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Department of Zoology



1976 – 1986            Assistant Curator of Insects, University Museum of Zoology, Cambridge

1986 – 2016            Lecturer, Senior Lecturer, Curator of Insects, Department of Zoology

1976 – present        Fellow of Clare College, Cambridge

1997 – 2015            Editor-in-Chief, Biological Reviews

2003 – 2015            Deputy Head of Department (Teaching), Department of Zoology

2016 – present        Director of Alumni Relations, Department of Zoology


I am interested in the behaviour and ecology of insects and in particular in how natural selection has moulded the behaviour of individual insects to their own specific ecology. My main current research interests are in the ecology of insects from oil palm plantations in South East Asia and in the evolution of social behaviour in digger wasps.

I am part of the Insect Ecology group, run by Dr Edgar Turner. We are carrying out a collaborative project with the oil palm industry, the BEFTA Project, which experimentally manipulates the understory habitat complexity within plantations to test its effect on a wide range of taxa and ecosystem processes. The aim of this work is to establish management practices that can be employed to enhance both biodiversity and important ecosystem functions, such as pest control, in tropical agricultural landscapes.

My initial research was on the biology of saltmarsh and marine insects, but in more recent years I have become fascinated by the origins of social behaviour in insects, in particular in aphids, paper wasps, hover wasps, and the solitary sphecid wasps.


Key publications: 
  • Field J., Savill C., & Foster W.A. (2023). Brood parasites that care: alternative nesting tactics in a subsocial wasp. The American Naturalist 202: 655-666
  • Uematsu K., Yang M-M, & Foster W.A. (2023) Eusocial evolution without a nest: kin structure of social aphids forming open colonies on bamboo. Behavioral Ecology and Sociobiology 77: 38
  • Hood A.S.C., Advento A.D., Stone J., Fayle T.M., Fairnie A.L.M., Waters H.S., Foster W.A., Snaddon J.L., Ps S., Caliman J-P., Naim M., & Turner E.C. (2020) Removing understory vegetation in oil palm agroforestry reduces ground-foraging ant abundance but not species richness. Basic & Applied Ecology 48: 26-36
  • Field, J.P., Accleton, C. & Foster, W.A. (2018). Crozier’s effect and the acceptance of intraspecific brood parasites. Current Biology 28: 1-6.
  • Luke, S.H., Dow, R.A., Butler, S., Chey, V.K., Aldridge, D.C., Foster, W.A., & Turner, E.C. (2017). The impacts of habitat disturbance on adult and larval dragonflies (Odonata) in rainforest streams in Sabah, Malaysian Borneo. Freshwater Biology 62: 491–506.
  • Fayle, T.M., Eggleton, P., Manica, A., Yusah, K.M. & Foster, W.A. (2015). Experimentally testing and assessing the predictive power of species assembly rules for tropical canopy ants. Ecology Letters 18: 254-62.
  • Foster, W.A., Snaddon, J.L., Turner, E.C., Fayle, T.M., Cockerill, T.D., Ellwood, M.D.F., Broad, G.R., Chung, A.Y.C., Eggleton, P., Chey, V.K. & Yusah, K.M. (2011). Establishing the evidence base for maintaining biodiversity and ecosystem function in the oil palm landscapes of South East Asia. Phil.Trans.R.Soc.Lond.B. 366: 3277 - 3291. 
  • Fayle T.M., Turner E.C., Snaddon J.L., Chey V.K., Chung A.Y., Eggleton P.E. & Foster W.A. (2010). Oil palm expansion into rain forest greatly reduces ant biodiversity in canopy, epiphytes and leaf litter. Basic and Applied Ecology. 11: 337-345. 
  • Ellwood, M.D.F., Manica, A. & Foster, W.A. (2009). Stochastic and deterministic processes jointly structure tropical arthropod communities. Ecology Letters 12: 277-284. 
  • Turner, E.C. & Foster, W.A. (2009). The impact of forest conversion to oil palm on arthropod abundance and biomass in Sabah, Malaysia. Journal of Tropical Ecology 25: 23 -30. 
  • Ellwood, M.D.F. & Foster, W.A. (2004). Doubling the estimate of invertebrate biomass in a rainforest canopy. Nature 429: 549-551. 
  • Sumner, S., Casiraghi, M., Foster W. & Field, J. (2002). High reproductive skew in tropical hover wasps. Proc.R.Soc.Lond.B. 269: 179-186. 
Other publications: 



