Benjamin Normark

Photograph of First Last

Professor

Contact Info

Phone: 413-545-3330
Office: Fernald Hall 204B

Education

B.A., Yale University, 1985

Ph.D., Cornell University, 1994,

Postdoctoral

Harvard University, 1997-2000

N.S.F. International Research Fellow, Natural History Museum, London 1996-1997

A. P. Sloan Postdoctoral Fellow, University of Arizona, 1994-1996

Research Interests

Evolution of Unusual Genetic Systems

The laws of genetics are not universal. While many species have classical Mendelian genetics, in which both parents contribute equally to the genomes of all offspring, several other genetic systems exist. In thousands of insect species, females monopolize parentage of sons. In others, males are completely absent. This variation and its evolutionary significance remain poorly understood, illustrating the incompleteness of the synthesis of genetics with evolutionary biology that constitutes the theoretical underpinning of modern biology. My laboratory studies the evolution of unusual genetic systems -- especially paternal genome elimination and parthenogenesis -- in armored scale insects.

Niche explosion: evolution of extreme generalists
Parthenogenesis (asexual reproduction) in insects is frequently correlated with an extremely broad range of host plants. Other correlates include: flightless females, invasiveness, status as economic pests. To account for these correlations, I have proposed the niche explosion hypothesis, postulating a positive feedback loop between host range and population size that resulted in extreme polyphagy and abundance in several insect groups having flightless females, including scale insects, broad-nosed weevils, and several families of moths. We are working to test several of the genomic and ecological predictions of this hypothesis. Consistent with the hypothesis, we find that several cosmopolitan pest species of armored scales are abundant and truly polyphagous in a tropical rainforest canopy in Panama.

Systematics and molecular identification of armored scale insects
Identifying armored scale insects to species is a non-trivial problem. In part this is simply due to the fact that that only skillfully microscope-slide-mounted adult females can be identified, but in part it is due to interesting biological phenomena such as very large population sizes and cryptic species complexes. My lab is assembling a collection and database consisting of thousands of genomic DNA samples linked to individual well-mounted, well-identified specimens. This collection will enable us to test evolutionary hypotheses, reconstruct evolutionary history, and improve the classification of these insects. It will also make possible a reliable system of molecular identification.

Representative Publications

Normark, B. B.., R D. Normark, A. Vovides, L. Solís-Montero, R. González-Gómez, M. T. Pulido-Silva, M. A. Escobar-Castellanos, M. Dominguez, M. A. Perez-Farrera, M. Janda, and A. Cibrian-Jaramillo. 2017. Cycad Aulacaspis Scale (Aulacaspis yasumatsui Takagi, 1977) in Mexico and Guatemala: a threat to native cycads. BioInvasions Records, 6: 187-193. http://www.reabic.net/journals/bir/2017/Issue3.aspx

Christodoulides, N., A. R. Van Dam, D. A. Peterson, R. J. N. Frandsen, U. H. Mortensen, B. Petersen, S. Rasmussen, B. B. Normark, and N. B. Hardy. 2017. Gene expression plasticity across hosts of an invasive scale insect species. PLoS ONE, 12: e0176956.

Mullen, K. M., S. A. Schneider, and B. B. Normark. 2016. New single-copy markers for scale insect systematics. Redia, 99: 207-214.

Peterson, D. A, N. B. Hardy, and B. B. Normark. 2016. Micro- and macroevolutionary trade-offs in plant-feeding insects. American Naturalist, 188: 640-650.

Hardy, N. B, D. A. Peterson, and B. B. Normark. 2016. Nonadaptive radiation: pervasive diet specialization by drift in scale insects? Evolution, 70: 2421-2428.

Abell, K. J., R. Gwiazdowski, B. B. Normark, N. Kamata, and R. G. Van Dreische. 2016. The scale and parasitoid community on native hemlocks in Japan. Biological Control, 100: 7-17.

Hardy, N. B, D. A. Peterson, and B. B. Normark. 2015. Scale insect host ranges are broader in the tropics. Biology Letters, 11. DOI: 10.1098/rsbl.2015.0924.

Peterson, D. A, N. B. Hardy, G. E. Morse, I. C. Stocks, A. Okusu, and B. B. Normark. 2015. Phylogenetic analysis reveals positive correlations between adaptations to diverse hosts in a group of pathogen-like herbivores. Evolution, 69: 2785-2792.

Ross, L., and B. B. Normark. 2015. Evolutionary problems in centrosome and centriole biology. Journal of Evolutionary Biology, 28: 995-1004.

Normark, B. B., and L. Ross. 2014. Genetic conflict, kin, and the origins of novel genetic systems. Philosophical Transactions of the Royal Society, 369, 20130364.

Gwiazdowski, R. A., and B. B. Normark. 2014. An unidentified parasitoid community (Chalcidoidea) is associated with pine-feeding Chionaspis scale insects (Hemiptera: Diaspididae). Annals of the Entomological Society of America, 107: 356-363.

