Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

Ant Larvae as Players in Social Conflict: Relatedness and Individual Identity Mediate Cannibalism Intensity

Eva Schultner, Andy Gardner, Markku Karhunen and Heikki Helanterä
The American Naturalist
Vol. 184, No. 6 (December 2014), pp. E161-E174
DOI: 10.1086/678459
Stable URL: http://www.jstor.org/stable/10.1086/678459
Page Count: 14
Subjects: Ecology & Evolutionary Biology Biological Sciences
Find more content in these subjects: Ecology & Evolutionary Biology Biological Sciences
  • Download PDF
  • Add to My Lists
  • Cite this Item
We're having trouble loading this content. Download PDF instead.

Abstract

AbstractConflict arises among social organisms when individuals differ in their inclusive-fitness interests. Ant societies are excellent models for understanding how genetic relatedness mediates conflict intensity. However, although conflicts within colonies typically arise over offspring production, the role of larvae as actors in social conflict has received little attention. We develop and empirically test kin-selection theory of larval egg cannibalism in ant societies. Specifically, we investigate how selection for cannibalism is mediated by nestmate relatedness and larval sex in a mathematical model and then test the model’s predictions by measuring cannibalism levels in eight ant species with varying nestmate relatedness. In line with our theoretical predictions, cannibalism levels in larvae were significantly influenced by relatedness and sex. Increased relatedness was associated with reduced levels of cannibalism, indicating that larval behavior is mediated by inclusive-fitness considerations. Levels of cannibalism were significantly higher in male larvae, and our model suggests that this is due to sex differences in the benefits of cannibalism. By examining the selfish interests of larvae and the constraints they face in a social environment, our study presents a novel perspective on conflict in ants and on the evolution of selfish elements in social systems in general.

Notes and References

This item contains 142 references.

Literature Cited
  • ['Abell, A., B. Cole, R. Reyes, and D. C. Wiernasz. 1999. Sexual selection on body size and shape in the western harvester ant, Pogonomyrmex occidentalis Cresson. Evolution 53:535–545.']
  • ['Abouheif, E. 1999. A method for testing the assumption of phylogenetic independence in comparative data. Evolutionary Ecology Research 1:895–909.']
  • ['Akaike, H. 1974. A new look at the statistical model identification. IEEE Transactions on Automatic Control 19:716–723.']
  • ['Alexander, R. 1974. The evolution of social behavior. Annual Review of Ecology and Systematics 5:325–383.']
  • ['Amor, F., P. Ortega, M. J. Jowers, X. Cerdá, J. Billen, A. Lenoir, and R. R. Boulay. 2011. The evolution of worker-queen polymorphism in Cataglyphis ants: interplay between individual- and colony-level selections. Behavioral Ecology and Sociobiology 65:1473–1482.']
  • ['Baroni Urbani, C. 1991. Indiscriminate oophagy by ant larvae: an explanation for brood serial organization? Insectes Sociaux 38:229–239.']
  • ['Bates, D., M. Maechler, and B. M. Bolker. 2012. lme4: linear mixed-effects models using S4 classes. R package version 0.999999-0. http://cran.r-project.org/package=lme4.']
  • ['Baur, B. 1988. Egg-species recognition in cannibalistic hatchlings of the land snails Arianta arbustorum and Helix pomatia. Cellular and Molecular Life Sciences 44:276–277.']
  • ['Beekman, M., J. Komdeur, and F. L. W. Ratnieks. 2003. Reproductive conflicts in social animals: who has power? Trends in Ecology and Evolution 18:277–282.']
  • ['Beekman, M., and F. L. W. Ratnieks. 2003. Power over reproduction in social Hymenoptera. Philosophical Transactions of the Royal Society B: Biological Sciences 358:1741–1753.']
  • ['Bernasconi, G., and L. Keller. 1998. Phenotype and individual investment in cooperative foundress associations of the fire ant, Solenopsis invicta. Behavioral Ecology 9:478–485.']
  • ['Bhatkar, A., and W. Whitcomb. 1970. Artificial diet for rearing various species of ants. Florida Entomologist 53:229–232.']