  • Reiss-Woolever V.J. , Advento A.D., Aryawan A.A.K. , Caliman J.-P. , Foster W.A. , Naim M. , Pujianto , Purnomo D. ,  Snaddon J.L. , Soeprapto , Suhardi , Tariga R.S. , Wahyuningsih R. , Rambe T.D.S. , Sudharto Ps. , Widodo R.H. , Luke S.H.,4 and Turner E.C. (2023). Habitat heterogeneity supports day-flying Lepidoptera in oil palm plantations. Journal of Tropical Ecology 39: 1-12.
  • Stone J., Advento A.D., Pashkevich M.D., Aryawan A.A.K., Caliman J.P., Hood A.S.C., Foster W.A., Naim M., Pujianto, Purnomo D., Suhardi, Tarigan R.S., Rambe T.D.S., Widodo R.H., Luke S.H., Snaddon J.L.,Turner E.C. (2023). Maintaining understory vegetation in oil palm plantations supports higher assassin bug numbers. Ecological Solutions and Evidence 4: e12293
  • Harianja M.F., Luke S.H., Barclay H., Chey V.K. Aldridge D.C., Foster W.A. Turner E.C. (2023). Length–biomass equations to allow rapid assessment of semi-aquatic bug biomass in tropical streams. Entomologia experimentalis et applicata 171: 102-115
  • Pashkevich M.D., Spear D.M., Advento A.D., Caliman J.-P. , Foster W.A., Luke, S.H., Naim M., Sudharto Ps , Snaddon J.L., Turner E.C. (2022). Spiders in canopy and ground microhabitats are robust to changes in understory vegetation management practices in mature oil palm plantations (Riau, Indonesia). Basic and Applied Ecology 64: 120-133.
  • Hood A.S.C., Aryawan A.A.K., Advento A.D., Suberkah W.R., Ashton-Butt A.,  Sudharto Ps., Caliman J-P., Naim M., Foster W.A., Turner E.C.(2022). A whole-ecosystem method for experimentally suppressing ants on a small scale. Methods in Ecology and Evolution 13: 852-865
  • Foster, W.A. (2020). Desert Navigator: The Journey of an Ant. Nature 577: 162-3.
  • Amelia SC Hood, Andreas D Advento, Jake Stone, Tom M Fayle, Alice LM Fairnie, Helen S Waters, William A Foster, Jake L Snaddon, Sudharto Ps, Jean-Pierre Caliman, Mohammad Naim, Edgar C Turner (2020) Removing understory vegetation in oil palm agroforestry reduces ground-foraging ant abundance but not species richness. Basic and Applied Ecology 48: 25-36
  • Luke, S.H., Advento, A.D., Aryawan, A.A.K., Adhy, D.H., Ashton-Butt, A., Barclay, H., Dewi, J.P., Drewer, J., Dumbrell, A.J., Edi, Eycott, A.E., Harianja, M.F., Hinsch, J.K., Hood, A.S-C., Kurniawan, C., Kurz, D.J., Mann, D.J., Matthews Nicholass, K.J., Naim, M., Pashkevich, M.D., Prescott, G.W., Ps, S., Pujianto, Purnomo, D., Purwoko, R.R., Putra, S., Rambe, T.D.S., Soeprapto, Spear, D.M., Suhardi, Tan, D.J.X., Tao, H-H., Tarigan, R.S., Wahyuningsih, R., Waters, H.S., Widodo, R.H., Whendy, Woodham, C.R., Caliman, J-P., Slade, E.M., Snaddon, J.L., Foster, W.A., Turner, E.C. (2020). Managing oil palm plantations more sustainably: large-scale experiments within the Biodiversity and Ecosystem Function in Tropical Agriculture (BEFTA) Programme. Frontiers in Forests and Global Change 2: 75
  • Luke, S.H., Advento, A.D., Dow, R.A., Aryawan, A.A.K., Barclay, H., Eycott, A.E., Hinsch, J.K., Kurniawan, C., Naim, M., Mann, D.J., Pujianto, Purnomo, D., Rambe, T.D.S., Slade, E.M., Soeprapto, Ps, S., Suhardi, Tarigan, R.S., Wahyuningsih, R., Widodo, R.H., Caliman, J-P., Snaddon, J.L., Foster, W.A., Turner, E.C. (2020). Complexity within an oil palm monoculture: the effects of habitat variability and rainfall on adult dragonfly (Odonata) communities. Biotropica 52: 366–378. 
  • Eycott, A.E., Advento, A.D., Waters, H.S., Luke, S.H., Aryawan, A.A.K., Hood, A.S.C., Naim, M., Ps, S., Pujianto, Purnomo, D., Rambe, T.D.S., Soeprapto, Suhardi, Tarigan, R.S., Wahyuningish, R., Widodo, R.H., Caliman, J-P., Snaddon, J.L., Foster, W.A., Turner, E. C. (2019). Resilience of ecological functions to drought in an oil palm agroecosystem. Environmental Research Communications, 1: 101004
