Effect of Wall Thickness and Surface Conditions on Creep Behavior of a Single-Crystal Ni-Based Superalloy

The influence of wall thickness and specimen surface on the creep behavior of the single-crystal nickel-based superalloy MAR M247LC is studied. Specimens with wall thicknesses of 0.4, 0.8, 1 and 2 mm, with and without casting surface, are compared to specimens of the same wall thickness prepared from bulk material. Creep behavior turned out to be independent from surface conditions even for the thinnest specimens. The thickness debit effect is not pronounced for short creep rupture times (le;100 h at 980 deg;C), whereas it is significant for creep rupture times longer than ~200 h at 980 deg;C. The thickness debit effect is time-dependent and caused by oxidation and diffusion-controlled mechanisms

Spin dephasing and photoinduced spin diffusion in high-mobility 110-grown GaAs-AlGaAs two-dimensional electron systems

We have studied spin dephasing and spin diffusion in a high-mobility two-dimensional electron system, embedded in a GaAs/AlGaAs quantum well grown in the [110] direction, by a two-beam Hanle experiment. For very low excitation density, we observe spin lifetimes of more than 16 ns, which rapidly decrease as the pump intensity is increased. Two mechanisms contribute to this decrease: the optical excitation produces holes, which lead to a decay of electron spin via the Bir-Aranov-Pikus mechanism and recombination with spin-polarized electrons. By scanning the distance between the pump and probe beams, we observe the diffusion of spin-polarized electrons over more than 20 microns. For high pump intensity, the spin polarization in a distance of several microns from the pump beam is larger than at the pump spot, due to the reduced influence of photogenerated holes.Comment: 4 pages, 3 figure

An integrative approach to more nuanced estimates of personality–job–performance relations

This is the final version. Available on open access from Wiley via the DOI in this recordData availability statement: The data that support the findings of this study are openly available on OSF at https://osf.io/ys72j/?view_only=f48aeaf9414d46fb81019186030afbdcRecent research has suggested that self- and other-ratings of personality may provide different information about personality, which can be captured in the trait–reputation–identity (TRI) model. Based on the TRI model, we investigate the link between personality and aligned job performance criteria on domain and aspect levels of the Big Five personality traits. In five samples (overall N = 571 triplets of target self-ratings and two coworker other-ratings), we investigated the relationships between the shared information on personality and shared information about job performance. We found that all personality domains showed substantial criterion validity in predicting the corresponding job-performance dimensions. Furthermore, we found stronger estimates for aspects of agreeableness and openness. We discuss theoretical and practical implications for target replacement and performance management

Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at sNN\sqrt{s_{NN}} = 5.02 TeV

Two-particle angular correlations between unidentified charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum range 0.7 $< p_{\rm{T}, assoc} < p_{\rm{T}, trig} <$ 5.0 GeV/$c$ is examined, to include correlations induced by jets originating from low momen\-tum-transfer scatterings (minijets). The correlations expressed as associated yield per trigger particle are obtained in the pseudorapidity range $|\eta|<0.9$. The near-side long-range pseudorapidity correlations observed in high-multiplicity p-Pb collisions are subtracted from both near-side short-range and away-side correlations in order to remove the non-jet-like components. The yields in the jet-like peaks are found to be invariant with event multiplicity with the exception of events with low multiplicity. This invariance is consistent with the particles being produced via the incoherent fragmentation of multiple parton--parton scatterings, while the yield related to the previously observed ridge structures is not jet-related. The number of uncorrelated sources of particle production is found to increase linearly with multiplicity, suggesting no saturation of the number of multi-parton interactions even in the highest multiplicity p-Pb collisions. Further, the number scales in the intermediate multiplicity region with the number of binary nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/161

Multi-particle azimuthal correlations in p-Pb and Pb-Pb collisions at the CERN Large Hadron Collider

