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Die Verteilung eines Pflanzenschutzmittels im Pflanzenbestand ist ganz wesentlich von der Verfügbarkeit und Verwendung einer geeigneten Applikationstechnik abhängig. Nur eine gute Verteilung gewährleistet den sicheren Kontakt der Zielorganismen mit dem Wirkstoff. Das gilt insbesondere für Schädlinge die sich auf der Blattunterseite aufhalten. Die Auswirkung des Düsentyps sowie die Verwendung eines Netzmittels auf die Wirkstoffanlagerung an die Blattober- und -unterseite und die resultierende Wirksamkeit sind Gegenstand dieser Untersuchungen. Für die Ermittlung der Wirkstoffanlagerung wurde ein künstliches Blatt eingesetzt, bei dem die daran befestigten Glasfaserfilter als Blattober- bzw. -unterseite getrennt analysiert werden konnten. Die Verwendung einer Hohlkegeldüse erhöhte im Vergleich zu einer Flachstrahldüse die Anlagerung auf der Oberseite der künstlichen Blätter in schmalblättrigen Brachyscome multifida. Die Doppelflachstrahldüse unterschied sich nicht von den anderen Düsentypen. In breitblättrigen Pelargonium-Zonale-Hybriden und Fuchsia-Hybriden wurden keine Unterschiede zwischen den Düsentypen festgestellt. Die Wirkstoffanlagerung auf der Blattunterseite der künstlichen Blätter an der Fuchsia-Hybride und die Wirksamkeit auf Trialeurodes vaporariorum war unabhängig vom Düsentyp gering., Journal für Kulturpflanzen, Bd. 73 Nr. 1-2 (2021)

A soil washing apparatus was constructed and tested in collaboration with colleagues from the grant authority and project partners in Austria and Romania. It is based on a similar apparatus used in the USA but our apparatus can quickly process a large number of samples. The eggs were extracted by sieving and then floating on MgSO4-solution followed by sedimentation in water. Eggs of D. virgifera virgifera were separated from those of other species by studying the structure of egg surface. The efficiency of extraction of the apparatus was checked using samples spiked with blue coloured eggs. In co-operation with Austrian and Romanian colleagues a method was developed for sampling in the field. Eggs of D. virgifera virgifera were extracted from soil samples collected from fields in Austria and Romania in spring/summer and autumn 2011. The beetles did not appear to prefer to lay eggs at either the edges or centres of fields. As very few eggs were found at the edges of oil seed squash fields this crop does not appear to be a suitable habitat for egg laying.

The objective of this study was to obtain data that could be used to develop a model for forecasting the occurrence of Diabrotica virgifera virgifera. The model currently available is mainly based on results from American studies using non-diapausing beetles, but the biological performance (fitness and mobility) of American nondiapausing beetles and those of European origin could differ, which would affect the accuracy of this model when used for forecasting in Europe. Thus, it is important to know whether the biological performance of D. virgifera virgifera of European origin differ from that of non-diapausing American beetles. The following aspects of the effect of temperature on the biology of D. virgifera virgifera occurring in Europe were studied and compared with those of a non-diapausing strain from the US: - pre-diapause development of eggs, - post-diapause development of eggs, - effect of different temperatures and densities on the development of larvae. The results indicate that the American data based on studies of non-diapausing strains of D. virgifera virgifera are of only limited use for forecasting the occurrence of this pest in Europe. In particular, the results obtained for the development of eggs, larvae and adults provide information about this species’ biology that could be used to increase our understanding of the population dynamics of this pest in Europe.

In a series of greenhouse experiments the host status and quality of 49 biofuel plants for the larvae of WCR were evaluated. The plants tested (18 species and varieties of Sorghum, 16 forage grasses, 6 Miscanthus genotypes, 6 Panicum varieties and 3 broadleaf species) were grown for at least three weeks before they were used in the bioassays. The insects used in the experiments were obtained from a non diapausing laboratory strain originally from the US and maintained by BTL since 2006. Only neonate larvae (not older than 24 hours) were used in the bioassays. In each experiment up to six species or varieties of plants were tested each with 10 replicates (containers). A susceptible maize variety was used as a positive control in each experiment. Each plant container was infested with ten neonate WCR larvae using a fine art brush. After inoculation the plants were not watered for at least 24 hours to facilitate the establishment of the larvae. The experiments were terminated after 18 days. To extract surviving larvae the soil and roots of test plants were carefully examined by hand and then transferred to a modified MacFadyen heat extractor with an extraction temperature of 45 °C. To assess the host quality the number of larvae recovered, the widths of their head capsules and dry weights were recorded. The larvae were dried at 40 °C for at least 72 hours and then weighed on an electronic micro balance. Of the 21 forage and switch grasses examined 16 hosted WCR larvae. However, the percentage of larvae that survived for 18 days, their dry weights and head capsule widths were significantly less than that recorded for larvae that developed on maize roots. The roots of most (i.e. 15) of the 18 Sorghum species or varieties tested were unsuitable for the development of WCR larvae. For the remaining three Sorghum species a maximum of only two larvae (of 100 inoculated) were recovered. These results indicate that species of Sorghum are very poor quality hosts for WCR as previously reported in other studies. The opposite was true for the Miscanthus species tested. The number of larvae recovered from Miscanthus x giganteus roots, their dry weight and head capsule widths were the same as those recorded for larvae reared on the maize control. The other Miscanthus genotypes were less suitable than Mxg, but still more acceptable than all the forage and switch grasses tested in this study. In accordance with all previous studies, which used host plants other than maize, no larvae developed on the three broad leaf species.