  • Hood, A.S.C., Aryawan, A.A.K., Advento, A.D., Purnomo, D., Wahyuningsih, R., Luke, S.H., Ps, S., Snaddon, J.L., Foster, W.A., Caliman, J-P., Turner, E.C., Naim, M. (2019). Understory Vegetation in Oil Palm Plantations Promotes Leopard Cat Activity, but Does Not Affect Rats or Rat Damage. Frontiers in Forests and Global Change2:51
  • Luke, S. H., Purnomo, D., Advento, A. D., Aryawan, A. A. K., Naim, M., Pikstein, R. N., Ps, S., Rambe, T. D. S., Soeprapto, Caliman, J-P, Snaddon, J. L., Foster, W. A., Turner, E. C. (2019). Effects of Understory Vegetation Management on Plant Communities in Oil Palm Plantations in Sumatra, Indonesia. Frontiers in Forests and Global Change, 2:33
  • Rory A Dow, Andreas Dwi Advento, Edgar C Turner, Jean-Pierre Caliman, William A Foster, Jake Snaddon, Mohammad Naim, Sudharto Ps (2018) Odonata from the BEFTA Project area, Riau Province, Sumatra, Indonesia. Faunistic Studies in SE Asian and Pacific Island Odonata 1-22.
  • Foster W.A. (2018). There's a jungle in your bed. Nature 563: 31-33.
  • Spear D.M., Foster W.A., Advento A.D., Naim, M., Caliman, J-P, Luke, S.H., Snaddon, J.L., Ps, S., Turner, E.C. (2018) Simplifying understory complexity in oil palm plantations is associated with a reduction in the density of a cleptoparasitic spider, Argyrodes miniaceus (Araneae: Theridiidae), in host (Araneae: Nephilinae) webs. Ecology and Evolution 1–9 
  • Kalsum M Yusah, William A Foster, Glen Reynolds, Tom M Fayle (2018) Ant mosaics in Bornean primary rain forest high canopy depend on spatial scale, time of day, and sampling method. PeerJ 6: e4231
  • Foster, W.A. (2017). Safety in numbers. Journal of Experimental Biology 220: 4551-3.
  • Luke, S.H., Barclay, H., Bidin, K., Chey, V.K., Ewers, R.M., Foster, W.A., Nainar, A., Pfeifer, M., Reynolds, G., Turner, E.C., Walsh, R.P.D., Aldridge, D.C., (2017). The effects of catchment and riparian forest quality on stream environmental conditions across a tropical rainforest and oil palm landscape in Malaysian Borneo. Ecohydrology 10: e1827
  • Luke SH, Dow RA, Butler S, Chey VK, Aldridge DC, Foster WA, Turner EC (2017) The impacts of habitat disturbance on adult and larval dragonflies (Odonata) in rainforest streams in Sabah, Malaysian Borneo. Freshwater Biology 62: 491–506
  • Snaddon JL, Chey VK, Foster WA (2017) Nutrient Piracy: evidence for the role of litter-trapping fungi in forest nutrient cycles in Sabah, Malaysia. The Malayan Nature Journal 69
  • Yusah KM, Foster WA (2016) Tree size and habitat complexity affect ant communities (Hymenoptera: Formicidae) in the high canopy of Bornean rain forest. Mymecological News 23:15-23
  • MD Farnon Ellwood, Nico Blüthgen, Tom M Fayle, William A Foster, Florian Menzel (2016) Competition can lead to unexpected patterns in tropical ant communities. Acta Oecologica 75: 24-34
  • David J Kurz, Edgar C Turner, Agung A Aryawan, Hannah C Barkley, Jean‐Pierre Caliman, Oliver Konopik, Sudharto Ps, William A Foster (2016) Replanting reduces frog diversity in oil palm. Biotropica 48: 483-490
  • GW Prescott, JJ Gilroy, T Haugaasen, CAM Uribe, WA Foster, DP Edwards (2016) Reducing the impacts of Neotropical oil palm development on functional diversity. Biological Conservation 197: 139-145
  • GW Prescott, JJ Gilroy, T Haugaasen, CAM Uribe, WA Foster, DP Edwards (2016) Managing Neotropical oil palm expansion to retain phylogenetic diversity. Journal of Applied Ecology 53: 150-158