Measurements of multi-particle azimuthal correlations (cumulants) for charged particles in p-Pb and Pb-Pb collisions are presented. They help address the question of whether there is evidence for global, flow-like, azimuthal correlations in the p-Pb system. Comparisons are made to measurements from the larger Pb-Pb system, where such evidence is established. In particular, the second harmonic two-particle cumulants are found to decrease with multiplicity, characteristic of a dominance of few-particle correlations in p-Pb collisions. However, when a $|\Delta \eta|$ gap is placed to suppress such correlations, the two-particle cumulants begin to rise at high-multiplicity, indicating the presence of global azimuthal correlations. The Pb-Pb values are higher than the p-Pb values at similar multiplicities. In both systems, the second harmonic four-particle cumulants exhibit a transition from positive to negative values when the multiplicity increases. The negative values allow for a measurement of $v_{2}\{4\}$ to be made, which is found to be higher in Pb-Pb collisions at similar multiplicities. The second harmonic six-particle cumulants are also found to be higher in Pb-Pb collisions. In Pb-Pb collisions, we generally find $v_{2}\{4\} \simeq v_{2}\{6\}\neq 0$ which is indicative of a Bessel-Gaussian function for the $v_{2}$ distribution. For very high-multiplicity Pb-Pb collisions, we observe that the four- and six-particle cumulants become consistent with 0. Finally, third harmonic two-particle cumulants in p-Pb and Pb-Pb are measured. These are found to be similar for overlapping multiplicities, when a $|\Delta\eta| > 1.4$ gap is placed.Comment: 25 pages, 11 captioned figures, 3 tables, authors from page 20, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/87

Ants impact the energy reserves of natural enemies through the shared honeydew exploitation