  • ['Bier, K. 1952. Beziehungen zwischen Nährzellkerngröße und Ausbildung ribonukleinsäurehaltiger Strukturen in den Oocyten von Formica rufa rufo-pratensis minor Gößwald. Verhandlungen der Deutschen Zoologischen Gesellschaft Freiburg 40:369–374.']
  • ['———. 1954a. Über Phasen gesteigerter Protein- und Kohlehydrateinlagerung und die Fettverteilung im Hymenopterenovar. Zoologischer Anzeiger Supplement 18:422–429.']
  • ['———. 1954b. Über den Saisondimorphismus der Oogenese von Formica rufa rufo-pratensis minor Gössw. und dessen Bedeutung für die Kastendetermination. Biologisches Zentralblatt 73:170–190.']
  • ['Bilde, T., and Y. Lubin. 2001. Kin recognition and cannibalism in a subsocial spider. Journal of Evolutionary Biology 14:959–966.']
  • ['Bolton, B. 1995. A new general catalogue of the ants of the world. Harvard University Press, Cambridge, MA.']
  • ['Boomsma, J. J., and J. Isaaks. 1985. Energy investment and respiration in queens and males of Lasius niger (Hymenoptera: Formicidae). Behavioral Ecology and Sociobiology 18:19–27.']
  • ['Boot, W. J., J. N. M. Calis, and M. Allsopp. 2006. Differential feeding of larvae affects caste differentiation in Apis mellifera. Proceedings of the Netherlands Entomological Society Meeting 17:63–69.']
  • ['Bourke, A. F. G. 2011a. Principles of social evolution. Oxford University Press, Oxford.']
  • ['———. 2011b. The validity and value of inclusive fitness theory. Proceedings of the Royal Society B: Biological Sciences 278:3313–3320.']
  • ['Bourke, A. F. G., and N. R. Franks. 1995. Social evolution in ants. Princeton University Press, Princeton, NJ.']
  • ['Bourke, A. F. G., and F. L. W. Ratnieks. 1999. Kin conflict over caste determination in social Hymenoptera. Behavioral Ecology and Sociobiology 46:287–297.']
  • ['Brian, M. 1973. Feeding and growth in the ant Myrmica. Journal of Animal Ecology 42:37–53.']
  • ['Briskie, J. V., C. T. Naugler, and S. M. Leech. 1994. Begging intensity of nestling birds varies with sibling relatedness. Proceedings of the Royal Society B: Biological Sciences 258:73–78.']
  • ['Bulmer, M. 1994. Theoretical evolutionary ecology. Sinauer, Sunderland, MA.']
  • ['Carlin, N. 1988. Species, kin and other forms of recognition in the brood discrimination behavior of ants. Pages 267–295 in J. Trager, ed. Advances in myrmecology. Brill, New York.']
  • ['Cassill, D., J. Butler, S. Vinson, and D. E. Wheeler. 2005. Cooperation during prey digestion between workers and larvae in the ant, Pheidole spadonia. Insectes Sociaux 52:339–343.']
  • ['Chapuisat, M. 1996. Characterization of microsatellite loci in Formica lugubris B and their variability in other ant species. Molecular Ecology 5:599–601.']
  • ['Cotton, P. A., J. Wright, and A. Kacelnik. 1999. Chick begging strategies in relation to brood hierarchies and hatching asynchrony. American Naturalist 153:412–420.']
  • ['Craig, R. 1980. Sex investment ratios in social Hymenoptera. American Naturalist 116:311–323.']
  • ['Creemers, B., J. Billen, and B. Gobin. 2003. Larval begging behaviour in the ant Myrmica rubra. Ethology Ecology and Evolution 15:261–272.']
  • ['Crossland, M. R., M. N. Hearnden, L. Pizzatto, R. A. Alford, and R. Shine. 2011. Why be a cannibal? the benefits to cane toad, Rhinella marina [=Bufo marinus], tadpoles of consuming conspecific eggs. Animal Behaviour 82:775–782.']
