Gustavo Hormiga

Gustavo Hormiga

Title:
Ruth Weintraub Professor of Biology, Director of Graduate Studies
Office:
Lisner Hall 412 ; Bell Hall 405 (lab)
Address: 2023 G Street. NW
Washington, District Of Columbia
20052
Phone: 202-994-1095
Fax: 202-994-6100
Email:
hormiga@gwu.edu
Website:

Areas of Expertise

Systematics of spiders; evolutionary biology of spiders, especially orb weavers and their relatives.

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Current Research

The web of an adult female of the poorly known genus Exechopsis sp. (Linyphiidae), photographed in the lowland rain forests of Ecuador (Parque Nacional Yasuní).The research in the Hormiga laboratory focuses on the systematics and evolutionary biology of spiders, with emphasis on orbweavers and their close relatives (Orbiculariae). We use morphological, molecular and behavioral characters to reconstruct the phylogenetic relationships of our study groups. We tackle questions that span from species level taxonomic problems, addressed using a monographic approach, to intra and interfamilial phylogenetic relationships. We have an active fieldwork program that has taken us around the world in search of our study organisms. Our most recent fieldwork has been carried out in several countries of the Neotropical region, Madagascar and Equatorial Africa, Australia and New Zealand. 

We also use comparative phylogenetic methods to study more general questions such as the evolution and diversification of web architecture, the evolution of sexual size dimorphism or the patterns of insular diversification and colonization in oceanic archipelagoes.

 

 


Check out the following links to read more about some of our current projects:

Past project links:

Education

B.Sc., Universidad de Barcelona, 1985
M.S., Ph.D., University of Maryland at College Park, 1992, 1995

Publications

Click here for the complete list of the Hormiga Lab publications:

Hormiga, G. and S. Lew.  In press. Pimoidae. In: Darrell Ubick, Pierre Paquin, & Paula E. Cushing, (eds.) Spiders of North America: an identification manual.

Giribet, G. And G. Hormiga. In Press. Chapter 24. Phylum Arthropoda: The Chelicerata. In: Brusca, R. (Ed.) The Invertebrates, 3rd Edition.

Wang, F., Ballesteros, J. A., Hormiga, G., Chesters, D., Zhan, Y., Sun, N., Zhu, C., Chen, W. & Tu, L. 2015. Resolving the phylogeny of a speciose spider group, the family Linyphiidae (Araneae). Molecular phylogenetics and evolution.

Moreira TDS, Hormiga G. 2015. Redescription and phylogenetic placement of the Hispaniolan spider genus Lomaita, Bryant 1948 (Araneae, Linyphiidae). Zootaxa 3920 (2): 249–264 (http://dx.doi.org/10.11646/zootaxa.3920.2.2)

Sharma, P. P., Kaluziak, S., Pérez-Porro, A. R., González, V. L., Hormiga, G., Wheeler, W. C. & Giribet, G. 2014. Phylogenomic interrogation of Chelicerata reveals systemic conflicts in phylogenetic signal. Molecular Biology and Evolution 31 (11): 2963-2984. doi:10.1093/molbev/msu235

Lopardo, L., and G. Hormiga.  2015. Out of the twilight zone: Phylogeny and evolutionary morphology of the orb-weaving spider family Mysmenidae, with focus on spinneret spigot morphology in symphytognathoids (Araneae, Araneoidea). Zoological Journal of the
Linnaean Society 173, 527–786.

Fernández, R., G. Hormiga and G. Giribet. 2014. Phylogenomic analysis of spiders reveals nonmonophyly of orb weavers. Current Biology 24(15): 1772-1777. Published online July 17, 2014. DOI: (http://dx.doi.org/10.1016/j.cub.2014.06.035).

Hormiga, G. and J. Ballesteros Chávez. 2014. Chapter 26. Panarthropods: Arthropods and their closest relatives. In The Tree of Life (Edited by P. Vargas and R. Zardoya), pp. 305-314. Sinauer Associates.

