03183nas a2200169   4500008004100000020001400041245013200055210006900187260001000256300001200266490000700278520252300285100002002808700002302828700002702851856013502878       2010                        eng d  a0022-047700aUsing experiments, demography and population models to estimate interaction strength based on transient and asymptotic dynamics0 aUsing experiments demography and population models to estimate i  cMarch  a290-3010 v983 a1. Despite a large literature documenting the effects of mutualists and/or antagonists on plant performance, we still have limited insight into the strength of these interactions, as this involves quantifying how one species influences the population dynamics of another. 2. Here, we use data from two example systems, Cynoglossum officinale and Calathea ovandensis, to illustrate how experiments, demographic data and stage-based population models can be combined to estimate interaction strength of insect herbivores on plants. Because many plant populations may not be at equilibrium, we conduct transient analyses and contrast these results to more traditional asymptotic results. 3. We calculate three metrics of interaction strength, [DELTA][lambda]asymptotic, the change in asymptotic annual per capita plant population growth rate resulting from herbivore exclusion, [DELTA][lambda](t), the change in transient [lambda] caused by herbivores at t = M (where M = the time of their maximum effect during the transient phase) and [DELTA][lambda]transient, a time-averaged effect of consumers on [lambda] across the entire transient phase. 4. Fairly strong impacts of insect consumers on plant fecundity do not translate similarly to [DELTA][lambda]asymptotic. Results show that [DELTA];[lambda](t) can be larger (or smaller) than [DELTA][lambda]asymptotic but in our examples [DELTA]transient was similar in magnitude to [DELTA][lambda]asymptotic. 5. The transient effects of consumers on [lambda] were driven by changes in the elasticity of fecundity across the transient phase. These effects were dynamic even though consumer impacts on demography and vital rates were held constant. The importance of particular stages and transitions to annual population growth vary during the transient phase. 6.Synthesis. We describe three metrics of interaction strength, [DELTA][lambda]asymptotic, [DELTA][lambda](t) and [DELTA][lambda]transient. These metrics have several advantages over more commonly used trait or performance measures that quantify the outcome of interactions. We illustrate how the transient impacts of consumers on [lambda] are dynamic, with the changing stage distribution of a population and transient elasticities driving these effects. More generally, this study shows that the impacts of animals on plant performance do not translate equivalently to plant population growth, thereby underscoring the importance of using population models to extend the inference of individual-level experiments.1 aMaron, John, L.1 aHorvitz, Carol, C.1 aWilliams, Jennifer, L.  uhttps://weevil.myspecies.info/using-experiments-demography-and-population-models-estimate-interaction-strength-based-transient-a-003183nas a2200169   4500008004100000020001400041245013200055210006900187260001000256300001200266490000700278520252300285100002002808700002302828700002702851856013502878       2010                        eng d  a0022-047700aUsing experiments, demography and population models to estimate interaction strength based on transient and asymptotic dynamics0 aUsing experiments demography and population models to estimate i  cMarch  a290-3010 v983 a1. Despite a large literature documenting the effects of mutualists and/or antagonists on plant performance, we still have limited insight into the strength of these interactions, as this involves quantifying how one species influences the population dynamics of another. 2. Here, we use data from two example systems, Cynoglossum officinale and Calathea ovandensis, to illustrate how experiments, demographic data and stage-based population models can be combined to estimate interaction strength of insect herbivores on plants. Because many plant populations may not be at equilibrium, we conduct transient analyses and contrast these results to more traditional asymptotic results. 3. We calculate three metrics of interaction strength, [DELTA][lambda]asymptotic, the change in asymptotic annual per capita plant population growth rate resulting from herbivore exclusion, [DELTA][lambda](t), the change in transient [lambda] caused by herbivores at t = M (where M = the time of their maximum effect during the transient phase) and [DELTA][lambda]transient, a time-averaged effect of consumers on [lambda] across the entire transient phase. 4. Fairly strong impacts of insect consumers on plant fecundity do not translate similarly to [DELTA][lambda]asymptotic. Results show that [DELTA];[lambda](t) can be larger (or smaller) than [DELTA][lambda]asymptotic but in our examples [DELTA]transient was similar in magnitude to [DELTA][lambda]asymptotic. 5. The transient effects of consumers on [lambda] were driven by changes in the elasticity of fecundity across the transient phase. These effects were dynamic even though consumer impacts on demography and vital rates were held constant. The importance of particular stages and transitions to annual population growth vary during the transient phase. 6.Synthesis. We describe three metrics of interaction strength, [DELTA][lambda]asymptotic, [DELTA][lambda](t) and [DELTA][lambda]transient. These metrics have several advantages over more commonly used trait or performance measures that quantify the outcome of interactions. We illustrate how the transient impacts of consumers on [lambda] are dynamic, with the changing stage distribution of a population and transient elasticities driving these effects. More generally, this study shows that the impacts of animals on plant performance do not translate equivalently to plant population growth, thereby underscoring the importance of using population models to extend the inference of individual-level experiments.1 aMaron, John, L.1 aHorvitz, Carol, C.1 aWilliams, Jennifer, L.  uhttps://weevil.myspecies.info/using-experiments-demography-and-population-models-estimate-interaction-strength-based-transient-and02983nas a2200193   4500008004100000020001400041245016000055210006900215260001300284300001400297490000700311520222700318653002102545653002202566100002302588700001602611700002702627856013502654       2009                        eng d  a0022-047700aPre-dispersal acorn predation in mixed oak forests: interspecific differences are driven by the interplay among seed phenology, seed size and predator size0 aPredispersal acorn predation in mixed oak forests interspecific   cNovember  a1416-14230 v973 a1. Pre-dispersal seed predation (PSP) often occurs in multi-host-predator systems (e.g. several plant species exposed to a common array of granivorous insects). However, whether the interaction among seed phenology, seed size and predator size accounts for interspecific differences in PSP remains elusive. 