7. Lice and fleas Flashcards
Taxonomy of Arthropoda phylum
- class Insecta
- class Arachnida
Key points of Insecta and Arachnida morphology
Insecta
- segmented body
- external skeleton of chitin
- 1. head (mouthparts + sensory organs: antennae, palps)
2. thorax (3 pairs of jointed limbs, in most species wings)
3. abdomen (various organs)
Arachnida
- 1. cephalo-thorax (mouthparts with chelicerae and palps, 4 pairs of limbs, no antennae, no wings)
2. abdomen (various organs)
- no respiratory openings: respiration cutaneous
Gonochorism - ?
sexual dimorphism
Parthenogenesis - ?
asexual reproduction by infertilized females
Epimorphosis vs holometamorphosis vs hemimetamorphosis - ?
Insects:
Epimorphosis - egg -> 3/5 nymph stages -> adult
Holometamorphosis - egg -> 3-11 larvae stages -> pupa -> adult
Arachnids:
Hemimetamorphosis - egg -> hexapod larvae -> proto/deuto/tritonymph -> adult
Lice. Basics
- host-specific
- permanent ectoparasites living for 1-5 months
- spread by contact
- chewing/biting lice and blood-sucking lice
Lice. Morphology
- reduced or absent eyes
- wingless
- 9 adominal segments with 6 pairs of spiracles
- chewing lice: head wider than thorax, chewing parts ventrally,
- blood-sucking lice: head narrower than the thorax, piercing mouthparts within the head
Lice. Development
- epimorphosis with 3 nymphal stages (at last 1 month)
- sometimes partenogenesis (Bovicola bovis)
- eggs (nits) are firmly attached to hairs
Species of chewing or biting lice:
Pig, rabbit, man have none
- chicken: Menopon gallinae, Lipeurus caponis
- goose: Trinoton anserinum
- duck: Trinoton querquedulae
- horse: Werneckiella equi
- cattle: Bovicola bovis (parthenogenesis)
- sheep: Bovicola ovis
- goat: Bovicola caprae
- dog: Trichodectes canis
- cat: Felicola subrostratus
- pigeon: Columbicola columbae
Species of blood-sucking lice:
Cats, birds have none
- horse: Haematopinus asini
- cattle: Linognathus vituli, Haematopinus eurysternus, Solenopotes capillatus
- sheep: Linognathus ovillus, Linognathus pedalis (can cause lameness), Linognathus stenopsis (last one goat also)
- pig: Haematopinus suis
- dog: Linognathus setosus
- rabbit: Haemodipsus ventricosus
- rat: Polyplax spinulosa
- mouse: Polyplax serrata
- man: Pediculus humanus, Pediculus capitis, Phthirus pubis
Fleas. Basic info
- non host-specific
- permanent ectoparasites
- adults suck blood several times a day
- developent in the surroundings (i.e. immature stages are not parasitic)
Fleas. Species
- Ctenocephalides canis - dog, cat, man
- Ctenocephalides felis - cat, dog, man
- Pulex irritans - man, dog, cat, pig
- Spilopsyllus cuniculi - rabbit, cat, dog
- Ceratophyllus gallinae - poultry, man, pet animals
- Xenopsylla cheopis - rat, man
- Tunga penetrans - man
- Echidnophaga gallinacea - fowl, dog, cat, rabbit, horse, man
Fleas. Morphology
- laterally flattened, wingless
- eyes: ocellus (not compound)
- piercing-sucking mouthparts
- 3d pair of legs adapted for leaping -> bigger
Fleas. Development
- holometamorphosis with 3 larvae stages (at least 2 weeks)
- eggs laid on the host butt drop off
- larvae feed on the feces of the adults and on debris
Fleas. Clinical signs
- repeated flea bites may cause flea-bite allergy (FAD - flea allergy dermatitis) - hypersensitive reaction mainly in summer
- dogs: hot spot - lumbosacral and gluteal region: papule formation, self-licking due to intense pruritus, moist dermatitis, alopecia)
- cats: miliary dermatitis (scattered erythrema, papule and visicle formation, later becoming crusty, with mild pruritus
Orders of Insecta class
- Lice
- Fleas
- Bugs
- Lesser mealworm or darkling beetle (non-parasitic, economical pest)
- Diptera - everything that has single pair of wings
What is spiracle?
Spiracles — openings of the tracheal system of the integument of the insect
Chewing (biting) lice vs blood-sucking lice
