The phytopathogen powdery mildew affects food-searching behavior and survival of Coccinella septempunctata

The diet of entomophagous coccinellids is mainly based on aphids and other food sources such as pollen, nectar, or fungal spores. Knowledge of their foraging behavior on plants infected by powdery mildew and their survival on fungal spores is currently limited. In this study, we investigated the olfactory response of Coccinella septempunctata to odor emission of barley plants infected by powdery mildew and their survival on fungal spores in the presence or absence of aphids. Odors released by powdery-mildew infected plants were more attractive for ladybirds compared to those of uninfected controls. After 3days, the survival rate of ladybirds feeding only on powdery-mildew spores was less than 50%, while for ladybirds feeding exclusively on Rhopalosiphum padi aphids, the survival rate was close to 90%. After 15days, the highest survival rate (almost 80%) was observed for ladybirds feeding on plants with both aphids and powdery mildew. Molecular analyses confirmed the presence of fungal spores in ladybird guts when feeding either on powdery mildew or on a mixed diet. Our results provide new insights into foraging behavior of entomophagous coccinellids revealing the potential of powdery mildew to be utilized as important non-essential food in a mixed diet, but also its lethal effect if consumed alone

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

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)- štetočine paprike i paradajza

Aphids (Hemiptera: Aphididae) cause damage to pepper and tomato on open fields and in greenhouses. Production yield and quality are affected by aphids directly by feeding and indirectly - as being vectors of plant viruses. Many different aphid species are feeding on pepper and tomato: Aphis craccivora, Aphis fabae, Aphis gossypii, Aphis nasturtii, Aulacorthum solani, Macrosiphum euphorbiae and Myzus persicae. All species are very polyphagous. Basic information on their morphology, host plants, biology, vector competence and distribution is given in the text.Biljne vaši (Hemiptera: Aphididae) mogu predstavljati problem u proizvodnji paprike i paradajza na otvorenom polju i u zaštićenom prostoru. Direktne štete nanose ishranom, a indirektne prenošenjem biljnih virusa, što se negativno odražava na prinos i kvalitet ovog povrća. Na paprici i paradajzu se javlja više vrsta biljnih vaši: Aphis craccivora, Aphis fabae, Aphis gossypii, Aphis nasturtii, Aulacorthum solani, Macrosiphum euphorbiae i Myzus persicae. Reč je o izuzetno polifagnim vašima. U radu su navedeni osnovni morfološki podaci za svaku vrstu, biljke domaćini, biologija razvića, vektorska uloga i rasprostranjenje

Tačkasta lucerkina vaš, Therioaphis trifolii (Monell) (Hemiptera: Aphididae) - štetočina lucerke u Srbiji

Spotted alfalfa aphid Therioaphis trifolii (Monell) (Hemiptera, Aphididae) is one of the most important alfalfa pest on the world. Also, it is the most abundant alfalfa aphid in Serbia. This aphid cause damage to alfalfa directly by feeding and indirectly by vectoring plant-pathogenic viruses. Some notes of morphology, host plants, damage, biology, vector role and distribution of spotted alfalfa aphid are given. Abundance of this aphid on alfalfa, influence of climates changes on its abundance, as well as the most important natural enemies (Coleoptera: Coccinellidae and Hymenoptera: Aphidiidae) in Serbia were analyzed.Tačkasta lucerkina vaš Therioaphis trifolii (Monell) (Hemiptera, Aphididae) jedna je od najznačajnijih štetočina lucerke u svetu, takođe, to je najbrojnija vaš na lucerki u Srbiji. Pored direktnih šteta koje nanosi ona je i vektor najznačajnijih virusa lucerke. U radu su prikazani osnovni marfološki podaci, biljke domaćini, štetnost, biologija razvića, vektorska uloga i rasprostranjenje tačkaste lucerkine vaši. Analizirana je njena brojnost na lucerki, uticaj klimatskih promena na povećanje brojnosti, kao i najznačajniji prirodni neprijatelji (Coleoptera: Coccinellidae i Hymenoptera: Aphidiidae) na teritoriji Srbije

