The bottle fly is a species of the common blow fly which is found in almost all habitats of the world. While flying, this fly produces a characteristic buzzing sound. It is a scavenger and feeds on dead and decayed organic matter, meat, feces, etc. Nevertheless, when there is a shortage of decayed organic matter, the female feeds on the nectar of strongly-fragrant flowers for laying healthy eggs. Thus, this fly plays a major role as a pollinator in the ecosystem. Coming to its life cycle, it is similar to that of other flies and comprises four successive stages.
Life Cycle of a Bottle Fly
The bottle fly is a predominant type of large flying insect, in which the adults can be identified easily by their green or blue metallic coloration. They are categorized based on the body color. To be precise, the blue and green bottle fly life cycle is similar to the life cycle of the common bottle fly.
First Stage: Egg
The female lays about 130-180 eggs at a time. The eggs are small and pale-gray or yellowish in color. Depending on the prevailing climatic condition and temperature, the eggs hatch into larvae within two to three days. In warm temperature conditions, the eggs may hatch within 10 hours after laying.
Second Stage: Larva
The next stage is the larva, which measures about 10-14 millimeters in length and appears pale-white in color. The larval stage may last for 2-10 days, while passing through three larval instars. The larva is also referred to as a maggot. This maggot feeds voraciously only on dead organic matter, while leaving out live organisms. After the growing stops, the grubs start searching for dry pupation areas.
Third Stage: Pupa
Within a few days, the larva matures and pupates in a dry place. The resulting cocoons have a tough, brown-colored covering. As compared to other flies, the pupation stage of a bottle fly is very long (about 2 weeks). During low temperature conditions, a pupa may take about three weeks to emerge into an adult bottle fly.
Fourth Stage: Adult
The adult bottle fly measures about 1/4-inch to 3/8-inch in length. Depending upon the species, the adult color may be metallic-green, blue, bronze, or copper. Adults become sexually mature within 2 weeks after emerging. Following mating, the female breeds in damp areas, compost bins, and unprotected wounds of animals. Thus, the life cycle of the bottle fly starts again. Within one year, usually 3-4 generations of bottle flies are completed.
During cold climatic conditions, the pupae and adults hibernate until the temperature is warm and favorable. In general, the life span of a bottle fly is about 3 weeks, which may be shortened in warmer areas. It is mostly found outdoors. In case you find a fly indoors, check for the infestation site. Besides scavenging on dead organic matter, it is also a carrier of disease-causing microbes. Hence, it is often considered as a serious pest. If necessary, you can hire professional a pest control service to get rid of the infestation.