@article{demi_hughes_taylor_2022, title={Characterizing the role of phosphorus availability and periphytic algae in the food choice and performance of detritivorous caddisflies (Trichoptera:Limnephilidae)}, volume={41}, ISSN={2161-9549 2161-9565}, url={http://dx.doi.org/10.1086/717953}, DOI={10.1086/717953}, abstractNote={Organisms that rely on detritus as their primary food source may face particularly strong nutritional constraints on growth and development, given the characteristically poor quality of detrital resources. In freshwater ecosystems, the low content of P in detritus often limits detritivore growth. Additionally, a growing body of evidence suggests the biochemical composition of algae, such as essential fatty acids, can limit aquatic detritivore growth. We investigated feeding preference and growth responses of common aquatic detritivores by performing paired feeding-preference and growth experiments on 4 species of larval caddisflies (Trichoptera) from the family Limnephilidae: Asynarchus nigriculus, Anabolia bimaculata, Limnephilus externus, and Ecclisomyia sp. We manipulated both the P content and epiphytic algal biomass of a common detrital food resource (decomposing sedge [Carex sp.]) by conditioning the detritus under 2 different light (ambient, shaded) and P (ambient [low], +P) regimes. We tested 3 hypotheses that describe feeding preferences and performance under different scenarios of P limitation, algal limitation, and co-limitation by P and algae. We observed evidence of preferential feeding behavior for each of the 4 taxa, with 2 species exhibiting preferences for conditioned detritus with high algal biomass and 2 for detritus from the +P treatments. We observed agreement between feeding preferences and performance (growth, growth efficiency, mortality) for only 2 taxa, with A. nigriculus exhibiting higher growth rates and growth efficiency on their preferred high-P detritus, and L. externus experiencing lower mortality when reared on their preferred high algal biomass detritus. These findings provide an initial step toward characterizing the feeding preferences and performance responses of aquatic detritivores to 2 potentially common nutritional constraints: detrital P and algal supply.}, number={1}, journal={Freshwater Science}, publisher={University of Chicago Press}, author={Demi, Lee M. and Hughes, Donovan and Taylor, Brad W.}, year={2022}, month={Mar}, pages={18–32} }
 @article{balik_leitz_washko_cleveland_krejsa_perchik_stogsdill_vlah_demi_greig_et al._2022, title={Species-specific traits predict whole-assemblage detritus processing by pond invertebrates}, volume={199}, ISSN={0029-8549 1432-1939}, url={http://dx.doi.org/10.1007/s00442-022-05239-z}, DOI={10.1007/s00442-022-05239-z}, abstractNote={Functional trait diversity determines if ecosystem processes are sensitive to shifts in species abundances or composition. For example, trait variation suggests detritivores process detritus at different rates and make different contributions to whole-assemblage processing, which could be sensitive to compositional shifts. Here, we used a series of microcosm experiments to quantify species-specific coarse and fine particulate organic matter (CPOM and FPOM) processing for ten larval caddisfly species and three non-caddisfly species in high-elevation wetlands. We then compared trait-based models including life history, dietary, and extrinsic traits to determine which traits explained interspecific variation in detritus processing. Finally, we compared processing by mixed caddisfly assemblages in microcosms and natural ponds to additive predictions based on species-specific processing to determine if single-species effects are additive in multi-species assemblages. We found considerable interspecific variation in biomass-specific CPOM (13-fold differences) and FPOM (8-fold differences) processing. Furthermore, on a mass-specific basis, amphipods, chironomids, and caddisflies processed similar amounts of detritus, suggesting non-shredder taxa could process more than previously recognized. Trait models including dietary percent detritus, development rate, body size, and wetland hydroperiod explained 81 and 57% of interspecific variation in CPOM and FPOM processing, respectively. Finally, species-specific additive predictions were strikingly similar to mixed-assemblage processing in microcosms and natural ponds, with the largest difference being a 15% overestimate. Thus, additivity of species-specific processing suggests single-species rates may be useful for understanding functional consequences of shifting assemblages, and a trait-based approach to predicting species-specific processing could support generating additive predictions of whole-assemblage processing.}, number={4}, journal={Oecologia}, publisher={Springer Science and Business Media LLC}, author={Balik, Jared A. and Leitz, Cameron and Washko, Susan E. and Cleveland, Brittney and Krejsa, Dianna M. and Perchik, Marieke E. and Stogsdill, Alexander and Vlah, Mike and Demi, Lee M. and Greig, Hamish S. and et al.}, year={2022}, month={Aug}, pages={951–963} }
