Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

    We have a manual that explains all the features 

    Current refinement(s):

    Records 1 - 20 / 156

    • help
    • print

      Print search results

    • export

      Export search results

    Check title to add to marked list
    Uncovering the economic value of natural enemies and true costs of chemical insecticides to cotton farmers in China
    Huang, Jikun ; Zhou, Ke ; Zhang, Wei ; Deng, Xiangzheng ; Der Werf, Wopke van; Lu, Yanhui ; Wu, Kongming ; Rosegrant, Mark W. - \ 2018
    Environmental Research Letters 13 (2018)6. - ISSN 1748-9318
    biological control - economic value - insecticides - natural enemies - smallholder farming

    Little empirical evidence on the economic value of biological control of pests at farm level is available to improve economic decision-making by farmers and policy makers. Using insect sampling and household survey in an integrated bio-economic analysis framework, this paper studies farmers' crop management practices in cotton in the North China Plain, and estimates the marginal value of natural enemies and costs of chemical insecticides to farmers. Ladybeetles (mainly Harmonia axyridis, Propylea japonica, and Coccinella septempunctata), the dominant natural enemy group that controls the primary pest (aphid) in cotton in our study area, provide a significant economic benefit that is unknown to the farmers. Even at the current high levels of insecticide use, an additional ladybeetle provides an economic benefit of 0.05 CNY (almost USD 0.01) to farmers. The use of broad-spectrum insecticides by farmers is alarmingly excessive, not only undermining farmers' cotton profitability but also inducing social costs as well as disruption of the natural pest suppression system. Doubling current ladybeetle density in cotton field could gain an estimated USD 300 million for cotton farmers in China, providing a strong economic case for policies to move the pest control system towards a more ecologically-based regime, with positive consequences for farm income and environmental health. With rising use of biological control service provided by natural enemies such as ladybeetles in cotton fields, significant falls in farmers' insecticide use would be expected, which could raise the value of ladybeetles and other natural enemies even further. The results indicate that there is an urgent need to rationalize inputs and move forward to improved agro-ecosystem management in smallholder farming system. Raising knowledge and awareness on the costs and value of biological pest control versus insecticides among farmers and policy makers and having effective extension service, are priorities towards achieving a more ecologically-based approach to crop protection on smallholder farms.

    Combined effects of agrochemicals and ecosystem services on crop yield across Europe
    Gagic, Vesna ; Kleijn, David ; Báldi, András ; Boros, Gergely ; Jørgensen, Helene Bracht ; Elek, Zoltán ; Garratt, Michael P.D. ; Groot, Arjen de; Hedlund, Katarina ; Kovács-Hostyánszki, Anikó ; Marini, Lorenzo ; Martin, Emily A. ; Pevere, Ines ; Potts, Simon G. ; Redlich, Sarah ; Senapathi, Deepa ; Steffan-Dewenter, Ingolf ; Świtek, Stanislaw ; Smith, Henrik G. ; Takács, Viktória ; Tryjanowski, Piotr ; Putten, Wim H. van der; Gils, Stijn van; Bommarco, Riccardo - \ 2017
    Ecology Letters 20 (2017)11. - ISSN 1461-023X - p. 1427 - 1436.
    Agricultural intensification - biological pest control - ecological intensification - fertilisers - insecticides - landscape complexity - soil organic carbon - yield loss

    Simultaneously enhancing ecosystem services provided by biodiversity below and above ground is recommended to reduce dependence on chemical pesticides and mineral fertilisers in agriculture. However, consequences for crop yield have been poorly evaluated. Above ground, increased landscape complexity is assumed to enhance biological pest control, whereas below ground, soil organic carbon is a proxy for several yield-supporting services. In a field experiment replicated in 114 fields across Europe, we found that fertilisation had the strongest positive effect on yield, but hindered simultaneous harnessing of below- and above-ground ecosystem services. We furthermore show that enhancing natural enemies and pest control through increasing landscape complexity can prove disappointing in fields with low soil services or in intensively cropped regions. Thus, understanding ecological interdependences between land use, ecosystem services and yield is necessary to promote more environmentally friendly farming by identifying situations where ecosystem services are maximised and agrochemical inputs can be reduced.