  • ['Davidson, D. 1982. Sexual selection in harvester ants (Hymenoptera: Formicidae: Pogonomyrmex). Behavioral Ecology and Sociobiology 10:245–250.']
  • ['Dlussky, G. 1967. The ants of genus Formica (Hymenoptera, Formicidae, g. Formica). Akademiya Nauk, Moscow. [In Russian.]']
  • ['Dobata, S. 2012. Arms race between selfishness and policing: two-trait quantitative genetic model for caste fate conflict in eusocial Hymenoptera. Evolution 66:3754–3764.']
  • ['Dobler, R., and M. Kölliker. 2009. Kin-selected siblicide and cannibalism in the European earwig. Behavioral Ecology 21:257–263.']
  • ['Dussutour, A., and S. Simpson. 2009. Communal nutrition in ants. Current Biology 19:740–744.']
  • ['Elgar, M., and B. Crespi, eds. 1992. Cannibalism: ecology and evolution among diverse taxa. Oxford University Press, New York.']
  • ['Fisher, R. 1930. The genetical theory of natural selection. Clarendon, Oxford.']
  • ['Fjerdingstad, E. J., and L. Keller. 2004. Relationships between phenotype, mating behavior, and fitness of queens in the ant Lasius niger. Evolution 58:1056–1063.']
  • ['Forbes, S. 2011. Social rank governs the effective environment of siblings. Biology Letters 7:346–348.']
  • ['Frank, S. A. 1997. The price equation, Fisher’s fundamental theorem, kin selection, and causal analysis. Evolution 51:1712–1729.']
  • ['———. 1998. Foundations of social evolution. Princeton University Press, Princeton, NJ.']
  • ['Franks, N. R., and A. B. Sendova-Franks. 1992. Brood sorting by ants: distributing the workload over the work-surface. Behavioral Ecology and Sociobiology 30:109–123.']
  • ['Gardner, A., S. A. West, and G. Wild. 2011. The genetical theory of kin selection. Journal of Evolutionary Biology 24:1020–1043.']
  • ['Gilmore, R. G., O. Putz, and J. Dodrill. 2005. Oophagy, intrauterine cannibalism and reproductive strategy in lamnoid sharks. Pages 435–462 in W. C. Hamlett, ed. Reproductive biology and phylogeny of Chondrichthyes: sharks, batoids and chimaeras. Science, Enfield, NH.']
  • ['Giron, D., D. Dunn, I. Hardy, and M. R. Strand. 2004. Aggression by polyembryonic wasp soldiers correlates with kinship but not resource competition. Nature 430:676–679.']
  • ['Godfray, H. C. J. 1995. Signaling of need between parents and young: parent-offspring conflict and sibling rivalry. American Naturalist 146:1–24.']
  • ['Godfray, H. C. J., and R. A. Johnstone. 2000. Begging and bleating: the evolution of parent-offspring signalling. Philosophical Transactions of the Royal Society B: Biological Sciences 355:1581–1591.']
  • ['Goropashnaya, A. V., V. B. Fedorov, B. Seifert, and P. Pamilo. 2012. Phylogenetic relationships of Palaearctic Formica species (Hymenoptera, Formicidae) based on mitochondrial cytochrome b sequences. PLoS ONE 7:e41697.']
  • ['Gösswald, K. 1951. Über den Lebenslauf von Kolonien der roten Waldameise. Zoologische Jahrbücher Abteilung für Systematik Ökologie und Geographie der Tiere 80:27–63.']
  • ['———. 1989. Die Waldameise. AULA, Wiesbaden.']
  • ['Gösswald, K., and K. Bier. 1953. Untersuchungen zur Kastendeterminaton in der Gattung Formica. 2. Die Aufzucht von Geschlechtstieren bei Formica rufa pratensis (Retz.). Zoologischer Anzeiger 151:126–134.']
  • ['———. 1954. Untersuchungen zur Kastendetermination in der Gattung Formica. 3. Die Kastendetermination von Formica rufa rufo-pratensis minor Gößw. Insectes Sociaux 1:229–246.']
