Echidnophaga gallinacea
Taxonomic classification
Class: Insecta
Order: Siphonaptera
Genus: Echidnophaga gallinacea (sticktight flea)
Echidnophaga
gallinacea is an international sticktight flea, which may
infest a wide variety of birds and mammals. Echidnophaga gallinacea is the only species in the genus found in
Host spectrum
Poultry, rodents, rabbits, canids, felids, horses, and occasionally humans may all become infested.
Geographic distribution
Echidnophaga gallinacea is
found in the tropics, subtropics, and also in the
Morphology
Adults – The adults are approximately 1.5 to 4 mm in length and laterally flattened. They are dark brown in color, wingless, and have mouthparts that aid in both the piercing of the skin and sucking of the host’s blood. Neither genal nor pronotal combs are present. The adult fleas have heads that are flattened and angled acutely (not curved or rounded). The sticktight flea is one of the smallest fleas found on domestic animals.
Eggs – The eggs are approximately 0.5 mm in length. They are oval shaped and pearly white in color. Nonfertile females will produce eggs just as fertile females do, however, the eggs will be nonviable.
Larvae – The larvae are approximately 6 mm in length. They are maggot-like, creamy/yellow in color, and have thirteen segments with bristles on each segment.
Pupae - The pupa, with a loosely woven debris-collecting cocoon, is approximately 4 x 2 mm.
Life cycle (stages)
Before
mating occurs both sexes will hop around freely. The life cycle is similar to that of Pulex
irritans, except upon fertilization the females will remain attached to the
host and lay their eggs in ulcers that have formed. The larvae will then fall off and feed on
organic debris including the adult flea feces.
After many weeks the larvae will spin silken cocoons, becoming covered
with dust and dirt, in which they pupate. An adult may emerge within days,
weeks or even months depending on environmental conditions. The newly emerged
adult fleas will seek a host, mate, and the females will attach to the host to
produce another generation. The lifecycle requires approximately thirty to
sixty days. Female sticktight fleas attach and feed at one site on their hosts for
prolonged periods. These periods may
range from four to nineteen days. During
these feeding sessions, the surrounding tissue becomes swollen and ulcerated.
Males will feed for shorter periods and look to mate around the same time.
Site of infestation
Echidnophaga gallinacea will attach to the skin (especially bare spots), around the eyes, comb, wattles, and anus
Pathogenesis/clinical signs
Echidnophaga gallinacea primarily cause problems in outdoor birds. The attached fleas will cause both swelling and ulceration. Young birds may die from infestation, due to anemia produced by the fleas' feeding. The sheer numbers that may be present can make the eyes of the host swell shut, causing the host to starve to death.
Diagnosis
Diagnosis of Echidnophaga gallinacea is accomplished by finding the fleas on the host.
Treatment
Treatment of Echidnophaga gallinacea is difficult because the fleas are attached to the host. Sticktight fleas can be removed with tweezers by grasping and pulling firmly. In order to prevent infection, an antibiotic ointment should be applied to the area. If there are to many fleas to remove individually, a flea product registered for on-animal use should be applied according to label instructions. When applying the product, be careful not to come in contact with the host’s/animal's eyes. 5% malathion dust has also been effectively used for treatment.
Other control measures
Keep other hosts out of chicken pens, which can be a high area of flea infestation. To prevent reinfestation, treat the area to eliminate flea larval development. There are several insecticides registered for treatment of outdoor areas for fleas. Burning of infested organic material, such as animal bedding and poultry litter has also been a recommended form of treatment.
Public health significance
Echidnophaga gallinacea can infest humans. Although sticktight fleas are not known to transmit any diseases, their attachment can lead to problems such as secondary infections.
References Cited
http://www.cvm.missouri.edu/cvm/courses/vm556/Arthropods/Fleas/Fleas.htm#STICKTIGHT
http://edis.ifas.ufl.edu/MG236