Download ECTOPARASITES

ECTOPARASITES
Various arthropods, mainly from the Insect class, are vectors for infectious diseases. When living
on or interacting with the surface of the body, they are called ectoparasites.
Examples are:
o Hard body ticks (Ixodes) – Lyme disease caused by bacterium Borrelia burgdorferi
(Dermacentor) – tularemia caused by bacterium Francisella tularensis,
Rocky Mountain spotted fever caused by bacterium Rickettsia rickettsii
o Soft body tick (Ornithodoros) – Relapsing fever caused by bacterium Borrelia recurrentis
o body louse (Pediculus) – typhus caused by various Rickettsia species, (Pithirus) pubic
louse– STD – the “crabs”
o itch mite (Sarcoptes) – sarcoptic mange –STD - “scabies” (not a microbial infection)
o mosquito (Anopheles) – malaria caused by many species of the protozoan Plasmodium.
(Aedes) – dengue (viral) fever, viral encephalitis
o flea (Pulex) – plague caused by Yersinia pestis
These ectoparasite vectors are in the Kingdom
Animalia, generally in 2 classes---Insecta and
Ticks. Ticks and mites are in the Class Arachnida
(relative of spiders), while the others are in the
Class Insecta. Differences between the Insects
Arachnids include presence of wings, main body
parts, numbers of leg pairs, and presence of
antenna.
Arachnida.
and
hard ticks
Pulex (flea) – insect
Pediculus (louse) Insect
(arachnids)
Dept. of Medical Entomology, Univ. of Sydney
http://medent.usyd.edu.au/photos/insect%20photos.htm
OBJECTIVES:
Learn about various vectors of infectious diseases.
Identify representative ectoparasites under the microscope
(use common names, not scientific names)
Fall 2011 – Jackie Reynolds, Richland College
MATERIALS NEEDED:
soft tick
prepared slides of ectoparasites
flea
louse
bedbug
mosquito head
tick (hard bodied and soft bodied)
mite
THE PROCEDURES:
View various prepared slides using the low power of stereoscopic microscopes.
LABORATORY REPORT SHEET
QUESTIONS:
1. Record the views of the various parasites (on low power magnification)
flea
louse
bedbug
tick
mite
2. How many leg pairs does the Class Arachnid have compared to the class Insecta?
3. How does the body plan of Insects differ from Arachnids based on major divisions?
4. Why is malaria not common in the United States?