Scherer R.,Leibniz University of Hanover |
Scherer R.,Hannover Medical School |
Schaarschmidt F.,Leibniz University of Hanover |
Prescher S.,Julius Kuhn Institute |
Priesnitz K.U.,Institute for Plant Protection
Biometrical Journal | Year: 2013
Diversity indices might be used to assess the impact of treatments on the relative abundance patterns in species communities. When several treatments are to be compared, simultaneous confidence intervals for the differences of diversity indices between treatments may be used. The simultaneous confidence interval methods described until now are either constructed or validated under the assumption of the multinomial distribution for the abundance counts. Motivated by four example data sets with background in agricultural and marine ecology, we focus on the situation when available replications show that the count data exhibit extra-multinomial variability. Based on simulated overdispersed count data, we compare previously proposed methods assuming multinomial distribution, a method assuming normal distribution for the replicated observations of the diversity indices and three different bootstrap methods to construct simultaneous confidence intervals for multiple differences of Simpson and Shannon diversity indices. The focus of the simulation study is on comparisons to a control group. The severe failure of asymptotic multinomial methods in overdispersed settings is illustrated. Among the bootstrap methods, the widely known Westfall-Young method performs best for the Simpson index, while for the Shannon index, two methods based on stratified bootstrap and summed count data are preferable. The methods application is illustrated for an example. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Masten Milek T.,Institute for Plant Protection |
Pellizzari G.,University of Padua
Bulletin of Insectology | Year: 2016
The invasive mealybug Paracoccus burnerae (Brain) (Hemiptera Pseudococcidae) is recorded from Gran Canaria (Canary Islands) and Yemen for the first time. Comments on the present world distribution of this polyphagous species and new host-plant records are also provided. © 2016, Universita degli Studi di Bologna, Department of Agroenvironmental Sciences and Technologies. All rights reserved.
Bjelis M.,Institute for Plant Protection |
Radunic D.,Institute for Plant Protection |
Bulic P.,Ministry of Agriculture and Foresty
Journal of Applied Entomology | Year: 2013
A prototype of an improved automated ground release machine was assessed and found, with further improvements, to have the potential to be a promising tool for the release of quality sterile Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) flies in small- and medium-scale SIT control programmes. The following quality parameters of sterile flies were assessed: (i) flight ability, (ii) physical damage caused by the ground release machine, (iii) survival under stress conditions without food and water and (iv) water condensation on flies, after 0.5 and 2h under the automatically controlled abiotic conditions of 16±0.8°C and ∼58% relative humidity. A total number of seven different treatments, five involving flies held inside the ground release machine and two control treatments of chilled and non-chilled flies not held inside the ground release machine, were evaluated to assess sterile male quality. Flight ability was as high as 97% in the control treatment (no ground release), compared with the lowest value of 92.5% when a 1-m-long screw-auger, as part of the ground release machine, was tested. Use of a 1-m-long screw-auger significantly increased the percentage of damaged flies up to 7.2%, compared with ≤1.7% in the control treatments. It is confirmed that the length of the screw-auger is the most important factor affecting quality of the released flies in the ground release system tested. Also, interaction of duration of time inside the machine, screw-auger rotation and the effect of the directional discharge blower significantly increases the percentage of damaged flies. Evaluation of sterile fly survival under stress conditions, without food and water, confirms that movement or handling of the flies inside the ground release machine drastically decreases percentage of live insects from ≤ 4.5% after 24h and 0.0% after 48h, compared with 18.67-21.67% after 24h and 3.50-5.83% after 48h in the control treatments. The most important factors affecting sterile fly quality, such as condensation, compaction and damage, from moving mechanical parts are demonstrated to be minimized or eliminated by making adaptations to the ground release machine construction. © 2011 Blackwell Verlag, GmbH.
Priesnitz K.U.,Institute for Plant Protection |
Benker U.,Institute for Plant Protection |
Schaarschmidt F.,Leibniz University of Hanover
Journal of Plant Diseases and Protection | Year: 2013
The potential impact of a Bt maize hybrid expressing the coleopteran specific Cry3Bb1 on non-target organisms was assessed in a field release experiment. The study examined the relative abundance of ground beetles (Carabidae) in four maize varieties including the genetically engineered DKC 5143-Bt (event MON 88017), its near-isogenic line DKC 5143 and the two conventional varieties DK 315 and Benicia. Pitfall traps were used to collect the ground dwelling arthropods, which were analyzed to species level. Statistical comparisons showed no significant differences of ground beetle activity densities and diversity patterns between the Bt maize and the near isoline. The internal contents of the Bt protein Cry3Bb1 in ground beetles collected from the field were measured with ELISA. The Bt protein was found in 47% of the ground beetles sampled in Bt plots before the anthesis and in 66% of the individuals sampled after the beginning of maize anthesis. © Eugen Ulmer KG, Stuttgart.
