@article{shik_kay_silverman_2014, title={Aphid honeydew provides a nutritionally balanced resource for incipient Argentine ant mutualists}, volume={95}, ISSN={["1095-8282"]}, DOI={10.1016/j.anbehav.2014.06.008}, abstractNote={Food-for-protection mutualisms can provide resources that subsidize ecological dominance, although their stability often depends on the nutritional match between the traded food and traits to which it is allocated. A well-studied food-for-protection mutualism is the protection by Argentine ants, Linepithema humile, of hemipteran mutualists in return for honeydew, which is generally assumed to be a nutritionally imbalanced food, high in carbohydrates and low in protein. We tested an alternative hypothesis, that the nutritional value of honeydew depends on the composition of life history traits related to survival (worker maintenance) and colony growth (brood production). Using a factorial design, we manipulated ant colony access to aphids, baseline levels of nutritional deprivation, and, by adding or subtracting queens, the ability to invest in growth. We found that aphid access primarily benefited colonies on high-protein, low-carbohydrate diets, suggesting colony nutritional state influences the value of aphid associations. Unexpectedly, we found that worker survival and brood production were positively correlated across treatments, and both decreased with the ants' percentage of nitrogen mass, a proxy for body protein. Moreover, the workers' percentage of fat mass was generally lower in brood-producing colonies, particularly in high-protein treatments, suggesting strong competition among investments for limited carbohydrates. These results suggest that carbohydrate access generally constrains Argentine ant life history and clarifies the links between the nutritional composition of food rewards and the stability of ecologically important mutualisms.}, journal={ANIMAL BEHAVIOUR}, author={Shik, Jonathan Z. and Kay, Adam D. and Silverman, Jules}, year={2014}, month={Sep}, pages={33–39} } @article{shik_schal_silverman_2014, title={Diet specialization in an extreme omnivore: nutritional regulation in glucose-averse German cockroaches}, volume={27}, ISSN={1010-061X}, url={http://dx.doi.org/10.1111/jeb.12458}, DOI={10.1111/jeb.12458}, abstractNote={Organisms have diverse adaptations for balancing dietary nutrients, but often face trade‐offs between ingesting nutrients and toxins in food. While extremely omnivorous cockroaches would seem excluded from such dietary trade‐offs, German cockroaches (Blattella germanica) in multiple populations have rapidly evolved a unique dietary specialization – an aversion to glucose, the phagostimulant in toxic baits used for pest control. We used factorial feeding experiments within the geometric framework to test whether glucose‐averse (GA) cockroaches with limited access to this critical metabolic fuel have compensatory behavioural and physiological strategies for meeting nutritional requirements. GA cockroaches had severely constrained intake, fat and N mass, and performance on glucose‐based diets relative to wild‐type (WT) cockroaches and did not appear to exhibit digestive strategies for retaining undereaten nutrients. However, a GA × WT ‘hybrid’ had lower glucose aversion than GA and greater access to macronutrients within glucose‐based diets – while still having lower intake and survival than WT. Given these intermediate foraging constraints, hybrids may be a reservoir for this maladaptive trait in the absence of positive selection and may account for the rapid evolution of this trait following bait application.}, number={10}, journal={Journal of Evolutionary Biology}, publisher={Wiley}, author={Shik, J. Z. and Schal, C. and Silverman, J.