  • ['Götmark, F., and M. Ahlström. 1997. Parental preference for red mouth of chicks in a songbird. Proceedings of the Royal Society B: Biological Sciences 264:959–962.']
  • ['Gyllenstrand, N., P. Gertsch, and P. Pamilo. 2002. Polymorphic microsatellite DNA markers in the ant Formica exsecta. Molecular Ecology Notes 2:67–69.']
  • ['Hamilton, W. D. 1964. The genetical evolution of social behaviour. I, II. Journal of Theoretical Biology 7:1–16, 17–52.']
  • ['Hammond, R. L., M. W. Bruford, and A. F. G. Bourke. 2002. Ant workers selfishly bias sex ratios by manipulating female development. Proceedings of the Royal Society B: Biological Sciences 269:173–178.']
  • ['Harper, A. 1986. The evolution of begging: sibling competition and parent-offspring conflict. American Naturalist 128:99–114.']
  • ['Hasegawa, E., and S. Imai. 2004. Characterization of microsatellite loci in red wood ants Formica (s. str.) spp. and the related genus Polyergus. Molecular Ecology Notes 4:200–203.']
  • ['Heinze, J., S. Foitzik, and B. Oberstadt. 1999. A female caste specialized for the production of unfertilized eggs in the ant Crematogaster smithi. Naturwissenschaften 95:93–95.']
  • ['Helanterä, H., and F. L. W. Ratnieks. 2009. Sex allocation conflict in insect societies: who wins? Biology Letters 5:700–704.']
  • ['Helanterä, H., J. E. Strassmann, J. Carrillo, and D. Queller. 2009. Unicolonial ants: where do they come from, what are they and where are they going? Trends in Ecology & Evolution 24:341–349.']
  • ['Helanterä, H., and L. Sundström. 2007. Worker reproduction in Formica ants. American Naturalist 170:E14–E25.']
  • ['Hölldobler, B., and S. Bartz. 1985. Sociobiology of reproduction in ants. Pages 237–257 in B. Hölldobler and M. Lindauer, eds. Experimental behavioral ecology and sociobiology. Sinauer, Sunderland, MA.']
  • ['Hunt, J. H. 1984. Adult nourishment during larval provisioning in a primitively eusocial wasp, Polistes metricus Say. Insectes Sociaux 31:452–460.']
  • ['Hunt, J. H., I. Baker, and H. Baker. 1982. Similarity of amino acids in nectar and larval saliva: the nutritional basis of trophallaxis in social wasps. Evolution 36:1318–1322.']
  • ['Hunt, J. H., and M. Dove. 2002. Nourishment affects colony demographics in the paper wasp Polistes metricus. Ecological Entomology 27:467–474.']
  • ['Iida, H. 2003. Small within-clutch variance in spiderling body size as a mechanism for avoiding sibling cannibalism in the wolf spider Pardosa pseudoannulata (Araneae: Lycosidae). Population Ecology 45:1–6.']
  • ['Jombart, T., S. Devillard, and F. Balloux. 2010. Discriminant analysis of principal components: a new method for the analysis of genetically structured populations. BMC Genetics 11:94.']
  • ['Kaptein, N., J. Billen, and B. Gobin. 2005. Larval begging for food enhances reproductive options in the ponerine ant Gnamptogenys striatula. Animal Behaviour 69:293–299.']
  • ['Kilner, R. M. 1997. Mouth colour is a reliable signal of need in begging canary nestlings. Proceedings of the Royal Society B: Biological Sciences 264:963–968.']
  • ['Kilner, R. M., and R. A. Johnstone. 1997. Begging the question: are offspring solicitation behaviours signals of need? Trends in Ecology and Evolution 12:11–15.']
  • ['Le Conte, Y., L. Sreng, and S. Poitout. 1995. Brood pheromone can modulate the feeding behavior of Apis mellifera workers (Hymenoptera: Apidae). Journal of Economic Entomology 88:798–804.']
  • ['Le Masne, G. 1953. Observations sur les relations entre le couvain et les adultes chez les fourmis. Annales des Sciences Naturelles Zoologiques 15:1–56.']
