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 

Records 1 - 20 / 75

  • help
  • print

    Print search results

  • export

    Export search results

  • alert
    We will mail you new results for this query: q=Kos
Check title to add to marked list
Cross-seasonal legacy effects of arthropod community on plant fitness in perennial plants
Stam, Jeltje M. ; Kos, Martine ; Dicke, Marcel ; Poelman, Erik H. - \ 2019
Journal of Ecology 107 (2019)5. - ISSN 0022-0477 - p. 2451 - 2463.
In perennial plants, interactions with other community members during the vegetative growth phase may influence community assembly during subsequent reproductive years and may influence plant fitness. It is well known that plant responses to herbivory affect community assembly within a growing season, but whether plant‐herbivore interactions result in legacy effects on community assembly across seasons has received little attention. Moreover, whether plant‐herbivore interactions during the vegetative growing season are important in predicting plant fitness directly or indirectly through legacy effects is poorly understood.

Here, we tested whether plant‐arthropod interactions in the vegetative growing season of perennial wild cabbage plants, Brassica oleracea, result in legacy effects in arthropod community assembly in the subsequent reproductive season and whether legacy effects have plant fitness consequences. We monitored the arthropod community on plants that had been induced with either aphids, caterpillars or no herbivores in a full‐factorial design across two years. We quantified the plant traits ‘height', ‘number of leaves' and ‘number of flowers' to understand mechanisms that may mediate legacy effects. We measured seed production in the second year to evaluate plant fitness consequences of legacy effects.

Although we did not find community responses to the herbivory treatments, our data show that community composition in one year leaves a legacy on community composition in a second year: predator community composition co‐varied across years. Structural Equation Modelling analyses indicated that herbivore communities in the vegetative year correlated with plant performance traits that may have caused a legacy effect on especially predator community assembly in the subsequent reproductive year. Interestingly, the legacy of the herbivore community in the vegetative year predicted plant fitness better than the herbivore community that directly interacted with plants in the reproductive year.

Synthesis Thus, legacy effects of plant‐herbivore interactions affect community assembly on perennial plants across growth seasons and these processes may affect plant reproductive success. We argue that plant‐herbivore interactions in the vegetative phase as well as cross seasonal legacy effects caused by plant responses to arthropod herbivory may be important in perennial plant trait evolution such as ontogenetic variation in growth and defence strategies.
Data from: Cross-seasonal legacy effects of arthropod community on plant fitness in perennial plants
Stam, J.M. ; Kos, M. ; Dicke, M. ; Poelman, E.H. - \ 2019
Plant–herbivore interactions - community composition - community dynamics - log term effects - seed set - insect-plant interactions - priority effect - Brassica oleracea
1. In perennial plants, interactions with other community members during the vegetative growth phase may influence community assembly during subsequent reproductive years and may influence plant fitness. It is well known that plant responses to herbivory affect community assembly within a growing season, but whether plant-herbivore interactions result in legacy effects on community assembly across seasons has received little attention. Moreover, whether plant-herbivore interactions during the vegetative growing season are important in predicting plant fitness directly or indirectly through legacy effects is poorly understood. 2. Here, we tested whether plant-arthropod interactions in the vegetative growing season of perennial wild cabbage plants, Brassica oleracea, result in legacy effects in arthropod community assembly in the subsequent reproductive season and whether legacy effects have plant fitness consequences. We monitored the arthropod community on plants that had been induced with either aphids, caterpillars or no herbivores in a full-factorial design across two years. We quantified the plant traits ‘height’, ‘number of leaves’ and ‘number of flowers’ to understand mechanisms that may mediate legacy effects. We measured seed production in the second year to evaluate plant fitness consequences of legacy effects. 3. Although we did not find community responses to the herbivory treatments, our data show that community composition in one year leaves a legacy on community composition in a second year: predator community composition co-varied across years. Structural Equation Modelling analyses indicated that herbivore communities in the vegetative year correlated with plant performance traits that may have caused a legacy effect on especially predator community assembly in the subsequent reproductive year. Interestingly, the legacy of the herbivore community in the vegetative year predicted plant fitness better than the herbivore community that directly interacted with plants in the reproductive year. 4. Synthesis Thus, legacy effects of plant-herbivore interactions affect community assembly on perennial plants across growth seasons and these processes may affect plant reproductive success. We argue that plant-herbivore interactions in the vegetative phase as well as cross seasonal legacy effects caused by plant responses to arthropod herbivory may be important in perennial plant trait evolution such as ontogenetic variation in growth and defence strategies.
Effects of temperature and food source on reproduction and longevity of aphid hyperparasitoids of the genera Dendrocerus and Asaphes
Boer, Jetske G. de; Salis, Lucia ; Tollenaar, Ward ; Heumen, Lisa J.M. van; Costaz, Thibault P.M. ; Harvey, Jeffrey A. ; Kos, Martine ; Vet, Louise E.M. - \ 2019
BioControl 64 (2019)3. - ISSN 1386-6141 - p. 277 - 290.
Aphidius colemani - Fourth trophic level - Hymenoptera - Megaspilidae - Myzus persicae - Pteromalidae