Normark. B. B., G. E. Morse, A. Krewinski, and A. Okusu. 2014. Armored scale insects (Hemiptera: Diaspididae) of San Lorenzo National Park, Panama, with descriptions of two new species. Annals of the Entomological Society of America, 107: 37-49.

Japoshvili, G., K. J. Abell, B. B. Normark, and R. G. Van Driesche. 2013. Aphelinid and encyrtid (Hymenoptera, Chalcidoidea) parasitoids of armored scales (Hemiptera: Diaspididae) attacking hemlocks (Tsuga spp.) in Japan and the USA, with description of eight new species. Annals of the Entomological Society of America, 106: 541-554.

Schneider, S. A., J. H. Giliomee, J. W. Dooley, and B. B. Normark. 2013. The mutualism between Melissotarsus Emery ants (Hymenoptera: Formicidae) and armored scale insects (Hemiptera: Diaspididae): New armored scale species accounts and observations on a unique trophobiosis. Systematic Entomology, 38: 805-817.

Sabree, Z. L., C. Y. Huang, A. Okusu, N. A. Moran and B. B. Normark. 2013. The nutrient supplying capabilities of Uzinura, an endosymbiont of armored scale insects. Environmental Microbiology, 15: 1988-1999.

Vea, I. M., R. A. Gwiazdowski, and B. B. Normark. 2013. Corroborating molecular species discovery: four new pine-feeding species of Chionaspis. ZooKeys, . 270: 38-54.

Ross, L, N. B. Hardy, A. Okusu, and B. B. Normark. 2013. Large population size predicts the distribution of asexuality in scale insects. Evolution, 67: 196-206.

Ross, L., D. M. Shuker, B. B. Normark, and I. Pen. 2012. The role of endosymbionts in the evolution of haploid-male genetic systems in scale insects (Coccoidea). Ecology and Evolution, 2: 1071-1081.

Gwiazdowski, R. A., I. M. Vea, J. C. Andersen, and B. B. Normark. 2011. Discovery of cryptic species among North American pine-feeding Chionaspis scale insects (Hemiptera: Diaspididae). Biological Journal of the Linnean Society, 104: 47-62.

Normark, B. B., and N. A. Johnson. 2011. Niche explosion. Genetica, 139: 551-564.

Andersen, J. C., Wu, J., Gruwell, M. E. Gwiazdowski, R., Santana, S., Feliciano, N. M., Morse, G. E., and B. B. Normark. 2010. Phylogenetic analysis of armored scale insects (Hemiptera: Diaspididae) based on nuclear, mitochondrial, and endosymbiont DNA sequences. Molecular Phylogenetics and Evolution, 57: 992-1003.

Andersen, J. C., M. E. Gruwell, G. E. Morse, and B. B. Normark. 2010. Cryptic diversity in the Aspidiotus nerii complex in Australia. Annals of the Entomological Society of America, 103: 844-854.

Rugman-Jones, P., J. C. Andersen, J. Morse, B. B. Normark, and R. Stouthamer. 2010. Molecular phylogenetics of the recently described armored scale insect Abgrallaspis aguacatae and several congeners. Annals of the Entomological Society of America, 103: 30-38.

Gruwell, M. E., J. Wu, and B. B. Normark. 2009. Diversity and phylogeny of Cardinium bacteria associated with armored scale insects (Hemiptera: Diaspididae). Annals of the Entomological Society of America, 102: 1050-1061.

Burke, G. R., B. B. Normark, C. Favret, and N. A. Moran. 2009. Evolution and diversity of facultative symbionts from the aphid subfamily Lachninae. Applied and Environmental Microbiology, 75: 5328-5335.

Buckley, T. R., D. Attanayake, D.-C. Park, and S. Ravindran, T. R. Jewell, and B. B. Normark. 2008. Evolution of parthenogenesis in the New Zealand stick insect genus Acanthoxyla Uvarov (Phasmatodea: Phasmatidae): evidence from multiple loci. Molecular Phylogenetics and Evolution, 48: 335-349.

Gruwell, M. E., G. E. Morse, and B. B. Normark. 2007. Phylogenetic congruence of armored scale insects (Hemiptera: Diaspididae) and their primary endosymbionts from the phylum Bacteroidetes. Molecular Phylogenetics and Evolution, 44: 267-280.

Úbeda, F., and B. B. Normark. 2006. Sibling competition, male killers and the origins of paternal genome elimination. Theoretical Population Biology, 70: 511-526.

Gwiazdowski, R. A., R. G. Van Driesche, A. Desnoyers, S. Lyon, S. Wu, N. Kamata, and B. B. Normark. 2006. Possible geographic origin of beech scale, Cryptococcus fagisuga (Hemiptera: Eriococcidae), an invasive pest in North America. Biological Control, 39: 9-18.

