Fleas

1
Fleas
2
Insects as Weapons or "Bug Bombs"
3
What are the possibilities?

• Insects that sting
• Insects that carry disease
• Insects that bite/suck
• Insects that produce toxic substances
• Affect food supply

4
World War II

• Japan and the Pingfan Project
• Plague and fleas
• Mass produced (500 million fleas per year).
• Released fleas from aircraft
• Also developed other insect-vectored
• diseases.

5
Taxonomic classification

• Phylum Arthropoda
• Class Insecta
• Order Siphonaptera
• Genera
• Pulex irritans (human flea) ???,????
• Xenopsylla  cheopis ????
• Ctenocephalides canis (dog flea)
• Ctenocephalides felis (cat flea) the most
  prevalent of all flea species

6
Host spectrum

• Canids(????), felids(????), humans, calves,
  opossums(??), chickens, raccoons(??)(best found
  on cats, stray dogs and mongoose??)
• Host preferential rather than host specific

7
Geographic distribution

• Worldwide - survive best in humid conditions (90
  humidity).

8
Morphology

• Adults - 1.5 to 4 mm long, dark brown,
  laterally flattened, wingless, piercing-sucking
  mouthparts, genal (on the cheek) and pronotal (on
  the posterior border of the 1st thoracic segment)
  combs (ctenidia), rounded head

9
(No Transcript)
10
??
11
??????
12
(No Transcript)
13

• ???(Pulex  irritans)  ????,????????1?????????,???
  ???
• ????Xenopsylla  cheopis  ???1?,??????????????????
  ?,???????

14

• Eggs - about 0.5 mm long, oval, pearly white
  (nonfertile females will produce eggs, but they
  will be nonviable)

15
(No Transcript)
16

• Larvae - about 6 mm long, maggot-like,
  creamy-yellow, 13 segments with bristles on each

17
(No Transcript)
18

• Pupae - with a loosely woven cocoon which
  collects debris, about 4 x 2 mm

19
(No Transcript)
20
Life cycle
21
Life cycle (stages)

• Eggs are laid in the hosts bed, den ??, etc.
  (called environmental hot spots) or laid on the
  host, where they fall off easily because they are
  not sticky.
• Larvae feed on dry blood, feces, etc. and may
  remain in this stage as long as 200 days.

22

• Pupal stage is the most tolerant stage and can
  last from 10 days up to 50 weeks as pre-emergent
  adult, depending on environmental conditions
• Pre-emergent adults are stimulated to emerge by
  heat, carbon dioxide, movement (human or pet
  activity). Without stimuli, emergence will be
  delayed.
• Life cycle takes an average of 18-21 days but may
  take 20 months or more.

23
Habits

• Life span of adult 1 year, several months when
  unfed.
• Breeding places Eggs are laid in hostsnest or
  even hair.
• Feeding The larvae take adult fleas feces and
  other organic debris as their food. Both male and
  female adults are blood suckers. They have
  relative blood preference.

24
Habits

• Thermo-tropism Fleas prefer warmth.
• Seasonal distribution Majority are prevalent
  from May to October.
• Activity They may jump as far as 30-40 cm and as
  high as 20 cm, but their jumping is not
  directional. The transmission of flea is
  performed only by their host.

25
Fleas and Diseases

• Causes irritation, scratching, restlessness
• Vector of Yersinia pestis (plague)
• Endemic typhus or flea-borne typhus.
• Intermediate hosts of some tape-worm Dipylidium
  caninum, Hymenolepis nana.

26
Control

• Eradication of rodents.
• Eradication of fleas by burning, chemicals.
• Personal hygiene, rat-proof buildings, and do not
  let dogs and cats come into the houses.