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)

Atraktivnost mirisa infestirane i neinfestirane pšenice u zrnu i prekrupe za skladišne tvrdokrilce

Using a two-way olfactometer, the effects of the whole wheat grains and coarse wheat meal odors on the primary Sitophilus granarius (L.), S. oryzae (L.) and S. zeamais (Motch.) and secondary Tribolium castaneum (Herbst) and T. confusum (Du Val) stored-product pests behavior were examined. Whole wheat grains and coarse wheat meal were used in uninfested and infested form. Whole wheat grains were infested with S. oryzae adults and coarse wheat meal with T. castaneum adults. The odors of infested wheat grains depending on the insect species were 1.9 to 3 times more attractive than the uninfested wheat grains odors, except for the T. castaneum for whome the odors of infested and uninfested grains were equally attractive (p = 0.641). The greatest difference in the attractiveness of the infested and uninfested wheat grains odors was found for T. confusum (3 times longer in the arm with the odors of infested grain), and the smallest for S. granarius (1.9 times). We found that all primary and secondary stored-product pests, depending on the species, were 1.4 - 2.4 times more attracted to the odors of infested compared to the odors of uninfested wheat meal. The greatest difference in the atraction of infested and uninfested coarse wheat meal odors was recorded for the T. confusum, whose adults were 2.4 times longer in the arm with the odors of infested coarse wheat meal than in the arm with odors of uninfested wheat meal, while the smallest difference (1.4 times) was recorded for S. oryzae. The results of this study give a significant contribution to a better understanding of the storage insects behavior, which could be used in the design of new methods of monitoring of their presence in stored products.Pomoću dvokrakog olfaktometra ispitivan je uticaj mirisa pšenice u zrnu i pšenične prekrupe na ponašanje primarnih štetočina Sitophilus granarius (L.), Sitophilus oryzae (L.) i Sitophilus zeamais (Motch) i sekundarnih štetočina Tribolium castaneum (Herbst) i Tribolium confusum (Du Val). Pšenica u zrnu i pšenična prekrupa korišćeni su u neinfestiranom i infestiranom obliku, s tim da su zrna pšenice bila infestirana adultima S.oryzae a prekrupa adultima T. castaneum. Miris infestirane pšenice u zrnu je bio u zavisnosti od insekatske vrste od 1,9 do 3,0 puta atraktivniji od mirisa neinfestirane pšenice, osim za adulte T. castaneum za koje je bio podjednako privlačan (p=0,641). Najveća razlika u atraktivnosti mirisa infestirane i neinfestirane pšenice je zabeležena kod T. confusum (3 puta više vremena u kraku sa mirisom infestiranog zrna), a najmanja kod S. granarius (1,9 puta). Sve primarne i sekundarne štetočine su u zavisnosti od vrste bile od 1,4 - 2,4 puta više privučene mirisom infestirane, nego mirisom neinfestirane pšenične prekrupe. Najveća razlika u atraktivnosti mirisa infestirane i neinfestirane prekrupe, utvrđena je kod T. confusum, čiji su adulti proveli 2,4 puta više vremena u kraku sa mirisom infestirane prekrupe nego u kraku sa mirisom neinfestirane, a najmanja razlika (1,4 puta) zabeležena je kod S.oryzae. Rezultati ovih istraživanja daju značajan doprinos boljem poznavanju ponašanja skladišnih insekata, što bi moglo da se upotrebi u osmišljavanju novog načina praćenja njihovog prisustva u uskladištenim proizvodima

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

Uticaj etarskih uija iz tri vrste biljaka roda Cymbopogon na ponašanje kestenjastog brašnara (Tribolium castaneum Herbst)