Due to the great ecological plasticity and adaptability of the western corn rootworm, Diabrotica virgifera virgifera LeConte, the unilateral use of one control option could result in it becoming less effective within a few years. Therefore, no one option alone is sufficient for resolving the problem with D. virgifera virgifera. In fact all possibilities have to be considered and integrated. One possibility is to control the adult beetles and so minimize egg deposition and reduce the beetle population size below the economic threshold for the following year. By applying mixtures of insecticides with bitter substances from cucurbits, which are strong feeding stimulants for D. virgifera virgifera, it should be possible to reduce insecticide dosages by up to 95%. This would control the beetles and minimize undesired side-effects to the agro-ecosystem and non-target organisms. Therefore, the aim of this study was to determine (i) the interactions between cucurbitacins (Invite) and five insecticides with different odes of action (indoxacarb, neonicotinoids, organophosphates, pyrethroids and spinosyns), (ii) the effects of biological factors (age, gender and pre-contact) and (iii) the possibility of selection for resistance to bitter agents. In laboratory trials it was shown that the stimulatory effect Invite has on feeding had little or no effect on the efficacy of the five insecticides tested. The improvement in the efficacy after five hours of exposure to Avaunt (indoxacarb) and Biscaya (neonicotinoid) disappeared after 24 and 48 h, and is attributed to the slow initial effects of Avaunt and the recovery of beetles exposed to Biscaya, respectively. Although the LC-values of Biscaya and Avaunt were significantly greater than the corresponding values for mixtures with Invite, it was not possible to reduce the dosages of these active substances by up to 90%. There was no improvement in the efficacy after 48 h of exposure to any of the other insecticides analyzed. The assumption that contact (e. g. pyrethroides) and gas phase insecticides (e. g. organophosphate) are generally less suitable for mixing with Invite was only partly supported by our results. The lack of improvement in the efficacy of Spinosad when mixed with Invite is especially puzzling. Neonicotinoids and indoxacarb are suitable for mixing with Invite, especially in terms of delaying the selection for resistance. Carbamates, e. g. carbaryl (not analyzed in this study), were successfully applied in mixtures with cucurbitacins. The results indicate that biological factors such as gender, age and pre-contact have a strong effect on the attractiveness of Invite. In the experiments, the strength of the response of young beetles to the bitter agents was greater than that of old beetles and that of females less intense than that of males, and pre-contact markedly reduced the stimulatory effect for both sexes. These results and the findings of trials using D. virgifera virgifera caught in Austrian maize fields before and after applications of insecticide-Invite mixtures indicate that the attractiveness of cucurbitacins varies and is subject to selection. If this control strategy is applied extensively then it is likely that this beetle will develop resistance to the bitter agents. Thus, it is important to monitor the resistance of the beetles to these substances.

Pollen beetles (Nitidulidae, Meligethinae) are among the most abundant flower-visiting insects in Europe. While some species damage millions of hectares of crops annually, the biology of many species is little known. We assessed the utility of a 797 base pair fragment of the cytochrome oxidase 1 gene to resolve Molecular Operational Taxonomic Units in 750 adult pollen beetles sampled from flowers of 63 plant species sampled across the UK and continental Europe. We used the same locus to analyse region-scale patterns in population structure and demography in an economically important pest, Brassicogethes aeneus. We identified 44 Meligethinae at ca. 2% divergence, 35 of which contained published sequences. A few specimens could not be identified because the MOTUs containing them included published sequences for multiple Linnaean species, suggesting either retention of ancestral haplotype polymorphism or identification errors in published sequences. Over 90% of UK specimens were identifiable as Brassicogethes aeneus. Plant associations of adult B. aeneus were found to be far wider taxonomically than for their larvae. UK Brassicogethes aeneus populations showed contrasting affiliations between the north (most similar to Scandinavia and the Baltic) and south (most similar to western continental Europe), with strong signatures of population growth in the south.

