganata u suzbijanju skladišnih štetnika diljem svijeta uzrokovala je i razvoj rezistentnosti u znatnog broja skladišnih vrsta kukaca. S obzirom da se trženjem robe i poljoprivrednih proizvoda može očekivati i širenje rezistentnih populacija, prijeko je potrebno i u nas razviti sustavni program monitoringa rezistentnosti skladišnih štetnika na fumigante.Frequent use of fumigants in the control of storage pests around the world has also caused resistance development in a large number of insect species. Since the marketing of goods and agricultural products can be expected and the spread of resistant populations, it is necessary to develop a systematic program of monitoring of resistance stored pests on fumigants and in our country

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

Croatian diatomites and their possible application as a natural insecticide

In recent decades, there has been an increase in the use of diatomaceous earth (DE) as a natural insecticide because of its low mammalian toxicity, worker safety, low risk of food residues and the occurrence of resistant insect populations associated with the use of chemical insecticides.Therefore there is potential for research into known but previously undescribed Croatian mid-Miocene marine diatomites from the perspective of their potential as proper DE that could be mixed with plant extracts as a new formulation for grain storage protection. The marine diatomites belong to the Paratethyan near shore environment, deposited in the upwelling zone during a mid-Miocene temperate climate. Palaeontological, mineral and geochemical analyses were done on ten promising marly sediments from 26 outcrops and one borehole from the North Croatian Basin. The most important ingredient of diatomaceous sediments is silica (biogenic opal-Aand SiO2 bound in other silicate minerals including quartz, clay minerals, micas, etc.). The amorphous silica content of the tested Croatian diatomites is relatively low (<50%) in comparison with the Celatom® MN 51 standard (medium to high efficient DE) (73.6%), nevertheless they show insome part even slightly better efficacy against insects. It seems that the enhanced content of smectite in diatomaceous sediments also influences increased absorption of DE. Based on palaeontological results, the most efficient diatomites from the Podsusedsko Dolje and Markuševec (Medvednica Mt.) consist of the mid-sized planktonic Coscinodiscus group of species whereThalassionema nitzschioides dominate and is positively correlated with their absorption. The usage of Boströms’ standard formula for getting opal-A from geochemical data was abandoned because of negative results and the modified Murdmaas’ formula for hemipelagic sediments was applied. Preliminary results on the aforementioned diatomite (as inert dusts) show good efficacy against tested insects Sitophilus oryzae (LINNAEUS), Tribolium castaneum (HERBST) and Rhyzopertha dominica (FABRICIUS).</p

BIOAKTIVNOST 1,8-CINEOLA NA KUKULJICE KESTENJASTOGA BRAŠNARA TRIBOLIUM CASTANEUM (HERBST)

Red flour beetle Tribolium castaneum (Herbst) is a major pest of stored products. The aim of this study was to assess the potential fumigant effects of 1,8-cineole, essential oil component, on the T. castaneum pupae. The compound was tested in 6 doses; in two treatments (fumigation without grain and with wheat grain), exposed for 48 h, in 4 repetitions, for each gender. The compound 1,8-cineole had lethal effect on the treated pupae at both genders and in the both treatments. Total proportion of the normally developed beetles was decreased. In addition, 1,8-cineole had also a growth regulator effect, producing adultoids and deformed units, with males more susceptible. In the treatment with the grain there were significant lower dead pupae, normally developed live male beetles and also deformed female units in the stage 2. In general, compound 1,8-cineole has multiple effect against T. castaneum in pupal stage.Kestenjasti brašnar Tribolium castaneum (Herbst), je značajan štetnik uskladištenih poljoprivrednih proizvoda. Cilj rada je ispitati fumigantnu učinkovitost 1,8-cineola na kukuljice T. castaneum. Izolat je testiran u 6 doza; u dva tretmana (fumigacija bez zrna i sa zrnom pšenice) s ekspozicijom od 48 sati, u 4 ponavljanja, za svaki spol. Izolat 1,8-cineol je djelovao letalno na tretirane kukuljice kod oba spola i u oba tretmana. Smanjen je ukupni udio normalno razvijenih odraslih brašnara. Također, 1,8-cineol djelovao je i kao regulator rasta kukuljica, stvarajući adultoid i deformirane jedinke, s većom osjetljivošću muškoga spola. U tretmanu sa zrnom značajno je smanjen postotak uginulih kukuljica, normalno razvijenih živih muških jedinki, kao i deformiranih ženskih jedinki u stadiju 2. Može se zaključiti da je izolat 1,8-cineol višestruko učinkovit za suzbijanje T. castaneum u stadiju kukuljice