  • Wang WY, Foster WA (2016) Ground-foraging ant communities vary with oil palm age. Basic and Applied Ecology 17: 21-32
  • Foster WA (2016). Entomology: a life of insects and ire. Nature 529: 152-3
  • Wang WY, Foster WA (2015) The effects of forest conversion to oil palm on ground‐foraging ant communities depend on beta diversity and sampling grain. Ecology and Evolution 5: 3159-3170
  • TM Fayle, DP Edwards, WA Foster, KM Yusah, EC Turner (2015) An ant–plant by‑product mutualism is robust to selective logging of rain forest and conversion to oil palm plantation. Oecologia 178: 441-450
  • GW Prescott, DP Edwards, WA Foster (2015) Retaining biodiversity in intensive farmland: epiphyte removal in oil palm plantations does not affect yield. Ecology and Evolution 5: 1944-1954
  • Fayle TM, Turner EC & Foster WA (2013) Ant mosaics occur in SE Asian oil palm plantation but not rain forest and are influenced by the presence of nest-sites and non-native species. Ecography 36: 1051-1057
  • Ashford O.S., Foster WA, Turner BL, Sayer EJ, Sutcliffe L & Tanner EVJ (2013) Litter manipulation and soil arthropod communities in a lowland tropical forest. Soil biology and biochemistry 62: 5 - 12
  • Fayle TM, Edwards DP, Turner EC, Dumbrell AJ, Eggleton P & Foster WA (2012) Public goods, public services, and by-product mutualism in an ant-fern symbiosis. Oikos 121, 1279-1286.
  • Yusah K.M., Fayle T.M., Harris G. & Foster W.A. (2012). Optimising diversity assessment protocols for high canopy ants in tropical rain forest. Biotropica  44, 73 - 81
  • Foster, W.A., Jake L. Snaddon, Edgar C. Turner,Tom M. Fayle, Timothy D. Cockerill, M. D. Farnon Ellwood, Gavin R. Broad, Arthur Y. C. Chung, Paul Eggleton, Chey Vun Khen and Kalsum M. Yusah (2011). Establishing the evidence base for maintaining biodiversity and ecosystem function in the oil palm landscapes of South East Asia. Phil.Trans.R.Soc.Lond.B. 366: 3277 - 3291 PDF
  • Fayle T.M., Dumbrell A.J., Turner E.C & Foster W.A. (2011). Distributional patterns of epiphytic ferns are explained by the presence of cryptic species. Biotropica 43: 6-7.
  • Snaddon JL, Turner EC, Fayle TM, Chey VK, Eggleton P & Foster WA (2011) Biodiversity hanging by a thread: the importance of fungal litter-trapping systems in tropical rainforests. Biology Letters 8, 397-400.
  • Turner E.C., Snaddon J.L., Ewers R.M., Fayle T.M. and Foster W.A. (2011). The Impact of Oil Palm Expansion on Environmental Change: Putting Conservation Research in Context. In Bernardes M.A.S. (Ed.) Environmental Impact of Biofuels. InTech Press.
  • Fayle T.M., Turner E.C., Snaddon J.L., Chey V.K., Chung A.Y., Eggleton P.E. & Foster W.A. (2010). Oil palm expansion into rain forest greatly reduces ant biodiversity in canopy, epiphytes and leaf litter. Basic and Applied Ecology. 11: 337-345. PDF
  • Foster W.A. (2010) The Menopausal Aphid Glue-Bomb. Current Biology 20(13): 559-560
  • Jackson, L., van Noordwijk, M., Bengtsson, J., Foster, W.A., Lipper, L., Said, M., Snaddon, J.L. & Vodouhe, R. (2010). Biodiversity and agricultural sustainagility: from assessment to adaptive management. Current Opinion in Environmental Sustainability. 2: 80 - 87.PDF
  • Fayle, T.M., Chung, A.Y.C., Dumbrell, A.J., Eggleton, P & Foster, W.A. (2009). The effect of rain forest canopy architecture on the distribution of epiphytic ferns (Asplenium spp.) in Sabah, Malaysia. Biotropica(In press). PDF Suppl