Hormiga, G. and S. Lew.  2014. A new American species of the spider genus Pimoa (Araneae, Pimoidae). Zootaxa 3827 (1): 95–100.

Hormiga, G. and N. Scharff.  2014. The strange case of Laetesia raveni n. sp., a green linyphiid spider from Eastern Australia with a preference for thorny plants (Araneae, Linyphiidae). Zootaxa 3811 (1): 83–94.

Hormiga, G. and J. Ballesteros Chavez. 2014.  Chapter 26. Panarthropoda: Arthropods and their closest relatives. The Tree of Life, R. Zardoya and P. Vargas, Editors, pp. 305-314.

Cabra-García, J., G. Hormiga and A.D. Brescovit. 2014. Female genital morphology in the secondarily haplogyne spider genus Glenognatha Simon, 1887 (Araneae, Tetragnathidae), with comments on its phylogenetic significance. Journal of Morphology 275(9): 1027-1040. DOI: 10.1002/jmor.20280

Scharff, N. and G. Hormiga. 2013. On the Australian linyphiid spider Alaxchelicera ordinaria Butler, 1932 (Araneae). Zootaxa 3750 (2): 193–196.

Hormiga, G. and C.E. Griswold. 2014. Systematics, Phylogeny and Evolution of Orb-weaving Spiders. Annual Review of Entomology 59: 487-512.

Andriamalala, D. and G. Hormiga. 2013. Systematics of the goblin spider genusOpopaea (Araneae, Oonopidae) in Madagascar. Bulletin of the American Museum of Natural History 380: 1-156.

Gavish-Regev, E., G. Hormiga and N. Scharff. 2013. Pedipalp sclerite homologies and phylogenetic placement of the spider genus Stemonyphantes (Linyphiidae, Araneae) and its implications for linyphiid phylogeny. Invertebrate Systematics27(1): 38-52.

Murienne, J., Benavides, L. R., Prendini, L., Hormiga, G., Giribet, G. 2012. Forest refugia in Western and Central Africa as 'museums' of Mesozoic biodiversity. Biology Letters 9: 20120932.

Scharff, N. and G. Hormiga. 2012. First evidence of aggressive chemical mimicry in the Malagasy orb weaving spider Exechocentrus lancearius (Arachnida: Araneae: Araneidae) and description of a second species. Insect Systematics & Evolution 70(2): 107-118.

Dimitrov, D., L. Lopardo, G. Giribet, M. A. Arnedo, F. Álvarez-Padilla and G. Hormiga. 2012. Tangled in a sparse spider web: single origin of orb weavers and their spinning work unravelled by denser taxonomic sampling. Proceedings of the Royal Society B. 279 (1732):1341-1350. (doi:10.1098/rspb.2011.2011 )

Lopardo, L., G. Giribet and G. Hormiga. 2011. Morphology to the rescue: Molecular data and the signal of morphological characters in combined phylogenetic analyses—A case study from mysmenid spiders (Araneae, Mysmenidae), with comments on the evolution of web architecture. Cladistics 27, 278-330 (cover article). (doi:10.1111/j.1096-0031.2010.00332.x)

Dimitrov, D. and G. Hormiga. 2011. An extraordinary new genus of spiders from Western Australia with an expanded hypothesis on the phylogeny of Tetragnathidae (Araneae). Zoological Journal of the Linnean Society, 161: 735-768. (doi:10.1111/j.1096-3642.2010.00662.x)

Álvarez-Padilla, F. and G. Hormiga. 2011. Morphological and phylogenetic atlas of the orbweaving spider family Tetragnathidae (Araneae: Araneoidea). Zoological Journal of the Linnean Society 162(4): 713-880.

Tu, L., and G. Hormiga. 2011. Phylogenetic analysis and revision of the linyphiid spider genus Solenysa (Araneae: Linyphiidae: Erigoninae). Zoological Journal of the Linnean Society 161, 484–530. (doi:10.1111/j.1096-3642.2010.00640.x)

Michalik, P. and G. Hormiga. 2010. Ultrastructure of the spermatozoa in the spider genus Pimoa – new evidence for the monophyly of Pimoidae plus Linyphiidae (Arachnida: Araneae). American Museum Novitates 3682: 1-17.

