The Insecta: Lice, Bugs, and Aphids

• chewing lice: mallophaga
• Sucking lice: anoplura
• elephant and wart hog live: rhynchophthira

• World wide on animals and birds
• a. Inhabit the vestment of the host, including hair,
• feathers, and clothing

• b. Highly host specific- parallel evolution with
• hosts

c. Not found on reptiles other than birds

• Head lice in body hair
• Body lice in clothing
• Crab lice in axial hair

• Dorso-ventrally flattened
• claws and appendages with various adaptations for clinging to hair and feathers
• (not toilet seats)

• complete life history on the host
• apparently ametaboloys, actually derive from hemimetabolous ancestors
• -egg attached to hair or feathers-nits
• -hatches to asexual nymph, resembles adult
• -several nymphal molts to sexual adult
• -all stages feed similarly

• a. Chewing lice, chewing mouth parts
• 1) Laterally opposed mandibles
• 2) Feed on surface skin debris, oils etc
• dont suck on blood, gnaw at skin. just as irritating

• b. Sucking lice-Anoplura
• 1) Long thin piercing stylet like mouth parts
• 2) Feed by sucking blood from capillaries in the
• epidermis of the skin
• suck blood from capillaries
• c. Elephant and Wart hog lice-
• Rhynchophthira
• 1) Chewing sucking mouth parts at tip of
• long rostrum
• 2) Feed presumably on blood
• 3) Semi-permanent tick-like attachment
• to host
• d. Transmission through direct host contact

• 1. Hemimetabolous or incomplete life cycle
• a. Egg hatches to wingless nymph
• b. Several nymphal molts to winged adult
• c. All stages feed on same materials
• 2. Piercing sucking mouth parts within fascicle
• 3. Two pair wings, first hemielytra (hard shell like), second membranous

a. Dorso-ventrally compressed (flat)

b. Wingless, straw colored

c. 1/4-3/8" long

d. Walking legs

• e. Piercing sucking m’parts
• feed just like kissing bugs, cant dig jump or bore

• parasites of colonial or traditionally nesting hosts
• host specific nest parasites of birds, humans, bats

• usually found only in nest of host
• do not live on host directly-may ride occasionally
• complete dependency on host for food.

• a. Found  only  in  “nest”  of  host
• b. Cannot live freely in the environment
• c. Do not live on host directly
• d. Complete dependency on host for food
• e. Infest locations frequented by the host when quiescent
• f. No wings although development is incomplete
• g. No winged dispersal
• h. All life stages constrained by identical ecology
• i. All life stages constrained by identical physiology
• j. All life stages constrained by identical morphology
• k. All life stages compete for same resources

• a. Cimex lectularius- mostly temperate
• b. Cimex hemipterus – mostly tropical
• c. Two other African species – humans share with bats in East African huts
• d. C. lectularius in the United States (so far)
• e. Many other species specific for other colonial animals
• f. Identification very important!

• a. The mechanism: the basic mosquito model
• Fascicle swings forward, splits
• Stylets saw into tissues
• Salivation
• Descend into deep dermis
• Canulate vein or artery.

• b. Bite effects
• Transmit no pathogens
• Bite effects similar to mosquito
• Considerable variation with exposure
• c. Bed bug bite
• hypersensitivity-
• Sensitivity to bed bug saliva
• Anaphylaxis and death!
• Rare

• continual biting can lead to no response, not permanent though.
• d. Feeding frequencies
• Larval stages feed once between molts (like ticks)
• Adult stages feed multiple times between egg
• laying
• Feeding takes 4-10 minutes, weekly
• Usually only nocturnal
• May go 3 months w/o feeding

• e. Feed only on blood (like ticks) ever!
• 1. Blood lacks essential nutrients
• 2. Symbiotic bacteria provide nutrients

• f. Host location
• Locate host using host associated cues
• Use CO2, heat (IR radiation), water vapor
• CO2 principle bed bug stimulant for feeding, mating
• Host generally quiescent

• a. Traumatic insemination
• b. Females lay upto ~5 eggs per day; hidden in refugia
• Up to ~500 eggs in life time
• Temperature dependent
• hatching time: 6-30 days

• a. Human nest parasites- found
• where humans live
• Increasingly (?)  common  in  “high  end”  hotels
• In human domiciles- homes to barracks and
• dormitories
• Historically in theaters prior and during WWII
• c. Hide in dark, pre-existing,
• crevice-like protected refugia
• Mattress piping (classic location)
• Under surfaces of bedsteads, bed
• frames
• Joints and crevices in bed supports
• Cracks, crevices in walls, electrical
• outlets
• Protected locations in furniture local to bed

• a. Phoresis- transmission  to  new  “nests”  by  hitchhiking  on host animals
• Bat wing membranes (animal example)
• Human clothing!

• b. Movement of nest materials- accidental
• dispersal when relocating furniture, beds
• and bedding
• Contaminated moving vans
• Transportation in luggage

• c. Recycle of infested materials into new
• mattresses or bedding

d. Failure of mattress steam sterilization process

e. Recycle furniture & dumpster diving

• Feed only on blood
• blood lacks essential nutrients
• symbiotic bacteria provide nutrients

• Reduced features, no eyes or hind wings, short fore wings
• Adaptations for clinging to host- ctenidia, flattened spines
• Entire life history on host all
• stages blood feed
• Viviparous, nymphs in advanced state

• 1. Increasing focus on host
• 2. Kissing bug free living, loose association with nest
• 3. Bed bug not free living, close association with nest
• 4. Bat bug, louse like complete dependency on host