Department of Entomology


Allison Hansenentomology_entomology

Assistant Professor of Entomology

Location: 204 Entomology Bldg.

Tel:(951) 827-9271
Research Website



The Hansen lab is interested in ecological and evolutionary genomics of insect-microbe interactions. Our lab teases apart the molecular mechanisms that underpin insect-microbe co-evolution using comparative and functional genomics in an evolutionary framework. Broad objectives our lab explores are:

 1) Determine how microbes affect eukaryotic metabolisms, and how their individual metabolisms mechanistically interact together. 2) Identify which microbe genes and small RNAs are responsible for producing the extended insect host phenotype that may increase insect fitness in certain environments.Our lab uses insect and microbe genomics together with field and laboratory trials to provide novel insights into the complexity and dynamics of insect-microbe symbioses.


B.S., Forestry, 1999-2003, University of Montana, Missoula

M.S., Forestry and Conservation, 2003-2005, University of Montana, Missoula

Ph.D., Entomology, 2005-2009, University of California, Riverside 


2016- List of Teachers Ranked Excellent by their Students, University of Illinois, Urbana-Champaign 

2015- NSF/IGTRCN- Peer-to-Peer Training Fellowship.

2015- Joseph B. Hawkes Research Award

2015- Institute for Sustainability, Energy, and Environment Award

2011- USDA/NIFA- Postdoctoral Fellowship

2009- NIH- Postdoctoral Fellowship

2009- John Henry Comstock Award

2007- NSF- Doctoral Dissertation Improvement Grant (DDIG)

2007- First place in Graduate student Paper competition for the President’s prize award at the 55th Annual Meeting of the Entomological Society of America. December 9-12, 2007, San Diego, California.

2007- Don Dahlsten Memorial Fund Award- November 13-14th.

2006- The "Best Paper" in the C.C. Burkhardt Graduate Student Paper Competition at the 77th Rocky Mountain Conference of Entomologists, Colorado Springs, CO.

Former Institutions

Assistant Professor of Entomology- University of Illinois, Urbana- Champaign, Illinois,  2013-2017

Postdoctoral Fellow- Ecology and Evolutionary Biology, Yale University, New Haven, 4/2010-7/2013

Postdoctoral Fellow- Ecology and Evolutionary Biology, University of Arizona, Tucson, 5/2009-4/2010 


Thairu M.W., Cheng S, Hansen A.K. 2017. A sRNA in a reduced mutualistic symbiont genome regulates its own gene expression. Mol Ecol. 2017;00:1–11. https://doi.org/10.1111/mec.14424

Hansen A.K. and Skidmore, I.H.  2017. Psyllids, it's what's on the inside that counts: community cross talk facilitates prophage interactions. mSphere. 2:e00227-17. https://doi.org/10.1128/mSphere.00227-17.

Skidmore, I.H. and A.K. Hansen.  2017. The evolutionary development of plant-feeding insects and their nutritional endosymbionts. Insect Science. doi:10.1111/1744-7917.12463.

Riley, A.B., Kim, D., and A.K. Hansen. 2017. The Genome Sequence of Candidatus Carsonella ruddii strain BC, a Nutritional Endosymbiont of Bactericera cockerelli. Genome Announcements. 5:e00236-17. https://doi.org/10.1128/genomeA.00236-17.

Russell, J.A., Oliver, K.M., A.K. Hansen. 2017. Band-aids for Buchnera and B-vitamins for all. Molecular Ecology. 26: 2199–2203. doi:10.1111/mec.14047.

Thairu, M.W., I.H. Skidmore, R. Bansal, E. Nováková, T.E. Hansen, H. Li-Byarlay, S.A. Wickline, and A.K. Hansen. 2017. Efficacy of RNAi knockdown using aerosolized siRNAs bound to nanoparticles in three different aphid species. Insect Molecular Biology. 26: 356–368. doi:10.1111/imb.12301.

Muturi, E.J., J.J. Bara, A.P. Rooney, and A.K. Hansen. 2016. Midgut fungal and bacterial microbiota of Aedes triseriatus and Aedes japonicus shift in response to La Crosse virus infection. Molecular Ecology 25(16):4075-90.

Kim*,D., M.W. Thairu*, and A.K. Hansen. 2016. Novel Insights into Insect-Microbe Interactions- Role of Epigenomics and Small RNAs. Front. Plant Sci.7:1164. doi:10.3389/fpls.2016.01164.