Dimitrov D., Hormiga G. 2010. Mr.Darwin’s mysterious spider: On the type species of the genus Leucauge White, 1841 (Tetragnathidae, Araneae). ZOOTAXA2396:19–36.

Tu, L., and G. Hormiga. 2010. The female genitalic morphology of “micronetine” spiders (Araneae, Linyphiidae). Genetica (DOI 10.1007/s10709-009-9368-9).

Benjamin, S., and G. Hormiga. 2009. Phylogenetic placement of the enigmatic genus Labullinyphia Van Helsdingen, 1985, with redescription of Labullinyphia tersa (Simon, 1894) from Sri Lanka (Araneae: Linyphiidae). Contributions to Natural History 12: 161-181.

Dimitrov, D., Benjamin, S., and G. Hormiga. 2009. A revised phylogenetic analysis for the genus Clitaetra Simon, 1889 (Araneoidea, Nephilidae) with the first description of the male of the Sri Lankan species Clitaetra thisbe Simon, 1903. Bulletin of the Museum of Comparative Zoology 159(6): 301-323. (doi:10.3099/0027-4100-159.6.301).

Arnedo, M.A., G. Hormiga, and N. Scharff. 2009. Higher level phylogenetics of linyphiid spiders (Araneae, Linyphiidae) based on morphological and molecular evidence. Cladistics 25: 231-262.

Álvarez-Padilla F., Dimitrov D., Giribet G., Hormiga G. 2009. Phylogenetic relationships of the spider family Tetragnathidae (Araneae, Araneoidea) based on morphological and DNA sequence data. Cladistics 25:109-146. (doi:10.1111/j.1096-0031.2008.00242.x)

Tu, L., and G. Hormiga. 2009. The female genitalic morphology of “micronetine” spiders (Araneae, Linyphiidae). Genetica (DOI 10.1007/s10709-009-9368-9).

Arnedo, M.A., G. Hormiga, and N. Scharff. 2009. Higher level phylogenetics of linyphiid spiders (Araneae, Linyphiidae) based on morphological and molecular evidence. Cladistics 25: 231-262.

Álvarez-Padilla F., Dimitrov D., Giribet G., Hormiga G. 2009. Phylogenetic relationships of the spider family Tetragnathidae (Araneae, Araneoidea) based on morphological and DNA sequence data. Cladistics 25:109-146. (doi: 10.1111/j.1096-0031.2008.00242.x)

Santos, A.J., M. O. Gonzaga, and G. Hormiga. 2009. Notes on two problematic eastern Asian species of the spider genus Oecobius (Araneae: Oecobiidae, Linyphiidae). Journal of Arachnology 37:101-102.

Coddington, J.A., I. Agnarsson, J. A. Miller, M. Kuntner and G. Hormiga. 2009. Undersampling bias: the null hypothesis for singleton species in tropical arthropod surveys. Journal of Animal Ecology 78:573–584.

Dimitrov D., Hormiga, G. 2009. Revision and cladistic analysis of the orbweaving spider genus Cyrtognatha Keyserling, 1881 (Araneae, Tetragnathidae). Bulletin of the American Museum of Natural History 317:1-140. PDF available via the AMNH research library (very large file).

Hormiga, G. 2008 . On the spider genus Weintrauboa (Araneae, Pimoidae), with a description of a new species from China and comments on its phylogenetic relationships. ZOOTAXA 1814: 1-20.

Hormiga, G. and L. Tu. 2008. On Putaoa, a new genus of the spider family Pimoidae (Araneae) from southern China, with a cladistic test of its monophyly and phylogenetic placement. ZOOTAXA 1792: 1-21.

Kuntner, M., J. Coddington and G. Hormiga. 2008. Phylogeny of extant nephilid orb-weaving spiders (Araneae, Nephilidae): testing morphological and ethological homologies. Cladistics 24: 147-217.