UV-B induced changes in plants can influence sap-feeding insects through mechanisms that have not been studied. Herein the grain aphid, Sitobion avenae (Fabricius) (Hemiptera: Aphididae), was monitored on barley plants under the treatments of control [0 kJ/ (m2.d)], ambient UV-B [60 kJ/ (m2.d)], and enhanced UV-B [120 kJ/ (m2.d)] irradiation. Electrical penetration graph (EPG) techniques were used to record aphid probing behaviors. Enhanced UV-B irradiated plants negatively affected probing behaviors of S. avenae compared with control plants. In particular, phloem factors that could diminish sieve element acceptance appeared to be involved, as reflected by smaller number of phloem phase, shorter phloem ingestion, and fewer aphids reaching the sustained phloem ingestion phase (E2>10min). On the other hand, factors from leaf surface, epidermis, and mesophyll cannot be excluded, as reflected by higher number of non-probing, longer non-probing and pathway phase, and later the time to first probe.

Distribution of acetamiprid in roses after spray application, Julius-Kühn-Archiv, Nr. 454 (2016): 60. Deutsche Pflanzenschutztagung, 20. - 23. September 2016 Martin-Luther-Universität Halle-Wittenberg - Kurzfassungen der Vorträge und Poster

Schon Ende der 60er Jahre fanden in den USA Untersuchungen zum Wirtsspektrum der Larven des Westlichen Maiswurzelbohrers (Diabrotica virgifera virgifera LECONTE (Coleoptera, Chrysomelidae)) statt (BRANSON & ORTMAN 1967 & 1970). Dort wurden annähernd zwanzig ausschließlich monocotyledone Wirtspflanzen für Larven des Maiswurzelbohrers festgestellt. Dicotyledone Pflanzen scheinen als Wirtspflanzen dagegen nicht geeignet zu sein. Trotz der Bedeutung des Themas besonders im Hinblick auf die Fruchtfolge als IPM-Maßnahme fand dies bisher nur wenig Beachtung. Allerdings gewinnt dieses Thema im Zusammenhang mit der EU-Entscheidung zur Eradikation und Eindämmung des Käfers zusätzliches Interesse. Since the late 60s it is known that larvae of the Western Corn Rootworm (Diabrotica virgifera virgifera LECONTE 1868 (Coleoptera, Chrysomelidae)) do not only feed on maize. BRANSON & ORTMAN (1967 & 1970) recorded nearly twenty possible monocotyledonous host plants for the larvae of D. virgifera virgifera in the USA. For this reason we determined the suitability of different cereals and monocotyledonous weeds as hosts for larvae of D. virgifera virgifera which may be suitable in Europe. We determined 7 suitable plant species for the larvae out of 13 tested. The results need to be confirmed in field trials which have been initiated.

Blattläuse gelten in vielen landwirtschaftlichen Kulturen als bedeutende Schädlinge. In Kartoffeln (Solanum tuberosum) spielen sie vor allem wegen ihrer Fähigkeit zur Virusübertragung eine wichtige Rolle (RADCLIFFE & RAGSDALE 2002). Aus zahlreichen Untersuchungen ist die blattlausreduzierende Wirkung von Strohmulch bekannt, z.B. in Raps (HEIMBACH et al. 2002), Weizen (SCHMIDT et al. 2004), oder Leguminosen (EGGERS & HEIMBACH 2001). Über die Wirkung von Strohmulch in Kartoffeln auf Blattlausbefall und Befall mit dem Kartoffelvirus Y (PVY) in Kleinparzellenversuchen wurde bereits an anderer Stelle berichtet (SAUCKE & DÖRING 2004). In diesem Beitrag werden weitere Ergebnisse aus Praxisversuchen auf ökologisch wirtschaftenden Höfen präsentiert. Ein Schwerpunkt liegt dabei auf der Fragestellung, wie sich die Relation zwischen Dosis (d.h. Mulchmenge) und Wirkung (auf Blattlausbesatz und Virusbefall) gestaltet. Aphids are important pests in potatoes, mainly due to their ability to transmit virus diseases. 17 field experiments were conducted over 4 years at 4 sites on organically managed farms to investigate the effect of straw mulch, applied at various amounts (2–8 t ha-1) shortly after crop emergence, on aphid infestation of potato leaves. The percentage of leaves infested with aphids was repeatedly determined during the growing period in 10 experiments. It was significantly reduced in the mulched treatments at the time around 2 weeks after mulching in 4 experiments, and later, at peak infestation, in 8 experiments. The aphid population size was regularly determined in 11 experiments and was significantly reduced by mulching in 4 of them. In a small scale experiment, the response of aphids landing in green water traps to varied amounts of straw (0–800 g m-2) was investigated. Straw applied as a mulch patch of 60 × 83 cm under green water traps resulted in a general reduction of aphids landing in the traps compared to traps placed on bare soil. This effect was significant at application rates of 200 g m-2, 400 g m-2, or more, with differences among rates between 200 and 800 g m-2 not being significant. One of the possible mechanisms for straw mulch effects on aphids is seen in the interference with host finding behaviour.

