Connecticut State The Connecticut Agricultural Experiment Station

Philip M. Armstrong

Department of Entomology
The Connecticut Agricultural Experiment Station
123 Huntington Street
New Haven, CT 06511
Voice: (203) 974-8510 Fax: (203) 974-8502
E-mail: Philip.Armstrong@ct.gov

Expertise:

Dr. Armstrong has expertise on the molecular evolution, epidemiology, and ecology of arthropod-borne viruses (arboviruses). 

 

Education

B.A. Biology, University of California, Santa Cruz: 1991

S.M. Tropical Public Health, Harvard School of Public Health: 1994

Sc.D. Tropical Public Health, Harvard School of Public Health: 1998

 

Station Career:

Chief Scientist/Department Head: May 2024-present

Agricultural Scientist: 2014-May 2024

Associate Agricultural Scientist: 2008-2014

Assistant Scientist II: 2004-2008

 

Past Research:

Dr. Armstrong has conducted research on tick- and mosquito-borne viruses for more than 25 years (see selected publications below).

 

Current Research:

Dr. Armstrong’s current research program focuses on the eco-epidemiology and evolution of arboviruses transmitted in the eastern U.S., including eastern equine encephalitis, Powassan, and West Nile viruses. Genetic relationships of these viruses are compared to track the origin, spread, and long-term persistence of strains involved in disease outbreaks and to identify variants associated with increased transmission or virulence phenotypes. In addition, his group evaluates the role of different mosquito species to serve as vectors of arboviruses by determining their vector competence, host-feeding, and virus-infection patterns in nature. Dr. Armstrong’s group maintains a network of 108 fixed mosquito-trapping stations located in 88 municipalities in Connecticut as a part of a statewide surveillance program. Mosquitoes are trapped at each site on a weekly rotation June-October, identified to the species level, and tested for viral infection to assess risk and guide public health action. His group is also using this data to evaluate long-term changes to mosquito species composition and arbovirus risk in response to landscape and climate changes.

 

Selected publications available from the author, Philip.Armstrong@ct.gov

  • Johnson, R. M., Stopard, I. J., Byrne, H. M., Armstrong, P. M., Brackney, D. E., and Lambert, B. (2024). Investigating the dose-dependency of the midgut escape barrier using a mechanistic model of within-mosquito dengue virus population dynamics. PLoS Pathog. 20(4), e1011975.

  • Armstrong, P. M., Anderson, J. F., Sharma, R., Misencik, M. J., Bransfield, A., Vossbrinck, C. R., and Brackney, D. E. (2024). Field isolation and laboratory vector-host studies of Brazoran virus (Peribunyaviridae: Orthobunyavirus) from Florida. Am. J. Trop. Med. Hyg. 110(5), 968-970.

  • Johnson, R. M., Cozens, D. W., Ferdous, Z., Armstrong, P. M., and Brackney, D. E. (2023). Increased blood meal size and feeding frequency compromise Aedes aegypti midgut integrity and enhance dengue virus dissemination. PLoS Negl. Trop. Dis. 17(11), e0011703.

  • Shepard, J. J. and Armstrong, P. M. (2023). Jamestown Canyon virus comes into view: understanding the threat from an underrecognized arbovirus.  J. Med. Entomol. 60(6), 1242-1251.

  • Anderson, J. F., Main, A. J., Armstrong, P. M., and Andreadis, T. G. (2023). Seasonality of mosquitoes in North Dakota, 2003-2006, with four new state records. J. Am. Mosq. Control. Assoc. 39(2), 68-74.

  • Hill, V., Koch, R. T., Bialosuknia, S. M., Ngo, K., Zink, S. D., Koetzner, C. A., Maffei, J. G., Dupuis, A. P., Backenson, P. B., Oliver, J., Bransfield, A. B., Misencik, M. J., Petruff, T. A., Shepard, J. J., Warren, J. L., Gill, M. S., Baele, G., Vogels, C. B. F., Gallagher, G., Burns, P., Hentoff, A., Smole, S., Brown, C., Osborne, M., Kramer, L. D., Armstrong, P. M., Ciota, A. T., and Grubaugh, N. D. (2023). Dynamics of eastern equine encephalitis virus during the 2019 outbreak in the Northeast United States. Curr. Biol. 33(12), 2515-2527.