Benjamin PS., Dimitrov D., Gillespie RG., Hormiga, G. 2008. Family ties: molecular phylogeny of crab spiders (Araneae: Thomisidae). Cladistics 24(5): 708-722. (doi: 10.1111/j.1096-0031.2008.00202.x)

Lopardo, L. and G. Hormiga. 2008. Phylogenetic placement of the Tasmanian spider Acrobleps hygrophilus (Araneae, Anapidae) with comments on the evolution of the capture web in Araneoidea. Cladistics 24: 1-33.

Dimitrov D., Álvarez-Padilla F., Hormiga G. 2008. Until dirt do us apart: on the unremarkable palp morphology of the spider Sternospina concretipalpis Schmidt& Krause, 1993, with comments on the genus Prionolaema Simon, 1894 (Araneae, Tetragnathidae). ZOOTAXA, 1698: 49-56. 

Alvarez-Padilla, F. and G. Hormiga. 2008. A protocol for digesting internal soft tissues and mounting spiders for scanning electron microscopy. Journal of Arachnology 35: 538-542.

Dimitrov D., Alvarez-Padilla F., Hormiga,G. 2007. The female genitalic morphology of the orb weaving spider genus Agriognatha (Araneae, Tetraganthidae). Journal of Morphology 268(9): 758-770.

Hormiga, G., F. Alvarez-Padilla and S.P. Benjamin. 2007. First records of extant Hispaniolan spiders of the families Mysmenidae, Symphytognathidae and Ochyroceratidae (Araneae), including a new species of OchyroceraAmerican Museum Novitates 3577: 1-21.

Lopardo, L. and G. Hormiga. 2007. On the spider genus Cepheia Simon 1894(Araneae, Synaphridae). American Museum Novitates 3575: 1-18.

Ramírez, M.J., J.A. Coddington, W.P. Maddison, P.E. Midford, L. Prendini, J. Miller, C.E. Griswold, G. Hormiga, P. Sierwald, N. Scharff, S.P. Benjamin, and W.C. Wheeler. 2007. Linking of Digital Images to Phylogenetic Data Matrices Using a Morphological Ontology. Systematic Biology, 56 (2): 283-294.

Lopardo, L., G. Hormiga and A. Melic. 2007. Spinneret spigot morphology in synaphrid spiders (Araneae, Synaphridae), with comments on the systematics of the family and description of a new species of Synaphris Simon 1894 from Spain.American Museum Novitates, 3556: 1-26.

Hormiga, G. and S. Lew. 2005. Chapter 48: Pimoidae. In: Darrell Ubick, Pierre Paquin, Paula E. Cushing, & Vince Roth (eds.) Spiders of North America: an identification manual (pp. 197-198). Download PDF

Hormiga, G., D.J. Buckle and N. Scharff. 2005. Nanoa, an enigmatic new genus of pimoid spiders from western North America (Pimoidae, Araneae). Zoological Journal of the Linnean Society 145:249-262. Download PDF

Hormiga, G. and N. Scharff. 2005. Monophyly and phylogenetic placement of the spider genus Labulla Simon, 1884 (Araneae, Linyphiidae) and description of the new genus Pecado. Zoological Journal of the Linnean Society 143:359-404.Download PDF

Miller, J.A. and G. Hormiga. 2004. Clade Stability and the Addition of Data - A Case Study from Erigonine Spiders (Araneae: Linyphiidae, Erigoninae). Cladistics 20: 385-442. (cover article) Download PDF Download Software (Pest 3.0)

Hormiga, G. 2003. Weintrauboa, a new genus of pimoid spiders from Japan and adjacent islands, with comments on the monophyly and diagnosis of the family Pimoidae and the genus Pimoa (Araneoidea, Araneae). Zoological Journal of the Linnean Society, 139: 261-281. Download PDF