EFFECTIVNESS OF PURE DIATOMACEUS EARTH AND DIFFERENT MIXTURES OF DIATOMACEUS EARTH WITH PYRETHRINS

U radu su prikazani rezultati laboratorijskih pokusa na uskladištenoj mekanoj pšenici infestiranoj s dvije vrste skladišnih kukaca: rižin žižak - Sitophilus oryzae L. i kestenjasti brašnar - Tribolium castaneum Herbst., obrađenoj kombinacijama mješavina dijatomejske zemlje (DZ) i piretrina (Diatect V, Diatect II, Bug-B-Gon, Perma-Guard D-20) i DZ bez piretrina (Protect-It, Perma-Guard i DZ iz Hrvatske). Rezultati su pokazali opravdanost mješavina DZ i piretrina, jer su značajno djelotvornije na test kukce u odnosu na DZ bez piretrina. S obzirom na to da Hrvatska ima nalazišta DZ-a i autohtoni buhač, moguće je mješavinom DZ i piretrina razviti ekološko prihvatljiv hrvatski insekticid za domaće potrebe, a, isto tako, i za izvoz u druge zemlje.This study shows results of laboratory experiments on stored soft white wheat infested with two stored pest species: rice weevil - Sitophilus oryzae (L.), and red flour beetle - Tribolium castaneum (Herbst), treated with different mixtures of Diatomaceus earth (DE) and pyrethrins (Diatect V, Diatect II, Bug-B-Gon, Perma-Guard D-20 ), and DE without pyrethrins (Protect-It, Perma-Guard and DE from Croatia). The obtained results confirmed that the mixture of DE and pyrethrin and PBO is useful against test-insects and generated significantly higher effectiveness when compared with the results obtained with DE without pyrethrins. Due to the fact that Croatia has the sources of good DE and indigenous Dalmatian pyrethrum, it is possible to develop and produce safe, natural and ecologically acceptable Croatian insecticide by using mixture of DE and pyrethrins, for domestic market and export

HARMFUL ENTOMOPHAUNA IMPACTS ON QUALITY OF MERCANTILE WHEAT AND FLOUR

Utjecaj štetne entomofaune na kakvoću merkantilne pšenice i brašna proučavan je u okviru trogodišnjeg istraživanja. Korišteni materijal je uskladištena merkantilna pšenica u silosima, a ispitivanje kvalitete reoloških osobina i prisutnosti štetne entomofaune vršena su u laboratoriju silosa «Žitoprerada» d.o.o. Valpovo i Zavoda za zaštitu bilja Poljoprivrednog fakulteta u Osijeku. Utvrđeno je prisustvo štetne entomofaune, kakvoća uskladištene merkantilne pšenice i reološke osobine brašna. Od štetne entomofaune utvrđeno je prisustvo Acarinae (grinja), primarnih štetnih kukaca reda Coleoptera i Lepidoptera, sekundarnih kukaca reda Coleoptera, mikofagnih kukaca reda Psocoptera te korisnih kukaca – predatora reda Hymenoptera. Utjecaj štetne entomofaune očituje se u promjeni kvantitativnih osobina uskladištene pšenice (sadržaj vode, hektolitarska masa, primjese). Umanjenje kakvoće brašna dobivenog meljavom zaražene pšenice očituje se kroz promjenu reoloških osobina: stabilnosti tijesta, upijanja vode, razvoja tijesta, rezistencije, energije, rastezljivosti, otpora, maksimalnog otpora, početka bubrenja i viskoziteta.Presence of harmful insects and mites is almost inevitable in mercantile wheat stored in warehouses. They cause significant damages and therefore it is necessary to perform pest control and chemical treatment. Study of harmful and destructive entomophauna impacts on quality of mercantile wheat and flour has been presented. Mercantile wheat stored in silos has been used in the study. Testing of quality of rheological properties and presence of harmful entomophauna were done in the labs within the silos «Žitoprerada d.o.o. Valpovo « and Department of Plant Protection on Faculty of Agriculture in Osijek. Presence of harmful entomophauna, quality of mercantile wheat stored in a warehouse and rheological flour properties were determined. The following harmful entomophauna were found: mites (Acarinae), primary pests of order Coleoptera and Lepidoptera, secondary pests of order Coleoptera and other insects found belong to Coleoptera, Psocoptera and useful insects of Hymenoptera orders. Influence of harmful entomophauna on quality of mercantile wheat is manifested by reduced quality of stored wheat due to decrease of water content and hectoliter mass. Lower quality of flour obtained by milling of infected wheat is manifested by change in rheological properties: dough stability, water absorption, growth, resistance, energy, extensibility, maximum resistance, start of puffing up, and viscosity

