Philip S. Ward

Research interests

In many terrestrial habitats - especially those of the lowland tropics - ants rival other arthropods in numerical abundance, ecological importance and species richness. My research is concerned with unraveling details about the evolutionary history of ants and attempting to understand the processes that have generated such an extraordinary diversity of form and function. This work entails both species-level taxonomy and analyses of phylogenetic relationships. Components of this research include:

1. determining the limits of intra- and interspecific variation,
2. providing pragmatic tools for the identification of species,
3. inferring phylogenetic relationships among recognized taxa, and
4. using the phylogeny as a framework for analyzing the evolution of biological features of interest.

A focal taxon for the last 20 years has been the ant subfamily Pseudomyrmecinae, a tropicopolitan group of mostly arboreal (twig-dwelling) ants that includes a significant minority of ant-plant mutualists (Ward, 1991). A recent phylogenetic study (Ward & Downie, 2005), drawing on both morphological and DNA sequence data, confirmed most relationships suggested earlier on the basis of morphology alone (Ward, 1989, 1990, 1993, 1999b, 2001), but also indicated the Paleotropical genus Tetraponera is paraphyletic (and source of the more diverse New World clade Pseudomyrmex). The sister group of Pseudomyrmecinae is the subfamily Myrmeciinae, which implicates a Cretaceous origin of stem-group pseudomyrmecines.

Other research includes faunistic and taxonomic studies on the myrmecofauna of California and Baja California (Johnson & Ward, 2002; Boulton & Ward, 2002; Ward, 2005a; see also images of California ants on AntWeb); investigations of relationships among myrmeciine and dorylomorph ants (Ward & Brady, 2003; Brady & Ward, 2005; Ward, 2005b);  and analyses of leaf litter ant communities (Ward, 2000b). A project completed about a decade ago involved the compilation of an exhaustive bibliography of ant systematics (Ward et al., 1996).