  • ['Linksvayer, T. A., O. Kaftanoglu, E. Akyol, S. Blatch, G. V. Amdam, and R. E. Page Jr. 2011. Larval and nurse worker control of developmental plasticity and the evolution of honey bee queen-worker dimorphism. Journal of Evolutionary Biology 24:1939–1948.']
  • ['Michaud, J., and A. Grant. 2004. Adaptive significance of sibling egg cannibalism in Coccinellidae: comparative evidence from three species. Annals of the Entomological Society of America 97:710–719.']
  • ['Miller D., III, and F. L. W. Ratnieks. 2001. The timing of worker reproduction and breakdown of policing behaviour in queenless honey bee (Apis mellifera L.) societies. Insectes Sociaux 48:178–184.']
  • ['Mock, D., H. Drummond, and C. Stinson. 1990. Avian siblicide. American Scientist 78:438–449.']
  • ['Mock, D., and G. Parker. 1997. The evolution of sibling rivalry. Oxford University Press, New York.']
  • ['———. 1998. Siblicide, family conflict and the evolutionary limits of selfishness. Animal Behaviour 56:1–10.']
  • ['Nonacs, P. 1993. Male parentage and sexual deception in the social Hymenoptera. Pages 384–401 in D. Wrensch and M. Ebbert, eds. Evolution and diversity of sex ratio in insects and mites. Chapman & Hall, New York, NY.']
  • ['Ohba, S., K. Hidaka, and M. Sasaki. 2006. Notes on paternal care and sibling cannibalism in the giant water bug, Lethocerus deyrolli (Heteroptera: Belostomatidae). Entomological Science 9:1–5.']
  • ['Osawa, N. 1992. Sibling cannibalism in the ladybird beetle Harmonia axyridis: fitness consequences for mother and offspring. Researches on Population Ecology 34:45–55.']
  • ['———. 2002. Sex-dependent effects of sibling cannibalism on life history traits of the ladybird beetle Harmonia axyridis (Coleoptera: Coccinellidae). Biological Journal of the Linnean Society 76:349–360.']
  • ['Pamilo, P. 2008. Multiple mating in Formica ants. Hereditas 97:37–45.']
  • ['Pamilo, P., and R. Rosengren. 1983. Sex ratio strategies in Formica ants. Oikos 40:24–35.']
  • ['Pamilo, P., and P. Seppä. 1994. Reproductive competition and conflicts in colonies of the ant Formica sanguinea. Animal Behaviour 48:1201–1206.']
  • ['Pamilo, P., D. Zhu, W. Fortelius, R. Rosengren, P. Seppä, and L. Sundström. 2005. Genetic patchwork of network-building wood ant populations. Annales Zoologici Fennici 42:179–187.']
  • ['Petralia, R., A. Sorensen, and S. Vinson. 1980. The labial gland system of larvae of the imported fire ant, Solenopsis invicta Buren. Cell and Tissue Research 156:145–156.']
  • ['Pfennig, D. W. 1997. Kinship and cannibalism. BioScience 47:667–675.']
  • ['Pfennig, D. W., H. K. Reeve, and P. W. Sherman. 1993. Kin recognition and cannibalism in spadefoot toad tadpoles. Animal Behaviour 46:87–94.']
  • ['Polis, G. 1981. The evolution and dynamics of intraspecific predation. Annual Review of Ecology and Systematics 12:225–251.']
  • ['Price, G. 1970. Selection and covariance. Nature 227:520–521.']
  • ['Price, G., and C. Smith. 1972. Fisher’s Malthusian parameter and reproductive value. Annals of Human Genetics 36:1–7.']
  • ['Queller, D. 1994. Male-female conflict and parent-offspring conflict. American Naturalist 144:S84–S99.']
  • ['Queller, D., and K. Goodnight. 1989. Estimating relatedness using genetic markers. Evolution 43:258–275.']
  • ['Ratnieks, F. L. W. 2001. Heirs and spares: caste conflict and excess queen production in Melipona bees. Behavioral Ecology and Sociobiology 50:467–473.']
