David P. Hughes, Ph.D.

Fellowships and Prizes

• 2018-2020 UN Fellow. Food and Agricultural Organization of United Nations 
• 2008-2011 Marie Curie International Outgoing Fellowship (Harvard & Exeter)
• 2006-2008 Marie Curie Intra-European Fellowship (Copenhagen)
• 2004 Varley-Gradwell Travelling Fellowship in Insect Ecology (Oxford)
• 1999-2003 Hope Studentship in Entomology (Oxford)
• 1999 Graham Kerr Prize in Zoology (Glasgow)

Research Interests

Food security

I have retired my work on ant behavior to focus 100% on Global Food secruity through PlantVillage 

The details below have not been updated for a long time. You can find more recent papers on Google Scholar 

Parasite manipulation of host behavior

Parasites can control hosts turning them into vehicles for parasite genes. To achieve transmission the behavior of the host can become an extended phenotype of the parasite[1]. Research into extended phenotypes can provide novel insights into parasite-host interactions because it integrates across a number of biological levels of the antagonism: expression of parasite genes leading to parasite phenotypes (e.g. secreted metabolites) that affect host process (CNS and motor-physiology) leading to altered behavior that affects con- and heterospecific responses (e.g. defense and predation respectively). If the altered behavior is non-transient then effects at the ecological level can occur as well. My work explores the integrative nature of parasite manipulation to address general issues in disease dynamics and virulence evolution. I recently developed as a model system one of the most dramatic examples of adaptive parasite manipulation of host behavior, the 'death grip' of ants infected by a fungus.

Ants are the dominant fauna of all terrestrial ecosystems and in tropical forests almost 70% of individual insects are ants (yet ants account for <2% of all insect species)[2]. As such they represent a prime resource for parasites. Fungi are probably the most important group of ant parasites in tropical forests[3]. The challenge facing fungi infecting ants is that the hygienic behavior of thousands of workers prevents fungal lifecycle completion inside the colony[4]. The fungus Ophiocordyceps unilateralis solves this problem in a most impressive manner.

Worker ants become infected when foraging in the forest and 3-9 days pass as the fungus develops inside the ant's body. Once ready to complete its lifecycle, the fungus manipulates the infected worker ant (Camponotus leonardi) to descend from its colony in the dry, hot canopy to the humid understory where the ant selects and bites into a leaf before dying (Fig 1) (Remaining in the nest or in the canopy results in zero fitness[5]). Leaves on the N-NW side of the plant in a narrow band 25cm above the ground are chosen. Having bitten a leaf the ant is killed and the fungus grows a stalk from its head from which spores are dispersed to infect other ants.

Most recently I have begun to look at this interaction across the globe. I have begun field work in Brazil (Atlantic Rainforests), USA (South Carolinian deciduous woods) and China (Yunnan Province). In the coming months I will aim to conduct further field collections in Ecuador, Japan, Australia and Honduras. This field work is in very close contact with Dr Harry Evans of CABI, UK who is the foremost authority on the ecology of Cordyceps (in the broad sense) in tropical forests. In addition I am building links with local scientists in Colombia, Guyana, Brazil, Peru, Malaysia, Papua New Guinea and Australia to promote coordinated surveys of ant-parasites across the globe.

Current and future directions

Currently my focus is progressing this system along a number of lines:

• The genomics and transcriptomics of behavioral manipulation.
• How does the finely detailed manipulation we observed in Southern Thailand vary geographically both in Thailand and in other areas where this host-parasite system occurs?
• What is the plant response to biting ants?
• How do natural enemies of O. unilateralis (and there are lots of them) impact disease dynamics?
• How do ants within the colony react to chimeras in the nest (ants + fungi) given that conflicts exist?
• How does a fungal disease spread in a tropical forest and how can individual and colony (superorganism) level behavior respond?

I will shortly develop these ideas further on lab website. I will also detail my previous work on Strepsiptera-manipulating wasp and ant behavior and the collaborative work on hairworm manipulation of crickets (with the excellent Fred Thomas and his team at Montpellier, France).