Die Anwendung von Strohmulch als eine mögliche Strategie zur Reduzierung von Bodenerosion, Virusinfektionen und Nachernte-Stickstoffverlusten in Kartoffeln wurde hinsichtlich der Effekte auf die Krautfäule (Phytophthora infestans [MONT.] DE BARY) und auf die Pockenkrankheit (Rhizoctonia solani KÜHN) in ökologisch geführten Feldexperimenten über drei Jahre an vier Standorten in Deutschland untersucht. Der Krautfäulebefall wurde in 15 Versuchen als Prozent befallener Blattfläche oder Prozent der Blätter mit Läsionen bonitiert. Rhizoctonia-Pocken auf den geernteten Knollen wurden bei 100 bis 220 Knollen pro Parzelle in 18 Feldversuchen bonitiert. Zusätzlich wurde in einem Feldversuch der Einfluss von Strohmulch auf die Lufttemperatur und die relative Luftfeuchte sowie, in einem weiteren Versuch, auf die Verdunstung im Kartoffelbestand gemessen. In 12 von 15 Feldversuchen hatte Strohmulch keinen signifikanten Einfluss auf die Befallsschwere der Krautfäule. Allerdings konnte in 13 von 15 Feldversuchen ein Trend zur Reduktion von Krautfäule durch Strohmulch beobachtet werden. Der Befall mit Rhizoctonia wurde von Strohmulch nicht beeinflusst, in 16 von 17 Feldversuchen waren die Effekte nicht signifikant. Die Effekte von Strohmulch auf das Mikroklima im Bestand waren von der Tageszeit abhängig. Nachts war die Luft in den gemulchten Parzellen geringfügig feuchter und kühler, am Tag jedoch etwas trockener und wärmer als in den Parzellen ohne Strohmulch. Dieser Effekt war in der 14-tägigen Periode direkt nach dem Mulchen deutlicher, und in der Periode 4 bis 6 Wochen danach weniger ausgeprägt. In einem Versuch wurde über vier Wochen eine konsistente Verringerung der Verdunstung im Kartoffelbestand durch Mulchen beobachtet.

Aphids are important pests in potatoes, mainly due to their ability to transmit virus diseases. 17 field experiments were conducted over 4 years at 4 sites on organically managed farms to investigate the effect of straw mulch, applied at various amounts (2–8 t ha-1) shortly after crop emergence, on aphid infestation of potato leaves. The percentage of leaves infested with aphids was repeatedly determined during the growing period in 10 experiments. It was significantly reduced in the mulched treatments at the time around 2 weeks after mulching in 4 experiments, and later, at peak infestation, in 8 experiments. The aphid population size was regularly determined in 11 experiments and was significantly reduced by mulching in 4 of them. In a small scale experiment, the response of aphids landing in green water traps to varied amounts of straw (0–800 g m-2) was investigated. Straw applied as a mulch patch of 60 × 83 cm under green water traps resulted in a general reduction of aphids landing in the traps compared to traps placed on bare soil. This effect was significant at application rates of 200 g m-2, 400 g m-2, or more, with differences among rates between 200 and 800 g m-2 not being significant. One of the possible mechanisms for straw mulch effects on aphids is seen in the interference with host finding behaviour.

Thieme Thomas. The Architectural Remains of Archaic Labraynda. In: Les Grands Ateliers d’architecture dans le monde égéen du VIe siècle av. J.-C. Actes du colloque d’Istanbul, 23-25 mai 1991, éd. J. des Courtils et J.-Ch. Moretti. Istanbul : Institut Français d'Études Anatoliennes-Georges Dumézil, 1993. pp. 47-55. (Varia Anatolica, 3)

Partially purified HL-A antigens, isolated by papain digestion from membranes of cultured lymphocytes, were subjected to a combination of immunoabsorbance and polyacrylamide gel electrophoresis. With four alloantisera, specific for the HL-A antigens characteristic of the cell line, each antigen could be completely separated from the other three. The results prove that the four HL-A antigens determined by a single genotype are present on four distinct molecular species.