Twelve years (2005-2017) of scientific and professional work in the field of stored products pests protection in Slovenia: Poster

Scientific and professional work in the field of stored products pests protection in Slovenia began in 2005, when we tested the efficacy of entomopathogenic nematodes against the granary weevil (Sitophilus granarius) and the sawtoothed grain beetle (Oryzaephilus surinamensis) adults under laboratory conditions. In 2007, we participated as partners in the project SEE-ERA.NET “Development of a non-toxic, ecologically compatible, natural-resource based insecticide from diatomaceous earth deposits of South Eastern Europe to control storedgrain insects pests” (coordinated by C. Athanassiou), and we thus became acquainted with the research work in the field of investigation the efficacy of diatomaceous earth in controlling beetles from the Sitophilus genus. We have continued the research of different aspects of diatomaceous earth (the influence of geochemical composition and abiotic factors on its efficiency, the effects of individual and combined application, the effects on various harmful insect pests, etc.). In search for comparable substances to diatomaceous earth (regarding the efficacy), we have studied insecticidal effects of quartz sand and entomopathogenic nematodes from Slovenia, plant powders and essential oils on various harmful beetles. In the recent years, our research work has been mainly dedicated to studying the efficacy of wood ash and zeolites as natural insecticides, which have demonstrated sufficient efficiency in suppressing Sitophilus beetles. In the same period, we studied the seasonal dynamics of the Indian mealmoth (Plodia interpunctella), the Mediterranean flour moth (Ephestia kuehniella) and the Angoumois grain moth (Sitotroga cerealella) in cereal stores, where we were also searching for possible indigenious natural enemies of stored product insects pests. We have confirmed the occurrence of two parasitoids, Anisopteromalus calandrae and Dibrachys microgastri. In 2017, we have organized the 11th Conference of the IOBC/wprs Working Group on Integrated Protection of Stored Products (Ljubljana, 3-5 July), which was attended by 136 participants from 25 countries. We also transfer knowledge to Slovenian agricultural specialists about the harmfulness and possible ways of controlling stored products insects pests. In 2014, we have organized a workshop on this topic (“From Technological Maturity to Storing of Cereals and Legumes“). In 2015, we have hosted C. Athanassiou as an invited lecturer at the 12th Slovenian Conference on Plant Protection with international participation in Ptuj. In recent years, we have been working with experts from other countries with the aim of studying the efficacy of environmentally acceptable insecticides (spinosad, spinetoram) and the influence of cereal production technologies on grains’ susceptibility to attack by Sitophilus beetles. Furthermore, we participate in the research regarding the efficiency of new formulations of insecticidal preparations. The paper presents the chronology of activities in this area of our work.Scientific and professional work in the field of stored products pests protection in Slovenia began in 2005, when we tested the efficacy of entomopathogenic nematodes against the granary weevil (Sitophilus granarius) and the sawtoothed grain beetle (Oryzaephilus surinamensis) adults under laboratory conditions. In 2007, we participated as partners in the project SEE-ERA.NET “Development of a non-toxic, ecologically compatible, natural-resource based insecticide from diatomaceous earth deposits of South Eastern Europe to control storedgrain insects pests” (coordinated by C. Athanassiou), and we thus became acquainted with the research work in the field of investigation the efficacy of diatomaceous earth in controlling beetles from the Sitophilus genus. We have continued the research of different aspects of diatomaceous earth (the influence of geochemical composition and abiotic factors on its efficiency, the effects of individual and combined application, the effects on various harmful insect pests, etc.). In search for comparable substances to diatomaceous earth (regarding the efficacy), we have studied insecticidal effects of quartz sand and entomopathogenic nematodes from Slovenia, plant powders and essential oils on various harmful beetles. In the recent years, our research work has been mainly dedicated to studying the efficacy of wood ash and zeolites as natural insecticides, which have demonstrated sufficient efficiency in suppressing Sitophilus beetles. In the same period, we studied the seasonal dynamics of the Indian mealmoth (Plodia interpunctella), the Mediterranean flour moth (Ephestia kuehniella) and the Angoumois grain moth (Sitotroga cerealella) in cereal stores, where we were also searching for possible indigenious natural enemies of stored product insects pests. We have confirmed the occurrence of two parasitoids, Anisopteromalus calandrae and Dibrachys microgastri. In 2017, we have organized the 11th Conference of the IOBC/wprs Working Group on Integrated Protection of Stored Products (Ljubljana, 3-5 July), which was attended by 136 participants from 25 countries. We also transfer knowledge to Slovenian agricultural specialists about the harmfulness and possible ways of controlling stored products insects pests. In 2014, we have organized a workshop on this topic (“From Technological Maturity to Storing of Cereals and Legumes“). In 2015, we have hosted C. Athanassiou as an invited lecturer at the 12th Slovenian Conference on Plant Protection with international participation in Ptuj. In recent years, we have been working with experts from other countries with the aim of studying the efficacy of environmentally acceptable insecticides (spinosad, spinetoram) and the influence of cereal production technologies on grains’ susceptibility to attack by Sitophilus beetles. Furthermore, we participate in the research regarding the efficiency of new formulations of insecticidal preparations. The paper presents the chronology of activities in this area of our work

