Population dynamics, flight activity and natural enemies of alfalfa aphids (Aphididae:Hemiptera)

Istraživanja biljnih vaši lucerke i njihovih prirodnih neprijatelja obavljena su na 44 lokaliteta iz 16 okruga na teritoriji Srbije. Utvrđeno je prisustvo tri vrste biljnih vaši: Acyrthosiphon pisum, Aphis craccivora i Therioaphis trifolii. Invazivna vrsta u Evropi - Acyrthosiphon kondoi, nije nađena na lucerki niti na drugim biljkama domaćinima. Na lucerištima u Srbiji nađeno je osam vrsta afidofagnih bubamara, šest vrsta primarnih parazitoida i tri vrste trombidoidnih grinja, od kojih je Erythraeus serbicus nova vrsta za nauku, a Allothrombium clavatum nova vrsta za faunu Srbije. Populaciona dinamika biljnih vaši i prirodnih neprijatelja istraživana je na područjima intenzivnog gajenja lucerke, na lokalitetima Ovča i Progar. Jedinke su prikupljane na svakih 10 dana tokom svih pet otkosa lucerke. Tokom trogodišnjih istraživanja populacione dinamike prikupljeno je više od 12000 jedinki vaši. Dominantna vaš na lucerki je T. trifolii, zastupljena u relativnoj brojnosti od 61%. Druga po brojnosti je A. pisum (34%), dok je A. craccivora ostvarila veoma malu relativnu (5%) i apsolutnu brojnost. Tokom 2011. godine na oba lokaliteta biljne vaši su najveću brojnost ostvarile u prvom otkosu, dok su sušne 2012. i 2013. godine najveću brojnost postigle u letnjim ili poslednjim otkosima lucerke. Tri najzastupljenije vrste afidofagnih bubamara u celokupnim istraživanjima su Coccinella septempunctata, Hippodamia variegata i invazivna vrsta Harmonia axyridis, koja je na teritoriji Srbije prvi put zabeležena pre osam godina. Utvrđena je statistički značajna pozitivna korelacija (iznad 0,5) između broja vaši i broja afidofagnih bubamara, za svaku godinu pojedinačno i ukupno za sve godine istraživanja. Na osnovu dvofaktorijalne analize varijanse (ANOVA) utvrđen je statistički značajan efekat različitih lokaliteta na brojnost vaši, a na brojnost afidofagnih bubamara statistički značajan efekat imaju različite eksperimentalne godine. Najveću stopu parazitiranosti imala je vrsta A. craccivora, a najbrojniji parazitoid ove vaši je Lysiphlebus fabarum. Aphidius ervi je dominantna vrsta primarnih parazitoida A. pisum. Najmanja stopa parazitiranosti zabeležena je na T. trifolii..