    Alternatieven voor neonicotinoïden in de sierteelt onder glas : bestrijding van tabakswittevlieg en bladluis in kuipplanten en perkgoed
    Messelink, Gerben ; Vijverberg, Roland ; Bloemhard, Chantal ; Leman, Ada - \ 2016
    Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1418) - 42
    tuinplanten - containerplanten - insectenplagen - bemisia tabaci - aphididae - kasgewassen - glastuinbouw - biologische bestrijding - insecticiden - lecanicillium muscarium - entomopathogene schimmels - roofinsecten - bedding plants - container grown plants - insect pests - bemisia tabaci - aphididae - greenhouse crops - greenhouse horticulture - biological control - insecticides - lecanicillium muscarium - entomogenous fungi - predatory insects
    The control of phloem feeding insects such as aphids, whiteflies, cicadas, mealybugs, scales and plant feeding bugs in greenhouse crops still largely depends on the use of neonicotinoids. However, the increased found negative effects on the environment will soon results in a total ban on the use of these pesticides. In this project we summarized the possible alternative control measures with pesticides and biological control agents. Furthermore, a number of preventive and curative control measures was evaluated for the control of aphids in bedding plants and the tobacco whitefly in container plants, with Calibrachoa and Mandevilla as model plants. An endophytic application of an isolate of the entomopathogenic fungus Lecanicillium gave a clear trend of 25% reduced population growth of aphids on Calibrachoa. Curative control of aphids with lacewings was not effective. Mullein plants enhanced tobacco whitefly control by the predatory bug Macrolophus pygmaeus in Mandevilla and increased predator survival and reproduction. Among the tested alternative control measures, we found 5 products that controlled tobacco whiteflies effectively in Mandevilla.
    The ACROPOLIS project: Its aims, achievements, and way forward
    Klaveren, J.D. van; Kennedy, M.C. ; Moretto, A. ; Verbeke, W. ; Voet, H. van der - \ 2015
    Food and Chemical Toxicology 79 (2015). - ISSN 0278-6915 - p. 1 - 4.
    dopaminergic pc12 cells - azole fungicides - insecticides
    Bestrijding van wolluis en schildluis in de sierteelt onder glas
    Wageningen UR, - \ 2015
    greenhouse horticulture - plant pests - ornamental horticulture - greenhouse vegetables - integrated pest management - control methods - methodology - biological control agents - insecticides
    Field evaluation of the efficacy of neem oil (Azadirachta indica A. Juss) and Beauveria bassiana (Bals.) Vuill. in cotton production
    Togbe, C.E. ; Haagsma, R. ; Zannou, E. ; Gbehounou, G. ; Déguénon, J.M. ; Vodouhe, S. ; Kossou, D. ; Huis, A. van - \ 2015
    Journal of Applied Entomology 139 (2015)3. - ISSN 0931-2048 - p. 217 - 228.