[EN] Ants, as well as many species of parasitoids and predators, rely on sugar-richfoodssuchashoneydewtofulfilltheirenergeticneeds.Thus,antsandnatural enemies may interact through the shared honeydew exploitation. 2.Ant-exclusionexperimentswereperformedinacitrusorchardtotestthehypothesis that ants may impact the energy reserves of predators and parasitoids through the competitionforhoneydew.Throughtheuseofhigh-performanceliquidchromatography (HPLC)thelevelofantactivitywiththeenergyreservesandfeedinghistoryofindividual specimens collected in the field during representative days of spring, summer, and autumn were related. 3. Out of 145 Aphytis chrysomphali Mercet parasitoids captured in the field, 65% were classified as sugar-fed and 24.7% as honeydew-fed. In summer, when ant activity peaked,therewasasignificant negativecorrelationbetweenthelevelofantactivityand the total sugar content and honeydew feeding incidence by A.chrysomphali. Out of 47 individuals of the predator Chrysoperla carnea sensu lato (Stephens), captured in the field, 55.3% were classified as sugar-fed. We found a significant negative effect of the level of ant activity on the sugar-feeding incidence by C.carneain spring. 4.Thepresentstudyprovidesevidencethatantscaninterferewiththeenergyreserves of natural enemies. This interaction may be widespread in various ecosystems with important consequences for the arthropod community composition and with practical implicationsforbiologicalcontrolgiventhatabsenceofsugarfeedingisdetrimentalfor thefitness of many species of predatorsand parasitoidsDr Jerome Casas is greatly acknowledged for valuable comments on earlier versions of the manuscript and Dr Petr Duelli for providing help with the Chrysoperla identifications. We also thank Dr Cristina Navarro Campos and Dr Aleixandre Beltra for their help in the field samplings and for stimulating discussions, Barbara Rodriguez for help in the laboratory analyses and the reviewers for their helpful comments. This work was supported by the project (RTA2010-00012-C02-02) assigned to F. G. M from the Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA), Spain and the project (BIO2013-48779-C4-1-R) from Spanish Ministry of Science and Innovation and COST action CM1303 on Systems Biocatalysis.Calabuig Gomar, A.; Tena Barreda, A.; Wäkers, FL.; Lucia Fernandez-Arrojo; Plou, FJ.; García Mari, F.; Pekas, A. (2015). Ants impact the energy reserves of natural enemies through the shared honeydew exploitation. Ecological Entomology. 40:687-695. https://doi.org/10.1111/een.12237S68769540Avidov, Z., Balshin, M., & Gerson, U. (1970). Studies onAphytis coheni, a parasite of the California red scale,Aonidiella aurantii in Israel. Entomophaga, 15(2), 191-207. doi:10.1007/bf02371871Bartlett, B. R. (1961). The Influence of Ants Upon Parasites, Predators, and Scale Insects1. Annals of the Entomological Society of America, 54(4), 543-551. doi:10.1093/aesa/54.4.543Bascompte, J., Jordano, P., & Olesen, J. M. (2006). Asymmetric Coevolutionary Networks Facilitate Biodiversity Maintenance. Science, 312(5772), 431-433. doi:10.1126/science.1123412Blüthgen, N., E. Stork, N., & Fiedler, K. (2004). Bottom-up control and co-occurrence in complex communities: honeydew and nectar determine a rainforest ant mosaic. Oikos, 106(2), 344-358. doi:10.1111/j.0030-1299.2004.12687.xCalabuig, A., Garcia-Marí, F., & Pekas, A. (2013). Ants affect the infestation levels but not the parasitism of honeydew and non-honeydew producing pests in citrus. Bulletin of Entomological Research, 104(4), 405-417. doi:10.1017/s0007485313000564Campbell, M. M. (1976). Colonisation of Aphytis melinus DeBach (Hymenoptera, Aphelinidae) in Aonidiella aurantii (Mask.) (Hemiptera, Coccidae) on citrus in South Australia. Bulletin of Entomological Research, 65(4), 659-668. doi:10.1017/s0007485300006350Carroll, C. R., & Janzen, D. H. (1973). Ecology of Foraging by Ants. Annual Review of Ecology and Systematics, 4(1), 231-257. doi:10.1146/annurev.es.04.110173.001311Cerdá, X., Palacios, R., & Retana, J. (2009). Ant Community Structure in Citrus Orchards in the Mediterranean Basin: Impoverishment as a Consequence of Habitat Homogeneity. Environmental Entomology, 38(2), 317-324. doi:10.1603/022.038.0203DUELLI, P. (1980). Adaptive dispersal and appetitive flight in the green lacewing, Chrysopa cornea. Ecological Entomology, 5(3), 213-220. doi:10.1111/j.1365-2311.1980.tb01144.xDuelli, P. (1980). Preovipository migration flights in the green lacewing, Chrysopa carnea (Planipennia, Chrysopidae). Behavioral Ecology and Sociobiology, 7(3), 239-246. doi:10.1007/bf00299370Eubanks, M. D., & Finke, D. L. (2014). Interaction webs in agroecosystems: beyond who eats whom. Current Opinion in Insect Science, 2, 1-6. doi:10.1016/j.cois.2014.06.005Faria, C. A., Wäckers, F. L., & Turlings, T. C. J. (2008). The nutritional value of aphid honeydew for non-aphid