  • McMillan, J. R., Chaves, L. F., and Armstrong, P. M. (2023). Ecological predictors of mosquito population and arbovirus transmission synchrony estimates. J. Med. Entomol. 60(3), 564-574.

  • Vogels, C. B. F., Brackney, D. E., Dupuis, A. P. II, Robich, R. M., Fauver, J. R., Brito, A. F., Williams, S. C., Anderson, J. F., Lubelczyk, C. B., Lange, R. E., Prusinski, M. A., Kramer, L. D., Gangloff-Kaufmann, J. L., Goodman, L. B., Baele, G., Smith, R. P., Armstrong, P. M., Ciota, A. T., Dellicour, S., and Grubaugh, N. D. (2023). Phylogeographic reconstruction of the emergence and spread of Powassan virus in the northeastern United States. Proc. Natl. Acad. Sci. USA. 120(16), e2218012120.

  • Gloria-Soria, A., Shragai, T., Ciota, A. T., Duval, T. B., Alto, B. W., Martins, A. J., Westby, K. M., Medley, K. A., Unlu, I., Campbell, S. R., Kawalkowski, M., Tsuda, Y., Higa, Y., Indelicato, N., Leisnham, P. T., Caccone, A., and Armstrong, P. M. (2022). Population genetics of an invasive mosquito vector, Aedes albopictus in the Northeastern USA. NeoBiota, 78, 99-127.

  • Bransfield, A. B., Misencik, M. J., Brackney, D. E., and Armstrong, P. M. (2022). Limited capacity for Aedes aegypti to mechanically transmit chikungunya virus and dengue virus. Am. J. Trop. Med. Hyg. 107(6), 1239-1241.

  • Field, E. N., Shepard, J. J., Clifton, M. E., Price, K. J., Witmier, B. J., Johnson, K., Boze, B., Abadam, C., Ebel, G. D., Armstrong, P. M., Barker, C. M., and Smith, R. C. (2022). Semi-field and surveillance data define the natural diapause timeline for Culex pipiens across the United States. Commun. Biol. 5(1), 1300.

  • McMillan, J. R., Olson, M. M., Petruff, T., Shepard, J. J., and Armstrong, P. M. (2022). Impacts of Lysinibacillus sphaericus on mosquito larval community composition and larval competition between Culex pipiens and Aedes albopictus. Sci. Rep. 12(1), 18013.

  • Gloria-Soria, A., Brackney, D. E., and Armstrong, P. M. (2022). Saliva collection via capillary method may underestimate arboviral transmission by mosquitoes. Parasite Vectors, 15(1), 103.
  • Armstrong, P. M., and Andreadis, T. G. (2022). Ecology and epidemiology of eastern equine encephalitis virus in the northeastern United States: An Historical Perspective. J. Med. Entomol. 59(1), 1-13.
  • Anderson, J. F., Fish, D., Armstrong, P. M., Misencik, M. J., Bransfield, A., Ferrandino, F. J., Andreadis, T. G., Stenglein, M. D., Kapuscinski, M. L. (2022). Seasonal dynamics of mosquito-borne viruses in the southwestern Florida Everglades, 2016, 2017. Am. J. Trop. Med. Hyg. 106(2), 610-622.
  • Khalil, N., Little, E. A. H., Akaratovic, K. I., Kiser, J. P., Abadam, C. F., Yuan, K. J., Misencik, M. J., Armstrong, P. M., and Molaei, G. (2021). Host associations of Culex pipiens: a two-year analysis of bloodmeal sources and implications for arboviral transmission in southeastern Virginia. Vector Borne Zoonotic Dis. 21(12), 961-972.
  • Sharma, R., Cozens, D. W., Armstrong, P. M., and Brackney, D. E. (2021). Vector competence of human-biting ticks Ixodes scapularis, Amblyomma americanum and Dermacentor variabilis for Powassan virus. Parasite Vectors, 14(1), 466.
  • Brown, S. C., Cormier, J., Tuan, J., Lier, A. J., McGuone D, Armstrong, P. M., Kaddouh, F., Parikh, S., Landry, M. L., and Gobeske, K. T. (2021). Four human cases of eastern equine encephalitis in Connecticut, USA, during a larger regional outbreak, 2019. Emerg. Infect. Dis. 27(8), 2042–51.
  • McMillan, J. R., Harden, C. A., Burtis, J. C., Breban, M. I., Shepard, J. J., Petruff, T. A., Misencik, M. J., Bransfield, A. B., Poggi, J. D., Harrington, L. C., Andreadis, T. G., and Armstrong, P. M. (2021). The community-wide effectiveness of municipal larval control programs for West Nile virus risk reduction in Connecticut, USA. Pest Manag. Sci. 77(11), 5186-5201.
  • Wilson, S. N., López K., Coutermash-Ott, S., Auguste, D. I., Porier, D. L., Armstrong, P. M., Andreadis, T. G., Eastwood, G., and Auguste, A. J. (2021). La Crosse virus shows strain-specific differences in pathogenesis. Pathogens, 10(4), 400.
  • Burtis, J. C., Poggi, J. D., McMillan, J. R., Crans, S. C., Campbell, S. R., Isenberg, A., Pulver, J., Casey, P., White, K., Zondag, C., Badger, J. R., Berger, R., Betz, J., Giordano, S., Kawalkowski, M., Petersen, J. L., Williams, G., Andreadis, T. G., Armstrong, P. M., and Harrington, L. C. (2021). NEVBD Pesticide Resistance Monitoring Network: establishing a centralized network to increase regional capacity for pesticide resistance detection and monitoring. J. Med. Entomol. 58(2), 787-797.
  • Petruff, T. A., McMillan, J. R., Shepard, J. J., Andreadis, T. G., and Armstrong, P. M. (2020). Increased mosquito abundance and species richness in Connecticut, United States 2001-2019. Sci Reports, 10(1), 19287.