    threshold-based interventions - helicoverpa-armigera hubner - west-africa - metarhizium-anisopliae - entomopathogenic fungi - pest-management - spider-mite - insecticides - resistance - benin
    Neem oil (Azadirachta indica A. Juss) alone and combined with the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin (isolate Bb11) was applied to control cotton pests. The efficacy of these treatments was compared with that of synthetic insecticides applied either in a calendar-based application or in the ‘Lutte Etagée Ciblée’ (LEC) strategy, consisting of using first calendar-based (half-dose) applications followed by threshold-based treatments. The experiment was carried out in collaborative research with farmers in three cotton agro-ecological zones differing in rainfall, pest prevalence, and farming practices. The neem oil and neem oil-Bb11 treatments required 2 to 6 applications, while conventional and LEC received 6 to 8 applications. The percentage of damaged reproductive organs in plots treated with neem oil and neem oil plus Bb11 was higher than that recorded under the conventional and LEC strategy, with exception of the zone with the highest rainfall; this resulted in yields being 25% and 39% lower, respectively. Yields in the biopesticide plots were 26–42% higher and in the conventional and LEC plots 44–59% higher than those in the control plots that received only water. Overall, the LEC regime scored best, both in yield and profitability. The incidence of natural enemies was highest in the control and in the plots treated with biopesticides. Although the use of entomopathogen Bb11 and neem oil avoids many problems associated with the application of synthetic insecticides, their efficacy needs to be enhanced by improved formulation or by combining them with other pesticides.
    Ook een honingbij ontgift zich : drugkoeriers en narcoticabrigades actief in de bij
    Scheer, H. van der; Blacquiere, T. - \ 2014
    Bijenhouden 8 (2014)1. - ISSN 1877-9786 - p. 29 - 31.
    honingbijen - foerageren - insecticiden - ontgifting - metabolische detoxificatie - diergezondheid - imidacloprid - bombus - honey bees - foraging - insecticides - detoxification - metabolic detoxification - animal health - imidacloprid - bombus
    Honingbijen komen bij het foerageren met allerlei stoffen in aanraking, ook met insecticiden.Maar ze zijn ook in staat tot ontgiften. Dit artikel geeft uitleg over het mechanisme daarvan enover recent onderzoek op dit gebied aan bijen.
    Field evaluation of the synergistic effects of neem oil with Beauveria bassiana (Hypocreales: Clavicipitaceae) and Bacillus thuringiensis var. kurstaki (Bacillales: Bacillaceae)
    Togbe, C.E. ; Zannou, E. ; Gbehounou, G. ; Kossou, D. ; Huis, A. van - \ 2014
    International Journal of Tropical Insect Science 34 (2014)4. - ISSN 1742-7584 - p. 248 - 259.
    metarhizium-anisopliae - azadirachta-indica - natural enemies - cotton bollworm - compatibility - insecticides - coleoptera - curculionidae - coccinellidae - lepidoptera
    In the present study, the synergistic effects of Beauveria bassiana (Bals.-Criv. Vuill.) (isolate Bb11) and Bacillus thuringiensis var. kurstaki (Berliner) with neem oil were evaluated in three agroecological zones in Be´nin. Four bioinsecticide treatments (neem oil, neem oil and B. bassiana used separately for different target pests, neem oil mixed with B. bassiana and neem oil mixed with B. thuringiensis) were compared with a calendar-based treatment using synthetic insecticides and a control without insecticides. The bioinsecticide treatments were less effective than the calendar-based treatment at controlling cotton pests. There was no difference in yields and the number of damaged bolls in plots under treatments with the four bioinsecticide formulations, suggesting an absence of synergy between neem oil and B. bassiana and neem oil and B. thuringiensis. The numbers of natural enemies in all the bioinsecticide treatment plots and the control plots were similar and higher than those in the calendar-based treatment plots. The highest yield and profitability were obtained with the calendar-based treatment. Screening the compatibility of plant-based products and biopesticides through bioassays is essential for a successful application of their combinations in any integrated pest management strategy.
