INSECTS
Relevant in food hygiene
An overview
General Characteristics
Most specious-rich class in the animal
kingdom
 1 Mio. insects described (realistic: between 1
Mio. and 80 Mio.)
 Central Europe: 40,000 insect species
 Polymorphic class:

 Size: a few tenth of a millimetre up to 30 cm wing
span
 With wings or wingless
 Unobtrusive colouring to striking patterns
Body Plan

Pronounced segmentation
 Head (Caput)
 Thorax
 Abdomen
Exoskeleton made of chitin
 Body surface is water and gas
impermeable; prevents dehydration and
protects from mechanical and chemical
impacts

Life Cycle

Metamorphosis
 Imperfect
 Complete
Oviposition
Larvae
Imago
(Adult)
Puppae
Insect Diet

Herbivore / Phytophagous insects
 E.g.: butterflies, sawflies, bees...

Wood eater / Xylophagous insects
 E.g.: bark beetle, wood drill, termites, horntail

Gall makers / Cecidozoa
 E.g.: gall wasp, gall mite, weevil...
Insect Diet

Feeding on dung / Coprophagic insects
 E.g.: dung beetle, dung fly...

Predator / Entomophagous insects
 E.g.: dragonfly, bug...

Parasites
 E.g.: mosquitos, bed bugs, fleas, lice
 Transmission of pathogens
Humans & Insects

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Insects since approx. 500 million years
Colonisation of a variety of habitats
Humans since approx. 2 million years
Useful insects: honey bee, silk moth...
Transmission of pathogens
Adaptation of insects to the human lifestyle
 Food stuff, commodities & garbage
Transmission of Pathogens

Virus
 Yellow fever via mosquitos
 Dengue fever via mosquitos

Bacteria
 Dysentery via flies
 Typhus via lice and fleas
 Pest via fleas

Plasmodia
 Malaria via Anopheles mosquitos

Flagellates
 Sleeping sickness via tsetse fly
Housefly – Musca domestica
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Attracted by food and
waste smells
Transmission of pathogens for
cholera and amoebic
dysentery
World occurance
Oviposition in manure and
garbage
One fly lies 500 eggs in 3
weeks
Sighting (pink):
J
F
M
A
M
J
J
A
S
O
N
D
Fruit Flies - Drosophilidae
 Tiny flies (1-6 mm)
 Attracted by putrescent smells,
left-overs
 More than 3000 species worldwide
 Most famous: Drosophila
melanogaster – Model organism of
geneticists
Stable Fly – Stomoxys calcitrans
Similar to housefly, but with forward-facing
proboscis
 World occurrence; close to stables
 Food: Males & females suck blood of warmblooded animals
 Oviposition in dung

J
F
M
A
M
J
J
A
S
O
N
D
Grey Flesh Fly – Sarcophaga carnaria
 Occurrence in entire Europe;
houses close to food stuff
 Attracted by smell of raw meet
 Oviposition on raw meet
 Transmission of bacteria, fungi,
viruses
J
F
M
A
M
J
J
A
S
O
N
D
Blue Meat Fly – Calliphora vicina
World occurrence
 Can smell fresh cadaver
over distance of 10 km
(forensic entomology)
 Oviposition on cadaver
and open wounds

J
F
M
A
M
J
J
A
S
O
N
D
Pale giant Horse Fly – Tabanus bovinus
Very large (20-25 mm), dipterous fly with
large green striped and iridescent
compound eyes
 Occurrence: Europe to Southern
Scandinavia, Middle East and Northern
Africa; always close to waters
 Food: Females suck blood of warmblooded animals (cattle); males visit flowers
 Horse-fly bites are painful

J
F
M
A
M
J
J
A
S
O
N
D
Mosquito – Culex pipiens
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Size: 6-7 mm
Occurrence: worldwide, close to fresh water,
brackwater, in swamps or meadows
Food: Females are dependent on blood of warmblooded animals
Reproduction: Oviposition in spring in waters
The malaria mosquito (Anopheles) appears
increasingly in Europe
J
F
M
A
M
J
J
A
S
O
N
D
Asian Tiger Mosquito – Stegomyia albopicta
Originally home to
southern and south-east
tropics
 Since the 1990s
spreading in Europe
(globalisation, climate
change)
 Transmission of
Chikungunya- and
Dengue fever
 Striking patterning

Wasp – Vespula vulgaris
Wasps are attracted by sugary syrups and
feed on fruits and sweets
 All wasps contain a poison sting

J
F
M
A
M
J
J
A
S
O
N
D
Hornet – Vespa crabro
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Occurrence from Europe to Asia
Size: 18-35 mm
Less obtrusive and harmful than wasps
Sting is painful but not more serious than
that of a wasp
Hornets prey on insects and small animals
J
F
M
A
M
J
J
A
S
O
N
D
Insect Poison Allergy
 Allergic reaction
to insect poisons
 Sting by wasps,
honeybees; also
hornets and
humble bees
 Potentially lethal
References
http://www.insektenbox.de/index.html
 GU Naturführer Insekten & Schmetterlinge
 http://de.wikipedia.org/wiki/Asiatische_Tige
rm%C3%BCcke