Hyperparasitoids of aphid parasitoids commonly occur in (sweet pepper) greenhouses, and can pose a threat to effective biological control of aphids. Here, we studied life history characteristics of laboratory colonies of Dendrocerus spp. Ratzeburg (Hymenoptera: Megaspilidae) and Asaphes spp. Walker (Pteromalidae) that originated from a commercial sweet pepper greenhouse. We aimed to clarify how these two hyperparasitoid taxa can coexist inside greenhouses. Hyperparasitoids of both taxa have a long lifespan that was extended significantly by food sources that are naturally available in a greenhouse environment, including aphid honeydew and sweet pepper flowers. Differences in sensitivity to decreased or increased temperatures did not appear to explain seasonal patterns in abundance of Dendrocerus spp. and Asaphes spp. in sweet pepper greenhouses. Instead, Dendrocerus spp. may have an advantage early in the season because it thrives on aphid honeydew, while Asaphes spp. may do better later in the season because of its long lifespan and extensive reproductive period.

Children’s Reflection-in-action during Collaborative Design-Based Learning
Zhang, Z. ; Bekker, T. ; Markopoulos, P. ; Brok, Perry den - \ 2018
In: The Challenges of the Digital Transformation in Education - Proceedings of the 21st International Conference on Interactive Collaborative Learning ICL2018 - Volume 1. - Springer Verlag (Advances in Intelligent Systems and Computing ) - ISBN 9783030119317 - p. 790 - 800.
Collaboration - Design-based learning - Reflection scaffolds - Reflection-in-action
Drought and soil fertility modify fertilization effects on aphid performance in wheat
Tamburini, Giovanni ; Gils, Stijn van; Kos, Martine ; Putten, Wim van der; Marini, Lorenzo - \ 2018
Basic and Applied Ecology 30 (2018). - ISSN 1439-1791 - p. 23 - 31.
Agricultural intensification - Cereals - Climate change - Grain aphid - Nitrogen - Soil organic matter - Water availability

Agricultural intensification and climate change are expected to affect pest performance through excessive inputs of chemical fertilizers and increased probability of extreme drought events. Potential interactive effects of fertilization and water availability on aboveground pest performance may depend on soil fertility because of its effect on nutrient availability. In a greenhouse experiment, we examined the effects of inorganic fertilization on the performance of the grain aphid (Sitobion avenae, F.), an important pest of wheat, under different conditions of soil fertility and water availability. We found soil fertility and water availability to influence the positive effects of inorganic fertilizers on aphid growth, i.e. fertilization promoted faster aphid development time and higher fecundity and biomass under low fertility and under well-watered conditions. Moreover, although increased soil fertility favored aphid growth under well-watered conditions, it simultaneously sustained plant development. The current practices promoting soil fertility do not have direct negative consequence on crop protection under conventional cropping systems.

