This is a presentation explaining different types of ecto parasites, explaining different type of parasitism and examples of parasitism.

1. ECTOPARASITES

2. Tick paralysis
• Australian tick paralysis…. A beautiful example
of parasitic Excellence….

3. ACT - Ectoparasite Id and Lifecycles 3
Arthropods
• Invertebrate animals
that have jointed
limbs, a segmented
body, and an
exoskeleton.
• Examples are
– Insects
– Arachnids
– Centipedes
– Crustaceans

4. ACT - Ectoparasite Id and Lifecycles 4
Arthropods As Parasites
Certain insects and arachnids become
parasites when they transmit pathologic
organisms, cause skin irritations, and produce
toxins.

5. ACT - Ectoparasite Id and Lifecycles 5
Insect Characteristics
• Insects have six legs
• Many have wings
• But some are wingless

6. ACT - Ectoparasite Id and Lifecycles 6
Arachnid Characteristics
• Have eight legs
• Wingless
• Some produce
toxins
• Some are so small
must be seen under
a microscope

7. ACT - Ectoparasite Id and Lifecycles 7
Flies
• “That person is so
nice.” “He wouldn’t
even harm a fly”.
• These two statements
sometimes give the
impression that the
fly, although
sometimes annoying, is
harmless.
• This is far from the
truth.

8. ACT - Ectoparasite Id and Lifecycles 8
Flies
• Running from flies will
cause the animal to use
up energy which
sometimes will result in
weight loss.
• Some flies bite, (female
mosquitoes), which
causes blood loss,
tissue damage, and can
transmit bacterial, viral,
and parasitic diseases
to the host.

9. ACT - Ectoparasite Id and Lifecycles 9
Biting and Nuisance Flies
• Biting
– Mosquitoes
– Black flies
– Horse flies
– Deer flies
– Stable flies
– Photo credit: Bastiaan (Bart) Drees
• Nuisance
– House flies
– Face flies
– Bottle flies

10. ACT - Ectoparasite Id and Lifecycles 10
Biting and Nuisance Flies
• Biting
– Deliver painful bites
– Loose weight
– Carry diseases
• Nuisance
– The do not bite
– Carry diseases
– Annoy by feeding on eye
and nose secretions

11. ACT - Ectoparasite Id and Lifecycles 11
The Stable Fly
• Carriers of disease
• Annoying blood
suckers
• Require moist
places to lay eggs
Photo by : Jim Kalisch, UNL Entomology

12. ACT - Ectoparasite Id and Lifecycles 12
Horn Flies
• Blood suckers and very
annoying
• Half the size of the
housefly
• Majority of lifecycle spent
on or near cattle
• Cow spends a majority of
her time trying to get
away from the pests thus
reducing production
• Photo by : Jim Kalisch, UNL Entomology
• Photo by: Jack Campbell, UNL Entomology

13. ACT - Ectoparasite Id and Lifecycles 13
Bot Flies
Cause animals to panic which is called “Gadding”
CREDITS: J. F. Butler, University of Florida

14. ACT - Ectoparasite Id and Lifecycles 14
Bot Flies
• Eggs hatch and penetrate the skin
CREDITS: Dr. Donald A. Rutz - Dr.
Phillip E. Kaufman, Cornell
University, Dept. of Entomology

15. ACT - Ectoparasite Id and Lifecycles 15
Bot Flies
• Maggots (larvae) are parasitic
• Migrate to back, form warbles, cut breathing
holes
• Damage to the hide
CREDITS: Dr. Donald A. Rutz - Dr. Phillip E. Kaufman, Cornell University, Dept. of
Entomology

16. ACT - Ectoparasite Id and Lifecycles 16
Cuterebra
Infect rabbits, mice, rats, and squirrels but rarely
problem in cats and dogs

17. ACT - Ectoparasite Id and Lifecycles 17
Cuterebra
Also known as bots
Photo by : Jim Kalisch
UNL Entomology

18. ACT - Ectoparasite Id and Lifecycles 18
Cuterebra
Larvae known as wolf or wolf worms
Courtesy of Shari Nelsen, Lincoln

19. ACT - Ectoparasite Id and Lifecycles 19
Sheep Keds
• Wingless fly spending entire lifecycle on sheep
• Deposits fully develop larvae in the wool not eggs
• Adults feed off the blood causing intense pain
• Spring shearing and some insecticides

20. ACT - Ectoparasite Id and Lifecycles 20
The Screwworm Fly
• Myiasis – Larval fly disease
• Eradication in U.S. in the 1950’s
• Sterilization of the male
• Importation restrictions
Photos by: The National Agricultural Library Special Collections

21. ACT - Ectoparasite Id and Lifecycles 21
Fleas
• They bite the animal and eat
the blood.
• Can be an intermediate host;
i.e. tapeworm
• Carries several diseases; i.e.
Bubonic plague
• Life cycle can be as short as 16
days or as long as 2 years
• The adult will lay her eggs but
they do not stick to the host
• “Flea dirt” is the source of
food for the larvae

22. ACT - Ectoparasite Id and Lifecycles 22
Flea Lifecycle - Ctenocephalides
1. Female flea
feeds on
host’s blood
and lays eggs
2. Eggs fall
off host
3. Eggs hatch in 2 to 12 days
4. Larvae pupates
for 7 days to 2 years
5. Adult emerges
and looks for
new host

23. ACT - Ectoparasite Id and Lifecycles 23
Are These Mites or Lice?
Two Orders of Lice
Anoplura – Sucking Lice Mallophaga – Biting Lice