Let biljnih vaši, potencionalnih vektora virusa, u usevu lucerke u Srbiji

Flight activity of aphids as potential vectors of viral infection of alfalfa plants were monitored in Serbia for the first time in Europe. Research was conducted at the location Progar (Srem) for two years using six yellow water traps. A total of 1626 individual winged aphids were collected. The collected specimens were classified into 49 different taxa. During the two-year study, maximum population density of aphids and maximum potential vector activity were noted at the beginning of June, during the second alfalfa intercut. More than 65% of the collected specimens were potential vectors of the most important alfalfa viruses, Alfalfa mosaic virus (AMV) and Cucumber mosaic virus (CMV). The most numerous winged aphid species on alfalfa were Aphis craccivora, Aphis fabae, Aphis gossypii, Aphis pomi/ spiraecola and Therioaphis trifolii. The Morisita-Horn similarity index was used to calculate similarities in species composition among the traps. High values of this index showed no significant differences among the aphids in traps. It indicates that one trap alone could provide good insight into the abundance, aphid diversity and number of potential vector species in small alfalfa fields.Praćenje leta biljnih vaši, potencijalnih vektora virusa, na lucerki istraživano je na teritoriji Srbije po prvi put u Evropi. Let biljnih vaši na lucerki praćen je na lokalitetu Progar (Srem) tokom dve godine korišćenjem šest žutih lovnih klopki. Sakupljeno je ukupno 1626 krilatih jedinki biljnih vaši. Prikupljene jedinke su klasifikovane u 49 različitih taksona. Tokom dve godine praćenja leta, najveća brojnost biljnih vaši, kao i najveća aktivnost potencijalnih vektora, registrovana je početkom juna, u drugom otkosu lucerke. Više od 65% prikupljenih jedinki su potencijalni vektori dva najvažnija virusa lucerke: virusa mozaika lucerke - Alfalfa mosaic virus (AMV) i virusa mozaika krastavca - Cucumber mosaic virus (CMV). Najbrojnije biljne vaši u klopkama na lucerki bile su: Aphis craccivora, Aphis fabae, Aphis gossypii, Aphis pomi/spiraecola i Therioaphis trifolii. U cilju poređenja sličnosti sastava biljnih vaši u lovnim klopkama, izračunat je Morisita-Horn indeks sličnosti. Visoke vrednosti ovog indeksa ukazuju da nema značajnih razlika u sastavu afidofaune poređenih klopki. Dovoljna je samo jedna lovna klopka radi uvida u brojnost i diverzitet biljnih vaši potencijalnih vektora virusa u lucerki

Potencijalna opasnost od pojave invazivne vaši Acyrthosiphon kondoi Shinji, 1938 (Hemiptera: Aphididae) na lucerki u Srbiji

Aphids (Hemiptera: Aphididae) are important pests of alfalfa all over the world. One of the most important ones is a blue alfalfa aphid - Acyrthosiphon kondoi Shinji. Morphology of the species is very similar to a green alfalfa aphid - Acyrthosipom pisum Harris. Saliva of A. kondoi is very toxic and this is why it is more important than other pest species. It can cause alfalfa wilting. Recently, A. kondoi was found in Europe, in Greece and France. It is expected to appear in other European countries. The presence of A. kondoi in Serbia was investigated from 2011 to 2015 on alfalfa and other host plants and it was not found.Biljne vaši (Hemiptera: Aphididae) svojom aktivnošću nanose značajne ekonomske gubitke u proizvodnji lucerke širom sveta. Jedna od najznačajnijih štetočina ove gajene biljke u svetu je plava lucerkina vaš - Acyrthosiphon kondoi Shinji. Ova vrsta je morfološki veoma slična zelenoj lucerkinoj vaši - Acyrthosipom pisum Harris. Zbog toksičnog sadržaja sekreta pljuvačnih žlezda A. kondoi je štetnija od drugih vaši koje se hrane na lucerki. Ishranom može prouzrokovati uvenuće biljaka lucerke. Acyrthosiphon kondoi je nedavno registrovana u Evropi, Grčkoj i Francuskoj. Postoji mogućnost pojave ove invazivne vrste i značajne štetočine lucerke u drugim evropskim zemljama. Tokom četvorogodišnjih istraživanja (2011-2015), prisustvo ove vaši nije utvrđeno na lucerki i drugim biljkama domaćinima na teritoriji Srbije

Zaštitna arheološka istraživanja nekropole na lokalitetu Više grobalja (Viminacijum) u 2020. godini

