Pests, Plagues & Politics Lecture 7

1. Pests, Plagues & Politics Lecture 7 BUGS ON YOU

2. Key PointsBugs Living on You • Historical Perspective • Obligate Parasites • 3 Types of Lice • Biology and control • Facultative Parasites • Human Flea, Bot Fly, Sand Fleas • Bed Bugs

3. Bugs On You Demodexfollicularum the human follicle mite

4. BUGS ON YOU “Even a superficial survey of the evolution of human cleanliness reveals that its development has lagged far behind the intellectual, aesthetic, and moral progress of man. Cleanliness has not been akin to godliness.” H. Zinsser, RATS, LICE & HISTORY

5. Bugs On You • Saint Benedict (6th century) • “Bathing shall seldom be permitted.” • Saint Francis of Assisi • “an unwashed body is the stinking badge of piety.” • Queen Isabelle of Castile • boasted of two baths in her life • Napoleon, in a letter to Josephine • “Be home in two weeks. Don’t bathe.”

6. Bugs On You • Colonial America • Pennsylvania & Virginia • laws which either banned or limited bathing • Philadelphia • bathing more than one a month prohibited • Why?? • Bathing meant nudity which could only promote promiscuity

7. The Strongest Bond

8. Bugs On You • OBLIGATE Insect Parasites of Humans • parasitism (Gr. Parasitos = eating with another) • LICE • Order Anoplura (“unarmed tail”) • The Sucking Lice • parasitic on mammals & birds • 15 families & ca. 500 species worldwide • Haemophagicwith piercing/sucking mouthparts. • Wingless with flattened bodies • Hemimetabolous (incomplete metamorphosis)

9. Human Lice • Three “types” - Two species • Pediculus humanus capitus • The Head Louse • Pediculus humanus humanus • The Body Louse • Pthirus pubis • The Crab Louse

10. Head Lice • Pre-WWI: head lice a familiar feature in American homes. • Now making a come back • est. 12,000,000 cases in the U.S. • Female Louse • 50 to 150 eggs (egg = NIT) in her life time • lays them at the base of hairs • eggs hatch in 5 to 10 days - three molts • three weeks “egg to egg” Adult louse Louse about to hatch from the egg. Louse egg on a human hair The NIT

11. First The Biology • Head lice • (Pediculus humanus capitis) are tiny insects about two millimeters long which live on the scalp and neck of humans. • They feed from human blood and must eat at least twice a day; they cannot survive for more than one day at room temperature off a human body.

12. Head Lice • Transmission • close physical contact • exchange of combs &/or hats • Slang • WWI & II • “motorized dandruff”

13. Common Chemical Treatments • Nix • Rid • Pronto • Clear

14. One other problem… • RESISTANCE: • Overuse of pediculicidal products has lead to decreased effectiveness • These survivors are breeding a new super race of lice, resistant to our chemicals • SAFER ALTERNATIVES: • Head Lice to Dead Lice • Incorporates a“5 step battle plan” • Promotes use of olive oil to kill resistant adult lice PART 1 - http://www.youtube.com/watch?v=UCoZP5Aso5U PART 2 - http://www.youtube.com/watch?v=UCoZP5Aso5U

15. Body Louse • P.h. humanus • Latin: Pedis - louse; Pediculus = small louse • English: Pedicular, an adj. = lousy • “A dozen white louses do become an old coat well; It’s a familiar beat to man and signifies love.” Wm. Shakespeare; Merry Wives of Windsor

16. Body Louse • Normally found on clothing • Louse is on you only during feeding • usually when you’re sleeping • Spends most of time in the seams of your clothing (ergo common name “seam squirrel”) • Eggs deposited on clothing • Transmitted via exchanged clothing • Average # lice per host = dozen • A known vector of typhus

17. Body Louse • Control • Allogrooming • vignette: Richard the Lion Hearted & his ‘permitted’ washer women • Chemical • DDT saved millions • The Whirlpool washing machine and a dramatic increase in personal hygiene.

18. Lice tell us when humans began to wear clothes!!! • Recent molecular DNA studies of head lice & body lice show: • Body lice diverged from head lice about 72,000  42,000 years ago • Body lice live in the clothing • Ergo humans ran around naked for longer than we thought. • Study also supports African origin for Homo.

19. Crab Louse • Also known as the pubic louse (& other nomens) • Infests the pubic regions • requires well spaced hair • stationary beast & spends long amounts of time feeding (quite irritating) • up to 30 eggs per female louse

20. Crab Louse • Transmission • Venereal (from Venus, Roman Goddess of Love) – an STD • Frequency • OSU Student Health Center • 2.4% of student population • Only one other species in the genus • Pthirus gorillae

21. Facultative Parasites of Humans • These are parasites that normally utilize non-human hosts, but can use humans as an alternative.

22. The “Human” Flea • Numerous species of fleas will feed on human blood. • Cat flea • Dog flea • Ground squirrel flea (which is a known vector of plague) • Human flea: Pulexirritans • cosmopolitan & normally a parasite of swine

23. The “Human” Flea • “It was often said that women were attacked by fleas more often than men were. The cause may conceivable have been a response to ovarian hormones.” • Miriam Rothschild, Scientific American (1965)

24. Human Bot Fly • Order Diptera • Dermatobia hominus • South & Central American distribution • Female fly lays her eggs on mosquito & other “bugs” • Mosquito bites human • fly larvae “pop” out of eggs and penetrate human • develop within the human and bore out to pupate

25. Human Bot Fly • Also known as the “torsalo” • 3 - 4 weeks in the larval stage undergoing three instars

26. Sand Flea • A true flea (Order Siphonaptera) • family Tungidae • Tunga penetrans • New World tropical & sub-tropical • Common names • jigger - chigger - chigoe • Minute: 1 mm in length • Female borrows into skin & feeds & grows • Larval fleas crawl out of host & spend their pupal phase in the ground/soil/sand

27. Sand Fleas & You

28. Sand fleas are well known to human civilizations. Chimu (pre-Incan) pottery from Peru depicting feet with punch holes, a result of sand flea infestation.

29. Bed Bugs • Order Hemiptera • Cimex lectularius • Haematophagous - a blood meal between each molt • Closest relative is the BAT bed bug • a’ha, where were we living 30,000 years ago??

30. “Night-night, dear, sleep tight…and don’t let the bedbugs bite.”

31. Corvallis G.T. – 28 November 2003

32. Key PointsBugs Living on You • Historical Perspective • Obligate Parasites • 3 Types of Lice • Biology and control • Facultative Parasites • Human Flea, Bot Fly, Sand Fleas • Bed Bugs