03644nas a2200433   4500008004100000020001400041245010700055210006900162260001200231300001200243490000700255520252000262653002302782653001602805653001402821653001702835653001102852653002102863653002102884653001802905653001402923653001402937653001502951653001302966653001402979653002002993653001603013653001403029653001303043653001403056653001603070653001403086653001703100653001903117100001803136700001503154700001703169856002403186       2000                        eng d  a0030-129900aHow leaf domatia and induced plant resistance affect herbivores, natural enemies and plant performance0 aHow leaf domatia and induced plant resistance affect herbivores   c2000///  a70 - 800 v893 aPredators and plant resistance may act together to control herbivorous arthropod populations or antagonistically, which would reduce the control of pest populations. In a field experiment we enhanced predation by adding simulated leaf domatia to plants. Leaf domatia are small structures that often harbor predaceous arthropods that are potentially beneficial to the plant. We also manipulated host plant duality by inducing resistance with controlled. early season exposure of seedlings to spider mite herbivory. Our manipulations had profound consequences for the natural community of arthropods that inhabited the plants. Leaf domatia had a direct positive effect on abundances of two species of bugs and one species of thrips, all of which are largely predators of herbivores. On leaves with domatia, each of the predators was found inside the domatia two to three times more often than outside the domatia. Eggs of predaceous bugs inside leaf domatia were protected from parasitism compared to eggs outside the domatia. The positive effects of leaf domatia on predator abundances were associated with reduced populations of herbivorous spider mites, aphids, and whiteflies. Plants with experimental leaf domatia showed significantly enhanced reproductive performance. Induced resistance also affected the community of arthropods. Of the abundant predators, all of which also fed on the plant, only minute pirate bugs were negatively affected by induced resistance. Populations of herbivorous spider mites and whiteflies were directly and negatively affected by induction. In contrast, aphid populations were higher on plants with induced resistance compared to uninduced plants. Effects of induced resistance and domatia were additive for each of the predators and for aphids. However, spider mite and whitefly populations were not suppressed Further by employing both induced resistance and domatia compared to each strategy alone. Our manipulations suggest that plant defense strategies can have positive effects on some species and negative effects on others. Negative effects of "resistance trails" on predators and positive effects on some herbivores may reduce the benefits of constitutive expression of resistance traits and may favor inducible defense strategies. Multiple plant strategies such as inducible resistance and morphological traits that aid in the recruitment of predators of herbivores may act together to maximize plant defenses, although they may also be redundant and not act additively10aBIOLOGICAL-CONTROL10aCOMMUNITIES10aCOMMUNITY10aCONSEQUENCES10aCOTTON10aDECIDUOUS FOREST10aDEFENSE STRATEGY10aFLOWER THRIPS10afood webs10aherbivory10aHOST-PLANT10amultiple10aMUTUALISM10aNATURAL ENEMIES10aPOPULATIONS10apredation10aPREDATOR10apredators10aRECRUITMENT10aSEEDLINGS10aSPIDER-MITES10aTROPHIC LEVELS1 aAgrawal, A.A.1 aKarban, R.1 aColfer, R.G.  uISI:00008622740000803065nas a2200361   4500008004100000020001400041245006400055210006400119260001200183300001400195490000700209520217200216653001602388653001402404653002202418653001502440653001202455653001402467653001402481653001402495653001702509653001002526653001402536653001002550653003302560653001102593653001602604653001402620653001602634653001102650100001802661856002402679       2011                        eng d  a0269-846300aCurrent trends in the evolutionary ecology of plant defence0 aCurrent trends in the evolutionary ecology of plant defence  c2011///  a420 - 4320 v253 aP>1. In this essay I summarize current trends in the evolutionary ecology of plant defence, while advocating for approaches that integrate community ecology with specific tests of classic evolutionary hypotheses. Several conclusions emerge. 2. The microevolution of defence is perhaps best studied by reciprocal transplant experiments of differentiated plant populations while simultaneously manipulating the presence of the herbivore(s) hypothesized to be the agent(s) of natural selection. 3. Although there is continued interest in the costs of defence, I argue that some empirical approaches to estimating costs (e.g. genetic engineering) may provide limited insight into evolutionary processes. 4. Essentially all plants employ several different lines of defence against herbivory. It is thus time to abandon searching for single silver bullet traits and the simple trade-off model (where traits are arbitrarily expected to negatively covary across genotypes or species). We still know very little about which trait combinations are most effective and have repeatedly evolved together. Thus, some of our prominent theories (e.g. a predicted trade-off between direct and indirect defence) need to be revised. 5. Studies of the macroevolution of plant defence are enjoying renewed interest due to available phylogenies and analytical methods. Although general trends are not currently surmisable, we will soon have strong case studies evaluating both biotic and abiotic drivers of convergent evolution in defence strategies and the role of defence evolution in the adaptive radiation of plant lineages. 6. The evolution of specificity is proposed as a final frontier in understanding complexity in plant-herbivore interactions. Although it is abundantly clear that plants can deploy highly specific defensive responses that are differentially perceived by herbivore species, how such responses evolve and are physiologically regulated remains an important gap. Relatively straightforward methodologies are now available to close the loop between plant perception of herbivory, hormonal responses, and production of defensive end-products across genotype or species10aCOMMUNITIES10aCOMMUNITY10acommunity ecology10aCOMPLEXITY10aecology10aEVOLUTION10aHERBIVORE10aherbivory10ainteractions10aMODEL10aphylogeny10aplant10aplant-herbivore interactions10aPLANTS10aPOPULATIONS10aRESPONSES10aSPECIFICITY10atheory1 aAgrawal, A.A.  uISI:000288501100012