Publications

1. Ward, P. S., Hebert, P., Harmsen, R. 1973. A note on the distribution of Oeneis chryxus strigulosa (Lepidoptera: Satyridae). Canadian Entomologist 105:1373-1374.
2. Harmsen, R., Hebert, P., Ward, P. S. 1974. On the origin of austral elements in the moth fauna of south-eastern Ontario, including a number of species new for Canada. Journal of Research on Lepidoptera 12:127-134.
3. Ward, P. S., Harmsen, R., Hebert, P. 1974. An annotated checklist of the macroheterocera of south-eastern Ontario. Journal of Research on Lepidoptera 13:23-42.
4. Hebert, P., Ward, P. S., Harmsen, R. 1974. Diffuse competition in Lepidoptera. Nature 252:389-391.
5. Hebert, P., Ward, P. S., Harmsen, R. 1975. Competition and species abundance - Reply. Nature 257:160-161.
6. Ward, P. S. 1976. Probing ponerine ants. Australian Natural History l8:384-387.
7. Ward, P. S. 1980. A systematic revision of the Rhytidoponera impressa group (Hymenoptera: Formicidae) in Australia and New Guinea. Australian Journal of Zoology 28:475-498. [Pdf file]
8. Ward, P. S. 1980. Genetic variation and population differentiation in the Rhytidoponera impressa group, a species complex of ponerine ants (Hymenoptera: Formicidae). Evolution 34:1060-1076. [Pdf file]
9. Ward, P. S., Taylor, R. W. 1981. Allozyme variation, colony structure, and genetic relatedness in the primitive ant Nothomyrmecia macrops Clark (Hymenoptera: Formicidae). Journal of the Australian Entomological Society 20:177-183.
10. Ward, P. S. 1981. Ecology and life history of the Rhytidoponera impressa group (Hymenoptera: Formicidae). I. Habitats, nest sites, and foraging behavior. Psyche 88:89-108. [Pdf file]
11. Ward, P. S. 1981. Ecology and life history of the Rhytidoponera impressa group (Hymenoptera: Formicidae). II. Colony origin, seasonal cycles, and reproduction. Psyche 88:109-126. [Pdf file]
12. Ward, P. S., Boussy, I. A., Swincer, D. E. 1982. Electrophoretic detection of enzyme polymorphism and differentiation in three species of spider mites (Tetranychus) (Acari: Tetranychidae). Annals of the Entomological Society of America 75:595-598.
13. Ward, P. S. 1983. Genetic relatedness and colony organization in a species complex of ponerine ants. I. Genotypic and phenotypic composition of colonies. Behavioral Ecology and Sociobiology 12:285-299.
14. Ward, P. S. 1983. Genetic relatedness and colony organization in a species complex of ponerine ants. II. Patterns of sex ratio investment. Behavioral Ecology and Sociobiology 12:301-307.
15. Ward, P. S. 1984. A revision of the ant genus Rhytidoponera (Hymenoptera: Formicidae) in New Caledonia. Australian Journal of Zoology 32:131-175. [Pdf file]
16. Ward, P. S. 1985. The Nearctic species of the genus Pseudomyrmex (Hymenoptera: Formicidae). Quaestiones Entomologicae 21:209-246. [Pdf file]
17. Ward, P. S. 1985. Taxonomic congruence and disparity in an insular ant fauna: Rhytidoponera in New Caledonia. Systematic Zoology 34:140-151. [Pdf file]
18. Tibayrenc, M., P. Ward, A. Moya and F. Ayala. 1986. Natural populations of Trypanosoma cruzi, the agent of Chagas' disease, have a complex multiclonal structure. Proceedings of the National Academy of Sciences U. S. A. 83:115-119.
19. Ward, P. S. 1986. Functional queens in the Australian greenhead ant, Rhytidoponera metallica (Hymenoptera: Formicidae). Psyche 93:1-12. [Pdf file]
20. Ward, P. S. 1987. Distribution of the introduced Argentine ant (Iridomyrmex humilis) in natural habitats of the lower Sacramento Valley, and its effects on the indigenous ant fauna. Hilgardia 55(2):1-16. [Pdf file]
21. Ward, P. S. 1988. Mesic elements in the western Nearctic ant fauna: taxonomic and biological notes on Amblyopone, Proceratium, and Smithistruma (Hymenoptera: Formicidae). Journal of the Kansas Entomological Society 61:102-124. [Pdf file]
22. Ward, P. S. 1989. Genetic and social changes associated with ant speciation. In Breed, M. D. & R. E. Page (Eds.). The genetics of social evolution. Boulder, Colorado: Westview Press, pp. 123-148.
23. Ward, P.S. 1989. Systematic studies on pseudomyrmecine ants: revision of the Pseudomyrmex oculatus and P. subtilissimus species groups, with taxonomic comments on other species. Quaestiones Entomologicae 25:393-468. [Pdf file]
24. Ward, P.S. 1990. The ant subfamily Pseudomyrmecinae (Hymenoptera: Formicidae): generic revision and relationship to other formicids. Systematic Entomology 15:449-489. [Pdf file]
25. Ward, P.S. 1991. Phylogenetic analysis of pseudomyrmecine ants associated with domatia-bearing plants. In Cutler, D.F. & C.R. Huxley (Eds.) Ant/plant interactions. Oxford: Oxford Univ. Press, pp. 335-352.
26. Frumhoff, P.C., Ward, P.S. 1992. Individual-level selection, colony-level selection, and the association between polygyny and worker monomorphism in ants. American Naturalist 139:559-590.
27. Baroni Urbani, C., Bolton, B., Ward, P.S. 1992. The internal phylogeny of ants (Hymenoptera: Formicidae). Systematic Entomology 17:301-329.
28. Ward, P.S. 1992. Ants of the genus Pseudomyrmex (Hymenoptera: Formicidae) from Dominican amber, with a synopsis of the extant Antillean species. Psyche 99:55-85. [Pdf file]
