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Ectoparasites
The document discusses various ectoparasites, primarily focusing on their characteristics, lifecycle, and impacts on hosts. It covers insects and arachnids such as ticks, fleas, lice, and bot flies, highlighting their roles as disease carriers and their interactions with animals and humans. Additionally, it explains the health risks associated with these parasites and their respective life cycles.
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Ectoparasites
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- 2. Tick paralysis • Australiantick paralysis…. A beautiful example of parasitic Excellence….
- 3. ACT - EctoparasiteId and Lifecycles 3 Arthropods • Invertebrate animals that have jointed limbs, a segmented body, and an exoskeleton. • Examples are – Insects – Arachnids – Centipedes – Crustaceans
- 4. ACT - EctoparasiteId 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 - EctoparasiteId and Lifecycles 5 Insect Characteristics • Insects have six legs • Many have wings • But some are wingless
- 6. ACT - EctoparasiteId and Lifecycles 6 Arachnid Characteristics • Have eight legs • Wingless • Some produce toxins • Some are so small must be seen under a microscope
- 7. ACT - EctoparasiteId 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 - EctoparasiteId 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 - EctoparasiteId 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 - EctoparasiteId 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 - EctoparasiteId 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 - EctoparasiteId 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 - EctoparasiteId and Lifecycles 13 Bot Flies Cause animals to panic which is called “Gadding” CREDITS: J. F. Butler, University of Florida
- 14. ACT - EctoparasiteId 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 - EctoparasiteId 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 - EctoparasiteId and Lifecycles 16 Cuterebra Infect rabbits, mice, rats, and squirrels but rarely problem in cats and dogs
- 17. ACT - EctoparasiteId and Lifecycles 17 Cuterebra Also known as bots Photo by : Jim Kalisch UNL Entomology
- 18. ACT - EctoparasiteId and Lifecycles 18 Cuterebra Larvae known as wolf or wolf worms Courtesy of Shari Nelsen, Lincoln
- 19. ACT - EctoparasiteId 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 - EctoparasiteId 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 - EctoparasiteId 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 - EctoparasiteId 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 - EctoparasiteId and Lifecycles 23 Are These Mites or Lice? Two Orders of Lice Anoplura – Sucking Lice Mallophaga – Biting Lice
- 24. ACT - EctoparasiteId 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 - EctoparasiteId 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 - EctoparasiteId 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 - EctoparasiteId 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 (Cimexlectularius) • 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 (Pulexirritans) • Are small, wingless, bloodsucking insects that act as vectors for the spread of such diseases as plague… •
- 31. Flea Biology andEcology 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 theBlack 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 probablefoci 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 anyof 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 parasiticto 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 threetypes 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 arthropodsbelonging 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 flattenedbody. (2) Claws adapted to grasp the host (3) All lice are wingless (4) Hemimetabolous Life Cycle Egg Nymph Adult
- 44. Tooth amoebas (Entamebagingivalis) • 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-suckingarachnid 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.
Editor's Notes
- #41 Ectoparasite: lives on surface of host, as opposed to inside the body (endoparasite) as with many other parasites we’ve seen. Do need blood meals to survive.Move by crawling: as opposed to flying or hopping, which affects the control and prevention measures needed. Feet are specifically adapted to human hair (cannot survive for that long if they fall off a human.) They can only live 1-2 days if they fall off of a human host. See photo on the top right of the slide for a zoomed-in look at the hooks on louse feet adapted to clinging to human hair.Humans as only host. There is no animal reservoir, which makes control measures different and potentially simpler than other parasites.Photo Credit: CDC http://www.cdc.gov/parasites/lice/head/gen_info/faqs.html