Normark, B. B. 2006. Perspective: maternal kin groups and the evolution of asymmetric genetic systems -- genomic imprinting, haplodiploidy, and parthenogenesis. Evolution, 60: 631-642.

Morse, G. E., and B. B. Normark. 2006. A molecular phylogenetic study of armoured scale insects (Diaspididae). Systematic Entomology, 31: 338-349.

Provencher, L. M., G. E. Morse, A. R. Weeks, and B. B. Normark. 2005. Parthenogenesis in the Aspidiotus nerii complex (Hemiptera: Diaspididae): a single origin of a worldwide, polyphagous lineage associated with Cardinium bacteria. Annals of the Entomological Society of America, 98: 629-635.

Normark, B. B. 2004. Haplodiploidy as an outcome of coevolution between male-killing cytoplasmic elements and their hosts. Evolution, 58: 790-798.

Normark, B. B. 2003. Evolution of alternative genetic systems in insects. Annual Review of Entomology, 48: 397-423.

Normark, B. B., O. P. Judson, and N. A. Moran. 2003. Genomic signatures of ancient asexual lineages. Biological Journal of the Linnean Society, 79: 69-84.

Normark, B. B., and N. A. Johnson. In press. Niche explosion.Genetica.

Andersen, J. C., Wu, J., Gruwell, M. E. Gwiazdowski, R., Santana, S., Feliciano, N. M., Morse, G. E., and B. B. Normark. 2010. Phylogenetic analysis of armored scale insects (Hemiptera: Diaspididae) based on nuclear, mitochondrial, and endosymbiont DNA sequences. Molecular Phylogenetics and Evolution, 57: 992-1003.

Andersen, J. C., Gruwell, M. E. Morse, G. E., and B. B. Normark. 2010. Cryptic diversity in the Aspidiotus nerii complex in Australia. Annals of the Entomological Society of America, 103: 844-854.

Rugman-Jones, P., J. C. Andersen, J. Morse, B. B. Normark and R. Stouthamer. 2010. Molecular phylogenetics of the recently described armored scale insect Abgrallaspis aguacatae and several congeners. Annals of the Entomological Society of America, 103: 30-38.

Gruwell, M. E., J. Wu, and B. B. Normark. 2009. Diversity and phylogeny of Cardinium bacteria associated with armored scale insects (Hemiptera: Diaspididae). Annals of the Entomological Society of America, 102: 1050-1061.

Burke, G. R., B. B. Normark, C. Favret, and N. A. Moran. 2009.
Evolution and diversity of facultative symbionts from the aphid subfamily Lachninae. Applied and Environmental Microbiology, 75: 5328-5335.

Buckley, T. R., D. Attanayake, D.-C. Park, and S. Ravindran, T. R. Jewell, and B. B. Normark. 2008. Evolution of parthenogenesis in the New Zealand stick insect genus Acanthoxyla Uvarov (Phasmatodea: Phasmatidae): evidence from multiple loci. Molecular Phylogenetics and Evolution, 48: 335-349.

Gruwell, M. E., G. E. Morse, and B. B. Normark. 2007. Phylogenetic congruence of armored scale insects (Hemiptera: Diaspididae) and their primary endosymbionts from the phylum Bacteroidetes. Molecular Phylogenetics and Evolution, 44: 267-280.

Úbeda, F., and B. B. Normark. 2006. Sibling competition, male killers and the origins of paternal genome elimination. Theoretical Population Biology 70: 511-526.

Gwiazdowski, R. A., R. G. Van Driesche, A. Desnoyers, S. Lyon, S. Wu, N. Kamata, and B. B. Normark. 2006. Possible geographic origin of beech scale, Cryptococcus fagisuga (Hemiptera: Eriococcidae), an invasive pest in North America. Biological Control, 39: 9-18.

Normark, B. B. 2006. Perspective: maternal kin groups and the evolution of asymmetric genetic systems -- genomic imprinting, haplodiploidy, and parthenogenesis. Evolution, 60: 631-642.

Morse, G. E., and B. B. Normark. 2006. A molecular phylogenetic study of armoured scale insects (Diaspididae). Systematic Entomology, 31: 338-349.

Provencher. L. M., G. E. Morse, A. R. Weeks, and B. B. Normark. 2005. Parthenogenesis in the Aspidiotus nerii complex (Hemiptera: Diaspididae): a single origin of a worldwide, polyphagous lineage associated with Cardinium bacteria. Annals of the Entomological Society of America, 98: 629-635.

Normark, B. B. 2004. Haplodiploidy as an outcome of coevolution between male-killing cytoplasmic elements and their hosts. Evolution, 58: 790-798.

Normark, B. B. 2003. Evolution of alternative genetic systems in insects. Annual Review of Entomology, 48: 397-423.

Normark, B. B., O. P. Judson, and N. A. Moran. 2003. Genomic signatures of ancient asexual lineages. Biological Journal of the Linnean Society, 79: 69-84.