Joseph Spagna

 Associate Professor

Office:  Rarely

Laboratory:  317 Science Hall West

Email:  spagnaj at

Phone: 973-720-2793        


  • BA: Claremont McKenna College
  • PhD: University of California, Berkeley

Spagna Lab


I received my Ph.D. from the University of California, Berkeley in 2006, under the guidance of Rosemary Gillespie, with extensive collaboration with Robert Full's Polypedal Lab. My dissertation research focused on the evolution of grass-spiders (family Agelenidae) and their kin in the RTA clade. Since then, I have worked primarily on the evolution of running ability in spiders, and the evolution of catapult-like jaws in trap-jaw ants. Other interests include phylogenetic methods, both for tree-building and comparing characteristics of animals of different lineages, and generally anything having to do with the evolution of insects. Favorite teaching topics include entomological methods (collecting, identifying, curating) and the history of evolutionary ideas. -J. Spagna




Comparative evolutionary physiology, biomechanics, phylogenetics, systematics, and entomology.



Evolution of extreme jaw-speed and force production in trap-jaw ants

There are over 100 species of ants with trap-jaws- oversized jaws that 'click' open and slam shut with extreme speed and punishing force. Different versions of this morphology have evolved independently at least 5 times, with most species belonging to two closely-related genera- Odontomachus and Anochetus. Some of these species even use their jaws to 'jump' by slamming them into hard surfaces thus shooting themselves into the air. We are developing a phylogeny for these ants, and growing a dataset of strike speed and force measurements to understand how these extreme speeds and forces, and the associated behaviors, have evolved. These projects integrate physiology, biomechanics, mathematical modeling, and comparative evolutionary study to answer questions related to fundamental issues in evolutionary biology, such as optimization, adaptation, and the generation of novel morphological and behavioral syndromes.


Modeling secondary structure of ribosomal genes for improved phylogenetic analyses

Ribosomal genes have proven extremely useful in phylogenetic studies of deep divergences in the tree of life, because they evolve extremely slowly. They also have properties of 'self-complementarity' where the RNA's they produce fold into the scaffolding of the ribosomes by pairing complementary stretches of bases together. This structurally-critical self-complementarity of these 'stem' structures are even more constrained, and evolve slower, than the rest of the ribosomal genes. By modeling the secondary structure and estimating model parameters for the more- and less-constrained portions of the gene separately, we can improve phylogenetic analyses and molecular clock estimates of deep evolutionary divergences, such as those that produced the insect orders and spider families during the Paleozoic era.


Evolution of endemic grass-spiders of North America

The spider family Agelenidae C.L. Koch 1837 is large (>1000 described species) and has a high level of endemicity in North and Central America.  In addition to being common, ecologically-important predators, spiders from this family have been used as models for toxicological and biomechanics research. Despite this, to date little phylogenetic work has been done on these taxa, providing little evolutionary context for this research. In collaboration with international colleagues from Baja, Mexico, the lab is sequencing and analyzing genetic data from a broad sampling of North and Central American species, covering 8 of 9 currently described genera. Starting with 3 genes (CO1, 16S and 28S) from the mitochondrial and nuclear genomes, we are developing a robust hypothesis to test numerous longstanding evolutionary hypotheses and provide a basis for future comparative and taxonomic studies of these spiders





  • Spagna, J.C.,  Larabee, F. and Suarez, A.V. Worker polymorphism provides an alternate axis for strike-force variation in a power-amplified jaw system.  For submission to Journal of Comparative Physiology A, in prep.
  • Straub, S.*, & Spagna, J.C. Predicting range expansion of the Red Oak Borer (Enapholodes rufulus) due to projected climate-change conditions using geospatial analyses. In revision, Sept 2014.
  • Mohan, V*. and Spagna, J.C., Jump performance in trap‐jaw ants: beyond trigger hairs.  Proceedings of the New Jersey Academy of Sciences, (in press).
  • Spagna, J.C. & Peattie, A.  (2012).Terrestrial locomotion in arachnids.  Journal of Insect Physiology 58: 599-606.
  • Abbot, P. et al.  (2011). Inclusive fitness theory and eusociality.  Nature 471: E1- E4. (Brief communication arising).
  • Spagna, J.C., Valdivia, E*. and Mohan, V*.  (2011) Gait characteristics of two fast-running spider species (Hololena adnexa and Hololena curta), including an aerial phase (Araneae: Agelenidae). Journal of Arachnology 39:84-91.
  • Spagna, J.C., S.C. Crews, and R.G. Gillespie.  (2010) Patterns of habitat affinity and Austral/Holarctic parallelism in dictynoid spiders (Araneae: Entelegynae)  Invertebrate Systematics 24:238-257.
  • Miller, J.A., Carmichael, A., Ramírez, M., Spagna, J.C., Haddad, C.R., Řezáč, M., Johannesen, J., Král, J., Wang, X., Griswold, C.E.  (2010) Phylogeny of Entelegyne Spiders: Affinities of the Family Penestomidae (NEW RANK), Generic Phylogeny of Eresidae, and Asymmetric Rates of Change in Spinning Organ Evolution (Araneae, Araneoidea, Entelegynae)  Molecular Phylogenetics and Evolution 55:786-804.
  • Gillespie, R.G. & Spagna, J.C.  (2009). “Spiders” in Encyclopedia of Insects (2nd ed.), V. Resh and R. Carde, eds.  San Diego:  Elsevier Press.  Pp. 941-951.
  • Suarez, A.V. and J. C. Spagna. (2009). ‘Trap-jaw ants.’ Pp 216-217 in Ant Ecology, L. Lach, C. Parr, and K. Abbott editors. Oxford University Press.
  • Spagna, J.C., A. Schelkopf*, T. Carrillo,* and A.V. Suarez. (2009)  Evidence of behavioral co-option from context-dependent variation in mandible use in trap-jaw ants (Odontomachus spp.).
  • Naturwissenschaften 96:243-350.




Students:  The lab welcomes WPU students who would like to work on established projects, or explore their own ideas.  Results from high-quality student projects are presented at local and national scientific meetings, and included in peer-reviewed journal articles with contributing students as co-authors.

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BIO WPU, September 15th 2014