    Kopstekers in de opkweek van linde : oorzaken en mogelijkheden voor beheersing
    Helsen, H.H.M. ; Sluis, B.J. van der - \ 2014
    Randwijk : Praktijkonderzoek Plant & Omgeving, Business Unit Bloembollen, Boomkwekerij en Fruit - 29
    tilia platyphyllos - dasineura - insecticiden - gewasbescherming - bestrijdingsmethoden - symptomen - cultivars - schade - proeven - herbiciden - tilia platyphyllos - dasineura - insecticides - plant protection - control methods - symptoms - cultivars - damage - trials - herbicides
    Het verschijnsel kopstekers in linde kan verschillende oorzaken hebben. De belangrijkste is de lindebladplooigalmug (Dasineura thomasiana). De larven van deze galmug zuigen aan de jongste bladeren waardoor die op typerende wijze samenvouwen. Bestrijding is mogelijk met een gerichte inzet van insecticiden. Naast de typische galmugschade vertonen verschillende soorten en cultivars ook symptomen die zeker niet door galmuggen worden veroorzaakt. Het gaat meestal om vergelende bladranden, komvormige blaadjes en “genepen blad”. In een veldproef werd aangetoond dat deze verschijnselen niet worden veroorzaakt door herbiciden of galmijten.
    Nieuwe technieken ter bestrijding van trips : eerste verkenning van nieuwe mogelijkheden om tripsschade te beheersen in de teelt van prei en sluitkool
    Huiting, H.F. ; Kruistum, G. van; Rozen, K. van - \ 2014
    Lelystad : Praktijkonderzoek Plant & Omgeving, Business Unit AGV - 28
    koolsoorten - allium porrum - plantenplagen - thrips tabaci - insecticiden - toepassing - aantasting - gevoeligheid van variëteiten - landbouwkundig onderzoek - cabbages - allium porrum - plant pests - thrips tabaci - insecticides - application - infestation - varietal susceptibility - agricultural research
    De schade door tabakstrips (Thrips tabaci Lind.) in prei treedt vooral op in warme zomers: hoe droger en warmer het weer, hoe groter de kans dat tabakstrips schade veroorzaakt. De tabakstrips is een polyfaag en zeer mobiel insect, dat zich snel kan vermeerderen. Tripsbeheersing vraagt veel aandacht van telers van kool en prei, doordat trips zeer mobiel kan zijn en een hoge reproductiesnelheid kan halen; onder Nederlandse omstandigheden zijn er 5 à 8 generaties per jaar. In Nederlandse buitenteelten is overwegend de tabakstrips (Thrips tabaci Lind.) problematisch. Het doel van dit onderzoek is het bepalen van de effectiviteit van twee toepassingsmethoden via de bodem en enkele insecticide–doseringscombinaties op tripsaantasting in prei en sluitkool.
    Analysis of organic contaminant desorption kinetic data for sediments and soils: Implications for the Tenax extraction time for the determination of bioavailable concentrations
    Noort, P.C.M. van; Poot, A. ; Koelmans, A.A. - \ 2014
    Science of the Total Environment 490 (2014). - ISSN 0048-9697 - p. 235 - 238.
    polybrominated diphenyl ethers - in-field sediments - black carbon - availability - insecticides - pyrethroids - sorption - predict - tool
    Solid-phase extractions with adsorbents like Tenax have been widely used to assess bioaccessible or bioavailable concentrations and non-extractable residues (NER) of organic contaminants in soils or sediments. This paper presents an analysis of literature rate constants and fractions for rapid, slow and very slow contaminant desorption from soils and sediments. Contaminant fractions desorbed from sediment to Tenax in 6 or 24. h were evaluated as to their adequacy as a proxy for rapidly desorbing fractions, which have been shown to correlate with bioavailable concentrations. Desorption rate constants appear to decrease with increasing contaminant n-octanol-water partition coefficient. The ratio of the fraction of contaminant desorbed from sediment to Tenax in 6. h and the rapidly desorbing fraction appeared to slightly decrease on increasing contaminant hydrophobicity. This was not the case for the extraction for 24. h. Rapidly desorbing fractions or bioavailable fractions can be estimated, within a factor of 1.4, by multiplying the fraction desorbed in 24. h by a factor of 0.7.
