insects relevant in food hygiene an overview. general characteristics most specious-rich class in...

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

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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

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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

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Blue Meat Fly – Calliphora vicina

World occurrence Can smell fresh

cadaver over distance of 10 km (forensic entomology)

Oviposition on cadaver and open wounds

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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

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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

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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

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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

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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