About Previous Investigations Regarding the Role of Glucosinolates in Controlling Brassica Insect Pests in Slovenia

The chapter presents previous field and laboratory investigations of cabbage flea beetles (Phyllotreta spp.) and cabbage stink bugs (Eurydema spp.) interactions with different Brassica crops in Slovenia. The special emphasis is given to an influence of different glucosinolates on injuries caused by mentioned economically important two genera of insect pests. In the study, we found out that the content of glucosinolates differs between different Brassica species, as well as between individual plant organs of the same species. The content of glucosinolates is conditioned also by environmental influences. Among the analysed glucosinolates, glucobrassicin was presented in all plant species. In almost all plant species, it inhibited the feeding of cabbage flea beetles, except in oil rape, where it had stimulative effects. We have established that the influence of individual glucosinolate on Phyllotreta spp. and Eurydema spp. is not identical as it differs between individual plant species. Because of the variability of glucosinolates as well as different preferences of the studied groups of harmful pests in regard to the plant species, one of the options for diminishing the damage caused by cabbage stink bugs and cabbage flea beetles is the use of mixed Brassica crops for trapping the pests in the growing season. In the future, glucosinolates should be employed to a greater extent in environmentally acceptable ways of food production, one of which is also the use of trap crops in order to reduce harmful effects of cabbage stink bugs

Comparison of insecticidal efficacy of four natural substances against granary weevil (Sitophilus granarius [L.]) adults: does the combined use of the substances improve their efficacy?

Laboratory tests were carried out to evaluate the insecticidal efficacy of different natural inert dusts (diatomaceous earth, wood ash, quartz sand) and the leaf powder of Azadirachta indica A. Juss. against granary weevil (Sitophilus granarius [L.]) adults. The efficacy of the substances was tested individually and in combination with each other. The substances were applied at different concentrations, and bioassays were carried out at four different temperatures (20, 25, 30 and 35°C) and two different relative humidity (RH) levels (55% and 75%). The adult mortality was recorded after the 7th, 14th and 21st days of exposure. The progeny production of individuals exposed to different combinations was also assessed. Wood ash proved to be the most efficient inert dust in our research. We detected 100% mortality in the treatment exposed to a higher concentration (5 w%) of wood ash at 35°C and 55% RH after 7 days of exposure. A lower RH level had also a negative impact on the progeny production. We can conclude that wood ash can be efficient in controlling granary weevil adults as a single substance or in combination with other substances. Further surveys should focus on the impact of the wood ash dose rates. Due to the high percentage of area covered with forest in some European countries, the main ingredient is present locally, but additional surveys are needed to help improve the practical use of wood ash

Glucosinolates in plant protection strategies: A review

This review discusses the importance of glucosinolates in plant protection. The Brassicaceae, which are cultivated worldwide, use glucosinolates and their decomposition products to defend themselves against attacks by harmful organisms. The glucosinolate content varies among individual plant species, plant organs and developmental stages. The glucosinolate content in plants is also affected by biotic and abiotic factors, while the type or quantity of glucosinolate determines the susceptibility of the plants to insect pests. These facts can pose a problem when implementing this knowledge in cultivation of the Brassicaceae, especially in regions with moderate climates where Brassicaceae crops are exposed to attacks by a large number of harmful organisms. Under these circumstances, it is essential to research new, or to improve the existing environmentally acceptable methods of protecting Brassicaceae plants against economically important pests