 @article{demi_taylor_reading_tordoff_dunn_2021, title={Understanding the evolution of nutritive taste in animals: Insights from biological stoichiometry and nutritional geometry}, volume={6}, ISSN={["2045-7758"]}, DOI={10.1002/ece3.7745}, abstractNote={A major conceptual gap in taste biology is the lack of a general framework for understanding the evolution of different taste modalities among animal species. We turn to two complementary nutritional frameworks, biological stoichiometry theory and nutritional geometry, to develop hypotheses for the evolution of different taste modalities in animals. We describe how the attractive tastes of Na, Ca, P, N and C containing compounds are consistent with principles of both frameworks based on their shared focus on nutritional imbalances and consumer homeostasis. Specifically, we suggest that the evolution of multiple nutritive taste modalities can be predicted by identifying individual elements that are typically more concentrated in the tissues of animals than plants. Additionally, we discuss how consumer homeostasis can inform our understanding of why some taste compounds (i.e., Na, Ca and P salts) can be either attractive or aversive depending on concentration. We also discuss how these complementary frameworks can help to explain the phylogenetic distribution of different taste modalities and improve our understanding of the mechanisms that lead to loss of taste capabilities in some animal lineages. The ideas presented here will stimulate research that bridges the fields of evolutionary biology, sensory biology and ecology.}, journal={ECOLOGY AND EVOLUTION}, author={Demi, Lee M. and Taylor, Brad W. and Reading, Benjamin J. and Tordoff, Michael G. and Dunn, Robert R.}, year={2021}, month={Jun} }
 @article{demi_benstead_rosemond_maerz_2020, title={Experimental N and P additions relieve stoichiometric constraints on organic matter flows through five stream food webs}, volume={89}, ISSN={["1365-2656"]}, DOI={10.1111/1365-2656.13197}, abstractNote={1.Human activities have dramatically altered global patterns of nitrogen (N) and phosphorus (P) availability. This pervasive nutrient pollution is changing basal resource quality in food webs, thereby affecting rates of biological productivity and the pathways of energy and material flow to higher trophic levels. 2.Here, we investigate how the stoichiometric quality of basal resources modulates patterns of material flow through food webs by characterizing the effects of experimental N and P enrichment on the trophic basis of macroinvertebrate production and flows of dominant food resources to consumers in five detritus-based stream food webs. 3.After a pre-treatment year, each stream received N and P at different concentrations for two years, resulting in a unique dissolved N:P ratio (target range from 128:1 to 2:1) for each stream. We combined estimates of secondary production and gut contents analysis to calculate rates of material flow from basal resources to macroinvertebrate consumers in all five streams, during all three years of study. 4.Nutrient enrichment resulted in a 1.5× increase in basal resource flows to primary consumers, with the greatest increases from biofilms and wood. Flows of most basal resources were negatively related to resource C:P, indicating widespread P-limitation in these detritus-based food webs. Nutrient enrichment resulted in a greater proportion of leaf litter, the dominant resource flow-pathway, being consumed by macroinvertebrates, with that proportion increasing with decreasing leaf litter C:P. However, the increase in efficiency with which basal resources were channeled into metazoan food webs was not propagated to macroinvertebrate predators, as flows of prey did not systematically increase following enrichment and were unrelated to basal resource flows. 5.This study suggests that ongoing global increases in N and P supply will increase organic-matter flows to metazoan food webs in detritus-based ecosystems by reducing stoichiometric constraints at basal trophic levels. However, the extent to which those flows are propagated to the highest trophic levels likely depends on responses of individual prey taxa and their relative susceptibility to predation.}, number={6}, journal={JOURNAL OF ANIMAL ECOLOGY}, author={Demi, Lee M. and Benstead, Jonathan P. and Rosemond, Amy D. and Maerz, John C.}, year={2020}, month={Jun}, pages={1468–1481} }