Annotated Hard Tick Species of New Jersey – Comprehensive Study Notes

Geographic & Ecological Context of New Jersey

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• NJ: Northeastern U.S.; smallest by area yet densest by human population (≈ $9.3\,\text{million} / 22,600\,\text{km}^2$)

• Five climatic zones (temperate ➜ humid-subtropical) along a north–south gradient

• Atlantic migratory flyway intersects state ➜ birds import/export ticks & pathogens

• Suburbanization replaces former farmland; fragmented 2ⁿᵈ-growth forests + high deer, mouse, & human densities = ideal tick–host–human interface

Methodology & Data Sources

• Systematic literature search: PubMed, Google Scholar; key phrases “ticks, New Jersey”, “ixodid, New Jersey”, plus genus/species variants

• Museum & repository checks:
  • U.S. National Tick Collection (USNTC) – accession numbers $\text{RML}$
  • Regional institutions in CT, DE, MD, NY, PA queried for informal lists

• New vouchers created: all new NJ specimens deposited in USNTC (see Supp. Table 1)

• Seasonality inference:
  • Questing ticks ➜ drag/flag sampling chronology
  • Nidicolous ticks ➜ host trapping chronology

Confirmed Ixodid (Hard) Tick Fauna of New Jersey ($n = 11$)

Amblyomma americanum – “Lone Star Tick”

• Earliest voucher: RML120584, $7\,\text{Jun}\,1991$, Pakim Pond (Burlington); 1 nymph (environment)

• Hosts: humans, pets, white-tailed deer; most common residential submission in Monmouth Co.

• Pathogens: $Ehrlichia\;chaffeensis$, $E.\;ewingii$, $Cytauxzoon\;felis$; linked to $\alpha$-gal meat allergy

• Seasonality (NJ):
  • Adults & nymphs: Apr – early Aug (peak Jun–Jul)
  • Larvae: late Apr–May & Aug–Oct (second peak larger ➜ possible overwinter mortality of unfed larvae)

• Habitat: forests, woodlands, fields, ecotones; established south, spreading north

Dermacentor albipictus – “Winter Tick”

• Voucher: RML119098, $19\,\text{Dec}\,1987$, Fort Monmouth (Monmouth); 1 nymph

• One-host tick; larvae emerge Sep–Nov ➜ nymphs Oct–Mar ➜ adults Feb–May (based on Alberta data)

• NJ host: white-tailed deer; elsewhere can exsanguinate moose

• Vector status: minimal; suspected but unproven for $Borrelia$ spp.

Dermacentor variabilis – “American Dog Tick”

• Earliest voucher: RML18497, $5\,Jul\,1909$, Lakehurst (Ocean); adult

• Immatures on meadow voles; adults on mid-sized mammals & humans

• Pathogens: $Rickettsia\;rickettsii$ (RMSF), $Francisella\;tularensis$; female saliva can cause tick paralysis

• Seasonality (MA ⮕ parallels NJ): Larvae/Nymphs bimodal (spring & late-summer), adults Mar–Aug

• Habitat: desiccation-tolerant; roadsides, fields, even beach grass

Haemaphysalis leporispalustris – “Rabbit Tick”

• New vouchers: RML128851, $11\,Jun\,2018$, Teterboro Airport; 2 ♂ 2 ♀ from eastern cottontail

• Nidicolous; all stages year-round on rabbits; larvae/nymphs abundant late-summer/fall

• Possible reservoir/vector for tularemia & spotted fever group $Rickettsia$ spp.

Haemaphysalis longicornis – “Asian Longhorned Tick” (EXOTIC)

• First U.S. free-living pop.: Hunterdon Co., Aug 2017 on Icelandic sheep

• NJ vouchers: RML128847 (larvae 23 Apr 2018) & RML128848 (nymphs/adult 26 Jun 2018) – Watchung Reservation (Union)

• Parthenogenetic lineage ➜ explosive growth potential

• Hosts detected: deer, raccoon, opossum, sheep, goats; global vectors of SFTS-virus, $R.\;japonica$ etc.

• Phenology (prelim. NJ): nymphs peak spring–early summer; adults midsummer; larvae late-summer–fall

• Habitat preference under study; thrives in tall humid grass elsewhere (> $50\,\text{mm}$ rainfall month⁻¹)

Ixodes brunneus

• Voucher: RML115824, $23\,Mar\,1943$, from winter wren (nidicolous, bird-specialist)

• All stages Nov–Apr on passerines; can cause avian tick paralysis; limited human relevance

Ixodes cookei

• Earliest extant voucher: Bishopp coll. pre-1966, 6 nymphs + 1 larva (location NA)

• Hosts: woodchucks, mink, other small–medium mammals; occasional human bites

• Pathogen: Powassan virus lineage I in woodchuck cycle

• Seasonality (NY): larvae peak May; nymphs Nov; adults May

Ixodes dentatus

• Voucher: RML122095, May 1995, Cranford (Union); 2 nymphs on vegetation

• Hosts: cottontail rabbits, small mammals, birds; rarely human-biting; may maintain $B.\;burgdorferi$ enzootically

