Insects - Flypoint

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...

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Wood eater / Xylophagous insects  E.g.: bark beetle, wood drill, termites, horntail

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Gall makers / Cecidozoa  E.g.: gall wasp, gall mite, weevil...

Insect Diet 

Feeding on dung / Coprophagic insects  E.g.: dung beetle, dung fly...

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Predator / Entomophagous insects  E.g.: dragonfly, bug...

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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

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Bacteria  Dysentery via flies  Typhus via lice and fleas  Pest via fleas

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Plasmodia  Malaria via Anopheles mosquitos

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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

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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 

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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 J

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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 warmblooded animals (cattle); males visit flowers  Horse-fly bites are painful 

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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

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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_Tige rm%C3%BCcke 