  • ['Ratnieks, F. L. W., K. R. Foster, and T. Wenseleers. 2006. Conflict resolution in insect societies. Annual Review of Entomology 51:581–608.']
  • ['Ratnieks, F. L. W., T. Monnin, and K. R. Foster. 2001. Inclusive fitness theory: novel predictions and tests in eusocial Hymenoptera. Annales Zoologici Fennici 38:201–214.']
  • ['Ratnieks, F. L. W., and T. Wenseleers. 2005. Policing insect societies. Science 307:54–56.']
  • ['Ribeiro, M. de F., H. H. W. Velthuis, M. J. Duchateau, and I. van der Tweel. 1999. Feeding frequency and caste differentiation in Bombus terrestris larvae. Insectes Sociaux 46:306–314.']
  • ['Ribeiro, M. de F., T. Wenseleers, P. de S. Santos, and D. de A. Alves. 2006. Miniature queens in stingless bees: basic facts and evolutionary hypotheses. Apidologie 37:191–206.']
  • ['Rosengren, R., L. Sundström, and W. Fortelius. 1993. Monogyny and polygyny in Formica ants: the result of alternative dispersal tactics. Pages 308–333 in L. Keller, ed. Queen number and sociality in insects. Oxford University Press, Oxford.']
  • ['Rosset, H., and M. Chapuisat. 2006. Sex allocation conflict in ants: when the queen rules. Current Biology 16:328–331.']
  • ['Rousset, F. 2004. Genetic structure and selection in subdivided populations. Princeton University Press, Princeton, NJ.']
  • ['Roy, H. E., H. Rudge, L. Goldrick, and D. Hawkins. 2007. Eat or be eaten: prevalence and impact of egg cannibalism on two-spot ladybirds, Adalia bipunctata. Entomologia Experimentalis et Applicata 125:33–38.']
  • ['Rüger, M. H., J. Fröba, and S. Foitzik. 2007. Larval cannibalism and worker-induced separation of larvae in Hypoponera ants: a case of conflict over caste determination? Insectes Sociaux 55:12–21.']
  • ['Rüppell, O., and J. Heinze. 1999. Alternative reproductive tactics in females: the case of size polymorphism in winged ant queens. Insectes Sociaux 46:6–17.']
  • ['Schultner, E., P. d’Ettorre, and H. Helanterä. 2013. Social conflict in ant larvae: egg cannibalism occurs mainly in males and larvae prefer alien eggs. Behavioral Ecology 24:1306–1311.']
  • ['Schultner, E., A. Gardner, M. Karhunen, and H. Helanterä. 2014. Data from: Ant larvae as players in social conflict: relatedness and individual identity mediate cannibalism intensity. American Naturalist, Dryad Digital Repository, http://doi.org/10.5061/dryad.7k5p1.']
  • ['Schwarz, G. 1978. Estimating the dimension of a model. Annals of Statistics 6:461–464.']
  • ['Seifert, B. 2000. A taxonomic revision of the ant subgenus Coptoformica Mueller, 1923 (Hymenoptera, Formicidae). Zoosystema 22:517–568.']
  • ['Sendova-Franks, A. B., S. R. Scholes, N. R. Franks, and C. Melhuish. 2004. Brood sorting by ants: two phases and differential diffusion. Animal Behaviour 68:1095–1106.']
  • ['Seppä, P., H. Helanterä, A. Chernenko, K. Trontti, P. Punttila, and L. Sundström. 2009. Population genetics of the black ant Formica lemani (Hymenoptera: Formicidae). Biological Journal of the Linnean Society 97:247–258.']
  • ['Smiseth, P. T., and A. J. Moore. 2007. Signalling of hunger by senior and junior larvae in asynchronous broods of a burying beetle. Animal Behaviour 74:699–705.']
  • ['Sorensen, A., T. Busch, and S. Vinson. 1983. Factors affecting brood cannibalism in laboratory colonies of the imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae). Journal of the Kansas Entomological Society 56:140–150.']
  • ['Sundström, L. 1995. Sex allocation and colony maintenance in monogyne and polygyne colonies of Formica truncorum (Hymenoptera: Formicidae): the impact of kinship and mating structure. American Naturalist 146:182–201.']