    Lokschapen vangen teken in het bos
    Sikkema, A. ; Wieren, S.E. van - \ 2014
    Wageningen UR/Stichting voor Duurzame Ontwikkeling
    schapen - gastheer parasiet relaties - vangmethoden - lokken - natuurgebieden - borrelia burgdorferi - humane ziekten - lyme-ziekte - infectieziekten - insecticiden - experimenten - wetenschappelijk onderzoek - bosecologie - sheep - host parasite relationships - trapping - baiting - natural areas - borrelia burgdorferi - human diseases - lyme disease - infectious diseases - insecticides - experiments - scientific research - forest ecology
    De Wageningse onderzoeker Sip van Wieren wil lokschapen inzetten om teken weg te vangen in natuurgebieden. Op die manier kunnen schaapskuddes er voor zorgen dat mensen prettig kunnen recreëren in het bos.
    Voorkomen van schade door bonenvlieg : effectiviteit van zaad- en bodembehandelingen en aanvullende maatregelen om stamslabonen te beschermen tegen de maden van de bonenvlieg (2013)
    Rozen, K. van; Vlaswinkel, M.E.T. - \ 2014
    Lelystad : PPO AGV - 28
    delia platura - insectenbestrijding - phaseolus vulgaris - gewasbescherming - vollegrondsgroenten - vollegrondsteelt - veldproeven - plagenbestrijding - groenteteelt - spinazie - insecticiden - delia platura - insect control - phaseolus vulgaris - plant protection - field vegetables - outdoor cropping - field tests - pest control - vegetable growing - spinach - insecticides
    In de bonenteelt veroorzaken de maden van de bonenvlieg vraatschade in de kiem- en opkomstperiode, wat kan leiden tot plantwegval en vervolgens opbrengstverlies. Het toegelaten middelenpakket beperkt zich tot één insecticide waarmee het zaad wordt behandeld. Nieuwe middelen met een laag negatief milieuprofiel, insect werende producten en praktische teeltmaatregelen zijn gewenst tegen de verschillende stadia van de bonenvlieg. Dit rapport geeft de resultaten van een veldproef en een demo uitgevoerd in 2013 weer en is het vervolg op de deskstudie en het veldonderzoek in 2012.
    Imidacloprid niet de oorzaak van wintersterfte bij bijen
    Steen, J.J.M. van der - \ 2014
    Boerderij 99 (2014)27. - ISSN 0006-5617 - p. 62 - 62.
    apidae - honingbijen - bijenziekten - imidacloprid - chemische bestrijding - insecticiden - gewasbescherming - mortaliteit - doodsoorzaken - apidae - honey bees - bee diseases - imidacloprid - chemical control - insecticides - plant protection - mortality - causes of death
    Volgens Wageningen UR heeft Imidacloprid geen invloed op de overwintering van bijen.
    Comparative antifeedant activities of polygodial and pyrethrins against whiteflies (Bemisia tabaci) and aphids (Myzus persicae)
    Prota, N. ; Bouwmeester, H.J. ; Jongsma, M.A. - \ 2014
    Pest Management Science 70 (2014)4. - ISSN 1526-498X - p. 682 - 688.
