Connecticut State The Connecticut Agricultural Experiment Station

Philip M. Armstrong

A photograph of Dr. Phil Armstrong, head of the Department of Entomology at the Connecticut Agricultural Experiment Station. 

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:

  • Nattoh G, Armstrong PM, Brackney DE (2025) Cellular and molecular keys to entry: mechanisms mediating Orthoflavivirus infection of the mosquito midgut. PLoS Pathog. 21(10): e1013617.
  • McMillan JR, Sun J, Chaves LF, Armstrong PM (2025) Using mosquito and arbovirus data to computationally predict West Nile virus in unsampled areas of the Northeast United States. PNAS Nexus 4(8):pgaf227.
  • Anderson JF, Bransfield A, Misencik MJ, Jones S, Main AJ, Armstrong PM, Andreadis TG, Molaei G (2025) Host-feeding behavior of mosquitoes (Diptera: Culicidae) in North Dakota, 2003 to 2006. J Med Entomol. 62(3): 621-632.
  • Ferdous Z, Dieme C, Sproch H, Kramer LD, Ciota AT, Brackney DE, Armstrong PM (2024) Multiple bloodmeals enhance dissemination of arboviruses in three medically relevant mosquito genera. Parasit Vectors 17(1):432.
  • Anderson JF, Molaei G, Fish D, Armstrong PM, Khalil N, Brudner S, Misencik MJ, Bransfield A, Olson M, Andreadis TG (2024) Host-Feeding Behavior of Mosquitoes in the Florida Everglades. Vector Borne Zoonotic Dis. 24(8): 520-531.
  • Johnson RM, Stopard IJ, Byrne HM, Armstrong PM, Brackney DE, 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 PM, Anderson JF, Sharma R, Misencik MJ, Bransfield A, Vossbrinck CR, Brackney DE (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 RM, Cozens DW, Ferdous Z, Armstrong PM, Brackney DE (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 JJ, Armstrong PM (2023) Jamestown Canyon virus comes into view: understanding the threat from an underrecognized arbovirus.J Med Entomol. 60(6):1242-1251.
  • Anderson JF, Main AJ, Armstrong PM, Andreadis TG (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 RT, Bialosuknia SM, Ngo K, Zink SD, Koetzner CA, Maffei JG, Dupuis AP, Backenson PB, Oliver J, Bransfield AB, Misencik MJ, Petruff TA, Shepard JJ, Warren JL, Gill MS, Baele G, Vogels CBF, Gallagher G, Burns P, Hentoff A, Smole S, Brown C, Osborne M, Kramer LD, Armstrong PM, Ciota AT, Grubaugh ND (2023) Dynamics of eastern equine encephalitis virus during the 2019 outbreak in the Northeast United States. Curr Biol. 33(12):2515-2527.
  • McMillan JR, Chaves LF, Armstrong PM (2023) Ecological predictors of mosquito population and arbovirus transmission synchrony estimates. J Med Entomol 60(3):564-574.
  • Vogels CBF, Brackney DE, Dupuis AP 2nd, Robich RM, Fauver JR, Brito AF, Williams SC, Anderson JF, Lubelczyk CB, Lange RE, Prusinski MA, Kramer LD, Gangloff-Kaufmann JL, Goodman LB, Baele G, Smith RP, Armstrong PM, Ciota AT, Dellicour S, Grubaugh ND (2023) Phylogeographic reconstruction of the emergence and spread of Powassan virus in the northeastern United States. Proc Natl Acad Sci U S A. 120(16): e2218012120.
  • Gloria-Soria A, Shragai T, Ciota AT, Duval TB, Alto BW, Martins AJ, Westby KM, Medley KA, Unlu I, Campbell SR, Kawalkowski M, Tsuda Y, Higa Y, Indelicato N, Leisnham PT, Caccone A, Armstrong PM (2022) Population genetics of an invasive mosquito vector, Aedes albopictus in the Northeastern USA. NeoBiota 78: 99-127.