Applied research at Penn State

Ants pose a significant threat to agriculture because of their mutualism with phloem feeding insects such as hemipterans. Much of the disease incidence and spread of diseases on plants is due to the hundreds of thousands of ants that protect plant-feeding insects that vector disease. Ants farm these sucking insects and 'milk' them for the by-product sugar they excrete. This is a strong mutualism and ant protection increases the populations of plant feeding insects, and in turn, this greatly increases the rate of disease spread between plants as the bugs transmit viral and bacterial infections and the hundreds of thousands of ant legs and mandibles introduce fungi and psuedo-fungi (oomycetes) into leaf tissue. Reflecting the successful integration found at Penn State I am interested in bringing diverse approaches to study agricultural diseases. We are working now on ants on small holder Cassava and Cocoa farms in Ghana. You see further details on my approach to plant pathology in my recent lecture.

Media Coverage

The first two papers to appear from Ophiocordyceps–ant work in Thailand received quite a bit of media attention. At the bottom of this page are a few of the links that I feel serve as very nice general introductions to the system. Particularly noteworthy are the Discovery Magazine Blog piece by expert parasite proponent, Carl Zimmer, the ScienceNews piece by Susan Milius and the Scientific American coverage.

There was also coverage by Science Shots, the BBC, ScienceDaily, MSNBC, the Ecological Society of America, LiveScience and FoxNews.

You can see coverage in other languages as well: German (n-tv.de and pressetext Austria), Finnish, French (lesoir.be and Abstrait Concret), Danish, Chinese, Norwegian, Vietnamese, Italian, Spanish, Portuguese and Russian.

The zombie metaphor used in a number of the above press pieces has been developed in rather interesting ways – for example, see these three: article one, article two and article three.

Working with Conrad Labandeira (Smithsonian) and Torsten Wappler (Steinmann Institute) we uncovered a 48 mya old fossil leaf showing the antiquity of fungal manipulation of ant behavior. This also captured media attention in specialist journals (e.g.Nature, Science), general science periodicals (e.g.New Scientist) and print media (e.g.New York Times, Telegraph, Guardian) and becoming an exhibition at the America Museum of Natural History. It also received attention in blogs (e.g.Discover) and on-line media outlets (e.g.MSNBC).

Publications

Articles and book chapters

* = senior author
** = MSc student

2016

Araújo, J., and D.P. Hughes (2016) Diversity of Entomopathogenic Fungi: Which Groups Conquered the Insect Body? Advances in Genetics Vol 93

Loreto, R and D.P. Hughes (2016) Disease Dynamics in Ants: A Critical Review of the Ecological Relevance of Using Generalist Fungi to Study Infections in Insect Societies Advances in Genetics Vol 93

Hughes, D.P. Araújo, J. Loreto, R., Quevillon, L., de Bekker, C. and H.C. Evans (2016) From So Simple a Beginning: The Evolution of Behavioral Manipulation by Fungi Vol 93 Genetics corrected proof Vol 93

2015

Hughes, D.P. and Salathé, M (2015) An open access repository of images on plant health to enable the development of mobile disease diagnostics

Hughes, D. P. (2015). Behavioral Ecology: Manipulative Mutualism. Current Biology 25:R806-R808.

de Bekker, C., R. A. Ohm, R. G. Loreto, A. Sebastian, I. Albert, M. Merrow, A. Brachmann, and D.P. Hughes (2015). Gene expression during zombie ant biting behavior reflects the complexity underlying fungal parasitic behavioral manipulation. BMC Genomics 16:620.

Quevillon, L. E., Hanks, E. M., Bansal, S., & Hughes, D. P. (2015). Social, spatial, and temporal organization in a complex insect society. Nature Scientific Reports 5:13393

Araújo, J., Evans, H. C., Geiser, D. M., & Hughes, D. P. (2015). Unraveling the diversity behind Ophiocordyceps unilateralis complex: Three new species of zombie-ant fungi from the Brazilian Amazon. Phytotaxa 220 (3): 224–23

NESCent Working Group on the Evolutionary Biology of the Built Environment: Martin, L.J., Adams, R.I, Bateman, A., Bik, H.M. Hawks, J. Hird, S.M. Hughes, D.P., Kembel, S.W., Kinney, K., Sergios-Orestis, K., Levy, G., McClain, C., Meadow, J.F., Medina, R.F., Mhuireach, G., Moreau, C.S., Munshi-South, J., Nichols, L.M., Palmer, C., Popova, L., Schal, C., Täubel, M., Trautwein, M., Ugalde, J.A. & R. R. Dunn (2015) Evolution of the indoor biome, Trends in Ecology & Evolution, Volume 30, Issue 4, April 2015, Pages 223-232, ISSN 0169-5347.

