2 Key Points Bugs Living on You Historical PerspectiveObligate Parasites3 Types of LiceBiology and controlFacultative ParasitesHuman Flea, Bot Fly, Sand FleasBed Bugs
3 Bugs On YouDemodex follicularumthe human follicle mite
4 BUGS ON YOU “Even a superficial survey of the evolution of human cleanliness reveals that its developmenthas 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) Saint Francis of Assisi “Bathing shall seldom be permitted.”Saint Francis of Assisi“an unwashed body is the stinking badge of piety.”Queen Isabelle of Castileboasted of two baths in her lifeNapoleon, in a letter to Josephine“Be home in two weeks. Don’t bathe.”
6 Bugs On You Colonial America Why?? Pennsylvania & Virginia laws which either banned or limited bathingPhiladelphiabathing more than one a month prohibitedWhy??Bathing meant nudity which could only promote promiscuity
8 Bugs On You OBLIGATE Insect Parasites of Humans LICE parasitism (Gr. Parasitos = eating with another)LICEOrder Anoplura (“unarmed tail”)The Sucking Liceparasitic on mammals & birds15 families & ca. 500 species worldwideHaemophagic with piercing/sucking mouthparts.Wingless with flattened bodiesHemimetabolous (incomplete metamorphosis)
9 Human Lice Three “types” - Two species Pediculus humanus capitus The Head LousePediculus humanus humanusThe Body LousePthirus pubisThe Crab Louse
10 Head Lice Pre-WWI: head lice a familiar feature in American homes. Now making a come backest. 12,000,000 cases in the U.S.Female Louse50 to 150 eggs (egg = NIT) in her life timelays them at the base of hairseggs hatch in 5 to 10 days - three moltsthree weeks “egg to egg”Adult louseLouse about to hatch from the egg.Louse egg on a human hairThe 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 Slang close physical contact exchange of combs &/or hatsSlangWWI & II“motorized dandruff”
14 One other problem… RESISTANCE: SAFER ALTERNATIVES: Overuse of pediculicidal products has lead to decreased effectivenessThese survivors are breeding a new super race of lice, resistant to our chemicalsSAFER ALTERNATIVES:Head Lice to Dead LiceIncorporates a“5 step battle plan”Promotes use of olive oil to kill resistant adult licePART 1 -PART 2 -
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 feedingusually when you’re sleepingSpends most of time in the seams of your clothing (ergo common name “seam squirrel”)Eggs deposited on clothingTransmitted via exchanged clothingAverage # lice per host = dozenA known vector of typhus
17 Body Louse Control Allogrooming vignette: Richard the Lion Hearted & his ‘permitted’ washer womenChemicalDDT saved millionsThe 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 agoBody lice live in the clothingErgo 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 regionsrequires well spaced hairstationary beast & spends long amounts of time feeding (quite irritating)up to 30 eggs per female louse
20 Crab Louse Transmission Frequency Only one other species in the genus Venereal (from Venus, Roman Goddess of Love) – an STDFrequencyOSU Student Health Center2.4% of student populationOnly one other species in the genusPthirus 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 fleaDog fleaGround squirrel flea (which is a known vector of plague)Human flea: Pulex irritanscosmopolitan & 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 distributionFemale fly lays her eggs on mosquito & other “bugs”Mosquito bites humanfly larvae “pop” out of eggs and penetrate humandevelop 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 TungidaeTunga penetransNew World tropical & sub-tropicalCommon namesjigger - chigger - chigoeMinute: 1 mm in lengthFemale borrows into skin & feeds & growsLarval fleas crawl out of host & spend their pupal phase in the ground/soil/sand