| Phylum, Arthropoda; Class, Insecta; Order, Diptera
|
Identifying Features 
Appearance (Morphology)
- Three body parts: head, thorax, abdomen
- One pair of fully developed wings
- Hind wings are reduced to halteres (small knob-like structures) used to maintain equilibrium.
- Adult mouth parts are sponging, lapping, or piercing
- All adults look like flies, but some may have a metallic color (blue bottle fly).
- Antennae may be difficult to see.
Adult Males and Females
Males and females are hard to distinguish. Females are usually larger and can extend the tip of the abdomen to form an ovipositor which is used to lay eggs. Sometimes males have enlarged eyes which meet on top of the head.
Immatures (different stages)
Flies are holometabolous, therefore they have four distinct morphological stages; egg, larva (maggot), pupa and adult. After hatching from the egg, larvae molt twice as they grow. Molting of maggots is difficult to see. Larvae are maggots with a legless soft body except for the dark mouth hooks. Pupae are dark, and look like a small barrel.
Natural History
Food
Larvae feed on decaying meat and feces. Adult flies feed on sugary food of any kind, including nectar and rotting fruit.
Habitat
Flies live in garbage and wherever animal feces are available. Dead animals attract flies within hours after death. Most flies are diurnal.
Predators
Many birds, bats, spiders, and insects such as dragonflies eat the adults. Predatory and parasitic insects eat the larvae.
Interesting Behaviors
- The eyes of flies are among the most complex in the insect world. They are compound eyes with many individual facets, each representing a separate light-detecting unit. The light reflected from the eye of a horsefly can form a rainbow.
- Flies taste, smell, and feel with the hairs that cover their bodies. The hairs on the fly's mouth parts and feet are used for tasting. Flies taste what they walk on. If they walk onto something tasty, they put down their mouth and taste it again.
- Flies use other hairs to tell them when they touch something. These hairs bend when touched.
- The eyes of a fly do not have eyelids, so flies rub their eyes with their feet to keep them clean.
- A fly cleans itself constantly.
- Flies walk on smooth surfaces using sticky soft pads that act like glue. This allows them to walk on vertical glass surfaces and upside down.
Impact on the Ecosystem
Positive
Flies and other insects, such as burying beetles, are very important in consuming and eliminating dead bodies of animals. Flies are also essential in the conversion of feces and decaying vegetation to soil. Flies serve as prey to many other animals. Some flies aid in pollination.
Negative
Because of their habits of being attracted to feces and decaying meat, flies have been implicated in transmission of disease such as dysentery, typhoid fever, and cholera. |
Drain Flies
Also called moth flies, sewer flies or filter flies these true flies have bodies and wings covered with numerous hairs. If crushed they leave a powdery smudge
Drain flies, or moth flies, can be found in moist, highly organic debris areas such as sink drains, sewage treatment facilities, storm drains, dung and rotten vegetation.
Adults range in size from 1/16 to ΒΌ inch . They may be yellow to brown /black in color.
During daylight, they will often be found resting on walls near drains.
Adult female drain /moth flies most often lay their eggs in masses on the surface of gelatinous film found in drains and sewers.
They may also breed in moist, shady areas outdoors such as under potted plants, in bird feeders and baths, in moss, in clogged roof gutters, under air conditioners, in thick mulch, or on wet ground areas.
The larvae feed on decaying material that collects in drains. In natural settings, moth fly larvae feed on decaying plants and animals. Most moth flies are harmless to humans, though they may transmit bacteria and other microorganisms from their breeding sites to areas where people are. Moth flies do not bite. Adults live about two weeks
Control
Finding the sources of breeding and eliminating them is the best control.
Floor drains, overflow cuts in sinks and tubs, sump pump pits and sewers can accumulate organic matter but often do not receive enough water to flush the waste down the drain.
They may be common in laundry and floor drains, toilet and shower drains.
The drain/moth fly larvae feed on the sides of the drain and in the drain trap if there is an accumulation of organic debris there. You can check it by placing some tape over the opening (leave some opening for air flow). If you find these flies stuck to the tape , you have discovered the source.
Pouring bleach down the drain is not effective. A bacterial digester may be used to break up the organic debris.
Re-grouting tiles to prevent water seepage into walls will stop breeding in those sites. If found in rotting vegetable matter, the source should be destroyed.
Clean dirty garbage containers, wet lint under the washing machine, and even standing water in containers under houseplant pots. Outside the home, inspect air conditioners, bird baths, shallow stagnant pools of water and sewage treatment facilities upwind as adult flies will travel with the wind.
If adults do not disappear within a week further treatments or looking for other breeding sources is needed .