Biron, D. Panek, J. Chetouhi, C. El Alaoui, H., Texier, C., Langin, T. de Bekker, C., Bonhomme, L. Urbach, S. Demettre, E. Misse, D. Holzmuller, P., Hughes, D.P. Zanzoni, A., Brun, C. (2015) Cross-talk in host-parasite associations: what do past and recent proteomics tools tell us? Infection, Genetics and Evolution Jul;33:84-94. doi: 10.1016/j.meegid.2015.04.015.

2014

Alisha Quandt, C. Kepler, R.M. Gams, W., Araújo, J. P., Ban, S., Evans, H. C., Hughes, D.P.Humber, R. Hywel-Jones, N. Li, Z, Luangsa-ard, J.J. Rehner, S.A. Sanjuan, T. Sato, H. Shrestha, B. Sung, G.H. Yao, Y. Zare, R and J. W. Spatafora (2014). Phylogenetic-based nomenclatural proposals for Ophiocordycipitaceae (Hypocreales) with new combinations in Tolypocladium. IMA fungus, 5(1), 121.

de Bekker,C, Quevillon, L., Smith, P. Patterson, A.D, Flemming, K., Ghosh, D. and D.P. Hughes Species-specific Ant Brain Manipulation by a Specialized Fungal Parasite BMC Evolutionary Biology 14.1 (2014): 166.

Loreto, R. G., Elliot, S. L., Freitas, M. L., Pereira, T. M., & Hughes, D. P. (2014) Long-Term Disease Dynamics for a Specialized Parasite of Ant Societies: A Field Study PloS One, 9(8), e103516.

Hughes, D.P. (2014) On the origins of parasite extended phenotypes Integrative and Comparative Biology 54 (2): 210-217

de Bekker, C., Merrow, M., and D.P. Hughes (2014) From behavior to molecular mechanisms: an integrative approach to parasitic host manipulation Integrative and Comparative Biology (2): 166-176.

Smith, R. A., & Hughes, D.P (2014). Infectious Disease Stigmas: Maladaptive in Modern Society. Communication Studies, 65(2), Special Issue on Stigma.

2013

Lachaud, J. P., Lenoir, A., & D.P. Hughes (2013). Ants and Their Parasites 2013. Psyche: A Journal of Entomology Vol 2013 1-5

Loreto RG, Hart A, Pereira TM, Freitas ML, Hughes DP, Elliot SL (2013) Foraging ants trade off further for faster: use of natural bridges and trunk-trail permanency in carpenter ants. Naturwissenschaften Vol 100 Issue 10 pp 957-963

de Bekker, C. Smith, P. Patterson, A.D and D.P. Hughes (2013) Metabolomics reveals the heterogeneous secretome of two entomopathogenic fungi to ex vivo cultured insect tissues PloS One 8(8): e70609. doi:10.1371/journal.pone.0070609 (Article)

Maure, F. Brodeur, J. Hughes, D.P. and F. Thomas (2013) How much energy should manipulative parasites leave to their hosts to ensure altered behaviours? Journal of Experimental Biology 2012 216: 43-6. (Article)

Hughes, D.P. (2013) Pathways to understanding the extended phenotype of parasites in their hosts Journal of Experimental Biology 216:142-147 (Article)

2012

Hughes, D.P. Parasites and the Superogranism (2012). In Host Manipulation by Parasites Edited by David P. Hughes, Jacques Brodeur, and Frédéric Thomas

Andersen SB, Ferrari M, Evans HC, Elliot SL, Boomsma JJ, and D.P. Hughes (2012) Disease Dynamics in a Specialized Parasite of Ant Societies. PLoS ONE 7(5): e36352. doi:10.1371/journal.pone.0036352

Andersen SB and D.P. Hughes (2012) Host specificity of parasite manipulation –zombie ant death location in Thailand vs. Brazil Communicative & Integrative Biology 5:2, 1–3; March/April

2011

Harry C. Evans, Simon L. Elliot and David P. Hughes (2011) Ophiocordyceps unilateralis: A keystone species for unraveling ecosystem functioning and biodiversity of fungi in tropical forests? Communicative & Integrative Biology 4:5, 598-602 (Article)

Hoover, K., M. Grove, M. Gardner, D.P. Hughes, J. McNeil and J. Slavicek. (2011) A gene for an extended phenotype. Science 333: 1401. This paper has been designated a Faculty of 1000 Must Read Factor 8