Data from: Soil pathogen-aphid interactions under differences in soil organic matter and mineral fertilizer
Gils, S.H. van; Tamburini, Giovanni ; Marini, Lorenzo ; Biere, Arjen ; Agtmaal, M. van; Tyc, Olaf ; Kos, M. ; Kleijn, D. ; Putten, W.H. van der - \ 2017
Wageningen University & Research
Rhizoctonia solani - Sitobion avenae - Triticum aestivum
There is increasing evidence showing that microbes can influence plant-insect interactions. In addition, various studies have shown that aboveground pathogens can alter the interactions between plants and insects. However, little is known about the role of soil-borne pathogens in plant-insect interactions. It is also not known how environmental conditions, that steer the performance of soil-borne pathogens, might influence these microbe-plant-insect interactions. Here, we studied effects of the soil-borne pathogen Rhizoctonia solani on aphids (Sitobion avenae) using wheat (Triticum aestivum) as a host. In a greenhouse experiment, we tested how different levels of soil organic matter (SOM) and fertilizer addition influence the interactions between plants and aphids. To examine the influence of the existing soil microbiome on the pathogen effects, we used both unsterilized field soil and sterilized field soil. In unsterilized soil with low SOM content, R. solani addition had a negative effect on aphid biomass, whereas it enhanced aphid biomass in soil with high SOM content. In sterilized soil, however, aphid biomass was enhanced by R. solani addition and by high SOM content. Plant biomass was enhanced by fertilizer addition, but only when SOM content was low, or in the absence of R. solani. We conclude that belowground pathogens influence aphid performance and that the effect of soil pathogens on aphids can be more positive in the absence of a soil microbiome. This implies that experiments studying the effect of pathogens under sterile conditions might not represent realistic interactions. Moreover, pathogen-plant-aphid interactions can be more positive for aphids under high SOM conditions. We recommend that soil conditions should be taken into account in the study of microbe-plant-insect interactions.
Soil pathogen-aphid interactions under differences in soil organic matter and mineral fertilizer
Gils, Stijn van; Tamburini, Giovanni ; Marini, Lorenzo ; Biere, Arjen ; Agtmaal, Maaike van; Tyc, Olaf ; Kos, Martine ; Kleijn, David ; Putten, Wim H. van der - \ 2017
PLoS ONE 12 (2017)8. - ISSN 1932-6203 - 14 p.

There is increasing evidence showing that microbes can influence plant-insect interactions. In addition, various studies have shown that aboveground pathogens can alter the interactions between plants and insects. However, little is known about the role of soil-borne pathogens in plant-insect interactions. It is also not known how environmental conditions, that steer the performance of soil-borne pathogens, might influence these microbe-plant-insect interactions. Here, we studied effects of the soil-borne pathogen Rhizoctonia solani on aphids (Sitobion avenae) using wheat (Triticum aestivum) as a host. In a greenhouse experiment, we tested how different levels of soil organic matter (SOM) and fertilizer addition influence the interactions between plants and aphids. To examine the influence of the existing soil microbiome on the pathogen effects, we used both unsterilized field soil and sterilized field soil. In unsterilized soil with low SOM content, R. solani addition had a negative effect on aphid biomass, whereas it enhanced aphid biomass in soil with high SOM content. In sterilized soil, however, aphid biomass was enhanced by R. solani addition and by high SOM content. Plant biomass was enhanced by fertilizer addition, but only when SOM content was low, or in the absence of R. solani. We conclude that belowground pathogens influence aphid performance and that the effect of soil pathogens on aphids can be more positive in the absence of a soil microbiome. This implies that experiments studying the effect of pathogens under sterile conditions might not represent realistic interactions. Moreover, pathogen-plant-aphid interactions can be more positive for aphids under high SOM conditions. We recommend that soil conditions should be taken into account in the study of microbe-plant-insect interactions.