    drimane sesquiterpenoids - biological-control - plant-viruses - trpa1 - insecticides - microcapsules - transmission - aleyrodidae - penetration - parasitoids
    BACKGROUND Polygodial, a sesquiterpene dialdehyde of the drimane family, has been shown to have deterrent and antifeedant effects on various insect species, including Myzus persicae (Sulzer), Spodoptera spp. and Leptinotarsa decemlineata (Say). This compound may have potential as a broad-spectrum biocontrol agent, similar to pyrethrins, given that it was previously reported to improve yield when sprayed on barley fields. RESULTS This study compares the deterrent effect of polygodial and pyrethrins against the silverleaf whitefly Bemisia tabaci (Gennadius) and the green peach aphid M. persicae in dual-choice assays using compound-coated tomato leaf discs. B. tabaci adults were deterred by polygodial at an ED50 (effective dose at which 50% of the insects are deterred) of about 25 µg g-1 fresh weight (FW), and green peach aphids at about 54 µg g-1 FW. Bioassays were benchmarked with pyrethrins that had a 20-fold lower ED50 of approximately 1.4 µg g-1 FW against whiteflies, but only a twofold lower ED50 (about 28 µg g-1 FW) against peach aphids. Polygodial showed moderate phytotoxic effects (score of 2 on a scale of 1–5) on tomato leaves at concentrations above the ED50 concentrations (=90 µg g-1 FW). CONCLUSION The sesquiterpene dialdehyde polygodial is 2–20 times less deterrent than pyrethrins, depending on the insect species, but it could provide a useful complement to pyrethrin sprays as it has a different mode of action, is food grade and has low volatility. However, a formulation that reduces the risks of phytotoxic effects should be developed. © 2013 Society of Chemical Industry
    Bestrijding van trips in prei : effectiviteit van twee insecticiden, in verschillende doseringen en toepassingsintervallen, op tripsaantasting in prei
    Huiting, H.F. ; Kruistum, G. van - \ 2013
    Lelystad : Praktijkonderzoek Plant & Omgeving, Business Unit AGV - 18
    preien - stengelgroenten - allium porrum - gewasbescherming - insecticiden - thrips tabaci - efficiëntie - proeven - klimaatfactoren - toelating van bestrijdingsmiddelen - veldproeven - vollegrondsgroenten - insectenplagen - leeks - stem vegetables - allium porrum - plant protection - insecticides - thrips tabaci - efficiency - trials - climatic factors - authorisation of pesticides - field tests - field vegetables - insect pests
    Door innovatieve tripsbestrijding kan een effectievere beheersing van de schade en/of een aanzienlijke reductie van de insecticide-inzet. Tabakstrips (Thrips tabaci Lind.) is kan zich snel vermeerderen en prei onverkoopbaar maken bij zware aantasting. Er wordt steeds gezocht naar aanvullende nieuwe middelen met een betere en/of andere werking om resistentie-ontwikkeling voor te zijn. In twee veldproeven werden twee nieuwe middelen onderzocht. De aantasting werd beoordeeld en tripslarven geteld. De proef werd uitgevoerd met kleine planten om een hoge tripsdruk te krijgen. Toch was de uiteindelijke tripsdruk laag; alleen in de tweede planting klom de populatiedruk naar een acceptabele waarde. De referentie-behandeling met Tracer resulteert in het beste resultaat in de proef, maar gaf niet bij elke waarneming een betrouwbaar verschil ten opzichte van onbehandeld. Behandelingen met N2012TP gaven geen gewasbeschermingseffect. Toepassingen van PAI05001 resulteerden in een gering bestrijdingseffect. Toevoeging van 4 kg/ha lokfructose aan 0,23 kg/ha PAI05001 evenals 0,5 kg/ha PAI05001 gaven verschillen met onbehandeld, maar de effecten waren echter niet consequent statistisch betrouwbaar.
    Consumer and farmer safety evaluation of application of botanical pesticides in black pepper crop protection
    Hernandez-Moreno, J. ; Soffers, A.E.M.F. ; Wiratno, ; Falke, H.E. ; Rietjens, I. ; Murk, A.J. - \ 2013
    Food and Chemical Toxicology 56 (2013). - ISSN 0278-6915 - p. 483 - 490.