Milek T.M.,Institute for Plant Protection |
Simula M.,Institute for Plant Protection |
Markotic V.,Institute for Plant Protection
Acta Zoologica Bulgarica | Year: 2014
During eight years of faunistic research on scale insects in Croatia (2006-2013), eight scale insect (Hemiptera: Coccoidea) species of two families were found on Pistacia spp. (Anacardiacae): Coccidae: Ceroplastes rusci (L.), Coccus hesperidum L., Lichtensia viburni (Signoret), Saissetia oleae (Olivier) and Diaspididae: Chrysomphalus dictyospermi (Morgan), Epidiaspis gennadii (Leonardi), Lepidosaphes ulmi (L.) and Saharaspis ceardi (Balachowsky). This is the first record of S. ceardi in Croatia. The localities where scale insects have been collected are listed.
Renco M.,Slovak Academy of Sciences |
Sasanelli N.,Institute for Plant Protection |
Papajova I.,Slovak Academy of Sciences |
Maistrello L.,University of Modena and Reggio Emilia
Helminthologia | Year: 2012
Summary: Recently, tannins have been reported for their nematicidal activity against the root-knot nematode Meloidogyne javanica both in vitro and in pot experiments in addition to a biocidal effect on a wide range of fungi, bacteria and yeasts. However, no information is available on the effect of these polyphenols on plant parasitic cyst nematodes. Therefore, an in vitro and a pot experiments on potato were undertaken to investigate the nematicidal activity of tannin aqueous solutions at different concentrations on the potato cyst nematode Globodera rostochiensis. In the in vitro experiment different tannin concentrations in a geometric scale (from 0. 32 to 20. 48 g/l) were tested for their effect on the egg hatch of the nematode. All tested tannin concentrations were effective to reduce egg viability from 56 to 87%, in comparison to the untreated control. In the pot experiment, tannins, as aqueous solutions at rates of 100, 250 and 450 g/m 2, were applied to soil at two different application times (at sowing and at sowing and two weeks later). All tested doses were effective to reduce the number of cyst/100 g soil, eggs and juveniles/g soil and reproduction rate in comparison to untreated control. The number of eggs and juveniles/cyst was not influenced by the different applied rates of tannins. © 2012 Versita Warsaw and Springer-Verlag Wien.
Renco M.,Slovak Academy of Sciences |
Sasanelli N.,Institute for Plant Protection |
Kovacik P.,Slovak University of Agriculture
Helminthologia | Year: 2011
Summary: A pot experiment on potato was carried out to verify the nematicidal effect of four composts of different origin (C1: 70 % horse manure + 15 % sugar beet pomace + 5 % poultry manure + 10% grape pomace; C2: 100 % pig manure decomposed by juveniles of Musca domestica; C3: 100 % vermicompost from medical plants wastes; C4: 100% vermicompost from cattle manure) on the potato cyst nematodes G. rostochiensis (Ro1) and G. pallida (Pa2 and Pa3). Composts at different rates (1.0, 2.5 and 5.0 % w/w) were mixed with the nematode infested soils. Pots with unamended soils were used as control. Pots (4 l) were arranged in a glasshouse according to a randomized block design with four replications per each treatment. A significant reduction in number of cysts, eggs and juveniles/cyst and eggs and juveniles/g soil was observed in each compost in comparison to unamended soil. The suppressive nematode effect increased according to the compost NH 4 + content and compost rate. © 2011 © Versita Warsaw and Springer-Verlag Wien.