Data from: Species-specific plant-soil feedback effects on above-ground plant-insect interactions
Kos, Martine ; Tuijl, M.A.B. ; Roo, J. de; Mulder, Patrick ; Bezemer, T.M. - \ 2016
Netherlands Institute of Ecology (NIOO-KNAW)
Brachycaudus cardui - plant-soil (below-ground) interactions - Aphis jacobaeae - Jacobaea vulgaris - Soil fungal community - amino acids - aphid - Pyrrolizidine alkaloids
1. Plant–soil feedback (PSF) effects on plant performance strongly depend on the plant species that conditioned the soil. Recent studies have shown that PSF can change above-ground plant–insect interactions via soil-mediated changes in plant quality, but whether these effects depend on species-specific soil conditioning is unknown. We examined how PSF effects of several plant species influence above-ground plant–aphid interactions. 2. We grew ragwort (Jacobaea vulgaris) in field soil conditioned specifically by 10 plant species, belonging to three functional groups (grasses, forbs and legumes), in a multispecies mixture of the conditioned soils and in control (unconditioned) field soil. We measured plant biomass, concentrations of primary (amino acids) and secondary (pyrrolizidine alkaloids) metabolites in phloem exudates, and performance of the generalist aphid Brachycaudus cardui and the specialist Aphis jacobaeae. 3. We observed that plant species, via species-specific effects on soil fungal communities, exerted unique plant–soil effects on J. vulgaris biomass, amino acid concentrations in phloem exudates and aphid performance. The direction and magnitude of the species-specific PSF effects on aphid performance differed between both aphid species. PSF effects on soil fungal communities, plant biomass and A. jacobaeae performance also differed between grasses, forbs and legumes, with soil conditioning by forbs resulting in lowest plant biomass and aphid performance. 4. Synthesis. Our study provides novel evidence that PSF effects on above-ground plant–insect interactions are highly species specific. Our results add a new dimension to the rapidly developing research fields of PSF and above-below-ground interactions, and highlights that these fields are tightly linked.
Complexity of plant volatile-mediated interactions beyond the third trophic level
Poelman, E.H. ; Kos, M. - \ 2016
In: Deciphering chemical language of plant communication / Blande, James D., Glinwood, Robert, Cham : Springer International Publishing Switzerland (Signaling and Communication in Plants ) - ISBN 9783319334967 - p. 211 - 225.
016-3967
Food chains of plant-associated communities typically reach beyond three trophic levels. The predators and parasitoids in the third trophic level are under attack by top predators or parasitised by hyperparasitoids. These higher trophic level organisms respond to plant volatiles in search of their prey or host. Thereby, plant volatiles affect community processes such as competition and intraguild predation among predators and parasitoids at the terminal end of the food chain. The response of fourth trophic level organisms to plant volatiles potentially reduces the benefit of these volatiles as indirect defence for the plant. In the application of parasitoids as biological control agents of herbivore pests, hyperparasitoids may diminish the effectiveness of parasitoids. Detailed understanding of the use of plant odours by hyperparasitoids may provide tools to further optimise biological control.
Development of a solitary koinobiont hyperparasitoid in different instars of its primary and secondary hosts
Harvey, Jeffrey A. ; Fei, Minghui ; Lammers, Mark ; Kos, Martine ; Zhu, Feng ; Heinen, Robin ; Poelman, Erik H. ; Gols, Rieta - \ 2016
Journal of Insect Physiology 90 (2016). - ISSN 0022-1910 - p. 36 - 42.
Cotesia glomerata - Growth - Instar - Larva - Mesochorus gemellus - Pieris brassicae - 016-3949

Parasitoid wasps are excellent organisms for studying the allocation of host resources to different fitness functions such as adult body mass and development time. Koinobiont parasitoids attack hosts that continue feeding and growing during parasitism, whereas idiobiont parasitoids attack non-growing host stages or paralyzed hosts. Many adult female koinobionts attack a broad range of host stages and are therefore faced with a different set of dynamic challenges compared with idiobionts, where host resources are largely static. Thus far studies on solitary koinobionts have been almost exclusively based on primary parasitoids, yet it is known that many of these are in turn attacked by both koinobiont and idiobiont hyperparasitoids. Here we compare parasitism and development of a primary koinobiont hyperparasitoid, Mesochorus gemellus (Hymenoptera: Ichneumonidae) in larvae of the gregarious primary koinobiont parasitoid, Cotesia glomerata (Hymenoptera: Braconidae) developing in the secondary herbivore host, Pieris brassicae (Lepidoptera: Pieridae). As far as we know this is the first study to examine development of a solitary primary hyperparasitoid in different stages of its secondary herbivore host. Pieris brassicae caterpillars were parasitized as L1 by C. glomerata and then these parasitized caterpillars were presented in separate cohorts to M. gemellus as L3, L4 or L5 instar P. brassicae. Different instars of the secondary hosts were used as proxies for different developmental stages of the primary host, C. glomerata. Larvae of C. glomerata in L5 P. brassicae were significantly longer than those in L3 and L4 caterpillars. Irrespective of secondary host instar, every parasitoid cluster was hyperparasitized by M. gemellus but all only produced male progeny. Male development time decreased with host stage attacked, whereas adult male body mass did not, which shows that M. gemellus is able to optimally exploit older host larvae in terms of adult size despite their decreasing mass during the pupal stage. Across a range of cocoon masses, hyperparasitoid adult male body mass was approximately 84% as large as primary parasitoids, revealing that M. gemellus is almost as efficient at exploiting host resources as secondary (pupal) hyperparasitoids.