  • Bransfield AB, Misencik MJ, Brackney DE, Armstrong PM (2022) Limited capacity for Aedes aegypti to mechanically transmit chikungunya virus and dengue virus. Am J Trop Med Hyg. 107(6):1239-1241.
  • Field EN, Shepard JJ, Clifton ME, Price KJ, Witmier BJ, Johnson K, Boze B, Abadam C, Ebel GD, Armstrong PM, Barker CM, Smith RC (2022) Semi-field and surveillance data define the natural diapause timeline for Culex pipiens across the United States. Commun Biol. 5(1):1300.
  • McMillan JR, Olson MM, Petruff T, Shepard JJ, Armstrong PM (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 DE, Armstrong PM (2022) Saliva collection via capillary method may underestimate arboviral transmission by mosquitoes. Parasit Vectors 15(1):103.
  • Armstrong PM, Andreadis TG (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 JF, Fish D, Armstrong PM, Misencik MJ, Bransfield A, Ferrandino FJ, Andreadis TG, Stenglein MD, Kapuscinski ML (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 EAH, Akaratovic KI, Kiser JP, Abadam CF, Yuan KJ, Misencik MJ, Armstrong PM, 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 DW, Armstrong PM, Brackney DE (2021) Vector competence of human-biting ticks Ixodes scapularis, Amblyomma americanum and Dermacentor variabilis for Powassan virus. Parasit Vectors 14(1):466.
  • Brown SC, Cormier J, Tuan J, Lier AJ, McGuone D, Armstrong PM, Kaddouh F, Parikh S, Landry ML, Gobeske KT (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 JR, Harden CA, Burtis JC, Breban MI, Shepard JJ, Petruff TA, Misencik MJ, Bransfield AB, Poggi JD, Harrington LC, Andreadis TG, Armstrong PM (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 SN, López K, Coutermash-Ott S, Auguste DI, Porier DL, Armstrong PM, Andreadis TG, Eastwood G, Auguste AJ (2021) La Crosse virus shows strain-specific differences in pathogenesis. Pathogens 10(4):400.
  • Burtis JC, Poggi JD, McMillan JR, Crans SC, Campbell SR, Isenberg A, Pulver J, Casey P, White K, Zondag C, Badger JR, Berger R, Betz J, Giordano S, Kawalkowski M, Petersen JL, Williams G, Andreadis TG, Armstrong PM, Harrington LC (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 TA, McMillan JR, Shepard JJ, Andreadis TG, Armstrong PM (2020) Increased mosquito abundance and species richness in Connecticut, United States 2001-2019. Sci Reports 2020 Nov 6;10(1):19287.
  • Eastwood G, Shepard JJ, Misencik MJ, Andreadis TG, Armstrong PM (2020) Local persistence of novel regional variants of La Crosse virus in the Northeast USA. Parasit Vectors 13(1):569.
  • McMillan JR, Armstrong PM, Andreadis TG (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 AK, Shepard JJ, Misencik MJ, Bedoukian R, Cole L, Armstrong PM, Andreadis TG (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 PA, Eastwood G, Collins-Palmer K, Katz M, Falco RC, Bajwa WI, Armstrong PM, Andreadis TG, Diuk-Wasser MA (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 PM, Ehrlich HY, Magalhaes T, Miller MR, Conway PJ, Bransfield A, Misencik MJ, Gloria-Soria A, Warren JL, Andreadis TG, Shepard JJ, Foy BD, Pitzer VE, Brackney DE (2020) Successive blood meals enhance virus dissemination within mosquitoes and increase transmission potential. Nat Microbiol 5(2):239-247.
  • Uraki R, Hastings AK, Brackney DE, Armstrong PM, Fikrig E (2019) AgBR1 antibodies delay lethal Aedes aegypti-borne West Nile virus infection in mice. NPJ Vaccines. 4:23.
