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INSECTSRelevant 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
Puppae
Imago(Adult)
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...
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
Insect Diet
Humans & Insects
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 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
J F M A M J J A S O N D
Sighting (pink):
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
warm-blooded 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 warm-blooded 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
Size: 6-7 mm Occurrence: worldwide, close to fresh water,
brackwater, in swamps or meadows Food: Females are dependent on blood of warm-
blooded 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
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_Tigerm%C3%BCcke