Mapping earthworm communities in Europe
Rutgers, M. ; Orgiazzi, A. ; Gardi, C. ; Römbke, J. ; Jansch, S. ; Keith, A. ; Neilson, R. ; Boag, B. ; Schmidt, O. ; Murchie, A.K. ; Blackshaw, R.P. ; Pérès, G. ; Cluzeau, D. ; Guernion, M. ; Briones, M.J.I. ; Rodeiro, J. ; Pineiro, R. ; Diaz Cosin, D.J. ; Sousa, J.P. ; Suhadolc, M. ; Kos, I. ; Krogh, P.H. ; Faber, J.H. ; Mulder, C. ; Bogte, J.J. ; Wijnen, H.J. van; Schouten, A.J. ; Zwart, D. de - \ 2016
Applied Soil Ecology 97 (2016). - ISSN 0929-1393 - p. 98 - 111.
Existing data sets on earthworm communities in Europe were collected, harmonized, collated, modelled and depicted on a soil biodiversity map. Digital Soil Mapping was applied using multiple regressions relating relatively low density earthworm community data to soil characteristics, land use, vegetation and climate factors (covariables) with a greater spatial resolution. Statistically significant relationships were used to build habitat–response models for maps depicting earthworm abundance and species diversity. While a good number of environmental predictors were significant in multiple regressions, geographical factors alone seem to be less relevant than climatic factors. Despite differing sampling protocols across the investigated European countries, land use and geological history were the most relevant factors determining the demography and diversity of the earthworms. Case studies from country-specific data sets (France, Germany, Ireland and The Netherlands) demonstrated the importance and efficiency of large databases for the detection of large spatial patterns that could be subsequently applied at smaller (local) scales.
Mapping earthworm communities in Europe
Rutgers, Michiel ; Orgiazzi, A. ; Gardi, C. ; Rombke, J. ; Jänsch, S. ; Keith, A.M. ; Neilson, R. ; Boag, B. ; Schmidt, O. ; Murchie, A.K. ; Blackshaw, R.P. ; Rod, P. ; Pérès, G. ; Cluzeau, D. ; Guernion, M. ; Briones, M.J.I. ; Rodeiro, J. ; Pineiro, R. ; Diaz Cosin, D.J. ; Trigo, Dolores ; Sousa, Paulo J. ; Suhadolc, M. ; Kos, I. ; Krogh, Paul Henning ; Faber, J.H. ; Mulder, Christian ; Bogte, J.J. ; Wijnen, H.J. van; Schouten, A.J. ; Zwart, D. de - \ 2015
Existing data sets on earthworm communities in Europe were collected, harmonized and
modelled to illustrate our current knowledge on their European diversity and geographical
distribution. Digital Soil Mapping was applied using multiple regression techniques relating
relatively low density earthworm community data to soil characteristics, land use, vegetation
type and climate factors, that had a greater spatial resolution. Statistically significant
relationships were used to build habitat-response models to construct earthworm maps for
abundance, species richness, and diversity data. Although a number of environmental
predictors were significant in our multiple regressions, geographical factors alone were less
relevant than climatic factors. Despite differing earthworm sampling protocols, land use and
geological history were the main factors determining demography and diversity of the
earthworms across Europe. Case studies from country-specific data sets (France, Germany,
Ireland and The Netherlands) demonstrated the importance and efficiency of these large
databases for the detection of large spatial patterns that could be subsequently applied at
smaller (local) scales. Additional datasets have been later incorporated (e.g. Portugal, Italy,
England, Wales, Belgium, Finland, Austria and some countries from Eastern Europe) to
improve our predictions of earthworm geographical patterns. The improved maps will be
submitted for publication in the Global Soil Biodiversity Atlas.
A Kalman decomposition to detect temporal linear system srtucture
Willigenburg, L.G. Van; Koning, W.L. De - \ 2015
In: 2007 European Control Conference, ECC 2007. - Institute of Electrical and Electronics Engineers Inc. - ISBN 9783952417386 - p. 1721 - 1726.

Feedback controllers for non-linear systems are often based on a linearized dynamic model. Such a linearized model may be temporarily uncontrollable and/or unreconstructable. This paper introduces the so-called differential Kalman decomposition of time-varying linear systems. It is based on differential controllability and differential reconstructability in conjunction with a linear time-varying continuous-time system description that allows the system structure and dimensions to change at certain time-instants. We show how these together enable the detection of what will be called temporal system structure. This structure among other things reveals the temporal loss of controllability and/or reconstructability. Moreover this paper shows how time-varying state-dimensions enable a satisfactory realization theory for time-varying linear systems and how our Kalman decomposition is linked to the conventional ones.