  • Eastwood, G., Shepard, J. J., Misencik, M. J., Andreadis, T. G., and Armstrong, P. M. (2020). Local persistence of novel regional variants of La Crosse virus in the Northeast USA. Parasite Vectors, 13(1), 569.

  • McMillan, J. R., Armstrong, P. M., and Andreadis, T. G. (2020). Patterns of mosquito and arbovirus community composition and ecological indexes of arboviral risk in the northeast United States. PLoS Negl.Trop. Dis. 14(2):e0008066.

  • Eastwood, G., Donnellycolt, A. K., Shepard, J. J., Misencik, M. J., Bedoukian, R., Cole, L., Armstrong, P. M., and Andreadis, T. G. (2020). Evaluation of novel trapping lures for monitoring exotic and native container-inhabiting Aedes spp. (Diptera: Culicidae) mosquitoes. J. Med. Entomol., 57(2), 534-541.

  • Kache, P. A., Eastwood, G., Collins-Palmer, K., Katz, M., Falco, R. C., Bajwa, W. I., Armstrong, P. M., Andreadis, T. G., and Diuk-Wasser, M. A. (2020). Environmental determinants of Aedes albopictus abundance at a northern limit of its range in the United States. Am. J. Trop. Med. Hyg., 102(2), 436-447.

  • Armstrong, P. M. , Ehrlich, H. Y., Magalhaes, T., Miller, M. R., Conway, P. J., Bransfield, A., Misencik, M. J., Gloria-Soria, A., Warren, J. L., Andreadis, T. G., Shepard, J. J., Foy, B. D., Pitzer, V. E., Brackney, D. E. (2020). Successive blood meals enhance virus dissemination within mosquitoes and increase transmission potential. Nat. Microbiol. 5(2), 239-247.

  • Uraki, R., Hastings, A. K., Brackney, D. E., Armstrong, P. M., Fikrig, E. (2019). AgBR1 antibodies delay lethal Aedes aegypti-borne West Nile virus infection in mice. NPJ Vaccines, 4, 23.

  • Keyel, A. C., Elison Timm, O., Backenson, P. B., Prussing, C., Quinones, S., McDonough, K. A., Vuille, M., Conn, J. E., Armstrong, P. M., Andreadis, T. G., Kramer, L. D. (2019). Seasonal temperatures and hydrological conditions improve the prediction of West Nile virus infection rates in Culex mosquitoes and human case counts in New York and Connecticut. PLoS One, 14(6), e0217854.