            *Co-first authors - Contributed equally

Hansen, A.K. and P.H. Degnan. 2014. Widespread expression of conserved small RNAs in small symbiont genomes. ISME J. 8, 2490–2502; doi: 10.1038/ismej.2014.121.

Casteel, C.L. and Hansen, A.K. 2014. Evaluating insect- microbiomes at the plant-insect interface. Journal of Chemical Ecology. 40(7):836-47; doi: 10.1007/s10886-014-0475-5.

Hansen, A.K. and N.A. Moran 2014. The impact of microbial symbionts on host plant utilization by herbivorous insects. Molecular Ecology. 23(6):1473-96.

Sabree, Z.L., A.K. Hansen, and N.A. Moran 2012. Independent studies using deep sequencing resolve the same set of core bacterial species dominating gut communities of honey bees. PLoS ONE 7(7): e41250.

Hansen, A.K. and N.A. Moran 2012. Altered tRNA characteristics and 3' maturation in bacterial symbionts with reduced genomes. Nucleic Acids Research 40(16), 7870-7884.

Moran, N.A., A.K. Hansen, J.E. Powell, and Z.L. Sabree 2012. Distinctive gut microbiota of honey bees assessed using deep sampling from individual worker bees. PLoS ONE. 7(4): e36393.

Hansen*, A.K., C.L. Casteel*, L.L. Walling, and T.D. Paine 2012. Manipulation of plant defense responses by the tomato psyllid (Bactericera cockerelli) and its associated endosymbiont Liberibacter psyllaurous. PLoS ONE. 7(4): e35191.

            *Co-first authors - Contributed equally

Hansen, A.K., C. Vorburger, and N.A. Moran 2012. Genomic basis of endosymbiont-conferred protection against an insect parasitoid. Genome Research. 22:106-114.

Hansen, A.K. and N.A. Moran 2011. Aphid genome expression reveals host-symbiont cooperation in the production of amino acids. Proceedings of the National Academy of Sciences USA. January 31, 2011.

Six, D.L., M. Poulsen, A.K. Hansen, M.J. Wingfield, J. Roux, P. Eggleton, B. Slippers, and T.D. Paine 2011. Anthropogenic effects on interaction outcomes: examples from insect-microbial symbioses in forest and savanna ecosystems. Symbiosis. 53:101-121.

Degnan, P.H., L.S. Bittleston, A.K. Hansen, Z.L. Sabree, N.A. Moran, and R.P. Almeida 2011. Origin and examination of a leafhopper facultative endosymbiont. Current Microbiology. 62(5): 1565-1572.

Hansen, A.K., D.L. Six, and Y.K. Ortega 2009. Comparison of ground beetle (Coleoptera: Carabidae) assemblages in Rocky Mountain savannas invaded and un-invaded by an exotic forb, spotted knapweed. Northwest Science. Volume 83 Issue 4: 348–360.

Hansen, A.K., J.T. Trumble, R. Stouthamer, and T.D. Paine 2008. New Huanglongbing (HLB) Candidatus species,"C. Liberibacter psyllaurous", found to infect tomato and potato is vectored by the psyllid Bactericerca cockerelli (Sulc). Applied and Environmental Microbiology. Vol. 74, No. 18: 5862-5865.

Mc Donnell, R.J., A. Hansen, T.D. Paine, and M.J. Gormally 2008. A record of the invasive slug, Veronicella cubensis (Pfeiffer, 1840) in California. The Veliger. Vol. 50, No. 2: 81-82.

Hansen, A.K., G. Jeong, T.D. Paine, and R. Stouthamer 2007. Frequency of secondary symbiont infection in an invasive psyllid relates to parasitism pressure on a geographic scale in California. Applied and Environmental Microbiology. Vol. 73, No. 23: 7531-7535.

Reed, D.A., K.A. Luhring, C.A. Stafford, A.K. Hansen, J.G. Millar, L.M. Hanks, and T.D. Paine 2007. Host defensive response against an egg parasitoid involves cellular encapsulation and melanization. Biological Control 41(2), 214-222. 


General Campus Information

University of California, Riverside
900 University Ave.
Riverside, CA 92521
Tel: (951) 827-1012

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Dept of Entomology Information

417 Entomology Bldg.

Fax: (951) 827-3086
Prospective Grad Students: (800) 735-0717
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