Interactive effects of above- and belowground herbivory and plant competition on plant growth and defence
Jing, Y. ; Raaijmakers, C. ; Kostenko, O. ; Kos, M. ; Mulder, P.P.J. ; Bezemer, T.M. - \ 2015
Basic and Applied Ecology 16 (2015)6. - ISSN 1439-1791 - p. 500 - 509.
Competition and herbivory are two major factors that can influence plant growth and plant defence. Although these two factors are often studied separately, they do not operate independently. We examined how aboveground herbivory by beet armyworm larvae (Spodoptera exigua) and belowground herbivory by wireworms (Agriotes lineatus) influenced competition between the plant species Jacobaea vulgaris and Leucanthemum vulgare exposed to three competition levels (no, intra-, and interspecific competition). In addition, we studied the effects of herbivory and competition on pyrrolizidine alkaloid (PA) concentrations in leaves of J. vulgaris. For J. vulgaris, aboveground herbivory significantly reduced shoot biomass while belowground herbivory increased root biomass. Biomass of L. vulgare was not affected by herbivory. Competition caused a reduction in biomass for both plant species, but herbivory did not affect the outcome of the competition. However, competition significantly influenced the amount of leaf damage experienced by the plants. A L. vulgare plant had significantly less damage from aboveground herbivores when grown together with J. vulgaris than when grown alone or in intraspecific competition, while a J. vulgaris plant experienced lowest damage in conditions of intraspecific competition. The total PA concentration in J. vulgaris leaves was highest for plants exposed to interspecific competition. Root herbivory caused an increase in the relative concentration of N-oxides, the less toxic form of PAs, in leaves of plants that were grown without competition, but a decrease in plants exposed to competition. Our study shows that competition and herbivory but also the type of competition and whether herbivory occurs above- or belowground, all influence plant performance. However, overall, there was no evidence that herbivory affects plant–plant competition.
Inhibition of NF-kB in tumor cells exacerbates immune celll activation following photodynamic therapy
Broekgaarden, M. ; Kos, M. ; Jurg, F.A. ; Beek, A.A. van; Gulik, M. van; Heger, M. - \ 2015
International Journal of Molecular Sciences 16 (2015)8. - ISSN 1661-6596 - p. 19960 - 19977.
Although photodynamic therapy (PDT) yields very good outcomes in numerous types of superficial solid cancers, some tumors respond suboptimally to PDT. Novel treatment strategies are therefore needed to enhance the efficacy in these therapy-resistant tumors. One of these strategies is to combine PDT with inhibitors of PDT-induced survival pathways. In this respect, the transcription factor nuclear factor ¿B (NF-¿B) has been identified as a potential pharmacological target, albeit inhibition of NF-¿B may concurrently dampen the subsequent anti-tumor immune response required for complete tumor eradication and abscopal effects. In contrast to these postulations, this study demonstrated that siRNA knockdown of NF-¿B in murine breast carcinoma (EMT-6) cells increased survival signaling in these cells and exacerbated the inflammatory response in murine RAW 264.7 macrophages. These results suggest a pro-death and immunosuppressive role of NF-¿B in PDT-treated cells that concurs with a hyperstimulated immune response in innate immune cells.
Species-specific plant-soil feedback effects on above-ground plant-insect interactions
Kos, M. ; Tuijl, M.A.B. ; Roo, J. de; Mulder, P.P.J. ; Bezemer, T.M. - \ 2015
Journal of Ecology 103 (2015)4. - ISSN 0022-0477 - p. 904 - 914.
below-ground herbivory - pyrrolizidine alkaloids - senecio-jacobaea - multitrophic interactions - community composition - tyria-jacobaeae - responses - succession - pathogens - nutrients
1.Plant–soil feedback (PSF) effects on plant performance strongly depend on the plant species that conditioned the soil. Recent studies have shown that PSF can change above-ground plant–insect interactions via soil-mediated changes in plant quality, but whether these effects depend on species-specific soil conditioning is unknown. We examined how PSF effects of several plant species influence above-ground plant–aphid interactions. 2.We grew ragwort (Jacobaea vulgaris) in field soil conditioned specifically by 10 plant species, belonging to three functional groups (grasses, forbs and legumes), in a multispecies mixture of the conditioned soils and in control (unconditioned) field soil. We measured plant biomass, concentrations of primary (amino acids) and secondary (pyrrolizidine alkaloids) metabolites in phloem exudates, and performance of the generalist aphid Brachycaudus cardui and the specialist Aphis jacobaeae. 