  • Ellwood, M.D.F., Manica, A., & Foster, W.A. (2009). Stochastic and deterministic processes jointly structure tropical arthropod communities. Ecology Letters 12: 277-284. PDF
  • Turner, E.C. & Foster, W.A. (2009). The impact of forest conversion to oil palm on arthropod abundance and biomass in Sabah, Malaysia. Journal of Tropical Ecology 25: 23 -30. PDF
  • Snaddon, J.L., Turner, E.C . & Foster, W.A. (2008). Children’s perceptions of rainforest biodiversity: which animals have the lion’s share of environmental awareness. PLoS ONE 3(2) e2579. PDF
  • Pike, N.P. & Foster, W.A. (2008). The ecology of altruism in a clonal insect. In: Ecology of Social Evolution (eds. J. Korb & J. Heinze) pp 37 - 56. Springer: Berlin. PDF
  • Turner, E.C., Snaddon, J.L., Fayle, T.M. & Foster, W.A. (2008) Oil palm research in context: identifying the need for biodiversity assessment. PLoS ONE 3(2) e1572. PDF
  • Morris, G. & Foster, W.A. (2008). Duelling aphids: electrical penetration graphs reveal the value of fighting for a feeding site. Journal of Experimental Biology 211: 1490 - 1494. PDF
  • Fayle TM, Ellwood MDF, Turner EC, Snaddon JL, M. Yusah K & Foster WA (2008) Bird’s Nest Ferns: islands of biodiversity in the rainforest canopy. Antenna 32, 34-37.
  • Pike, N.P., Whitfield, J.A. & Foster, W.A. (2007). Ecological correlates of sociality in Pemphigus aphids, with a partial phylogeny of the genus. BMC Evolutionary Biology 7: 185. PDF
  • Turner, E.C., Snaddon, J.L., Johnson, H.R. & Foster, W.A. (2007) The impact of bird’s nest ferns on stemflow nutrient concentration in a primary rain forest, Sabah, Malaysia. J. Trop.Ecol. 23: 1 - 4. PDF
  • Field, J.P., Turner, E.C., Fayle, T. & Foster, W.A. (2007). Costs of egg-laying and offspring provisioning in multifaceted parental investment in a digger wasp. Proceeding of the Royal Society of London B 274: 445-451. PDF
  • Dial, R.J., Ellwood, M.D.F., Turner, E.C. & Foster, W.A. (2006). Arthropod abundance, canopy structure, and microclimate in a Bornean Lowland Tropical Rain Forest. Biotropica 38: 643-652. PDF
  • Turner, E.C. & Foster, W. (2006). Assessing the influence of bird’s nest ferns (Asplenium spp.) on the local microclimate across a range of habitat disturbances in Sabah, Malaysia. Selbyana 27: 195-200.
  • Ellwood, M.D.F. and Foster, W.A. (2004) Doubling the estimate of invertebrate biomass in a rainforest canopy. Nature 429: 549-551. PDF
  • Ellwood, M.D.F., Jones, D.T. and Foster, W.A. (2002) Canopy ferns in lowland dipterocarp forest support a prolific abundance of ants, termites and other invertebrates. Biotropica 34: 575-583. PDF
  • Johnson, P.C.D., Whitfield, J.A., Foster, W.A. and Amos, W. (2002) Clonal mixing in the soldier-producing aphid Pemphigus spyrothecae (Hemiptera: Aphididae). Molecular Ecology11: 1525-1531. PDF
  • Pike, N., Richard, D., Foster, W., and Mahadevan, L. (2002) How aphids lose their marbles. Proceedings of the Royal Society B. 269: 1211-1215. PDF
  • Foster, W.A. (2002) Aphid sex ratios. In: Sex Ratio Handbook: concepts and research methods (ed I. Hardy). Chapter 12. pp 254-265. Cambridge University Press.
  • Rhoden P.K. and Foster, W.A. (2002) Soldier behaviour and division of labour in the aphid genus Pemphigus (Hemiptera, Aphididae). Insectes Sociaux 49: 257-263. PDF
  • Foster, W.A. (2002) Soldier aphids go cuckoo. Trends in Ecology and Evolution 17: 199-200. PDF
  • Sumner, S., Casiraghi, M., Foster W. & Field, J. (2002). High reproductive skew in tropical hover wasps. Proc.R.Soc.Lond.B. 269: 179-186 PDF
Director of Alumni Relations
Senior Lecturer and Curator of Insects (Emeritus)