Applicability of invasive alien plants in controlling harmful organisms of cultivated plants

With a rapid growth invasive alien plants cause a lot of problems not only to indigenous varieties of plants, but also for people, as they are often the cause of many health problems, such as allergies, and they also contribute to greater economic loss. Plant protection is an activity which, on the basis of appropriate scientific knowledge by means of various methods and an economical manner, protects cultivated plants from harmful organisms. In Slovenia, as well as worldwide, the use of pesticides in plant protection programmes is the most widespread method due to price and other benefits. Researchers are looking for new, environmentally more acceptable ways of protecting plants against harmful organisms due to adverse environmental effects of pesticides, their non-target activity, the occurence of resistance to pesticides, and increasingly stringent environmental policies. One such measure is also the study of plant extracts in the suppresing of economically important harmful organisms. In a review article, we focused on the literature review of the usefeulness of plant extracts of several invasive alien plant species in plant protection: knotweeds (Fallopia japonica [Houtt.] Ronse Decr), F. x bohemica (Chrtek & Chrtková) Bailey), goldenrods (Solidago canadensis L., S. gigantea Aiton), stag's-horn sumac (Rhus typhina L.), tree of heaven (Ailanthus altissima [Mill.] Swingle), false indigo (Amorpha fruticosa L.) and stinkwort (Dittrichia graveolens [L.] Greuter), which we are studying within the project ApPLAuSE

QUANTITY OF GLUCOSINOLATES IN 10 CABBAGE GENOTYPES AND THEIR IMPACT ON THE FEEDING OF MAMESTRA BRASSICAE CATERPILLARS

Abstract -In 2011, we studied the glucosinolate content in 5 cultivars and 5 cabbage hybrids grown outdoors in order to study their influence on the feeding of cabbage moth caterpillars (Mamestra brassicae). The selected genotypes were categorized into three groups, early (the growth period from 55 to 70 days), mid-early (80-90 days) and mid-late (110-140 days), while the samples of cabbage for glucosinolate analysis were taken at five intervals, during which we also assessed genotypes for the extent of damage caused by caterpillars. We found that the feeding of caterpillars affected primarily the mid-early and mid-late genotypes of cabbage, and that the glucosinolate content among the different cabbage genotypes varies. The highest content of the analyzed glucosinolates was established in mid-late genotypes. Glucobrassicin was the only glucosinolate found in all cabbage genotypes, yet its antixenotic effect (r=0.20) was very low. We found that sinalbin negatively affects the feeding of cabbage moth caterpillars in mid-early cabbage genotypes (r=-0.34), while the same effect of sinigrin on the extent of damage can be observed in mid-late genotypes (r=-0.27). We have established a strong or moderate correlation between the gluconapin (r=0.87) and progoitrin (r=0.66) contents in mid-late genotypes and the extent of damage caused by caterpillars. Our research proves that different cabbage genotypes are responsible for different susceptibilities to damage by the cabbage moth, and that one of the factors of natural resistance of cabbage are also glucosinolates. Despite this, due to their variability in cabbage we cannot precisely determine the set of genotypes that would ensure a higher cabbage yield as a result of less damage caused by the cabbage moth. Thus, we need to identify in more detail the reasons for the time and quantum variability of glucosinolates in Brassicaceae

Predatory mites (Acari: Phytoseiidae) first recorded on cultivated plants in Slovenia in the period 2012-2017

In the period 2012-2017 we investigated the occurrence of indigenous species of predatory mites in different cultivated plants in Slovenia. In a comprehensive study we confirmed the occurrence of the following predatory mites: Amblyseius andersoni (Chant, 1957), Euseius finlandicus (Oudemans, 1915), Euseius gallicus (Kreiter & Tixier, 2009), Euseius stipulatus (Athias-Henriot, 1960), Kampimodromus abberans (Oudemans, 1930), Neoseiulus californicus (McGregor, 1954), Paraseiulus triporus (Chant & Shaul, 1982) and Phytoseius horridus (Ribaga, 1904). In the paper all seven species are presented, but for the field of biological control A. andersoni, E. gallicus and N. californicus are the most interesting species. The first two of them are already on the List of indigenous organisms for the purpose of biological control, while the third will be placed into it in the near future. All three of them have a great potential in biological control, since they can be found in different host plants