Resistance of different wheat cultivars to granary weevil (Sitophilus granarius L.)

Ciljevi ovog rada bili su utvrditi razlike u otpornosti različitih sorata pšenice na pšeničnog žiška i koliki su gubici od žižaka u masi zrna tijekom 20 tjedana skladištenja. Istraživanje je provedeno u laboratoriju Zavoda za specijalnu proizvodnju bilja Agronomskog fakulteta Sveučilišta u Zagrebu na 3 sorte pšenice: Divana, Renan i Sana. U staklenke (720 ml) stavljeno je 100 g zrna i 20 nasumično odabranih odraslih žižaka. Staklenke sa zrnom i žišcima bile su 20 tjedana smještene u laboratoriju pri prosječnoj temperatura zraka od 24,9°C i prosječnoj relativnoj vlazi zraka od 64,7%. Tijekom perioda skladištenja, uočen je rast populacije pšeničnog žiška kod sve tri sorte pšenice. Najveći broj žižaka zabilježen je kod sorte Sana, što čini povećanje početne populacije za 28 puta, dok je kod sorata Renan i Divana početna populacija povećana za 1,8, odnosno 1,6 puta. Nakon 20 tjedana skladištenja gubitak mase zrna iznosio 1,30% za sortu Renan, 1,70% za sortu Divana te 12,45% za sortu Sana. Žišci su se hranili i razmnožavali više na zrnima sorte Sana jer ima mekanije zrno od sorata Divana i Renan koje su tvrđeg zrna. Obzirom da su u ovom istraživanju promatrani samo neki čimbenici koji mogu utjecati na otpornost pšenice na žiške, potrebno je nastaviti istraživanja i pri tome uzeti i druge čimbenike u razmatranje kako bi se što bolje istražile razlike u otpornosti između sorata pšenice.The objectives of this study were to determine the differences in the resistance of some wheat cultivars to granary weevil (Sitophilus granarius L.) and grain weight loss during 20 weeks of storage caused by granary weevil. The research was carried out in the laboratory of Department of Field Crops, Forage and Grassland, Faculty of Agriculture, University of Zagreb, on three wheat cultivars: Divana, Renan and Sana. 20 randomly selected adult insects were placed in 720ml glass jars containing 100 g of whole seed of a particular cultivar. Glass jars were placed in the laboratory for 20 weeks. The mean temperature and relative humidity were 24,9°C and 64,7%. During storage period, weevil population growth was found in grains all three wheat cultivars. The highest number of weevils was observed in the seeds of Sana cultivar, which is an increase of the initial population by 28 times, while in the seeds of Renan and Divana cultivars the initial population increased by 1.8 and 1.6 times, respectively. After 20 weeks of storage, grain weight loss was 1.30% for Renan, 1.70% for Divana and 12.45% for Sana. The granary weevils are fed and propagated more on the grains of Sana cultivar because it has a softer grain than the Divana and Renan cultivars, which have harder grains. It is necessary to continue the research and take in consideration other factors to better explain differences in resistance of different wheat cultivars to granary weevil