Teritorija južnih nekropola grada Viminacijuma se u velikoj meri preklapa sa prostorom na kome se danas nalazi Termoelektrana Kostolac B u Drmnu, što je dovelo do toga da se ovde sprovedu obimna zaštitna arheološka iskopavanja, pre svega prilikom izgradnje Elektrane 70-ih i 80-ih godina prošlog veka (Зотовић, Јордовић 1990; Korać, Golubović 2009), ali i kasnije, prilikom izgradnje novih i modifikacije starih postrojenja (Jovičić et al. 2017; Jovičić et al. 2021; Redžić et al. 2017; Redžić et al. 2018; Redžić et al. 2021a; Redžić et al. 2021b). Istraživanjima je otkriven veliki broj grobova iz rimskog perioda (Korać et al. 2018, 47–48), ali i latena (Jovanović 2018), Seobe naroda (Ivanišević et al. 2006) i razvijenog srednjeg veka (Спасић 1990). Lokacija poznata pod toponimom Više grobalja obuhvata istočni deo Termoelektrane i do sada je na ovom prostoru istraženo oko 4300 grobova. Starija istraživanja su bila fokusirana uglavnom na centralni deo nekropole, gde je konstatovano sahranjivanje od kraja 1. do sredine 3. veka (Зотовић, Јордовић 1990, 3–4). Poslednjih godina, u okviru novih zaštitnih iskopavanja istraživan je i severni deo ove nekropole. Uočeno je da se na ovom prostoru javljaju i nešto poznije sahrane, sa kraja 3. i iz 4. veka (Jovičić et al. 2021). Zaštitna arheološka iskopavanja na lokalitetu Više grobalja sprovedena 2020. godine predstavljaju nastavak istraživanja iz 2018. i 2019. godine (sl. 1) (Jovičić et al. 2021; Redžić et al. 2021b). Sprovedena su u krugu Termoelektrane Kostolac B, na lokaciji predviđenoj za izgradnju treće deponijske linije uglja i njene prateće infrastrukture. Istražena je ukupna površina od 2371 m2, u okviru trinaest sondi (Sonde 303–315)

Impact of the Covid-19 Pandemic on Foreign Direct Investment

Foreign direct investment is an important instrument in the economic growth and development of each national economy. At the same time, they are considered one of the key elements of the globalization process, as they significantly affect the mobility of production factors and world trade flows. Decisions on location choice and form of investment can be made by foreign investors depending on the political and economic situation in the country or the development and stability of specific sectors. The main goal of this paper is to determine whether the crisis caused by the COVID-19 virus has affected FDI mobility. That is, whether in 2020, as the first year of the pandemic, compared to the previous period (2018-2019), there were significant changes in FDI flows. The period covered by the research is from 2018 to 2020. The methodology applied in this research is based on a quantitative approach using available secondary data from the UNCTAD database. The results show that the crisis caused by the COVID-19 virus contributed to a significant reduction in the fluctuation of capital. Specifically, total FDI decreased by about 35% in 2020 compared to 2019, which indicates the negative impact of the COVID-19 crisis on FDI flows

Factors affecting host plant selection in alfalfa aphids

Alfalfa (Medicago sativa L.) hosts several species of aphid, Acyrthosiphon pisum (Harris), Aphis craccivora Koch and Therioaphis trifolii (Monell). The preference of the aphids of alfalfa plants for dense assemblies or individual plants, as well as for healthy or infested plants, was investigated in the field as in the laboratory. Years of field research have revealed the specific preferences of all three species of aphid. A. pisum and T. trifolii are most commonly found in alfalfa crops, while A. craccivora is mostly found on alfalfa weeds. Also, a single species of aphid alone is usually present on a plant. In order to determine the reason for this clear preference and to establish whether at the very beginning, i.e. at the stage of choosing a host, aphid species distance themselves from each other, we tested the effect of the volatiles of healthy and infested plants on their attractiveness to aphids. A. craccivora is repelled by the volatiles of dense crops and plants previously infested with one of the other two species. A. pisum and T. trifolii choose a dense assembly of plants, repelled by the volatiles of plants previously infested with A. craccivora. A. pisum displays the weakest competitive traits, and A. craccivora the strongest. This research showed that competition between aphid species does not occur only when they find themselves on the same plant at the same time, fighting for resources, but also in the choice of plant, in order to avoid later competition. © 2023 The Author(s). Published by Cambridge University Press