• Seasonality (MO data): Larvae peaks May & Sep; nymphs erratic peak fall/winter; adults peak May

Ixodes scapularis – “Blacklegged Tick”

• Voucher: RML18554, $1\,Dec\,1933$, from cottontail rabbit (Mercer)

• Now established all $21$ counties; principal NJ vector of $B.\;burgdorferi$ (Lyme), $B.\;miyamotoi$, $Anaplasma\;phagocytophilum$, $Babesia\;microti$, DTV/POWV lineage II

• Life-cycle (NJ):
  • Larvae hatch Aug–Sep ➜ overwinter
  • Nymphs Apr–Jul following year (human disease peak)
  • Adults Oct–Dec & Apr–May; quest whenever > $4^{\circ}\text{C}$

• Highly desiccation-sensitive ➜ leaf-litter, shaded understory

Ixodes texanus

• Voucher: RML122620, Feb 1998, Cranford; 3 ♀ from raccoon

• Raccoon specialist; all stages can co-feed; active year-round; cold-tolerant

• Pathogens: occasional $B.\;burgdorferi$, $Babesia\;lotori$ (unknown zoonotic impact)

Rhipicephalus sanguineus s.l. – “Brown Dog Tick” (EXOTIC/INDOOR)

• Voucher: RML60065, $6\,Jun\,1936$, Atlantic City; 32 ♀ collected indoors

• Cosmopolitan; completes entire life-cycle indoors ➜ kennel & household infestations; resistant to many acaricides

• Pathogens: $Ehrlichia\;canis$, $R.\;rickettsii$; globally also $Anaplasma$, $Coxiella$, $Babesia$, $Hepatozoon$, $Theileria$

• Year-round presence indoors; outdoor survival limited in temperate NJ climate

Unconfirmed / Possible Additional Species (Voucher-lacking)

• Haemaphysalis chordeilis – bird tick; reported surrounding states; likely transient on avifauna

• Ixodes angustus – rodent tick; found NY & PA; occasionally implicated in Lyme-like illness

• Ixodes banksi – beaver/muskrat ear tick; CT/NY/PA records; historic beaver die-off (MI 1956)

• Ixodes marxi – squirrel chipmunk tick; earlier NJ citation without voucher; vector of POWV

• Ixodes muris – rodent/bird tick; competent lab vector of $B.\;burgdorferi$; causes swelling in pets (ME)

Species Currently Expanding Northward ➜ Watch List

Amblyomma maculatum – “Gulf Coast Tick”

• Detected ≤ $20\,\text{km}$ from NJ (DE Bombay Hook NWR)

• Open grass habitats; aggressive human biter; vector $R.\;parkeri$ (Tidewater spotted fever) & $Hepatozoon\;americanum$ (canine)

Ixodes affinis

• Moving north to VA; adults share hosts with $I.\;scapularis$; larvae/nymphs on birds; competent for $B.\;burgdorferi$

Comparative State Presence (Table 2 Synopsis)

• Neighbor counts (voucher-unverified):
  • NY $16$ spp. • PA $15$ • MD $15$ • CT $13$ • DE $10$

• NJ confirmed: $11$ (matches/lag vs neighbors highlights surveillance gaps)

Importance of Voucher Specimens

• Provide verifiable evidence for distribution, enable taxonomic revision & molecular study ("museum genomics")

• NJ historically under-vouchered; several early reports (e.g., Kalm 1754 lone star, Cooley & Kohls 1945 I. marxi) lack physical proof

• Authors deposited new vouchers (Supp. Table 1) ➜ strengthens baseline for future surveillance & policy

Surveillance & Public-Health Recommendations

• Statewide standardized program should stratify by:
  • Habitat (forest, meadow, suburban, indoor kennel)
  • Tick behavior (questing vs nidicolous)
  • Host community (small mammals, birds, deer, companion animals)

• Combine drag/flag, CO₂ traps, host-trapping & citizen submissions

• Integrate pathogen screening (PCR/serology) for human & veterinary agents

• Education: clinicians, veterinarians, public on seasonality peaks (e.g., nymphal $I.\;scapularis$ May–June)

Key Numbers, Equations & Metrics

• Confirmed species in NJ: $n = 11$ (9 native + 2 exotic)

• Additional potential species discussed: $n = 7$

• Reported 2017 NJ canine ehrlichiosis cases: $5,383$

• Economic burden Lyme disease U.S.: > 1\,\text{billion USD\;yr}^{-1}

Ethical & Practical Considerations

• Host trapping for nidicolous ticks must follow Animal Care & Use Committee (1998) standards to avoid undue stress

• Indoor R. sanguineus infestations pose socio-economic issues (costly eradication, pesticide resistance)

• Increasing tick diversity & range shifts linked to climate change, land-use, wildlife recovery ➜ necessitate adaptive management

Conceptual Connections & Broader Implications

• “Tick–Host–Pathogen” triad: changes in any vertex (e.g., deer density, climate) cascade into disease risk

• Parthenogenesis in H. longicornis mirrors other invasive arthropod successes (high $R_0$)

• Voucher-based baselines critical to detect introductions (e.g., early capture of Gulf Coast tick spread)