presentation on medical entomology

1. Course: Medical Entomology
Credit Hours: 3
COURSE CODE: 7232
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Nusrat Jahan (PhD UK Postdoctorates USA)
Distinguished Professor
Department of Zoology, Government College University,
Lahore, Pakistan

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What is Medical Entomology?
 Medical Entomology is a field of Science, deals with the
understanding, preventing and controlling of arthropod
borne diseases.
 It investigates the relationship of insects and other
arthropods to the health of humans, domestic animals and
wild-life.

3. Medical Entomology
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Veterinary Entomology
 Study of arthropods and their
effects on pets, livestock and
wild-life
 It has two primary sub divisions
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1. Public Health Entomology
 Study of arthropods and
human health

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Insects of Medical Importance
 Three important areas of public health
Personal pests
Lice Fleas, Bedbugs, Ticks and Scabies mites. They are ectoparasites of
avian and most mammalian orders.
Bedbugs
Lice
Ticks
1

5. Insects of Medical Importance
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Fleas
Scabies mite
Personal pests
1

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Insects carrying enteric disorders
The Housefly
Common and cosmopolitan species which
transmits diseases to human.
Amoebic and Bacillary dysenteries
Typhoid fever, also known as
enteric fever
Poliomyelitis
Cholera and hepatitis
Housefly
2

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Biting insects
Mosquitoes, Biting midges, (Sandflies), Blackflies, Horse Flies,
Stable flies.
Major human diseases are caused by these insect
vectors.
Biting midge
Aedes aegypti fed with
blood
Aedes aegypti
Anopheles stephensi
3

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Biting insects
Tsetse fly
Stable fly
Blackfly
Horse Fly (Tabanus sp.)
3

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Aedes albopictus from GCU (2006)

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Male Aedes albopictus from GCU (2008)

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Diseases transmitted by insect vectors
Diseases carried by insects and other arthropod vectors
affect more than 700 million people every year, and are
considered the most sensitive to climatic and environment
conditions. Major diseases are:
 Dengue fever: caused by Aedes aegypti (main vector) Aedes
albopictus (minor vector) threatens -50 million people are infected
by dengue annually, 25,000 die. Threatens 2.5 billion people in
more than 100 countries.
Malaria: Vectors Anopheles mosquitoes - 500 million become
severely ill with malaria every year and more than 1 million die.

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Leishmaniasis: Vectors are sand flies: species in the genus
Lutzomyia in the New World and Phlebotomus in the Old World.
2 million people infected.
Bubonic plague: Principle vector Fleas; Xenopsylla cheopis At
least 100 flea species can transmit plague. Several thousand
human cases per year.
Sleeping sickness: Vector tsetse fly not all species. Sleeping
sickness threatens millions of people in 36 countries of sub-
Saharan Africa.
Typhus: Vectors mites, fleas and body lice, 16 million cases a
year, resulting in 600,000 deaths annually.
Filariasis: Wuchereria bancrofti the most common vectors are
the mosquito species: Culex, Anopheles, Mansonia, and Aedes;
affects over 120 million people.

13. Phylum Arthropoda General Characters
 Bilaterally Symmetrical
 Exoskeletons of Chitin
 Jointed appendages
 True segmentation with replication of body parts (muscles, ganglia).
 Tagmatosis (segments of the body are modified and grouped together to form
mouth parts and body regions).
 Growth through metamorphosis
 Digestive tract is complete with mouth and anus
 Nervous system is ventral with series of ganglia related to body segments.
 Body cavity is hemocoele, circulatory system is o[pen, blood is not contained in
the vessels.
 Reproduction is sexual with number of forms
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General characters of Arthropods

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17. Class Insecta
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Insect Body-parts

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Digestive System

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Respiratory System

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Special wing modifications
Halteres - small, club-shaped organs of
balance found in Diptera (flies) on each side of
the thorax (metathorax) just behind the
forewings and thought to be modified vestigial
hindwings
Elytra (singular: elytron) - the hard, leathery
forewings of Coleoptera (beetles) and
Dermaptera (earwigs), that serve as protective
coverings or 'wing-cases' for the membranous
hindwings. The hindwings (if present) are
usually folded out of sight under the elytra
when at rest.

26. Growth and Development
Ametabola: No Metamorphosis
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Typical development of an apterygote insect with little or no metamorphosis
e.g. Bristletail (Order Thysanura)

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Typical development of a pterygote insect with a simple metamorphosis
(Exopterygota)
e.g. Locust (Order Orthoptera)

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Typical development of a pterygote insect with a complex metamorphosis
(Endopterygota)
e.g. Moth (Order Lepidoptera)

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Complete metamorphosis