3.We observed that plant species, via species-specific effects on soil fungal communities, exerted unique plant–soil effects on J. vulgaris biomass, amino acid concentrations in phloem exudates and aphid performance. The direction and magnitude of the species-specific PSF effects on aphid performance differed between both aphid species. PSF effects on soil fungal communities, plant biomass and A. jacobaeae performance also differed between grasses, forbs and legumes, with soil conditioning by forbs resulting in lowest plant biomass and aphid performance. 4.Synthesis. Our study provides novel evidence that PSF effects on above-ground plant–insect interactions are highly species specific. Our results add a new dimension to the rapidly developing research fields of PSF and above-below-ground interactions, and highlights that these fields are tightly linked.
Plant-soil feedback effects on plant quality and performance of an aboveground herbivore interact with fertilisation
Kos, M. ; Maarten, A. ; Tuijl, M.A.B. ; Roo, J. de; Mulder, P.P.J. ; Bezemer, T.M. - \ 2015
Oikos 124 (2015)5. - ISSN 0030-1299 - p. 658 - 667.
below-ground herbivory - pyrrolizidine alkaloids - senecio-jacobaea - tyria-jacobaeae - multitrophic interactions - nitrate fertilization - community composition - insect community - aphid - pathogens
Plant–soil feedback (PSF) effects on plant performance can be influenced by the availability of nutrients in the soil. Recent studies have shown that PSF effects can also change aboveground plant–insect interactions via soil-mediated changes in plant quality, but whether this is influenced by soil nutrient availability is unknown. We examined how fertilisation influences PSF effects on aboveground plant-aphid interactions in ragwort Jacobaea vulgaris. We grew J. vulgaris in soil conditioned by conspecific plants and in unconditioned soil at two levels of fertilisation and measured soil fungal communities, plant biomass, concentrations of primary (amino acids) and secondary (pyrrolizidine alkaloids; PAs) metabolites in phloem exudates, performance of the specialist aphid Aphis jacobaeae and sequestration of PAs by the aphid. We observed a strong interaction between soil conditioning and fertilisation on amino acid and PA concentrations in phloem exudates of J. vulgaris and on aphid performance, with opposite effects of soil conditioning at the two fertilisation levels. Plant biomass was reduced by soil conditioning and increased by fertilisation. Aphids contained high PA concentrations, converted N-oxides into tertiary amines and preferentially sequestered certain PA compounds, but PA sequestration was not affected by any of the treatments. We conclude that effects of PSF and fertilisation on plant chemistry and aphid performance are interdependent. Our study highlights the need to consider the importance of abiotic soil conditions on the outcome of PSF effects on aboveground plant–insect interactions.
Disentangling above- and belowground neighbor effects on the growth, chemistry and arthropod community on a focal plant
Kos, M. ; Bukovinszky, T. ; Mulder, P.P.J. ; Bezemer, T.M. - \ 2015
Ecology 96 (2015)1. - ISSN 0012-9658 - p. 164 - 175.
soil feedback - associational susceptibility - vegetational diversity - competition - herbivores - root - resistance - responses - fertilization - density
Neighboring plants can influence arthropods on a focal plant and this can result in associational resistance or associational susceptibility. These effects can be mediated by above- and belowground interactions between the neighbor and focal plant, but determining the relative contribution of the above- and belowground effects remains an open challenge. We performed a common garden experiment with a design that enabled us to disentangle the above- and belowground effects of five different plant species on the growth and chemistry of the focal plant ragwort (Jacobaea vulgaris), and the arthropod community associated to this plant. Aboveground effects of different neighboring plant species were more important for the growth and quality of J. vulgaris and for the arthropod abundance on this plant than belowground effects of neighbors. This remained true when only indirect neighbor effects (via affecting the biomass or quality of the focal plant) were considered. The aboveground neighbor effects on arthropod abundance on the focal plant were strongly negative. However, the magnitude of the effect depended on the identity of the neighboring species, and herbivore abundance on the focal plant was higher when surrounded by conspecific than by heterospecific plants. We also observed interactions between above- and belowground neighbor effects, indicating that these effects may be non-additive. We conclude that above- and belowground associational effects are not equally strong, and that neighbor effects on plant-arthropod interactions occur predominantly aboveground.