  • Keyel AC, Elison Timm O, Backenson PB, Prussing C, Quinones S, McDonough KA, Vuille M, Conn JE, Armstrong PM, Andreadis TG, Kramer LD (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 ND, Misencik MJ, Armstrong PM, Stenglein MD, Ebel GD, Brackney DE (2018) Adventitious viruses persistently infect three commonly used mosquito cell lines. Virology 2018 521:175-180.
  • Tan Y, Tsan-Yuk Lam T, Heberlein-Larson LA, Smole SC, Auguste AJ, Hennigan S, Halpin RA, Fedorova N, Puri V, Stockwell TB, Shilts MH, Andreadis T, Armstrong, PM, Tesh RB, Weaver SC, Unnasch TR, Ciota AT, Kramer LD, Das SR (2018) Large scale complete genome sequencing and phylodynamic analysis of eastern equine encephalitis virus reveal source-sink transmission dynamics in the United States. J Virol92:e00074-18.
  • Anderson JF, Armstrong PM, Misencik MJ, Bransfield AB, Andreadis TG, 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 PE, Armstrong PM, Liu P, Bova JE, Bernick JN, McMillan BE, Weidlich BG, Paulson SL (2018) Cache Valley Virus in Aedes japonicus japonicus mosquitoes, Appalachian Region, United States. Emerg Infect Dis. 24(3):553-557.
  • Skaff NK, Armstrong PM, Andreadis TG, and Cheruvelil (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 PM, Powell JF, and Turner PE (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 PM, Andreadis TG, Shepard JJ, and Thomas MC (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 ME, Yao Y, Nock D, Armstrong PM, Andreadis TG, Diuk-Wasser MA, Montgomery RR (2017) West Nile Virus Seroprevalence, Connecticut, USA, 2000-2014. Emerg Infect Dis 23(4):708-710.
  • Grubaugh ND, Rückert C, Armstrong PM, Bransfield A, Anderson JF, Ebel GD, Brackney DE (2016) Transmission bottlenecks and RNAi collectively influence tick-borne flavivirus evolution. Virus Evol 2(2):vew033.
  • Brackney DE and Armstrong PM (2016) Transmission and evolution of tick-borne viruses.Curr Opin in Virol 21:67-74.
  • Misencik MJ, Grubaugh ND, Andreadis TG, Ebel GD, and Armstrong PM (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 MC, Muller T, Medlock J, Shepard JJ, Armstrong PM, and Andreadis TG (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.
  • Molaei G, Armstrong PM, Graham AC, Kramer LD, and Andreadis TG (2015) Insights into the recent emergence and expansion of eastern equine encephalitis virus in a new focus in the Northern New England USA.Parasit Vectors 8: 516.
  • Molaei G, Armstrong PM, Abadam CF, Akaratovic KI, Kiser JP, and Andreadis TG (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 PM, Andreadis TG, and Anderson JF (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 JF, Main AJ, Armstrong PM, Andreadis TG, and Ferrandino FJ (2015) Arboviruses in North Dakota, 2003-2006.Am J Trop Med Hyg 92: 377-93.
  • Andreadis TG, Armstrong PM, Anderson JF, and Main AJ (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: 763-73.
  • Armstrong PM, Anderson JF, Farajollahi A, Healy SP, Unlu I, Crepeau TN, Gaugler R, Fonseca DM, Andreadis TG (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): 1310-14.
  • Armstrong PM and Andreadis TG. (2013) Eastern equine encephalitis virus--old enemy, new threat.  N Engl J Med 368:1670-3.
  • Molaei G, Andreadis TG, Armstrong PM, Thomas MC, Deschamps T, Cuebas-Incle E, Montgomery W, Osborne M, Smole S, Matton P, Andrews W, Best C, Cornine F 3rd, Bidlack E, Texeira T (2013) Vector-host interactions and epizootiology of eastern equine encephalitis virus in Massachusetts. Vector Borne Zoonotic Dis 13:312-23.
  • Anderson JF and PM Armstrong (2012) Prevalence and genetic characterization of Powassan virus strains infecting Ixodes scapularis in Connecticut. Am J Trop Med Hyg 87:754-9.