Hormiga, G., Arnedo, M. Gillespie, R. G. 2003. Speciation on a Conveyor Belt: Sequen-tial Colonization of the Hawaiian Islands by Orsonwelles Spiders (Araneae, Linyphiidae). Systematic Biology 52(1): 70-88 (cover article). Download PDF
Hormiga, G. 2002. Orsonwelles, a new genus of giant linyphiid spiders (Araneae) from the Hawaiian Islands. Invertebrate Systematics 16:369-448 (cover article). Download PDF

Hormiga, G., N. Scharff, and J. Coddington. 2000. The Phylogenetic Basis of Sexual Size Dimorphism in Orb-Weaving Spiders (Araneae, Orbiculariae). Systematic Biology 49(3):435-462. Download PDF

Hormiga, G. 2000a. Higher level phylogenetics of erigonine spiders (Araneae, Linyphiidae, Erigoninae). Smithsonian Contributions to Zoology, 609:1-160.

Griswold, C., J. Coddington, G. Hormiga, and N. Scharff. 1998. Phylogeny of the orb web building spiders (Araneomorphae, Orbiculariae). Zoological Journal of the Linnean Society, 123:1-99. Download PDF

Coddington, J.A., G. Hormiga, and N. Scharff. 1997. Giant Female or Dwarf Male Spiders? Nature, 385:687-688. Download PDF

Hormiga, G., W.G. Eberhard, and J.A. Coddington. 1995. Web construction behavior in Australian Phonognatha and the phylogeny of nephiline and tetragnathid spiders (Araneae, Tetragnathidae). Australian Journal of Zoology, 43:313-364. Download PDF

Hormiga, G. 1994a. A revision and cladistic analysis of the spider family Pimoidae (Araneae: Araneoidea). Smithsonian Contributions to Zoology, 549:1-105.

Hormiga, G. 1994b. Cladistics and the comparative morphology of linyphiid spiders and their relatives (Araneae, Araneoidea, Linyphiidae). Zoological Journal of the Linnean Society, 111:1-71. Download PDF

Hormiga, G. 1993a. Implications of the phylogeny of Pimoidae for the systematics of linyphiid spiders (Araneae, Araneoidea, Linyphiidae). Memoirs of the Queensland Museum, 33(2):533-542.

For reprint requests, please send an email to hormiga@gwu.edu

 


Current Students:

Ligia Rosario Benavides (Ph.D. Student. Systematics of pirate spiders, Mimetidae)

Jesus Ballesteros Chavez (Ph.D. Student. Systematics of Leucauge)

Jimmy Cabra (PhD student from Universidade de São Paulo, Brazil. Systematics of Araneidae)

Thiago da Silva Moreira (Ph.D. Student. Systematics of Neotropical Linyphiidae)

Robert Kallal (Ph.D. Student. Spider Systematics)

Lidianne Salvatierra (Ph.D. Student from INPA, Manaus, Brazil. Systematics of Uloboridae)


Past Postdoctoral Researchers:

Suresh Benjamin (ATOL: Assembling the Tree of Life: Phylogeny of Spiders)

Dimitar Dimitrov (PEET: Systematics and Monography of Araneoid Spiders)


Past Students:

Jeremy Miller (Ph.D. 2003); Ingi Agnarsson (Ph.D. 2004); Matjaz Kuntner (Ph.D. 2005); Fernando Alvarez-Padilla (Ph.D. 2007); Lara Lopardo (Ph.D. 2009); Daniela Andriamalala (Ph.D. 2013).


WWW Links of interest:

Systematics and Monography of Araneoid Spiders

LinyGen: Linyphioid Genera of the World (Pimoidae and Linyphiidae), an Illustrated Catalog

International Society of Arachnology

American Arachnological Society

Arachnology Home Page

Willi Hennig Society

Systematic Biology

Zoological Record

Nomenclator Zoologicus

NSF-PEET program

Classes Taught

BISC 2000 - The Wonder of Life: Biodiversity studies in a changing planet
BISC 6210 - Phylogenetic Systematics (Fall)
BISC 6213 - Principles of Taxonomy: Documenting Diversity (Fall, even years)
BISC 6207 - Current Topics in Systematic Biology
Courses in Systematics and Evolution at GW