  • Weger-Lucarelli, J., Rückert, C., Grubaugh, N. D., Misencik, M. J., Armstrong, P. M., Stenglein, M. D., Ebel, G. D., Brackney, D. E. (2018). Adventitious viruses persistently infect three commonly used mosquito cell lines. Virology, 521, 175-180.

  • Tan, Y., Tsan-Yuk Lam, T., Heberlein-Larson, L. A., Smole, S. C., Auguste, A. J., Hennigan, S., Halpin, R. A., Fedorova, N., Puri, V., Stockwell, T. B., Shilts, M. H., Andreadis, T., Armstrong, P. M., Tesh, R. B., Weaver, S. C., Unnasch, T. R., Ciota, A. T., Kramer, L. D., Das, S. R. (2018). Large scale complete genome sequencing and phylodynamic analysis of eastern equine encephalitis virus reveal source-sink transmission dynamics in the United States. J. Virol.  92:e00074-18

  • Anderson, J. F., Armstrong, P. M., Misencik, M. J., Bransfield, A. B, Andreadis, T. G., and Molaei, G. (2018). Seasonal distribution, blood feeding habits, and viruses of mosquitoes in an open-faced quarry in Connecticut, 2010 and 2011. J. Am. Mosq. Cont. Assoc. 34(1), 1-10.

  • Yang, F., Chan, K., Marek, P. E., Armstrong, P. M., Liu, P., Bova, J. E., Bernick, J. N., McMillan, B. E., Weidlich, B. G., Paulson, S. L. (2018). Cache Valley Virus in Aedes japonicus japonicus mosquitoes, Appalachian Region, United States. Emerg. Infect. Dis., 24(3), 553-557.

  • Skaff, N. K., Armstrong, P. M., Andreadis, T. G., and Cheruvelil, K. S. (2017). Wetland characteristics linked to broad-scale patterns in Culiseta melanura abundance and eastern equine encephalitis virus infection. Parasit Vectors, 10, 501.

  • Gloria-Soria, A., Armstrong, P. M., Powell, J. F., and Turner P. E. (2017). Infection rate of Aedes aegypti mosquitoes with dengue virus depends on the interaction between temperature and mosquito genotype. Proc Biol Sci., 284, 20171506.

  • Armstrong, P. M., Andreadis T. G., Shepard J. J., and Thomas, M. C. (2017). Northern range expansion of the Asian tiger mosquito (Aedes albopictus): Analysis of mosquito data form Connecticut USA. PLoS. Negl. Trop. Dis. 11(5), e0005623.

  • Cahill, M. E., Yao, Y., Nock, D., Armstrong, P. M., Andreadis T. G., Diuk-Wasser, M. A., Montgomery, R. R. (2017). West Nile Virus Seroprevalence, Connecticut, USA, 2000-2014. Emerg. Infect. Dis. 23(4), 708-710.

  • Grubaugh, N. D., Rückert, C., Armstrong, P. M., Bransfield, A., Anderson, J. F., Ebel, G. D., and Brackney, D. E. (2016). Transmission bottlenecks and RNAi collectively influence tick-borne flavivirus evolution. Virus Evol., 2(2), vew033.