Genetic engineering of plant volatile terpenoids: effects on a herbivore, a predator and a parasitoid
Kos, M. ; Houshyani Hassanzadeh, B. ; Overeem, A.J. ; Bouwmeester, H.J. ; Weldegergis, B.T. ; Loon, J.J.A. van; Dicke, M. ; Vet, L.E.M. - \ 2013
Pest Management Science 69 (2013)2. - ISSN 1526-498X - p. 302 - 311.
arabidopsis-thaliana - natural enemies - tritrophic interactions - tetranychus-urticae - biological-control - transgenic plants - prey interactions - host-plant - aphid - attraction
BACKGROUND: Most insect-resistant transgenic crops employ toxins to control pests. A novel approach is to enhance the effectiveness of natural enemies by genetic engineering of the biosynthesis of volatile organic compounds (VOCs). Before the commercialisation of such transgenic plants can be pursued, detailed fundamental studies of their effects on herbivores and their natural enemies are necessary. The linalool/nerolidol synthase gene FaNES1 was constitutively expressed from strawberry in three Arabidopsis thaliana accessions, and the behaviour of the aphid Brevicoryne brassicae L., the parasitoid Diaeretiella rapae McIntosh and the predator Episyrphus balteatus de Geer was studied. RESULTS: Transgenic FaNES1-expressing plants emitted (E)-nerolidol and larger amounts of (E)-DMNT and linalool. Brevicoryne brassicae was repelled by the transgenic lines of two of the accessions, whereas its performance was not affected. Diaeretiella rapae preferred aphid-infested transgenic plants over aphid-infested wild-type plants for two of the accessions. In contrast, female E. balteatus predators did not differentiate between aphid-infested transgenic or wild-type plants. CONCLUSION: The results indicate that the genetic engineering of plants to modify their emission of VOCs holds considerable promise for facilitating biological control of herbivores. Validation for crop plants is a necessary next step to assess the usefulness of modified volatile emission in integrated pest management. Copyright (C) 2012 Society of Chemical Industry
Effects of glucosinolates on a generalist and specialist leaf-chewing herbivore and an associated parasitoid
Kos, M. ; Houshyani, B. ; Wietsma, R. ; Kabouw, P. ; Vet, L.E.M. ; Loon, J.J.A. van; Dicke, M. - \ 2012
Phytochemistry 77 (2012). - ISSN 0031-9422 - p. 162 - 170.
mustard oil bomb - brassica-oleracea - arabidopsis-thaliana - pieris-rapae - brevicoryne-brassicae - chemical diversity - diaeretiella-rapae - cabbage aphid - defense - plants
Glucosinolates (GLS) are secondary plant metabolites that as a result of tissue damage, for example due to herbivory, are hydrolysed into toxic compounds that negatively affect generalist herbivores. Specialist herbivores have evolved specific adaptations to detoxify GLS or inhibit the formation of toxic hydrolytic products. Although rarely studied, GLS and their breakdown products may also affect parasitoids. The objectives were to test the effects of GLS in a multitrophic system consisting of the generalist herbivore Spodoptera exigua, the specialist herbivore Pieris rapae, and the endoparasitoid Hyposoter ebeninus. Three ecotypes of Arabidopsis thaliana that differ in their GLS composition and concentrations and one transformed line that constitutively produces higher concentrations of aliphatic GLS were used, the latter allowing a direct assessment of the effects of aliphatic GLS on insect performance. Feeding by the generalist S. exigua and the specialist P. rapae induced both higher aliphatic and indole GLS concentrations in the A. thaliana ecotypes, although induction was stronger for indole than aliphatic GLS. For both herbivores a negative correlation between performance and aliphatic GLS concentrations was observed. This suggests that the specialist, despite containing a nitrile-specifier protein (NSP) that diverts GLS degradation from toxic isothiocyanates to less toxic nitriles, cannot completely inhibit the formation of toxic GLS hydrolytic products, or that the costs of this mechanism are higher at higher GLS concentrations. Surprisingly, performance of the parasitoid was positively correlated with higher concentrations of aliphatic GLS in the plant, possibly caused by negative effects on host immune responses. Our study indicates that GLS can not only confer resistance against herbivores directly, but also indirectly by increasing the performance of the parasitoids of these herbivores.
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.