    clove oil - rotenone - ingestion - insecticides - toxicology - calamus - rat
    This study presents a consumer and farmer safety evaluation on the use of four botanical pesticides in pepper berry crop protection. The pesticides evaluated include preparations from clove, tuba root, sweet flag and pyrethrum. Their safety evaluation was based on their active ingredients being eugenol, rotenone, ß-asarone and pyrethrins, respectively. Botanical pesticides from Acorus calamus are of possible concern because of the genotoxic and carcinogenic ingredient ß-asarone although estimated margins of exposure (MOE) for consumers indicate a low priority for risk management. For the other three botanical pesticides the margin of safety (MOS) between established acute reference doses and/or acceptable daily intake values and intake estimates for the consumer, resulting from their use as a botanical pesticide are not of safety concern, with the exception for levels of rotenone upon use of tuba root extracts on stored berries. Used levels of clove and pyrethrum as botanical pesticides in pepper berry crop production is not of safety concern for consumers or farmers, whereas for use of tuba root and sweet flag some risk factors were defined requiring further evaluation and/or risk management. It seems prudent to look for alternatives for use of sweet flag extracts containing ß-asarone
    Geografische patronen in sterfte / geen sterfte
    Scheer, H. van der; Blacquière, T. - \ 2013
    Bijenhouden 6 (2013)september. - ISSN 1877-9786 - p. 19 - 22.
    apidae - honingbijen - wilde bijenvolken - rassen (dieren) - doodsoorzaken - wereld - varroa - insecticiden - virussen - varroa jacobsoni - resistentie van variëteiten - dierziekten - apidae - honey bees - wild honey bee colonies - breeds - causes of death - world - varroa - insecticides - viruses - varroa jacobsoni - varietal resistance - animal diseases
    Sinds 2006 worden uit Europa en Noord-Amerika op grote schaal ernstige verliezen van honingbijvolken gemeld; maar niet uit andere werelddelen. Er ijn verschillende oorzaken aan te wijzen. Neonicotinen worden aangewezen als (mede) oorzaak van de verliezen, maar waarom worden die verliezen dan vooral uit Europa en Noord-Amerika en slechts incidenteel uit het Midden-Oosten en Azië (Japan) gemeld? De gewraakte insecticiden worden wereldwijd toegepast. Om verschillende redenen moet er eerder aan problemen door varroamijten en virussen worden gedacht.
    Interactions between conventional and organic farming for biocontrol services across the landscape
    Bianchi, F.J.J.A. ; Ives, A.R. ; Schellhorn, N.A. - \ 2013
    Ecological Applications 23 (2013). - ISSN 1051-0761 - p. 1531 - 1543.
    generalist natural enemies - pest-control - biological-control - soybean aphid - pea aphid - biodiversity - populations - management - predators - insecticides
    While the area of organic crop production increases at a global scale, the potential interactions between pest management in organic and conventionally managed systems have so far received little attention. Here, we evaluate the landscape-level co-dependence of insecticide-based and natural enemy-based pest management using a simulation model for parasitoid–host interactions in landscapes consisting of conventionally and organically managed fields. In our simulations conventional management consists of broad-spectrum or selective insecticide application, while organic management involves no insecticides. Simulations indicate that insecticide use can easily result in lose–lose scenarios whereby both organically and conventionally managed fields suffer from increased pest loads as compared to a scenario where no insecticides are used, but that under some conditions insecticide use can be compatible with biocontrol. Simulations also suggest that the pathway to achieve the insecticide reduction without triggering additional pest pressure is not straightforward, because increasing the proportion of organically managed fields or reducing the spray frequency in conventional fields can potentially give rise to dramatic increases in pest load. The disruptive effect of insecticide use, however, can be mitigated by spatially clustering organic fields and using selective insecticides, although the effectiveness of this mitigation depends on the behavioral traits of the biocontrol agents. Poorly dispersing parasitoids and parasitoids with high attack rates required a lower amount of organically managed fields for effective pest suppression. Our findings show that the transition from a landscape dominated by conventionally managed crops to organic management has potential pitfalls; intermediate levels of organic management may lead to higher pest burdens than either low or high adoption of organic management.