  • Brackney, D. E.and Armstrong, P. M. (2016). Transmission and evolution of tick-borne viruses. Curr. Opin. in Virol., 21, 67-74.
  • Misencik M. J., Grubaugh, N. D., Andreadis, T. G., Ebel, G. D., and Armstrong, P. M. (2016). Isolation of a novel insect-specific flavivirus from Culiseta melanura in the northeastern United States. Vector-Borne Zoonotic Dis. 16(33),181-190.
  • Molaei, G., Thomas, M. C., Muller, T., Medlock, J., Shepard, J. J., Armstrong, P. M., and Andreadis, T. G. (2016). Dynamics of vector-host interactions in avian communities in four eastern equine encephalitis virus foci in the northeastern U.S. PLoS Negl. Trop. Dis. 10(1), e0004347.
  • Nelson, R., Esponda-Morrison, B., Armstrong, P., and Shepard, J. (2015). West Nile virus- Connecticut, 2015. Conn Epidemiol., 35(7), 25-26.
  • Molaei, G., Armstrong, P. M., Graham, A. C., Kramer, L. D., and Andreadis, T. G. (2015). Insights into the recent emergence and expansion of eastern equine encephalitis virus in a new focus in the Northern New England USA. Parasites & Vectors, 8, 516.
  • Molaei, G., Armstrong, P. M., Abadam, C. F., Akaratovic, K. I., Kiser, J. P., and Andreadis, T. G. (2015). Vector-host interactions of Culiseta melanura in a focus of eastern equine encephalitis virus activity in southeastern Virginia.  PLoS One, 10(9), e0136743.
  • Armstrong, P. M., Andreadis T. G., and Anderson, J. F. (2015). Emergence of a new lineage of Cache Valley virus (Bunyaviridae: Orthobunyavirus) in the northeastern United States. Am. J. Trop. Med. Hyg., 93, 11-17.
  • Anderson, J. F., Main, A. J., Armstrong, P. M., Andreadis, T. G., and Ferrandino, F. J. (2015). Arboviruses in North Dakota, 2003-2006.  Am. J. Trop. Med. Hyg., 92, 377-93.
  • Andreadis T. G., Armstrong, P. M., Anderson, J. F., and Main, A. J. (2014). Spatial-temporal analysis of Cache Valley virus infection in Anopheline and Culicine mosquitoes in the northeastern United States, 1997-2012. Vector-Borne Zoonotic Dis. 14, 763-773.
  • Nelson, R., Ciesielski, T., Andreadis, T., and Armstrong, P. (2014). Human case of eastern equine encephalitis- Connecticut, 2013. Conn. Epidemiol. 34(3), 9-10.
  • Nelson R., Esponda, B., Andreadis, T., and Armstrong, P. (2014). West Nile virus Connecticut, 2000-2013. Conn. Epidemiol. 34(2), 5-7.
  • Armstrong, P. M., Anderson, J. F., Farajollahi, A., Healy, S. P., Unlu, I., Crepeau, T. N., Gaugler, R., Fonseca, D. M., and Andreadis, T. G. (2013). Isolations of Cache Valley virus from Aedes albopictus (Diptera: Culicidae) in New Jersey and evaluation of its role as a regional arbovirus vector. J. Med. Entotomol. 50(6), 1310-1314.
  • Armstrong, P. M. and Andreadis, T. G. (2013). Eastern equine encephalitis virus--old enemy, new threat.  N. Engl. J. Med., 368, 1670-1673.
  • Molaei, G., Andreadis T. G., Armstrong, P. M., Thomas, M. C., Deschamps, T., Cuebas-Incle, E., Montgomery, W., Osborne, M., Smole, S., Matton, P., Andrews, W., Best, C., Cornine, F. III, Bidlack, E., and Texeira, T. (2013). Vector-host interactions and epizootiology of eastern equine encephalitis virus in Massachusetts. Vector Borne Zoonotic Dis., 13, 312-323.
  • Anderson, J. F. and Armstrong, P. M. (2012). Prevalence and genetic characterization of Powassan virus strains infecting Ixodes scapularis in Connecticut. Am. J. Trop. Med. Hyg., 87, 754-759.
  • Armstrong, P. M., Prince, N., and Andreadis, T. G. (2012). Development of a multi-target TaqMan assay to detect eastern equine encephalitis virus variants in mosquitoes. Vector Borne Zoonotic Dis., 12, 872-876.
  • Armstrong, P. M., Vossbrinck, C. R., Andreadis, T. G., Anderson, J. F., Pesko, K. N., Newman, R. M., Lennon, N. J., Birren, B. W., Ebel, G. D. and Henn, M. R. (2011). Molecular evolution of West Nile virus in a northern temperate region: Connecticut, USA 1999-2008. Virology, 417, 203-210.