Biljne vaši (Aphididae, Hemiptera) u semenskom krompiru

Aphids (Aphididae, Hemiptera) are efficient vectors of plant viruses and a significant problem in potato growing. Production of healthy seed potato is possible if the number of aphids is reduced, as well as their ability to come into contact with the plant and transfer the virus. Research related to the presence and abundance of aphid species in different parts of Serbia was carried out on 30 sites in four years: 2007, 2008, 2009 and 2010. Yellow water traps were placed in potato crop immediately after potato emergence. Samples were taken once per week until the drying of the above-ground mass. Over 11,500 specimens were collected and a total of 106 different taxa of aphids were identified. This publication analyses vector pressures for two most important potato viruses (PVY and PLRV) for different localities. The best conditions for the production of healthy seed potato exist on the Golija mountain, at altitudes above 1100 m, in comparison to other tested sites. The pressure of vectors on the mountain is low and so is the risk of potato plants viral infection because of late potato planting and low aphid occurrence.Biljne vaši (Aphididae, Hemiptera) su efi kasni vektori biljnih virusa i predstavljaju značajan problem u proizvodnji krompira. Proizvodnja zdravog semenskog krompira moguća je u uslovima smanjene brojnosti vašiju i mogućnosti da vaši dođu u kontakt sa biljkom i prenesu virus. Istraživanja prisustva vrsta i brojnosti biljnih vašiju na različitim područjima Srbije obavljena su tokom 2007, 2008, 2009. i 2010. godine. Na ukupno 30 lokaliteta, u zasade krompira, postavljane su žute lovne posude odmah nakon nicanja krompira, a uzorci uzimani jednom nedeljno do sušenja nadzemne mase. Sakupljeno je preko 11.500 jedinki i utvrđeno ukupno 106 različitih taksona biljnih vašiju. U radu je analiziran pritisak vektora za dva najznačajnija virusa krompira (PVY i PLRV) na različitim lokalitetima. Od analiziranih područja, najbolji uslovi za proizvodnju zdravog semenskog krompira su na planini Golija, na nadmorskim visinama iznad 1.100 m. Usled kasne setve krompira i male brojnosti biljnih vašiju i pritisak vektora je nizak, a tako i rizik od zaražavanja krompira virusima

Biljne vaši (Hemiptera: Aphididae) na pšenici

Aphids (Hemiptera: Aphididae) are regularly occurring on wheat, more or less numerous, depending of the year. Direct damage, as yield losses and spoiled the baking quality of the grain, is made by aphids feeding on phloem sap. Transmitting of viruses is very important indirect damage. Many aphid species could be found on wheat in Serbia. The most important species are: grain aphid (Sitobion avenae), bird cherry-oat aphid (Rhopalosiphum padi) and rose-grain aphid (Metopolophium dirodum). Some notes on morphology, host plants, biology, damage, distribution, vector role and most important natural enemies (Coccinellidae, Syrphidae i Aphidiidae) are given for every of these three species.Biljne vaši (Hemiptera: Aphididae) se redovno javljaju na pšenici, u manjoj ili većoj brojnosti, zavisno od godine. Direktne štete nanose isisavanjem biljnih sokova prouzrokujući smanjenje prinosa i kvalitet zrna. Indirektna štetnost, koja se ogleda u prenošenju biljnih virusa, može da bude izuzetno visoka i da premaši direktnu štetnost. Na pšenici kod nas, može se naći više vrsta biljnih vašiju. U radu su prikazane ekonomski najznačajnije vrste: velika žitna vaš (Sitobion avenae), sremzina vaš (Rhopalosiphum padi) i zelena ružina vaš (Metopolophium dirodum). Navedeni su osnovni morfološki podaci za svaku vrstu, biljke domaćini, biologija razvića, štetnost, rasprostranjenje, vektorska uloga, kao i najznačajniji prirodni neprijatelji (Coccinellidae, Syrphidae i Aphidiidae)

Diverzitet i let biljnih vaši (Hemiptera: Aphididae) potencijalnih vektora virusa mrkve