  • ['Sundström, L., M. Chapuisat, and L. Keller. 1996. Conditional manipulation of sex ratios by ant workers: a test of kin selection theory. Science 274:993–994.']
  • ['Sundström, L., P. Seppä, and P. Pamilo. 2005. Genetic population structure and dispersal patterns in Formica ants—a review. Annales Zoologici Fennici 42:163–177.']
  • ['Taylor, P. D. 1990. Allele-frequency change in a class-structured population. American Naturalist 135:95–106.']
  • ['———. 1996. Inclusive fitness arguments in genetic models of behaviour. Journal of Mathematical Biology 34:654–674.']
  • ['Taylor, P. D., and S. A. Frank. 1996. How to make a kin selection model. Journal of Theoretical Biology 180:27–37.']
  • ['Taylor, P. D., G. Wild, and A. Gardner. 2007. Direct fitness or inclusive fitness: how shall we model kin selection? Journal of Evolutionary Biology 20:301–309.']
  • ['Trivers, R. L. 1974. Parent-offspring conflict. American Zoologist 14:249–264.']
  • ['Trivers, R. L., and H. Hare. 1976. Haplodiploidy and the evolution of the social insects. Science 191:249–263.']
  • ['Vijendravarma, R., S. Narasimha, and T. Kawecki. 2013. Predatory cannibalism in Drosophila melanogaster larvae. Nature Communications 4:1789.']
  • ['Wagner, D., and D. M. Gordon. 1999. Colony age, neighborhood density and reproductive potential in harvester ants. Oecologia (Berlin) 119:175–182.']
  • ['Wenseleers, T., A. G. Hart, F. L. W. Ratnieks, and J. Quezada-Euán. 2004a. Queen execution and caste conflict in the stingless bee Melipona beecheii. Ethology 110:725–736.']
  • ['Wenseleers, T., H. Helanterä, A. G. Hart, and F. L. W. Ratnieks. 2004b. Worker reproduction and policing in insect societies: an ESS analysis. Journal of Evolutionary Biology 17:1035–1047.']
  • ['Wenseleers, T., and F. L. W. Ratnieks. 2004. Tragedy of the commons in Melipona bees. Proceedings of the Royal Society B: Biological Sciences 271:S310–S312.']
  • ['———. 2006a. Comparative analysis of worker reproduction and policing in eusocial Hymenoptera supports relatedness theory. American Naturalist 168:E163–E179.']
  • ['———. 2006b. Enforced altruism in insect societies. Nature 444:6–9.']
  • ['Wenseleers, T., F. L. W. Ratnieks, and J. Billen. 2003. Caste fate conflict in swarm-founding social Hymenoptera: an inclusive fitness analysis. Journal of Evolutionary Biology 16:647–658.']
  • ['Wheeler, D. E. 1986. Developmental and physiological determinants of caste in social Hymenoptera: evolutionary implications. American Naturalist 128:13–34.']
  • ['Wheeler, W. 1918. A study of some ant larvae, with a consideration of the origin and meaning of the social habit among insects. Proceedings of the American Philosophical Society 57:293–343.']
  • ['Wiernasz, D. C., and B. Cole. 2003. Queen size mediates queen survival and colony fitness in harvester ants. Evolution 57:2179–2183.']
  • ['Wiernasz, D. C., A. Sater, A. Abell, and B. Cole. 2001. Male size, sperm transfer, and colony fitness in the western harvester ant, Pogonomyrmex occidentalis. Evolution 55:324–329.']
  • ['Wiernasz, D. C., J. Yencharis, and B. J. Cole. 1995. Size and mating success in males of the western harvester ant, Pogonomyrmex occidentalis (Hymenoptera: Formicidae). Journal of Insect Behavior 8:523–531.']
  • ['Wilson, E. O. 1971. The insect societies. Harvard University Press, Cambridge, MA.']
  • ['Wise, D. H. 2006. Cannibalism, food limitation, intraspecific competition, and the regulation of spider populations. Annual Review of Entomology 51:441–465.']

Supplements