@article {21733, title = {Phylogenetic trophic specialization: a robust comparison of herbivorous guilds}, journal = {Oecologia}, volume = {185}, year = {2017}, pages = {551-559}, chapter = {551}, abstract = {

\"Resource specialization is a key concept in ecology, but it is unexpectedly difficult to parameterize. Differences in resource availability, sampling effort and abundances preclude comparisons of incompletely sampled biotic interaction webs. Here, we extend the distance-based specialization index (DSI) that measures trophic specialization by taking resource phylogenetic relatedness and availability into account into a rescaled version, DSI*. It is a versatile metric of specialization that expands considerably the scope and applicability, hence the usefulness, of DSI. The new metric also accounts for differences in abundance and sampling effort of consumers, which enables robust comparisons among distinct guilds of consumers. It also provides an abundance threshold for the reliability of the metric for rare species, a very desirable property given the difficulty of assessing any aspect of rare species accurately. We apply DSI* to an extensive dataset on interactions between insect herbivores from four folivorous guilds and their host plants in Papua New Guinean rainforests. We demonstrate that DSI*, contrary to the original DSI, is largely independent of sample size and weakly and non-linearly related with several host specificity measures that do not adjust for plant phylogeny. Thus, DSI* provides further insights into host specificity patterns; moreover, it is robust to the number and phylogenetic diversity of plant species selected to be sampled for herbivores. DSI* can be used for a broad range of comparisons of distinct feeding guilds, geographical locations and ecological conditions. This is a key advance in elucidating the interaction structure and evolution of highly diversified systems.\"

}, keywords = {DISTANCE-BASED SPECIALIZATION INDEX, FOODPLANT EVOLUTION, FOODPLANT SPECIFICITY, HERBIVORY, PAPUA NEW GUINEA}, doi = {10.1007/s00442-017-3980-7}, author = {Jorge, L.R. and Novotny, V. and Segar, S.T. and Weiblen, G.D. and Miller, S.E. and Basset, Y. and Lewinsohn, T.M.} } @article {21732, title = {Variably hungry caterpillars: predictive models and foliar chemistry suggest how to eat a rainforest}, journal = {Proceedings of the Royal Society B}, volume = {284}, year = {2017}, pages = {20171803}, chapter = {20171803}, abstract = {

\"A long-term goal in evolutionary ecology is to explain the incredible diversity of insect herbivores and patterns of host plant use in speciose groups like tropical Lepidoptera. Here, we used standardized food-web data, multigene phylogenies of both trophic levels and plant chemistry data to model interactions between Lepidoptera larvae (caterpillars) from two lineages (Geometridae and Pyraloidea) and plants in a species-rich lowland rainforest in New Guinea. Model\  parameters were used to make and test blind predictions for two hectares of an exhaustively sampled forest. For pyraloids, we relied on phylogeny alone and predicted 54\% of species-level interactions, translating to 79\% of all trophic links for individual insects, by sampling insects from only 15\% of local woody plant diversity. The phylogenetic distribution of host-plant associations in polyphagous geometrids was less conserved, reducing accuracy. In a truly quantitative food web, only 40\% of pair-wise interactions were described correctly in geometrids. Polyphenol oxidative activity (but not protein precipitation capacity) was important for understanding the occurrence of geometrids (but not pyraloids) across their hosts. When both foliar chemistry and plant phylogeny were included, we predicted geometrid\–plant occurrence with 89\% concordance. Such models help to test macroevolutionary hypotheses at the community level.\"

}, keywords = {FOODPLANT CHEMISTRY, FOODPLANT EVOLUTION, FOODPLANT SPECIFICITY, GEOMETRIDAE, HERBIVORY, NEW GUINEA, POLYPHENOLS, PYRALOIDEA}, doi = {10.1098/rspb.2017.1803}, url = {http://dx.doi.org/10.1098/rspb.2017.1803}, author = {Segar, S.T. and Volf, M. and Isua, B. and Sisol, M. and Redmond, C.M. and Rosati, M.E. and Gewa, B. and Molem, K. and Dahl, C. and Holloway, J.D. and Basset, Y. and Miller, S.E. and Weiblen, G.D. and Salminen, J.-P. and Novotny, V.} } @article {21731, title = {Community structure of insect herbivores is driven by conservatism, escalation and divergence of defensive traits in Ficus}, journal = {Ecology Letters}, year = {2017}, type = {Early view}, abstract = {

\"Escalation (macroevolutionary increase) or divergence (disparity between relatives) in trait values are two frequent outcomes of the plant-herbivore arms race. We studied the defences and caterpillars associated with 21 sympatric New Guinean figs. Herbivore generalists were concentrated on hosts with low protease and oxidative activity. The distribution of specialists correlated with phylogeny, protease and trichomes. Additionally, highly specialised Asota moths used alkaloid rich plants. The evolution of proteases was conserved, alkaloid diversity has escalated across the studied species, oxidative activity has escalated within one clade, and trichomes have diverged across the phylogeny. Herbivore specificity correlated with their response to host defences: escalating traits largely affected\  generalists and divergent traits specialists; but the effect of escalating traits on extreme specialists was positive. In turn, the evolution of defences in Ficus can be driven towards both escalation and divergence in individual traits, in combination providing protection against a broad spectrum of herbivores.\"

}, keywords = {AGANAINAE, ALKALOIDS, ASOTA, CHOREUTIDAE, COEVOLUTION, CYSTEINE PROTEASE, DEFENCE, EREBIDAE, FICUS, FOODPLANT SPECIFICITY, HERBIVORY, MORACEAE, NEW GUINEA, POLYPHENOLS, PYRALOIDEA, TRAITS, TRICHOMES}, doi = {10.1111/ele.12875}, author = {Volf, M. and Segar, S.T. and Miller, S.E. and Isua, B. and Sisol, M. and Aubona, G. and {\v S}imek, P. and Moos, M. and Laitila, L. and Kim, J. and Zima_Jr, J. and Rota, J. and Weiblen, G.D. and Wossa, S. and Salminen, J.-P. and Basset, Y. and Novotny, V.} }