ENTO 208 1st Edition Lecture 9 Outline of Lecture 8I. Epidemiologya. Disease Triadb. Definitionsc. Ecosystem Healthd. Epidemiology & modelinge. Vector-borne diseasesOutline of Lecture 9LiceI. CharacteristicsII. Lice Speciesa. Humansb. AnimalsIII. Broad importanceIV. TreatmentCurrent Lecture (9)Lice Order: PthirapteraSuborders: AnopluraAmblyceraIschnorceraRhynchopteraCharacteristics:SmallSecondarily winglessDorso-ventrally flattenedHave lost the compound eyeOften host specific (speciation to specific hosts also)Adapted and changed as bird hosts changed, lack of gene flow facilitates speciation Chewing Head is larger than thoraxChewing mouthparts, feed on skin, hair, etc.SuckingHead is smaller than thoraxThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Feed on host blood Hippobscid flies facilitate host switching in wing lice (ischnocera) Life cycleEggs (nits) attached (cemented to hair) or feathers17 days after laid, females are laying eggs Louse multiplicationStart with 1:1 -> 4 months later: 6,250,000Human Species Human louse (head louse)Spend entire life on headPrimarily on young childrenNot a vector for disease transmission Human louse (body louse)Concerned with poor hygiene/povertyVagabond's disease: skin discoloration from chronic body liceNits laid on clothesDisease transmissionEpidemic typhus; Rickettsia: Concentrations camps during WWIILouse-borne relapsing fever; Borrelia spirochetesTrench fever; bartonella: world war trench soldiers Human louse (crab louse)Pubic regionsTransmitted by direct contactBody is crab like (small head large abdomen)Not considered a vector for disease Video: head lice videoWet hairCleanse creamGo through with a lice comb Lice of veterinary importance*Lice are not vectors, impact is "direct"Cattle biting louse (chewing)Longnosed cattle louse (sucking)Treated differentlySucking found around neckChewing found on back/midlineAnimal Species Horses: 2 speciesPigs 1Sheep3, two sucking, one chewing Dogs2, chewing and suckingCat1, chewingChicken: six species, only chewingTurkey: two, chewingNo diseases vectoredBigger problem for debeaked birdsWildlife: majority of species occur on wildlifeUsually no effect on health unless host's immune system is suppressed/weak. Stressed, unable to groomFeral HogsCarry lots of pathogens and parasitesBroad importance (impact from lice on hosts)Sucking lice are typically more damagingJuvenile mortality in hostsReduced weight gain, milk productionAnemiaAbortionCompromised immune systemPhysical injuryDeathVector-borne diseaseTreatmentTopical treatment (spray, dip, dust): chewing liceSystemic treatment (drugs): sucking lice (drugs get into bloodstream and are eaten by
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