parasitoids. Basic and Applied Ecology, 9(3), 286-297. doi:10.1016/j.baae.2007.02.001Finney, G. L. (1948). Culturing Chrysopa californica and Obtaining Eggs for Field Distribution. Journal of Economic Entomology, 41(5), 719-721. doi:10.1093/jee/41.5.719HEIMPEL, G. E., & COLLIER, T. R. (1996). THE EVOLUTION OF HOST-FEEDING BEHAVIOUR IN INSECT PARASITOIDS. Biological Reviews, 71(3), 373-400. doi:10.1111/j.1469-185x.1996.tb01279.xHeimpel, G. E., Rosenheim, J. A., & Mangel, M. (1997). Predation on adult Aphytis parasitoids in the field. Oecologia, 110(3), 346-352. doi:10.1007/s004420050168Heimpel, G. E., Rosenheim, J. A., & Kattari, D. (1997). Adult feeding and lifetime reproductive success in the parasitoid Aphytis melinus. Entomologia Experimentalis et Applicata, 83(3), 305-315. doi:10.1046/j.1570-7458.1997.00185.xHOGERVORST, P. A. M., WÄCKERS, F. L., & ROMEIS, J. (2007). Detecting nutritional state and food source use in field-collected insects that synthesize honeydew oligosaccharides. Functional Ecology, 21(5), 936-946. doi:10.1111/j.1365-2435.2007.01297.xHölldobler, B., & Wilson, E. O. (1990). The Ants. doi:10.1007/978-3-662-10306-7Holway, D. A., Lach, L., Suarez, A. V., Tsutsui, N. D., & Case, T. J. (2002). The Causes and Consequences of Ant Invasions. Annual Review of Ecology and Systematics, 33(1), 181-233. doi:10.1146/annurev.ecolsys.33.010802.150444James, D. G., Stevens, M. M., O’Malley, K. J., & Faulder, R. J. (1999). Ant Foraging Reduces the Abundance of Beneficial and Incidental Arthropods in Citrus Canopies. Biological Control, 14(2), 121-126. doi:10.1006/bcon.1998.0678JERVIS, M. A., & KIDD, N. A. C. (1986). HOST-FEEDING STRATEGIES IN HYMENOPTERAN PARASITOIDS. Biological Reviews, 61(4), 395-434. doi:10.1111/j.1469-185x.1986.tb00660.xJervis, M. A., Kidd, N. A. C., Fitton, M. G., Huddleston, T., & Dawah, H. A. (1993). Flower-visiting by hymenopteran parasitoids. Journal of Natural History, 27(1), 67-105. doi:10.1080/00222939300770051Kaplan, I., & Eubanks, M. D. (2005). APHIDS ALTER THE COMMUNITY-WIDE IMPACT OF FIRE ANTS. Ecology, 86(6), 1640-1649. doi:10.1890/04-0016Lach, L. (2007). Argentine ants displace floral arthropods in a biodiversity hotspot. Diversity and Distributions, 14(2), 281-290. doi:10.1111/j.1472-4642.2007.00410.xLaverty, T. M., & Plowright, R. C. (1985). Competition between hummingbirds and bumble bees for nectar in flowers of Impatiens biflora. Oecologia, 66(1), 25-32. doi:10.1007/bf00378548LeVan, K. E., Hung, K.-L. J., McCann, K. R., Ludka, J. T., & Holway, D. A. (2013). Floral visitation by the Argentine ant reduces pollinator visitation and seed set in the coast barrel cactus, Ferocactus viridescens. Oecologia, 174(1), 163-171. doi:10.1007/s00442-013-2739-zTeresa Martinez-Ferrer, M., Grafton-Cardwell, E. E., & Shorey, H. H. (2003). Disruption of parasitism of the California red scale (Homoptera: Diaspididae) by three ant species (Hymenoptera: Formicidae). Biological Control, 26(3), 279-286. doi:10.1016/s1049-9644(02)00158-5McEwen, P. K., Clow, S., Jervis, M. A., & Kidd, N. A. C. (1993). Alteration in searching behaviour of adult female green lacewingsChrysoperla carnea (Neur.: Chrysopidae) following contact with honeydew of the black scaleSaissetia oleae (Hom.: Coccidae) and solutions containing acidhydrolysed L-tryptophan. Entomophaga, 38(3), 347-354. doi:10.1007/bf02374452Miller, T. E. (1994). Direct and Indirect Species Interactions in an Early Old-Field Plant Community. The American Naturalist, 143(6), 1007-1025. doi:10.1086/285646Moreno, D. S., Haney, P. B., & Luck, R. F. (1987). Chlorpyrifos and Diazinon as Barriers to Argentine Ant (Hymenoptera: Formicidae) Foraging on Citrus Trees1. Journal of Economic Entomology, 80(1), 208-214. doi:10.1093/jee/80.1.208Ohgushi, T. (2008). Herbivore‐induced indirect interaction webs on terrestrial plants: the importance of non‐trophic, indirect, and facilitative interactions. Entomologia Experimentalis et Applicata, 128(1), 217-229. doi:10.1111/j.1570-7458.2008.00705.xOLSON, D. M., & WÄCKERS, F. L. (2006). Management of field margins to maximize multiple ecological services. Journal of Applied Ecology, 44(1), 13-21. doi:10.1111/j.1365-2664.2006.01241.xPace, M. L., Cole, J. J., Carpenter, S. R., & Kitchell, J. F. (1999). Trophic cascades revealed in diverse ecosystems. Trends in Ecology & Evolution, 14(12), 483-488. doi:10.1016/s0169-5347(99)01723-1Pekas, A., Aguilar, A., Tena, A., & Garcia-Marí, F. (2010). Influence of host size on parasitism by Aphytis chrysomphali and A. melinus (Hymenoptera: Aphelinidae) in Mediterranean populations of California red scale Aonidiella aurantii (Hemiptera: Diaspididae). Biological Control, 55(2), 132-140. doi:10.1016/j.biocontrol.2010.07.010Pekas, A., Tena, A., Aguilar, A., & Garcia-Marí, F. (2010). Effect of Mediterranean Ants (Hymenoptera: Formicidae) on California Red Scale (Hemiptera: Diaspididae) Populations in Citrus