Hughes, D.P., Andersen, S.* Hywel-Jones, N.L. , Himaman, W., Bilen, J and J.J. Boomsma. Behavioral mechanisms and morphological symptoms of zombie ants dying from fungal infection BMC Ecology 2011, 11:13doi:10.1186/1472-6785-11-1 (Article)

Evans, H.E., Elliot, S.L, and D.P. Hughes (2011) Hidden diversity behind the Zombie-Ant fungus Ophiocordyceps unilateralis: Four new species described from Carpenter ants in Minas Gerais, Brazil PloS One. 2nd March 2011

Semenova, T,** Hughes, D.P. Boomsma, J.J. & Schioett (2011) Evolutionary patterns of proteinase activity in attine ant fungus gardens BMC Microbiology. BMC Microbiology 11:15

D.P. Hughes (2011) Recent developments in sociobiology and the scientific method Trends in Ecology and Evolution Vol 26 (2) 57-8

2010

D.P. Hughes, Wappler, T, & C. C. Labandeira (2010) Ancient death-grip leaf scars reveal ant fungal parasitism Biology Letters 18th August doi:10.1098/rsbl.2010.0521

D.P. Hughes (2010) A philosophical view of biology Trends in Ecology and Evolution Vol 25 (7) 384-385

2009

Andersen, SB, ** S. Gerritsma, ** K.M. Yusah, D. Mayntz, N.L. Hywel-Jones, J. Billen, J.J. Boomsma & D.P. Hughes* (2009). The life of a dead ant - the expression of an extended phenotype. American Naturalist 174: 424–433

Pontoppidan, M-B, ** W. Himaman, N.L. Hywel-Jones, J.J. Boomsma & D.P. Hughes* (2009). Graveyards on the move: The spatio-temporal distribution of dead Ophiocordyceps infected ants. PloS One 4(3): e4835 doi:10.1371/journal.pone.0004835

Hughes, D.P. (2009). Altruists since life began: the evolution of the superorganism (book review). Trends in Ecology and Evolution 24(8): 417–418

Hughes, D.P., H.C. Evans, N.L. Hywel-Jones, J.J. Boomsma & S.A.O. Armitage (2009). Emerging fungal diseases in complex leaf-cutting ant societies. Ecological Entomology in 34: 214–220

Lefevre, T., S. Adamo, D.G. Biron, D. Misee, *D.P. Hughes & F. Thomas (2009). Invasion of the Body Snatchers: The Diversity and Evolution of Manipulative Strategies in Host–Parasite Interactions. Advances in Parasitology 68: 45–83

2008

Cremer, S., L.V. Ugelvig, F.P. Drijfhout, B.C. Schlick-Steiner, F.M. Steiner, B. Seifert, D.P. Hughes, A. Schultz, K.S. Petersen, H. Konrad, C. Stauffer, K. Kiran, X. Espadaler, P. d'Ettorre, N. Aktaç, J. Eilenberg, G.R. Jones, D.R. Nash, J.S. Pedersen, J.J. Boomsma (2008). The Evolution of Invasiveness in Garden Ants. PLoS ONE 3(12): e3838

Hughes, D.P., N.E. Pierce & J.J. Boomsma (2008). Social insect symbionts: evolution in homeostatic fortresses. Trends in Ecology and Evolution. 23(12): 672-677

Hughes, D.P. (2008). The extended phenotype within the colony and how it obscures social communication. (book chapter in Sociobiology of Communication eds. P. d'Ettorre and D.P. Hughes)

Hughes, D.P., D.J.C. Kronauer & J. J. Boomsma (2008). Extended Phenotype: Nematodes turn ants into bird-dispersed fruits. Current Biology. 18: R294–R295

Sánchez, M.I., F. Ponton, A. Schmidt-Rhaesa, D.P. Hughes, D. Missé & F. Thomas (2008). Two steps to suicide in insects harbouring hairworms. Animal Behaviour, 75(5): 1621–1624

2007

Sánchez, M.I., F. Ponton, D. Missé, D.P. Hughes & F. Thomas (2007). Hairworm response to notonectid attacks. Animal Behaviour 75(3): 823–826

Hughes, D.P. & S. Cremer (2007). Plasticity in anti-parasite behaviours and its suggested role in invasion biology. Animal Behaviour 74(5): 1593–1599