29. Gullan, P. J., Buckley, R. C., Ward, P. S. 1993. Ant-tended scale insects (Hemiptera: Coccidae: Myzolecanium) within lowland rainforest trees in Papua New Guinea. Journal of Tropical Ecology 9:81-91. [Pdf file]
30. Ward, P. S. 1993. Systematic studies on Pseudomyrmex acacia-ants (Hymenoptera: Formicidae: Pseudomyrmecinae). Journal of Hymenoptera Research 2:117-168. [Pdf file]
31. Ward, P. S. 1994. Adetomyrma, an enigmatic new ant genus from Madagascar (Hymenoptera: Formicidae), and its implications for ant phylogeny. Systematic Entomology 19:159-175.
32. Rejmánek, M., Ward, P. S., Webster, G. L., Randall, J. M. 1994. Systematics and biodiversity. [Correspondence.] Trends in Ecology and Evolution 9:228-229.
33. Olson, D. M., Ward, P. S. 1996. The ant fauna (Hymenoptera: Formicidae) of Kirindy Forest (tropical dry forest) in western Madagascar. Pp. 161-164 in Ganzhorn, J. U., Sorg, J.-P. (eds.). Ecology and economy of a tropical dry forest in Madagascar. Primate Report 46-1. Göttingen: German Primate Center (DPZ), 382 pp.
34. Ward, P. S., Bolton, B. B., Shattuck, S. O., Brown, W. L., Jr. 1996. A bibliography of ant systematics. University of California Publications in Entomology 116:1-417.
35. Ward, P. S. 1996. A new workerless social parasite in the ant genus Pseudomyrmex (Hymenoptera: Formicidae), with a discussion of the origin of social parasitism in ants. Systematic Entomology 21:253-263. [Pdf file]
36. Ward, P. S. 1997. Ant soldiers are not modified queens. Nature 385:494-495.
37. Ward, P. S. 1999a. Deceptive similarity in army ants of the genus Neivamyrmex (Hymenoptera: Formicidae): taxonomy, distribution and biology of N. californicus (Mayr) and N. nigrescens (Cresson). Journal of Hymenoptera Research 8:74-97.
38. Gadau, J., Brady, S. G., Ward, P. S. 1999. Systematics, distribution, and ecology of an endemic California Camponotus quercicola (Hymenoptera: Formicidae). Annals of the Entomological Society of America 92:514-522.
39. Ward, P. S. 1999b. Systematics, biogeography and host plant associations of the Pseudomyrmex viduus group (Hymenoptera: Formicidae), Triplaris- and Tachigali-inhabiting ants. Zoological Journal of the Linnean Society 126:451-540. [Pdf file]
40. Wetterer, J. K., Ward, P. S., Wetterer, A. L., Longino, J. T., Trager, J. C., Miller, S. E. 2000. Ants (Hymenoptera: Formicidae) of Santa Cruz Island, California. Bulletin. Southern California Academy of Sciences 99:25-31.
41. Ward, P. S. 2000a. On the identity of Pheidole vaslitii Pergande (Hymenoptera: Formicidae), a neglected ant from Baja California. Journal of Hymenoptera Research 9:85-98. [Pdf file]
42. Ward, P. S. 2000b. Broad-scale patterns of diversity in leaf litter ant communities. Pp. 99-121 in: Agosti, D., Majer, J. D., Alonso, L. E., Schultz, T. R. (eds.) Ants. Standard methods for measuring and monitoring biodiversity. Washington: Smithsonian Institution Press, xix + 280 pp.
43. Brady, S. G., Gadau, J., Ward, P. S. 2000. Systematics of the ant genus Camponotus (Hymenoptera: Formicidae): a preliminary analysis using data from the mitochondrial gene cytochrome oxidase I. Pp. 131-139 in: Austin, A. D., Dowton, M. (eds.) Hymenoptera. Evolution, biodiversity and biological control. Collingwood, Victoria: CSIRO Publishing, xi + 468 pp.
44. Ward, P. S. 2001. Taxonomy, phylogeny and biogeography of the ant genus Tetraponera (Hymenoptera: Formicidae) in the Oriental and Australian regions. Invertebrate Taxonomy 15:589-665. [Pdf file]
45. Gronlund, C. J., Deangelis, M. D., Pruett-Jones, S., Ward, P. S., Coyne, J. A. 2002. Mate grasping in Drosophila pegasa.  Behaviour 139:545-572.
46. Johnson, R. A., Ward, P. S. 2002.  Biogeography and endemism of ants (Hymenoptera: Formicidae) in Baja California, Mexico: a first overview.  Journal of Biogeography 29:1009-1026. [Pdf file]
47. Boulton, A. M., Ward, P. S. 2002.  Ants.  Pp. 112-128 in Case, T. J., Cody, M. L. & Ezcurra, E. (eds.) A new island biogeography of the Sea of Cortés.  Oxford: Oxford University Press, xvii + 669 pp
48. Ward, P. S., Boulton, A. M. 2002.  Checklist of the ants of the Gulf of California islands.  Pp. 545-553 in Case, T. J., Cody, M. L. & Ezcurra, E. (eds.) A new island biogeography of the Sea of Cortés.  Oxford: Oxford University Press, xvii + 669 pp.
49. Ward, P. S., Brady, S. G.  2003.  Phylogeny and biogeography of the ant subfamily Myrmeciinae (Hymenoptera: Formicidae).  Invertebrate Systematics 17:361-386. [Pdf file]
50. Ward, P. S.  2003.  Subfamilia Pseudomyrmecinae.  Pp. 331-333 in Fernández, F. (ed.) Introducción a las hormigas de la región Neotropical. Bogotá, Colombia: Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, xxvi + 398 pp. [Pdf file]
51. Kaspari, M., Ward, P. S., Yuan, M. 2004. Energy gradients and the geographic distribution of local ant diversity. Oecologia 140:407-413. [Pdf file]
52. Ward, P. S., Downie, D. A.  2005.  The ant subfamily Pseudomyrmecinae (Hymenoptera: Formicidae): phylogeny and evolution of big-eyed arboreal ants.  Systematic Entomology 30:310-335. [Pdf file]
53. Ward, P. S.  2005a.  A synoptic review of the ants of California (Hymenoptera: Formicidae).  Zootaxa 936:1-68. [Pdf file]