Boine B.,Institute for Plant Protection |
Renner A.-C.,Institute for Plant Protection |
Zellner M.,Institute for Plant Protection |
Nechwatal J.,Institute for Plant Protection
European Journal of Plant Pathology | Year: 2014
Rhizoctonia solani AG2-2IIIB is the causal agent of late crown and root rot in sugar beet. In a 4-year field study we analyzed the impact of different plant residue management systems of sugar beet and maize as well as of growing wheat (non-host) and different maize varieties on the soil inoculum density of R. solani. Sugar beet remains were either tilled or removed from the field; maize was then grown during the two following years and also tilled or removed. The soil inoculum potential of R. solani was studied using three different on- and off-site monitoring systems. A monthly assessment of root damage indices of maize and sugar beet and broad bean as an indicator plant was carried out. In addition, an indirect quantitative real-time PCR assay using quinoa seed baits was developed to analyze field soil samples for R. solani AG2-2 soil concentration at the end of each year. The results show that the non-host wheat as a pre-crop to sugar beet reduced the Rhizoctonia inoculum potential in the soil significantly. Additionally, the incorporation of host plant debris (sugar beet + maize) into the soil increased the Rhizoctonia soil inoculum potential and the incidence of sugar beet rot. Although the maize genotypes’ susceptibility to R. solani differed, their plant debris did not significantly influence growth and survival of R. solani in the soil. This work describes methods that allow elucidating the effect of agricultural practice on Rhizoctonia levels in the soil and on disease development in the field. © 2014, Koninklijke Nederlandse Planteziektenkundige Vereniging.
Ivic D.,Institute for Plant Protection
Journal of Plant Pathology | Year: 2014
The effect of 15 Fusarium species on seed germination and early plant development was examined in a laboratory study, together with the potential toxigenicity of selected isolates and the possibility of T-2 toxin production on soybean and pea grain. In germination tests, 33 out of 47 isolates of Fusarium chlamydosporum, F. pseudograminearum, F. sporotrichioides, F. crookwellense, F. verticillioides, F. equiseti, F. semitectum, F. solani, F. poae, F. sambucinum and F. compactum significantly reduced the number of normal soybean seedlings, while only six out of 48 isolates of F. sporotrichioides, F. semitectum and F. chlamydosporum significantly reduced the number of normal pea seedlings. When inoculated on plants grown in Hoagland’s media, nearly all Fusarium isolates caused necrosis of soybean and pea root, but neither of them significantly reduced shoot and root dry mass of pea plants, or shoot dry mass of soybean plants. Amplification of tri5 and FUM1 genes, required for trichothecene and fumonisin biosynthesis, was carried out by PCR in 45 Fusarium isolates from soybean and 40 isolates from pea. Positive tri5 PCR reaction was recorded in 19 isolates of F. sporotrichioides, F. crookwellense, F. pseudograminearum, F. poae, F. sambucinum, F. culmorum, F. equiseti and F. chlamydosporum. Positive FUM1 PCR reaction was recorded in 35 out of 38 F. verticillioides and F. proliferatum isolates. The content of T-2 toxin produced by eight F. sporotrichioides isolates inoculated on autoclaved soybean, pea and barley grain ranged from 69.4 to 2595.5 μg/kg. No significant differences were determined between T-2 toxin production on soybean and barley grain, nor on pea and barley grain. © 2014, Edizioni ETS. All rights reserved
Kaemmerer D.,Institute for Plant Protection
Journal of Plant Diseases and Protection | Year: 2012
Currently plant infectivity assays (bioassays) seem most reliable to determine viability of potato cyst nematodes (Globodera rostochiensis and G. pallida), but they are time consuming and labour-intensive. Hence, the objective of the present investigation was to establish a reliable and time-saving reverse transcription PCR (RT-PCR) assay for determining viability of potato cyst nematodes. Sensitivity of the developed test was very high enabling the detection of the gpd1 mRNA of one untreated second-stage juvenile (J2) in 200 μl of water in 5 out of 10 tested samples. The adopted RT-PCR protocol was used to study the thermo-sensitivity of G. rostochiensis and G. pallida between 35 and 55°C as well as the fate during anaerobic digestion at 38°C. The test proved to be very robust concerning PCR inhibiting factors, mRNA detection of ten untreated J2 in 200 μl of digester substrate was always successful. Results of the RT-PCR assay and the bioassay congruently showed that 4 days of anaerobic digestion were suitable to decontaminate plant material containing cysts of G. rostochiensis or G. pallida. Whereas usefulness of the RT-PCR to estimate the viability of heat treated cysts was limited to long incubation times or temperature treatments above 45°C, because mRNA persisted unexpectedly long at short incubation times or temperature treatments below 45°C. Nevertheless the presented RT-PCR method may be useful for selected applications that require a fast and sensitive determination of the vitality of potato cyst nematodes. © Eugen Ulmer KG, Stuttgart.