Behavior bioassays were conducted in the laboratory (23 ± 1°C and 50 ± 5% r.h.) using the olfactometer to determine the effects of essential oils of three plant species in the Cymbopogon genus (Lemongrass), Cymbopogon nervatus, C. proximus and C. schoenanthus, on adults of Tribolium castaneum. The effect of essential oils was compared to a commercial biopesticide based on azadirachtin at three concentrations (0.0001, 0.001 and 0.01%). The results showed that all essential oils and the azadirachtin-based biopesticide had significant (p lt 0.05) repellent effects on T. castaneum adults at all tested concentrations, except C. proximus essential oil which showed a neutral effect at the lowest concentration. The highest concentrations of the essential oils of C. nervatus and C. proximus had significantly stronger repellent effects (p lt 0.05) than the lowest concentration. At the concentrations of 0.0001 and 0.001% all tested essential oils and azadirachtin showed a similar repellent effect without statistically significant difference, whereas the oil of C. nervatus had the highest repellent effect on adults of T. castaneum at the 0.01% concentration. Considering all tested variations, the essential oils of plants of the genus Cymbopogon showed similar or stronger repellent effects on T. castaneum adults than the biopesticide based on azadirachtin.U laboratorijskim uslovima (24±1°C i 50±5% r.v.v.) je pomoću olfaktometra ispitivan uticaj etarskih ulja iz tri biljne vrste roda limunovih trava (Cymbopogon nervatus, Cymbopogon proximus i Cymbopogon schoenanthus) na ponašanje (atraktivnost/repelentnost) adulta T. castaneum. Uticaj etarskih ulja na ponašanje kestenjastog brašnara, poređen je sa uticajem biopesticida na bazi azadirahtina u tri koncentracije: 0.0001, 0.001 i 0.01%. Rezultati testiranja pokazali su da sva etarska ulja i biopesticid na bazi azadirahtina u svim ispitivanim koncentracijama ispoljavaju statistički značajan odbijajući uticaj - repelentni efekat na adulte kestenjastog brašnara, osim najniže koncentracije ulja iz biljke C. proximus koja je ispoljila neutralan efekat na brašnara. Najviša koncentracija ulja iz biljaka C. nervatus i C. proximus je ispoljila statistički značajno jači repelentni efekat u odnosu na najnižu koncentraciju. Sva ispitivana etarska ulja i azadirahtin su u koncentracijama 0.0001 i 0.001% ispoljila sličan repelentni efekat bez statistički značajne razlike, dok je ulje iz biljke C. nervatus u koncentraciji 0.01% prouzrokovalo statistički značajno jači repelentni efekat na adulte kestenjastog brašnara u odnosu na ostale ispitivane supstance. Na osnovu rezultata istraživanja sa adultima kestenjastog brašnara može se zaključiti da su etarska ulja iz tri vrste biljaka iz roda Cymbopogon ispoljila sličan i/ili jači repelentni efekat od biopesticida na bazi azadirahtina. Takođe, dobijeni rezultati pokazuju značajan potencijal upotrebe ulja ovih biljaka kao prirodnog sredstva za zaštitu uskladištenih biljnih proizvoda

Macrosiphoniella helichrysi (Hemiptera: Aphididae), potencijalna štetočina smilja u Srbiji

New insect species for the fauna of Serbia has been found on immortelle in Zemun; it is the immortelle aphid - Macrosiphoniella helichrysi Remaudière 1952 (Hemiptera: Aphididae). The aphid is monoecious oligophagous species, living without host alternation on a few Helichrysum plants. All over the world this aphid is anholocyclic, which has been proved in Zemun, and only apterous and winged viviparous parthenogentic females have been found. M. helichrysi is reported to be a pest on immortelle in Hercegovina and its presence on immortelle fields in Serbia need special attention.Nova vrsta insekta za faunu Srbije, vaš smilja-Macrosiphoniella helichrysi Remaudière 1952 (Hemiptera: Aphididae) nađena je u Zemunu. To je monoecična oligofagna vrsta koja tokom vegetacije ne menja biljku domaćina, a kolonije osim na smilju formira i na drugim vrstama roda Helichrysum. Razviće M. helichrysi je anholociklično, u kolonijama se nalaze beskrilne i krilate viviparne partenogenetske ženke. Ovaj insekt pričinjava štete smilju u Hercegovini i zato treba obratiti pažnju na njegovo prisustvo u zasadima smilja u Srbiji