Abstracts, Reviews

• Ward, P. S. 1982. Colony structure and genetic relatedness in a species complex of ponerine ants. In Breed, M. D., Michener, C. D., Evans, H. E. (eds.) The biology of social insects; proceedings of the Ninth Congress IUSSI. Boulder: Westview Press, pp. 413-414 [Abstract].
• Ward, P. S. 1983. Sex-ratio interactions between queenright and queenless colonies in rainforest ants of the Rhytidoponera impressa group. In Proceedings 18th Intern. Ethol. Conference, Brisbane, Qld., p. 299 [Abstract].
• Ward, P. S. 1985. Review of: Wehner, R. et al. Foraging strategies in individually searching ants, Cataglyphis bicolor. Animal Behaviour 33:336-337.
• Ward, P. S. 1995. Ants on the run. [Review of Gotwald, W. H., Jr. 1995. Army ants. The biology of social predation. Ithaca, New York: Cornell University Press, xviii + 302 pp.] Science 270:319-320.
• Ward, P. S. 1998. Phylogeny and biogeography of host plant associations in Neotropical pseudomyrmecine ants (Hymenoptera: Formicidae). P. 499 in: Schwarz, M. P., Hogendoorn, K. (eds.) Social insects at the turn of the millenium. Proceedings of the XIII International Congress of IUSSI. Adelaide, Australia. 29 December 1998 – 3 January 1999. Adelaide: XIII Congress of IUSSI, 535 pp. [Abstract].
• Brady, S. G., Gadau, J., Ward, P. S. 1999. Is the ant genus Camponotus paraphyletic? Pp. 27-28 in: 4th International Hymenopterists Conference, 6-11th January 1999, Canberra, Australia. Program and abstracts. Glen Osmond, South Australia: 4th International Hymenopterists Conference, 96 pp. [Abstract].
• Ward, P. S.; Brady, S. G.  2002.  Phylogeny and biogeography of the ant genera Myrmecia and Nothomyrmecia (Hymenoptera: Formicidae) and related fossil taxa.  P. 156 in: XIV International Congress of IUSSI. The Golden Jubilee Proceedings. 27 July - 3 August 2002, Hokkaido University, Sapporo, Japan.  Sapporo: XIV International Congress of IUSSI, 233 pp. [Abstract.].

Limited Distribution

• Sugden, E. A., Ward, P. S., Shapiro, A. M., Teague, S. 1985. Invertebrates. Pp. 47-62 in: Weathers, W. W., Cole, R. (eds.) Flora and fauna of the Stebbins Cold Canyon Reserve, Solano County, California. Institute of Ecology Publication No. 29. University of California, Davis. vi + 84 pp.
• Ward, P. S. 1990. The endangered ants of Mauritius: doomed like the dodo? Notes from Underground No. 4 (Spring 1990):3-5.
• Ward, P. S. 1994. Les fourmis. P. 30 in: Goodman, S. N., Langrand, O. (eds.) Inventaire biologique Forêt de Zombitse. Recherches pour le Développement. Série Sciences Biologiques. No. Spécial. Antananarivo, Madagascar: Centre d'Information et de Documentation Scientifique et Technique, 106 pp.

Philip S. Ward Department of Entomology and Center for Population Biology University of California at Davis Davis, CA 95616, USA email: psward@ucdavis.edu

http://entomology.ucdavis.edu/faculty/ward/res_int.html last modified 20/vi/2005