  • Armstrong, P. M., Andreadis, T. G., Finan, S. L., Shepard, J. J., Thomas, M. C. (2011). Detection of infectious virus from field-collected mosquitoes by Vero cell culture assay. J. Vis. Exp. 52: pii: 2889. DOI: 10.3791/2889.30.
  • Molaei, G., Cummings, R. F., Su, T., Armstrong, P. M., Williams, G. A., Chen, M. L., Webb, J. P., and Andreadis, T. G. (2010). Vector-host interactions governing epidemiology of West Nile virus in southern California.  Am. J. Trop. Med. Hyg., 83, 1269-1282.
  • Armstrong, P. M. and Andreadis, T. G. (2010). Eastern equine encephalitis virus in mosquitoes and their role as bridge vectors.  Emerg. Infect. Dis. 16,1869-1874.
  • Andreadis T. G., Armstrong, P. M., and Bajwa, W. I. (2010). Studies on hibernating populations of Culex pipiens from a West Nile virus endemic focus in New York City: parity rates and isolation of West Nile virus. J. Am. Mosq. Cont. Assoc., 26, 257-64.
  • Diuk-Wasser, M. A., Molaei, G., Simpson, J. E., Folsom-O’Keefe, C. M., Armstrong, P. M. and Andreadis, T. G. (2010). Avian communal roosts as amplification foci for West Nile virus in urban areas in northeastern United States. Am. J. Trop. Med. Hyg. 82, 337-43.
  • Molaei, G., Frajollahi, A., Armstrong, P. M., Oliver, J., Howard, J. J., Andreadis, T. G. (2009). Identification of blood meals in Anopheles quadrimaculatus and Anopheles punctipennis from eastern equine encephalitis virus foci in northeastern U.S.A. Med. Vet. Entomol. 23, 350-6.
  • Armstrong, P. M., Andreadis, T. G., Anderson, J. F., Stull, J. W., Mores, C. N. (2008). Tracking eastern equine encephalitis virus perpetuation in northeastern U.S. by phylogenetic analysis. Am. J. Trop. Med. Hyg., 79, 291-6.
  • Molaei, G., Andreadis, T. G., Armstrong, P. M., and Diuk-Wasser, M. (2008). Host-feeding patterns of mosquito vectors of arboviral agents in Connecticut, USA: molecular analysis of blood meals from twenty-three species of Aedes, Anopheles, Culex, Coquillettidia, Psorophora, and Uranotaenia. J. Med. Entomol., 45, 1143-51.
  • Andreadis T. G., Anderson, J. F., Armstrong, P. M., and Main, A. J. (2008). Isolations of Jamestown Canyon virus (Bunyaviridae: Orthobunyavirus) from field collected mosquitoes (Diptera: Culicidae) in Connecticut, USA: a ten-year analysis, 1997-2006. Vector Borne Zoonotic Dis. 8, 175-88.
  • Armstrong, P. M. and Andreadis, T. G. (2007). Genetic relationships of Jamestown Canyon virus strains (Bunyaviridae: Orthobunyavirus) infecting Connecticut mosquitoes. Am. J. Trop. Med. Hyg., 77, 1157-62.
  • Molaei, G., Andreadis, T. G., Armstrong, P. M., Bueno, R., Dennett, J., Real, S. V., Sargent, C., Bala, A., Randle, Y., Guzman, H., Travassos Da Rosa, A., Wuithiranyagool, T, and Tesh, R. B. (2007). Host feeding pattern of Culex quinquefasciatus and its role in transmission of West Nile virus in Harris County, Texas. Am. J. Trop. Med. 77, 73-81.
  • Andreadis, T. G. and Armstrong, P. M. (2007). A two-year evaluation of elevated canopy trapping for Culex mosquitoes and West Nile virus in an operation surveillance program in the northeastern United States. J. Am. Mosq. Cont. Assoc. 23, 137-148.
  • Molaei, G., Oliver, J., Andreadis, T. G., Armstrong, P. M., and Howard, J. J. (2006). Molecular identification of blood-meal sources in Culiseta  melanura and Culiseta morsitans from an endemic focus of eastern equine encephalitis virus in New York.  Am.  J. Trop. Med. Hyg. 75, 1140-1147.
  • Armstrong, P. M. and Andreadis, T. G. (2006). A new genetic variant of La Crosse virus isolated from New England. Am. J. Trop. Med. Hyg. 75, 491-496.
  • Molaei, G., Andreadis, T. G., Armstrong, P. M., Anderson, J. F., and Vossbrinck, C. R. (2006). Host feeding patterns of Culex mosquitoes and West Nile virus transmission, northeastern United States. Emerg. Infect. Dis. 12, 468-474.
  • Armstrong, P. M., Andreadis, T. G., Anderson, J. F., and Main, A. J. (2005). Isolations of Potosi virus from mosquitoes collected in Connecticut. J. Med. Entomol. 42, 875-881.