Humpbacked fly (Megaselia scalaris)

Size:

• Body length: 2 to 3 mm

Look:

• Yellowish to grey-brown body
• Characteristic hump-like chest (thorax)
• Clearly winged with irregular venation
• Noticeable, jerky running motion instead of constant flight
• Compact, slightly convex abdomen

Way of life:

• Extremely adaptable to a wide variety of ecological conditions
• Development in animal and plant decomposition material
• Larvae can also be found in medical tissue or sterile environments.
• Active movement on the ground, rarely over longer distances in flight.

Reproduction:

• Egg laying in decaying material, carrion, feces, waste or food scraps
• Development from egg to fly takes 10 to 28 days, depending on the temperature.
• Multiple generations per year are possible
• Development even under extreme environmental conditions (low oxygen, contaminated with germs)

Infestation sites:

• Locations where bodies were found, sewage shafts, siphons
• Kitchen waste, dirty mops or rags
• Garbage rooms, leftover feed, compost, excrement
• Medical equipment, contaminated wounds, dressings

Nutrition:

• Larvae feed on decomposing organic material.
• Also active in sterile substances, e.g., medical tissue
• Adult flies suck liquids from rotting substrates.
• Feeding often occurs in the immediate vicinity of egg laying.

Behave:

• Crawling movement, irregular and fast
• They sit on floors, joints, walls and container edges.
• Strongly odor-oriented, they often appear suddenly in contaminated areas.
• In case of disturbance, rapid dispersal or relocation to adjacent rooms.

Hygiene risks:

• Transmission of bacteria from carrion, wastewater or excrement to surfaces
• In medical facilities, a potential trigger of myiasis (infestation of living tissue by larvae)
• Spread of germs to critical areas such as operating rooms, laboratories or care facilities
• Maggot infestation at undiscovered sources of decomposition

Indicator infestation:

• Their occurrence is considered an indication of heavy organic contamination, the smell of death, or leaking sewage systems.
• Often occurs in connection with blowflies, mites, or mold.
• Can provide initial indications of structural hygiene deficiencies.

Disease transmission:

• Potential cause of myiasis (infestation of living tissue by larvae)
• Spread of germs and bacteria

Structural and hygienic measures:

• Tightly sealing covers for wastewater and waste areas
• Clean joints, cracks and floor drains regularly and keep them dry.
• Disinfect walls and floors in case of decomposition or liquid ingress.
• Dealt immediately with crime scenes or sewage problems by specialists

Monitoring and control:

• Visual inspection of floor joints, shafts, wet areas and behind equipment
• Use of UV light traps or sticky traps
• Documentation of the development for tracing the breeding source

Behave:

• Empty organic material such as cleaning cloths, compost bins or organic waste bins daily.
• Raise staff awareness of hidden breeding grounds and biological residues
• Conduct hygiene checks systematically and in a structured manner