    Geïntegreerde bestrijding van rozenschildluis Aulacapsis rosae in roos
    Pijnakker, J. ; Leman, A. ; Hennekam, M. - \ 2013
    Wageningen : Wageningen UR Glastuinbouw (Rapport / Wageningen UR Glastuinouw 1235) - 58
    sierteelt - rozen - coccoidea - geïntegreerde plagenbestrijding - organismen ingezet bij biologische bestrijding - plaagbestrijding met predatoren - insecticiden - vergelijkend onderzoek - ornamental horticulture - roses - coccoidea - integrated pest management - biological control agents - predator augmentation - insecticides - comparative research
    In dit project is gekeken naar de bestrijdingsmogelijkheden van de rozenschildluis Aulacaspis rosae met insecticiden en met natuurlijke vijanden. Daarnaast werd de ontwikkeling van de plaag in de praktijk nauwkeurig vervolgd. Bij telers zijn twee spontaan optredende sluipwespen gevonden: Arrhenophagus chionaspidis en Adelencyrtus aulacaspidis. Gedetailleerde kooiproeven zijn uitgevoerd om het effect van natuurlijke vijanden te vergelijken en praktijkervaring is opgedaan met de introductie van de commercieel beschikbare predatoren Rhizobius lophantae, Chilocorus nigritus en Karnyothrips melaleucus en de sluipwesp Encarsia citrina. Elk van deze natuurlijke vijanden blijkt in de praktijk een bijdrage te kunnen leveren aan de bestrijding van de schildluis. Het lieveheersbeestje Rhizobius lophantae gaf het beste resultaat. De predator kon zich jaarrond vestigen, mits schildluis aanwezig was en geen breedwerkende middelen werden toegepast. Binnen het project werden de gangbare insecticiden en fungiciden getest op deze predator. Vooral neonicotinoïden en tripsmiddelen zoals Conserve en Vertimec zijn dodelijk voor het lieveheersbeestje. Het in roos veel gebruikte fungicide Meltatox zou alleen bovendoor toegepast moeten worden om de vestiging van Rhizobius niet te storen. Hygiëne en het op tijd signaleren van de plaag blijven de eerste stappen naar de uitroeiing van de plaag. Telers kunnen kiezen voor vroegtijdig spuiten bij lage druk van schildluizen en de verspreiding van schildluis op deze manier beperkt houden. Uitroeiing van de plaag is echter vaak een onmogelijke taak. In een aantal gevallen verspreidt de plaag zich volvelds en is niet meer in te tomen met insecticiden. De rol van natuurlijke vijanden, voornamelijk van Rhizobius lophantae, wordt dan belangrijk in een geïntegreerde aanpak. This project aimed at developing strategies to help rose growers to improve management of the rose scale Aulacaspis rosae. The development of A. rosae in the presence of absence of beneficials was studied on commercial rose farms in a detailed field study. Two spontaneous occurring parasitoids were found at growers: Arrhenophagus chionaspidis and Adelencyrtus aulacaspidis. Commercially available predators Rhizobius lophantae, Chilocorus nigritus and Karnyothrips melaleucus, and the parasitoid Encarsia citrina were released in experimental cages as well as at growers and their efficacy were evaluated. The cocinellid Rhizobius lophantae gave the best results. The project aimed also at gaining a clearer understanding of the incidence of pesticides on some natural enemies of the rose scale. Neonicotinoids and the insecticides against thrips Conserve (spinosad) and Vertimec (abamectine) need to be avoided, as they are both lethal for Rhizobius. Negative side-effects of the fungicide Meltatox (dodemorf) might be reduced by spraying the crop only from above, thereby minimizing the direct contact with predators In the crop. Hygiene and early detection of the pest remain the first steps towards the eradication of the pest. Growers can opt for early sprays at low infestation level of scales and limit in this way the spread of Aulacaspis. But eradication of the pest is often an impossible task. In some cases, the pest spreads in the entire greenhouse and is not controlled anymore with insecticides. The role of natural enemies, aspecially Rhizobius lophantae, is than from great importance in an integrated approach.
    Check title to add to marked list
    << previous | next >>

    Show 20 50 100 records per page

     
    Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.