2. We studied PSP in a mixed-oak forest with two oaks (the larger-seeded Quercus humilis and the smaller-seeded Q. ilex), both depredated by two acorn weevils (the smaller Curculio glandium and the larger C. elephas). We intensively monitored acorn production and infestation phenology and we identified the weevil species depredating acorns by means of DNA taxonomy. 3. The minimum acorn size required for infestation was lower for C. glandium than for C. elephas, in accordance with their different body sizes. This resulted in an earlier infestation phenology in C. glandium and the ability of this species to infest both smaller and larger acorns. Above a minimum acorn size threshold, no selection for larger acorns by weevils was observed. 4. Initial acorn crop size was similar in the two oaks. Nonetheless, the earlier acorn phenology and the production of larger acorns in Q. humilis favoured the earlier infestation by C. glandium and the predation by both small and large weevils. Smaller acorns of Q. ilex almost excluded infestation by the larger C. elephas. 5. Although larger acorns of Q. humilis could better survive infestation (preserve the embryo), higher PSP in this species finally resulted in a lower mature acorn crop size than in Q. ilex. 6. Synthesis. In a multi-host-predator system, smaller-seeded species may benefit from a reduced PSP because they exclude larger granivorous insects, but also by means of a 'free-rider effect', if larger-seeded heterospecifics earlier reach a critical size to be depredated. These results also highlight the benefits of a small body size in granivorous insects to depredate seeds earlier and to forage on a wider range of seed sizes. Whether the advantage of 'being small' in this antagonistic plant-animal interaction is offset by other processes, or whether it results in a pressure towards seed and insect size reduction, deserves further attention.10aCurculio elephas10aCurculio glandium1 aEspelta, Josep, M.1 aBonal, Raul1 aSanchez-Humanes, Belen  uhttps://weevil.myspecies.info/pre-dispersal-acorn-predation-mixed-oak-forests-interspecific-differences-are-driven-interplay-among03263nas a2200181   4500008004100000020001400041245011800055210006900173260001200242300001000254490000700264520258300271653002602854100001902880700002102899700002602920856013502946       2011                        eng d  a0022-047700aConstitutive and induced subterranean plant volatiles attract both entomopathogenic and plant parasitic nematodes0 aConstitutive and induced subterranean plant volatiles attract bo  cJanuary  a26-350 v993 aIndirect plant defences are well documented for the above-ground constituents of plants. Although less investigated to date, below-ground defences that mediate multitrophic interactions are equally important. Entomopathogenic nematodes (Steinernema diaprepesi) are attracted to herbivore- induced volatiles from Swingle var. (Citrus paradisi [center dot] Poncirus trifoliata) when fed upon by root weevil, Diaprepes abbreviatus. 2. We examined the extent to which below-ground volatiles modify behaviour of nematode species representing various foraging strategies (cruisers versus ambushers) and trophic levels (plant parasites versus entomopathogens). We compared attraction to volatiles of weevil-infested and non-infested roots from Swingle citrus rootstock and a parent line of the Swingle hybrid, Poncirus trifoliata (Pt). 3. Swingle weevil-infested roots attracted more nematodes than non-infested roots irrespective of nematode foraging strategy and trophic status. The parental line, Pt, attracted all nematode species irrespective of insect herbivory. 4. Dynamic in situ collection and GC[long dash]MS analysis of volatiles from soil revealed that Pt roots release attracting cues constitutively. A different non-hybrid citrus species (sour orange, Citrus aurantium) released nematode attracting cues only in response to larval feeding, similar to responses found in Swingle. Volatile collections from above- and below-ground portions of citrus plants revealed that above-ground feeding by weevils does not induce production of nematode attracting cues analogous to that induced by root damage, nor does damage by larvae below-ground induce a similar volatile above ground. 5. Synthesis. Our results suggest that release of nematode attractants by citrus roots occurs broadly and can be constant or herbivore-induced. The major constituent of this indirect defence is produced by roots and not shoots and in response to below-ground, but not above-ground herbivory. Our findings suggest that this cue acts on nematode species broadly, attracting entomopathogenic nematodes that exhibit various foraging strategies. Unexpectedly, we also found that this cue attracts a plant parasitic nematode species. It appears, thus, that release of nematode attracting cues by citrus plants can cause ecological costs. The plants, however, appear to counteract against these costs, because constitutive release was found only in a cultivar that is resistant to phytopathogenic nematodes, while herbivore-induced release occurred in lines susceptible to pathogenic nematode species.10aDiaprepes abbreviatus1 aAli, Jared, G.1 aAlborn, Hans, T.1 aStelinski, Lukasz, L.  uhttps://weevil.myspecies.info/constitutive-and-induced-subterranean-plant-volatiles-attract-both-entomopathogenic-and-plant-parasi00313nas a2200133   4500008004100000245001500041210001400056300001200070490000700082653001800089653001400107100001800121856004000139       1948                        eng d00aCuscuta L.0 aCuscuta L  a356-3650 v3610aSmicronychini10aSmicronyx1 aVerdcourt, B.  uhttp://www.jstor.org/stable/2256682