1. Coumaphos affects food transfer between workers of honeybee Apis melliferaDanilo Bevk, Jasna Kralj, Andrej Čokl, 2012, original scientific article Abstract: We investigated whether coumaphos, an organophosphate used to control the parasitic mite Varroa destructor, affects trophallaxis in honeybees. Donors were treated with coumaphos 1 h before experiments. In this, uncontaminated food was transferred from donors to recipients. The amount of food transferred was measured (a) directly by weighing food or (b) indirectly by the number of recipients that died due to insufficient trophallaxis. A large reduction in the amount of transferred food was observed when the donors received 5 μg of coumaphos 1 h prior to the experiment. High mortality was observed among the recipients that were fed by donors treated with 2 or 5 μg of coumaphos indicating insufficient food transfer. Demonstrated side effects of coumaphos on trophallaxis could reduce distribution of this systemic agent in the colony and decreases its efficacy. The described assays are feasible and could be a useful tool to test the effects of pesticides on trophallaxis.
Keywords: trophallaxis, social behaviour, food
Published in DiRROS: 12.03.2025; Views: 113; Downloads: 71
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2. Pollinators communities differ across years and cropsDanilo Bevk, Janez Prešern, 2021, original scientific article Abstract: Insect pollination is one of the most important ecosystem services. Pollinator communities are rarely studied across years and crops in the same location. The aim of this study was to investigate the pollinator community structure on five different fruit crops, as well as the activity of different pollinator groups during the day and their temperature preferences. Pollinator activity was observed across two years on apple trees and blueberry, strawberry, blackcurrant and raspberry bushes. Pollinator community structure varied by plant and year. Honeybees were the most numerous pollinators on all plants except blueberry bushes (39-95% of visits). Bumblebee numbers were high on blackcurrant (up to 28%) and blueberry bushes (up to 61%). Solitary bees visited all plants except blueberries. Honeybees, solitary bees, and hoverflies were most active in the middle of the day, while bumblebees became active earlier in the morning and remained active later in the evening. Pollinators also differed greatly in their temperature preferences. This knowledge gained is necessary for less harmful pesticide application management and the development of more sustainable agriculture to maintain pollinator diversity and thus reliable pollination in extreme weather conditions.
Keywords: fruit pollination, agroecology, biodiversity, wild bees, conservation
Published in DiRROS: 04.03.2025; Views: 258; Downloads: 61
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4. Čmrlji in čebele samotarke - prezrti opraševalciDanilo Bevk, 2015, other monographs and other completed works Abstract: Kako privabiti divje opraševalce?
Število divjih opraševalcev najlažje povečamo tako, da jim zagotovimo dovolj hrane in varnih mest za gnezdenje. Hrano zagotovimo s sajenjem rastlin, na katerih nabirajo cvetni prah in medičino in z redkejšo košnjo dela travnikov. Pomembno je, da je hrana na razpolago tudi v času, ko kmetijske rastline, ki bi jih želeli opraševati, ne cvetijo. Gnezdilna mesta najlažje zagotovimo z nastavljanjem posebnih gnezdilnic. Pomembno je tudi, da opustimo ali vsaj zmanjšamo uporabo pesticidov. V ustreznem okolju se bodo opraševalci naselili sami in ne bodo zahtevali posebne skrbi.
Keywords: čmrlji, čebele samotarke, opraševanje
Published in DiRROS: 04.09.2024; Views: 481; Downloads: 366
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6. Pestrost opraševalcev za zanesljivo pridelavo hraneDanilo Bevk, 2018, other monographs and other completed works Abstract: Življenjsko okolje opraševalcev se je zelo spremenilo. Obilno gnojeni, zgodaj in pogosto košeni travniki ne zacvejo in zato opraševalcem ne zagotavljajo hrane. Obdelovalni stroji uničijo veliko gnezd čmrljev. Živih mej, kjer bi bila gnezda na varnem, skoraj ni več. Čebele samotarke so nekdaj gnezdile v slamnah strehah in luknjah v lesu, ki je bil glaven gradbeni material. Negaven je tudi vpliv prekomerne in nepravilne uporabe pescidov.
Keywords: opraševalci, pridelava hrane
Published in DiRROS: 04.09.2024; Views: 382; Downloads: 185
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7. Divje čebele - spregledane opraševalkeDanilo Bevk, other monographs and other completed works Abstract: Čebela ni ena sama
V Sloveniji je bilo doslej najdenih preko 500 vrst čebel. Kranjska čebela je le ena od njih. Poleg nje v Sloveniji živi še 35 vrst čmrljev in druge divje čebele, ki večinoma živijo samotarsko, zato jim pravimo čebele samotarke. Samotarke so zelo raznolike, najmanjše merijo samo 3 mm, največje pa kar 25 mm in so večje od čmrljev. Nekatere živijo tudi v mestih.
Published in DiRROS: 04.09.2024; Views: 323; Downloads: 146
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8. 20. maj, svetovni dan čebelJernej Kovač, Helena Gašperlin, Danilo Bevk, Peter Kozmus, other monographs and other completed works Abstract: Za jutrišnjo hrano v svetu Čebele in drugi opraševalci so zelo pomembni za obstoj človeštva, saj bistveno prispevajo k varnosti preskrbe s hrano v svetu. Tretjina svetovne proizvodnje hrane oziroma vsaka tretja žlica hrane je odvisna od opraševanja, pri katerem imajo čebele najpomembnejšo vlogo. Visoko hranilni proizvodi, kot so med, matični mleček in cvetni prah, prav tako povečujejo hranilno vrednost živil. Živila, ki so odvisna od opraševalcev, prispevajo k zdravi prehrani, saj so bogat vir nujno potrebnih hranil.
Keywords: čebelarstvo
Published in DiRROS: 04.09.2024; Views: 309; Downloads: 210
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9. Moja, tvoja, naša biodiverzitetaDanilo Bevk, Marjana Hönigsfeld Adamič, 2019, other monographs and other completed works Abstract: Radi imamo dišeč, pisan travnik. Radi imamo jutranjo pesem ptic. Radi imamo žuboreč potok in kačjega pastirja nad njim. Radi imamo…
Zakaj ne bi torej imeli radi biodiverzitete, ki nam vse to omogoča? Zbližajmo se z njo, spoznajmo njene čare! Kajti tisto, kar nam je blizu in kar poznamo, veliko lažje varujemo.
Keywords: biološka raznovrstnost
Published in DiRROS: 04.09.2024; Views: 310; Downloads: 230
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10. Kmetijstvo in biodiverziteta z roko v rokiMojca Pibernik, Blaž Koderman, Danilo Bevk, Aleš Tolar, Janko Rode, 2019, other monographs and other completed works Abstract: Biodiverziteta je vse živo
Biodiverziteta (biotska pestrost) je pestrost življenja na Zemlji od bakterij in gliv do rastlin in živali. Nastala je v milijardah let razvoja življenja. Pomembna značilnost biodiverzitete je izjemna povezanost organizmov, ki sami ne bi mogli preživeti, skupaj pa sestavljajo edinstven preplet, ki odločilno vpliva na razmere na našem planetu.
Keywords: kmetijstvo, biodiverziteta
Published in DiRROS: 04.09.2024; Views: 431; Downloads: 269
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