This document summarizes key characteristics of several parasites, including lice, bed bugs, ticks, and Cyclops. It describes physical features such as body shape, number of segments, presence or absence of wings, legs, antennae, and reproductive structures for males and females. For example, it notes that the human louse Pediculus humanus is flattened, wingless, with 3 pairs of clinging legs, and females have a notched posterior end while males have a pointed end with an aedeagus. The document contains labeled diagrams to illustrate adult and immature forms of parasites.

1. Medical parasitology
department
BY
MOHAMMED ABDELMONEIM

2. Anoplura (Lice):

4. Pediculus humanus
- Flattened dorsoventrally.
- Head: conical with one pair of simple eyes
- ; one pair of five-segmented antennae;
- piercing and sucking proboscis in both sexes
- (refracted within the head at rest).
- Thorax:
- 3 fused segments!
- wingless.
- 3 pairs of clinging legs (tibial process opposite the single claw).
- Abdomen:
8 segments with 6 pairs of respiratory spiracles on the 1st 6 ones:
▪ Female: notched posterior end,
vagina with 2 triangular gonopods.
▪ Male : pointed posterior end with spine-
like aedeagus, tibial processes of the 1st pair of legs
are more developed.

6. Phthirus pubis (Pubic or crab louse)
- It differs from Pediculus as regards: - Head: shorter.
- Thorax and abdomen compressed together.
- 1st pair of legs is not well-developed
- as compared with the other pairs.
- Abdomen: quadrate, the first segment
- carries 3 pairs of respiratory spiracles:
- ▪ Female: notched with 4 pairs of lateral processes.
▪ Male: not notched with
2 pairs of lateral processes
and straight aedeagus not protruded

7. Female Male

8. Egg of lice ( nit )
- Oval, 0.8mm
- operculated (crown-like)
- whitish.
- Cemented to hairs or
fibres of clothes.

9. Hemiptera ( bed bugs)

10. Cimex bug adult
Flattened dorsoventrally.
- Head: pentagonal in shape,
- One pair of four-segmented antennae.
- Piercing and sucking proboscis in both sexes
- Thorax: 3 segments:
- Prothorax extending anteriorly close to the eyes.
- Mesothorax carrying 2 hemi-
elytra (rudimentary wings).
- metathorax covered with the hemi-elytra. - 3 pair of legs.
Abdomen:
Female: rounded with the opening of organ of Berlese on the right
side of the 4th segment ventrally and vaginal orifice
on the 7th segment surrounded with triangular gonopods.
Male: pointed with curved aedeagus at the last abdominal segment

11. Male
Female

12. Triatoma bug adult
( DM microscope)
 Large insect, 2-3cm in length
 with bright colours.
 Head:
cone-shaped with eyes
one pair of four-segmented antennae
and long proboscis bent underneath the body at rest.
 Thorax:
with 2 complete pairs of wings
; the mesothoracic pair has the basal part chitinised
and the distal part membranous
while the metamoracic pair is membranous.
 Abdomen:
8 segments with sharp borders,
covered by the wings at rest

14. Ticks

16. Life cycle

17. Hard tick
Male
- Body: cephalothorax and abdomen fused together.
- Capitulum: terminal, protruding anteriorly (can be seen from
the dorsal surface).
- Scutum: present and covers the whole dorsal surface.
- Posterior end: festooned.
- Legs: each one ends with 2 claws and a pulvillus.
- Spiracles: behind the 4th pair of legs (one on each side).
Female
Similar to the male but the scutum is small covering only the
anterior portion of the dorsal surface.

18. Adult soft ticks (Ornithodorus)
-Body: sac- like with leathery
mamillated cuticle and thick margins.
- Capitulum: subtenninal,
ventral
i.e. can't be seen from the dorsal surface.
- Scutum: absent.
- Posterior end: no festooning.
- Legs: without pulvilli.
- Spiracles: in front of the
4th pair of legs.

20. Class: Crustacea (Cyclops)
- Size: l-3mm.
- Pear-shaped body,
broad anteriorly, formed of:
- Cephalothorax with 2 pairs of antennae
(a long pair of 17 segments and
a short pair of 4 segments)
and 4 pairs of legs ending biramously.
- Abdomen ends biramously
It is formed of 4 segments in female
and 5 in male.
o Female
carries 2 egg sacs on the sides of the abdomen.

21. Female
Male

26. Thanks my dear students