24. ACT - Ectoparasite Id and Lifecycles 24
Lice
• Lice can infest dogs and
cats year round
• Horses and cattle usually
get lice in the winter
• Lice are very host specific
• They must live on their
host at all times
• Can cause intense
itching, pain, and hair
loss

25. ACT - Ectoparasite Id and Lifecycles 25
Lice Lifecycle
2. Adult lice
must live on the
host at all times
3. Adult lice lay eggs
called nits that stick
to host’s hair
4. Nit develops into
an immature adult
stage (nymph), then
into an adult
1. Lice are passed to
others by direct
contact with an
infested host

26. ACT - Ectoparasite Id and Lifecycles 26
Lice Versus Mites
Hog Louse
– Insect
– 6 legs
– Can be seen
Scroptic Mange Mite
– Arachnids
– 8 legs
– Cannot be Seen

27. ACT - Ectoparasite Id and Lifecycles 27
Mites
• Not know if host specific
• Transmission to humans is by physical
contact.
• Secondary infections from scratching
• Female burrows into skin, lays eggs, larvae
migrate to the top and wanders around
causing intense irritation of the skin

28. Common bedbugs (Cimex lectularius)
• Are flattened, oval, reddish brown insects that
inhabits houses, furniture, and neglected
beds. They feed on man, usually at night,
causing itchy bites.
•

30. Human fleas (Pulex irritans)
• Are small, wingless, bloodsucking insects that
act as vectors for the spread of such diseases
as plague…
•

31. Flea Biology and Ecology
Order: Siphonaptera
• Hind legs are adapted for jumping
• Adults are exclusively blood suckers (most are mobile, but
some are attached)
• The “attached” species are like the ticks, they put their
mouthparts in host and stays there for a while.
• Unfed adults live a long time, but they can’t really leave the
area where they are so they just hang out waiting for a blood
meal, and they are very active when looking.
• Somewhat host specific (not as host specific as lice), and it
varies with species.

32. Life Cycle
• Holometabolous
• Egg  Larvae  Pupa  Adult
– 18 days to 20 months
• Eggs (3-18 at one time in several batches)
• Larvae need high humidity
– 9-15 days optimal (up to 200 days)
• Pupa
– 7 days to 1 year
• Adult
– Live up to 4 years.

33. History of the Black Death
• Named after the “bobos” that are produced.
• 1500-5000 cases each year.
• Originated in China
• Introduced to the U.S. at port cities, San Francisco.
• Occurs 4-5 times every 10-20 years.
• 200 million lives lost and counting…
• Minor disease in U.S. (N. Mex. 10-20 cases/year avg is 12)

34. Known and probable foci of plague. Plague is now largely
focal in distribution. It spreads rapidly in conditions of war
and other catastrophes, e.g. earthquakes. Epidemics still
occur from time to time.

35. Source: Dennis DT. 1998. Plague as an emerging disease. Emerging Infections 2. Scheld WM,
Craig WA and Hughes JM, Eds. ASM Press, Washington DC.

37. Leeches
• Are any of the annelids from the class
Hirudinea, especially Hirudo medicinalis. Some
species are bloodsuckers and were once used
to draw blood out of those who were ill.

38. Lice (singular louse)
• Are grayish, wingless, and somewhat flattened
parasetic insects that belong to the suborder
Anoplura. They are usually found in crowded
areas with poor sanitation and hygiene.
Infestations are called pediculosis. Lice live on the
blood of a host, obtained by piercing the skin and
sucking the blood through their mouth parts. The
area bitten becomes itchy and inflammed, and
often infected from scratching. They are often
vectors transmitting such diseases as typhus.

39. • Those parasitic to humans are:Human body louse
(Pediculus humanus corporis) lives on the body
and clothes of man.
• Head louse (Pediculus humanus capitis) attaches
itself to the hairs of the head, and are noted for
causing endemic outbreaks in school children.
• Pubic or crab louse (Phthirus pubis) is often
sexually transmitted. It resembles a miniature
crab, and causes intense itching in the pubic
area, but it can also infect the
eyebrows, eyelashes, and beards.

40. Vector Biology
All three types of lice:
• Are ectoparasites: lice live on the surface of
the host
• Move by crawling, as opposed to flying
• Have humans as their only host
• Have similar life cycles
Head Lice Body Lice Pubic Lice

42. Mites
• Are arthropods belonging to the order
Acarina. They differ from ticks in that they are
minute and usually either transparent or
semitransparent. They are sometimes called
chiggers. Mites often burrow into the skin,
causing intense itching resulting in inflammed
areas of the skin. Mites live under four days
outside the body

43. Biology
(1) Dorso-ventrally flattened body.
(2) Claws adapted to grasp the host
(3) All lice are wingless
(4) Hemimetabolous Life Cycle
Egg  Nymph  Adult

44. Tooth amoebas (Entameba gingivalis)
• Are microscopic parasites that hide in the tiny
crevices where the teeth meet the gums.
Brushing does not remove them because they
change shape to conform to their hiding places.
As a beneficial organism, they eat mouth bacteria
and only become harmful when the lack of
hygiene forces them to multiply too quickly.
•

45. Ticks
• Are blood-sucking arachnid parasites that are
seen by the naked eye and act as vectors for
certain bacteria known to cause disease in
humans. They are the only venonous creature
that hunts down humans. Others try to avoid
them. There are two kinds of ticks: hard and soft;
and each carries different diseases. Soft ticks do
not burrow into the skin. Hard ticks do, and must
be removed with care, keeping their heads intact.
Dog ticks bring slow paralysis and even death to
children.