Orchards. Environmental Entomology, 39(3), 827-834. doi:10.1603/en09207Pekas, A., Tena, A., Aguilar, A., & Garcia-Marí, F. (2010). Spatio-temporal patterns and interactions with honeydew-producing Hemiptera of ants in a Mediterranean citrus orchard. Agricultural and Forest Entomology, 13(1), 89-97. doi:10.1111/j.1461-9563.2010.00501.xRosen, D., & DeBach, P. (1979). Species of Aphytis of the World. doi:10.1007/978-94-009-9603-8Rosumek, F. B., Silveira, F. A. O., de S. Neves, F., de U. Barbosa, N. P., Diniz, L., Oki, Y., … Cornelissen, T. (2009). Ants on plants: a meta-analysis of the role of ants as plant biotic defenses. Oecologia, 160(3), 537-549. doi:10.1007/s00442-009-1309-xRudgers, J. A., & Gardener, M. C. (2004). EXTRAFLORAL NECTAR AS A RESOURCE MEDIATING MULTISPECIES INTERACTIONS. Ecology, 85(6), 1495-1502. doi:10.1890/03-0391Sheldon, J. K., & MacLeod, E. G. (1971). Studies on the Biology of the Chrysopidae II. The Feeding Behavior of the Adult of Chrysopa carnea (Neuroptera). Psyche: A Journal of Entomology, 78(2), 107-121. doi:10.1155/1971/505909Stelzl, M., & Devetak, D. (1999). Neuroptera in agricultural ecosystems. Agriculture, Ecosystems & Environment, 74(1-3), 305-321. doi:10.1016/s0167-8809(99)00040-7STEPPUHN, A., & WACKERS, F. L. (2004). HPLC sugar analysis reveals the nutritional state and the feeding history of parasitoids. Functional Ecology, 18(6), 812-819. doi:10.1111/j.0269-8463.2004.00920.xStyrsky, J. D., & Eubanks, M. D. (2006). Ecological consequences of interactions between ants and honeydew-producing insects. Proceedings of the Royal Society B: Biological Sciences, 274(1607), 151-164. doi:10.1098/rspb.2006.3701Tena, A., Hoddle, C. D., & Hoddle, M. S. (2013). Competition between honeydew producers in an ant–hemipteran interaction may enhance biological control of an invasive pest. Bulletin of Entomological Research, 103(6), 714-723. doi:10.1017/s000748531300045xTena, A., Llácer, E., & Urbaneja, A. (2013). Biological control of a non-honeydew producer mediated by a distinct hierarchy of honeydew quality. Biological Control, 67(2), 117-122. doi:10.1016/j.biocontrol.2013.07.018TENA, A., PEKAS, A., WÄCKERS, F. L., & URBANEJA, A. (2013). Energy reserves of parasitoids depend on honeydew from non-hosts. Ecological Entomology, 38(3), 278-289. doi:10.1111/een.12018Tena, A., Pekas, A., Cano, D., Wäckers, F. L., & Urbaneja, A. (2015). Sugar provisioning maximizes the biocontrol service of parasitoids. Journal of Applied Ecology, 52(3), 795-804. doi:10.1111/1365-2664.12426Völkl, W., Woodring, J., Fischer, M., Lorenz, M. W., & Hoffmann, K. H. (1999). Ant-aphid mutualisms: the impact of honeydew production and honeydew sugar composition on ant preferences. Oecologia, 118(4), 483-491. doi:10.1007/s004420050751Wackers, F. L. (2000). Do oligosaccharides reduce the suitability of honeydew for predators and parasitoids? A further facet to the function of insect-synthesized honeydew sugars. Oikos, 90(1), 197-201. doi:10.1034/j.1600-0706.2000.900124.xWäckers, F. L. (2001). A comparison of nectar- and honeydew sugars with respect to their utilization by the hymenopteran parasitoid Cotesia glomerata. Journal of Insect Physiology, 47(9), 1077-1084. doi:10.1016/s0022-1910(01)00088-9Wäckers, F. L. (2005). Suitability of (extra-)floral nectar, pollen, and honeydew as insect food sources. Plant-Provided Food for Carnivorous Insects, 17-74. doi:10.1017/cbo9780511542220.003Wäckers, F. L., van Rijn, P. C. J., & Heimpel, G. E. (2008). Honeydew as a food source for natural enemies: Making the best of a bad meal? Biological Control, 45(2), 176-184. doi:10.1016/j.biocontrol.2008.01.007Wade, M. R., Zalucki, M. P., Wratten, S. D., & Robinson, K. A. (2008). Conservation biological control of arthropods using artificial food sprays: Current status and future challenges. Biological Control, 45(2), 185-199. doi:10.1016/j.biocontrol.2007.10.024Way, M. J. (1963). Mutualism Between Ants and Honeydew-Producing Homoptera. Annual Review of Entomology, 8(1), 307-344. doi:10.1146/annurev.en.08.010163.001515Wilder, S. M., Barnum, T. R., Holway, D. A., Suarez, A. V., & Eubanks, M. D. (2012). Introduced fire ants can exclude native ants from critical mutualist-provided resources. Oecologia, 172(1), 197-205. doi:10.1007/s00442-012-2477-7YOO, H. J. S., KIZNER, M. C., & HOLWAY, D. A. (2013). Ecological effects of multi-species, ant-hemipteran mutualisms in citrus. Ecological Entomology, 38(5), 505-514. doi:10.1111/een.12042ZAPPALA, L., CAMPOLO, O., GRANDE, S. B., SARACENO, F., BIONDI, A., SISCARO, G., & PALMERI, V. (2012). Dispersal of Aphytis melinus (Hymenoptera: Aphelinidae) after augmentative releases in citrus orchards. European Journal of Entomology, 109(4), 561-568. doi:10.14411/eje.2012.070Zoebelein, G. (2009). Der Honigtau als Nahrung der Insekten: Teil I. Zeitschrift für Angewandte Entomologie, 38(4), 369-416. doi:10.1111/j.1439-0418.1956.tb01612.

