MEDICAL ENTOMOLOGY 2 Flashcards
What arthropods are covered in this document?
Pediculus humanus (adult, egg), Phtherus pubis (adult), mites (Sarcoptes scabies), hard ticks (male & female), soft ticks (adult), and Cyclops (adult).
Describe the adult Pediculus humanus.
Wingless, compressed dorsoventrally. Antennae consist of five segments. Female: last segment has a notch (inverted V shape). Male: absence of notch, but there is a well-developed spine-like penis protruding posteriorly.
Describe the egg (nit) of Pediculus humanus.
Oval in shape, cemented to hair or fibers of clothes, crown-shaped operculum, developed embryo.
Describe the adult Phtherus pubis.
Compressed dorsoventrally, shorter and broader than the head louse, the last abdominal segment is notched.
Describe the adult Sarcoptes scabies.
Small microscopic in size, body made up of one piece, 4 pairs of legs. The anterior 2 pairs have terminal stalks ending in minute disk-like suckers.
How do female and male Sarcoptes scabies differ in leg structures?
Female: Posterior two pairs of legs end with blisters. Male: 3rd pair of legs is provided with bristles, while others have disc-like suckers.
Describe the adult hard tick.
Large macroscopic, hypostome exposed with teeth, globular body, wingless with 4 pairs of legs, no antennae, spiracle situated behind the 4th leg.
What is the difference between male and female hard ticks regarding the scutum?
Scutum covers only the anterior portion in females but the entire body in males.
Describe the adult soft tick.
Absent scutum, mouth parts situated ventrally, spiracle between 3rd and 4th leg.
Describe the adult Cyclops.
Pear-shaped, segmented cephalothorax and abdomen. Cephalothorax has 2 pairs of antennae and a single median eye. 4 pairs of legs. Abdomen ends with 2 parts of long bristles.
What is the key visible difference between hard and soft ticks?
Hard ticks have a visible capitulum and dorsal shield, while soft ticks lack a scutum and have ventrally situated mouth parts.