}, year={2014}, month={Jul}, pages={2096–2105} } @article{bednar_shik_silverman_2013, title={Prey handling performance facilitates competitive dominance of an invasive over native keystone ant}, volume={24}, ISSN={["1465-7279"]}, DOI={10.1093/beheco/art069}, abstractNote={Studies of species coexistence in ant communities often suggest that competitive interactions are mediated by behavioral trade-offs between resource discovery and dominance. However, these studies have always measured foraging at artificial, static baits that omit traits of living prey items and potential coevolutionary predator–prey relationships. In a series of lab experiments, we compare the ability of ants to harvest live termites (Reticulitermes virginicus) in nests varying in defensive ability. Moreover, we compare foraging performance of 2 co-occurring ant species—the North American native Aphaenogaster rudis and the invasive Pachycondyla chinensis—differing in their evolutionary experience hunting R. virginicus. Our results show how the invasive P. chinensis may displace the native keystone A. rudis by directly killing A. rudis workers and reducing termite prey available for A. rudis. Specifically, P. chinensis is more sensitive to novel termite prey than the native A. rudis and then destroys termite colonies—even if they are highly defended by soldiers or nest architecture. Our results further show how whole colony behavioral dominance by P. chinensis is mediated by behavioral interactions among individual workers. More generally, our experimental approach using live prey to study interspecific competition can integrate evolutionary dynamics into studies of proximate behavioral factors governing species coexistence.}, number={6}, journal={BEHAVIORAL ECOLOGY}, author={Bednar, David M. and Shik, Jonathan Z. and Silverman, Jules}, year={2013}, pages={1312–1319} } @misc{shik_donoso_kaspari_2013, title={The life history continuum hypothesis links traits of male ants with life outside the nest}, volume={149}, number={2}, journal={Entomologia Experimentalis et Applicata}, author={Shik, J. Z. and Donoso, D. A. and Kaspari, M.}, year={2013}, pages={99–109} } @article{shik_silverman_2013, title={Towards a nutritional ecology of invasive establishment: aphid mutualists provide better fuel for incipient Argentine ant colonies than insect prey}, volume={15}, ISSN={["1573-1464"]}, DOI={10.1007/s10530-012-0330-x}, number={4}, journal={BIOLOGICAL INVASIONS}, author={Shik, Jonathan Z. and Silverman, Jules}, year={2013}, month={Apr}, pages={829–836} } @article{rice_shik_silverman_2012, title={Effect of Scattered and Discrete Hydramethylnon Bait Placement on the Asian Needle Ant}, volume={105}, ISSN={["1938-291X"]}, DOI={10.1603/ec12207}, abstractNote={ABSTRACT The Asian needle ant (Pachycondyla chinensis Emery) is invading natural and disturbed habitats across the eastern United States. While recent studies document the impact of P. chinensis on native ecosystems and human health, effective control measures remain unknown. Thus, we evaluated the field performance of a hydramethylnon granular bait, Maxforce Complete Granular Insect Bait, dispersed in clumps or scattered against P. chinensis. We also measured the effect of this bait on P. chinensis outside of the treatment zone. Surprisingly, unlike reports for other ant species, we achieved nearly complete P. chinensis population reductions 1 d after treatments were applied. Significant ant reductions were achieved until the end of our study at 28 d. No difference was recorded between clumped and scattered application methods. We found no overall difference in ant reductions from the edge out to 5 m beyond the treatment zone. Other local ant species appeared to be unaffected by the bait and foraging activity increased slightly after P. chinensis removal from treated areas. We suggest that Maxforce Complete Granular Insect Bait can be effective in an Asian needle ant treatment program.}, number={5}, journal={JOURNAL OF ECONOMIC ENTOMOLOGY}, author={Rice, Eleanor Spicer and Shik, Jonathan Z. and Silverman, Jules}, year={2012}, month={Oct}, pages={1751–1757} } @article{shik_hou_kay_kaspari_gillooly_2012, title={Towards a general life-history model of the superorganism: predicting the survival, growth and reproduction of ant societies}, volume={8}, number={6}, journal={Biology Letters}, author={Shik, J. Z. and Hou, C. and Kay, A. and Kaspari, M. and Gillooly, J. F.}, year={2012}, pages={1059–1062} } @article{shik_kaspari_yanoviak_2011, title={Preliminary assessment of metabolic costs of the nematode myrmeconema neotropicum on its host, the tropical ant cephalotes atratus}, volume={97}, number={5}, journal={Journal of Parasitology}, author={Shik, J. Z. and Kaspari, M. and Yanoviak, S. P.}, year={2011}, pages={958–959} }