A distinct CD38+CD45RA+ population of CD4+, CD8+, and double-negative T cells is controlled by FAS.

The identification and characterization of rare immune cell populations in humans can be facilitated by their growth advantage in the context of specific genetic diseases. Here, we use autoimmune lymphoproliferative syndrome to identify a population of FAS-controlled TCRαβ+ T cells. They include CD4+, CD8+, and double-negative T cells and can be defined by a CD38+CD45RA+T-BET- expression pattern. These unconventional T cells are present in healthy individuals, are generated before birth, are enriched in lymphoid tissue, and do not expand during acute viral infection. They are characterized by a unique molecular signature that is unambiguously different from other known T cell differentiation subsets and independent of CD4 or CD8 expression. Functionally, FAS-controlled T cells represent highly proliferative, noncytotoxic T cells with an IL-10 cytokine bias. Mechanistically, regulation of this physiological population is mediated by FAS and CTLA4 signaling, and its survival is enhanced by mTOR and STAT3 signals. Genetic alterations in these pathways result in expansion of FAS-controlled T cells, which can cause significant lymphoproliferative disease

Plant Species Loss Affects Life-History Traits of Aphids and Their Parasitoids

The consequences of plant species loss are rarely assessed in a multi-trophic context and especially effects on life-history traits of organisms at higher trophic levels have remained largely unstudied. We used a grassland biodiversity experiment and measured the effects of two components of plant diversity, plant species richness and the presence of nitrogen-fixing legumes, on several life-history traits of naturally colonizing aphids and their primary and secondary parasitoids in the field. We found that, irrespective of aphid species identity, the proportion of winged aphid morphs decreased with increasing plant species richness, which was correlated with decreasing host plant biomass. Similarly, emergence proportions of parasitoids decreased with increasing plant species richness. Both, emergence proportions and proportions of female parasitoids were lower in plots with legumes, where host plants had increased nitrogen concentrations. This effect of legume presence could indicate that aphids were better defended against parasitoids in high-nitrogen environments. Body mass of emerged individuals of the two most abundant primary parasitoid species was, however, higher in plots with legumes, suggesting that once parasitoids could overcome aphid defenses, they could profit from larger or more nutritious hosts. Our study demonstrates that cascading effects of plant species loss on higher trophic levels such as aphids, parasitoids and secondary parasitoids begin with changed life-history traits of these insects. Thus, life-history traits of organisms at higher trophic levels may be useful indicators of bottom-up effects of plant diversity on the biodiversity of consumers