An introduced generalist parasite, the sticktight flea (Echidnophaga gallinacea), and its pathology in the threatened Florida scrub-jay (Aphelocoma coerulescens)

J Parasitol. 2006 Oct;92(5):941-8. doi: 10.1645/GE-769R.1.


The sticktight flea, (Echidnophaga gallinacea), a major pest of the domestic chicken (Gallus gallus) that can cause severe pathology or death if untreated, is rarely recorded in free-living avian species. Sticktight fleas, however, were observed on the federally threatened Florida scrub-jay (Aphelocoma coerulescens) in February 2004, in south central Florida. Of the 81 Florida scrub-jays (FSJs) sampled before the 2004 breeding season, 12 were infested, with from 1 to as many as 57 fleas. Subsequent survivorship and variation in health indices led us to conclude that the sticktight flea caused the death of several jays. Within 4 mo, 46% of sticktight flea-infested (INF) jays died, whereas in the nonflea-infested (NINF) jays, only 5.9% died. Adult INF birds lost body mass in the time since a previous capture compared with NINF jays, and mass gain was slowed in 1-yr-old INF jays. Hematocrit of INF jays was dramatically impacted, as low as 17%, and was negatively correlated with the extent of infestation. Leukocyte counts were highest in INF jays; however, plasma immunoglobulin levels were lowest. Physiological stress levels, measured using plasma corticosterone, increased more rapidly in INF jays than NINF jays and were positively correlated with heterophil/lymphocyte ratios. The impact of the sticktight flea on the federally threatened FSJ negates previous findings that sticktight fleas are benign in wild avian hosts.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Bird Diseases / epidemiology
  • Bird Diseases / parasitology*
  • Bird Diseases / physiopathology
  • Blood Proteins / analysis
  • Body Weight
  • Corticosterone / blood
  • Ectoparasitic Infestations / epidemiology
  • Ectoparasitic Infestations / physiopathology
  • Ectoparasitic Infestations / veterinary*
  • Female
  • Florida / epidemiology
  • Hematocrit / veterinary
  • Immunoglobulin G / blood
  • Leukocyte Count / veterinary
  • Male
  • Microfilariae / isolation & purification
  • Passeriformes / parasitology*
  • Siphonaptera / pathogenicity*


  • Blood Proteins
  • Immunoglobulin G
  • Corticosterone