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 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 J F F M M A A M M J J J J A A S S O O N N D 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 J F F M M A A M M J J J J A A S S O O N N D 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 J F F M M A A M M J J J J A A S S O O N N D 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 J F F M M A A M M J J J J A A S S O O N N D 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 J F F M M A A M M J J J J A A S S O O N N D 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 J F F M M A A M M J J J J A A S S O O N N D 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 J F F M M A A M M J J J J A A S S O O N N D D

Hornet – Vespa crabro  Occurrence from Europe to Asia  Size: 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 J F F M M A A M M J J J J A A S S O O N N D D

Insect Poison Allergy  Allergic reaction to insect poisons  Sting by wasps, honeybees; also hornets and humble bees  Potentially lethal

References   GU Naturführer Insekten & Schmetterlinge  rm%C3%BCcke