Diversity and aphid flight activity in carrot crops have not been investigated in Serbia, so far. Monitoring of the flight activity of aphids, as potential vectors of carrot viruses was conducted at the locality of Opovo (South Banat) in 2017, using 12 color pan traps (6 green and 6 yellow). A total of 2108 individuals of winged aphids were collected and a total of 43 different aphid taxa were identified, including 12 species known as being vectors of carrot viruses. About 85% of collected aphid specimens were potential vectors of carrot viruses. Maximum population density of winged aphids and the highest flight activity of the potential vectors were observed in mid-June. The most numerous aphid species in pan traps were: Myzus persicae (54,7%), Therioaphis trifolii (12,8%), species of the genus Aphis (10,7%) and Acyrthosiphon pisum (9,3%). The differences in abundance of aphids and the number of recorded species in green and yellow water traps were not statistically significant, as confirmed by t-test.Diverzitet i let biljnih vaši u usevu mrkve do sada nije istraživan u Srbiji. Praćenje leta biljnih vaši potencijalnih vektora virusa u usevu mrkve obavljeno je na lokalitetu Opovo (Južni Banat) 2017. godine, korišćenjem 12 obojenih lovnih klopki (šest zelenih i šest žutih). Prikupljeno je ukupno 2108 krilatih jedinki biljnih vaši i determinisana su 43 različita taksona. Od svih determinisanih taksona, za 12 je poznato da su vektori virusa mrkve. Oko 85% svih prikupljenih jedniki činili su potencijalni vektori virusa mrkve. Najveća brojnost biljnih vaši, ujedno i najveća aktivnost potencijalnih vektora, registrovana je sredinom juna. Najbrojnije vrste u lovnim klopkama bile su: Myzus persicae (54,7% prikupljenih jedinki), Therioaphis trifolii (12,8%), vrste roda Aphis (10,7%) i Acyrthosiphon pisum (9,3%). Brojnost biljnih vaši i sastav vrsta u zelenim i žutim lovnim klopkama se nisu statistički značajno razlikovali, što je potvrđeno t-testom

Filamentous fungi isolated from grape marc as antagonists of botrytis cinerea

In this paper we report on the isolation and identification of three filamentous fungi from grape marc, and antifungal effect of their cell-free culture filtrates on the growth of Botrytis cinerea, causal agent of gray mold. Grape marc is a waste material that has been used as soil amendment in sustainable agriculture. Isolates originating from grape marc were identified on the basis of morphological features and internal transcribed spacer rDNA or beta-tubulin gene sequencing. The presence of three different species, Penicillium paneum, Penicillium chrysogenum and Aspergillus fumigatus has been detected expressing different effect on the growth of B. cinerea. The effect of crude culture filtrates of selected fungi on B. cinerea growth was tested. Heat sensitivity of the established inhibition effect was examined by autoclaving the crude culture filtrate prior to testing. Additional aim was to determine whether antifungal effect was influenced by previous exposure to B. cinerea in dual liquid cultures. Crude culture filtrate of A. fumigatus K16/2 showed the lowest suppression of B. cinerea growth. A maximal percentage inhibition achieved within the study was 38.2%, 39.8% and 23.8 for crude filtrates of P. paneum K7/1, P. chrysogenum K11/1 and A. fumigatus K16/2, respectively. Presence of B. cinerea in dual liquid culture induced significant increase in antifungal capacity of the culture filtrates in comparison to pure culture filtrates of the chosen isolates. The antifungal activity of all of the isolates' culture filtrates retained after heat treatment suggesting the presence of some thermostable antifungal metabolites. The results indicate the complexity and specificity of the interaction between filamentous fungi and B. cinerea. Grape marc is a good source for isolation od B. cinerea fungal antagonists and their antifungal metabolites. Specificity of fungal-fungal interactions suggests that further research on the antagonistic mechanisms and factors affecting them should be studied separately for each pair of antagonists