Lefevre, T., M. Sanchez, D.P. Hughes & F. Thomas (2007). Virulence and resistance in malaria: who drives the outcome of the infection? Trends in Parasitology 23(7): 299–302

2006

Ponton, F., C. Lebarbenchon, T. Lefevre, D.G. Biron, D. Duneau, D.P. Hughes & F. Thomas (2006). Hairworm anti-predator strategy: a study of causes and consequences. Parasitology 133(5): 631–638

Hughes, D.P. & J.J. Boomsma (2006). Muscling out malaria. Trends in Ecology and Evolution 21(10): 533–534

Ponton, F., C. Lebarbenchon, T. Lefevre, D.G. Biron, D. Duneau, *D.P. Hughes & F. Thomas (2006). Parasite survives predation on its host. Nature 440: 756–756

Kathirithamby J. & D.P. Hughes (2006). Description and biological notes of the first species of Xenos (Strepsiptera:Stylopidae) parasitic in Polistes carnifex (Hymenoptera: Vespidae) in Mexico. Zootaxa 1104: 35–45

2005

Hughes, D.P. & J. Kathirithamby (2005). Virulence under low extrinsic mortality: the benefit of parasitizing social insects? Oikos 110: 42–434

Hughes, D.P. (2005). Parasitic Manipulators: a social context. Behavioural Processes 68(3): 263–266

2004

Hughes, D.P., J. Kathirithamby & L. Beani (2004). Prevalence of the parasite Strepsiptera in adult Polistes wasps: field collections and literature overview. Ethology, Ecology and Evolution 16: 363–75

Johnston, S.J., L. Ross, L. Beani, D.P. Hughes & J. Kathirithamby (2004). Tiny genomes and endoreduplication in Strepsiptera. Insect Molecular Biology 13(6): 581–585

Hughes, D.P., J. Kathirithamby, S. Turillazzi & L. Beani (2004). Social wasps desert the colony and aggregate outside if parasitized: parasite manipulation? Behavioural Ecology 15(6): 1037–1043

Hughes, D.P., P. Pamilo & J. Kathirithamby (2004). Horizontal transmission of Wolbachia by strepsipteran endoparasites? A reply to Noda et al. 2001. Molecular Ecology 13(2): 507–9

2003

Hughes, D.P., G. Moya-Raygoza & J. Kathirithamby (2003). The first record among Dolichodernae (Formicidae) of parasitism by Strepsiptera. Insectes Sociaux. 50 (2): 148–150

Hughes, D.P., L. Beani, S. Turillazzi & J. Kathirithamby (2003). Prevalence of the parasite Strepsiptera in Polistes as detected by dissection of immatures. Insectes Sociaux 50(1): 62–68

2002

Hughes, D.P. (2002). The value of a broad mind: some natural history meanderings of W.D. Hamilton. Ethology, Ecology and Evolution 14 (2): 83–89

Kathirithamby, J. & D.P. Hughes (2002). Caenocholax fenyesi Pierce (Strepsiptera: Myrmecolacidae) parasitic in Camponotus planatus Roger (Hymenoptera: Formicidae) in Mexico: is this its original host? Annals of the Entomological Society of America 95 (5): 558–563

Books

P. D'Ettorre & D.P. Hughes (2008). Sociobiology of Communication. Edited book for Oxford University Press.
More information about the book can be found on the Oxford University Press website.

Host Manipulation by Parasites
Edited by David P. Hughes, Jacques Brodeur, and Frédéric Thomas
Preface by Richard Dawkins, University of Oxford, UK

Footnotes

[1] Dawkins, R. (1982). The Extended Phenotype. OUP, Oxford.
[2] Hölldobler B. & E.O. Wilson (1990). The Ants. Harvard University Press, Cambridge.
[3] Evans, H. (1990) Entomopathogenic fungi in tropical forests: an appraisal.
[4] Hughes, D.P., N.E. Pierce & J.J. Boomsma, 2008. Social insect symbionts: evoluion in homeostatic fortresses. Trends in Ecology and Evolution 23(12): 672–677
[5] Andersen, S.B., S. Gerritsma, K.M. Yusah, D. Mayntz, N.L. Hywel-Jones, J. Billen, J.J. Boomsma & D.P. Hughes (2009). The life of a dead ant - the expression of an extended phenotype. American Naturalist 174: 424–433.