Fruit Flies' Life Cycle

Things You Didn't Know About the Life Cycle of Fruit Flies

Fruit flies' life cycle comprises four stages : egg, larva, pupa and adult. The fruit fly undergoes complete metamorphosis, which means the juvenile form of the fly bears no semblance to the adult fly.
BiologyWise Staff
Last Updated: Apr 22, 2018
Who hasn't seen swarms of frenzy little fruit flies thriving on ripe fruits, vegetables, garbage bins, dirty dishwashers, etc. These flies are a year-round problem, although they most commonly thrive in summer and early fall.

Fruit flies are easily distinguishable by their bright red eyes and tiny one-eighth inch, light-yellow to tan-colored bodies. The very fact that these flies are attracted by the fermentation fragrance of overripe fruits, these flies are called fruit flies. Besides fruits, these insects also get attracted towards vegetables, vinegar and yeast, which is why they are also referred to as vinegar or pomace flies. Do you know where fruit flies come from, and what is their life cycle? Let's find out!

Life Cycle of Fruit Flies

The life cycle of a fruit fly is quite rapid and is completed within a short period of 8-14 days itself. It's because of this short life cycle of fruit flies, that scientists have extensively studied its life cycle. The fruit fly undergoes complete metamorphosis, which means the young or juvenile stage of the fly bears no semblance to the adult fly.

Egg: The male fruit fly deposits its sperms into the body of the female fruit fly, where fertilization of the eggs take place in the oviduct. Thus, begins the life of a fruit fly in the form of an embryo in the banana-shaped egg. The female fruit fly lays microscopic eggs, measuring half a millimeter in length, on the surface of any fermenting fruit or decomposing organic matter. She will lay about 500 eggs that are not visible to the naked eye that will hatch after one day of laying.

Larva: The first-instar larva hatches out after 24-30 hours after the egg has been laid. They emerge out and hungrily feed on the fermenting material, onto which the eggs were laid. After a day, the first-instar larva molts and then emerges the second larva stage. Even at this stage, the larva eats as much as it can. After another 2 days of feeding, these larva molt to form the third-instar larva. Three days later, the larva moves out of the fermenting material to drier areas, where they can pupate and enter the next stage in their life cycle. The larva stage lasts for 3-5 days.

Pupa: The larva stops moving after its third molt and then transforms into a pupa, with an oval, hard, brown puparium surrounding it. It is inside this puparium that the process of metamorphosis takes place and the insect begins taking the shape and form of the adult fly. The fruit fly gets its wings and color, from this stage and about 24 hours before the adult emerges from the puparium, the folded wings and red color of the eyes can be seen through the puparium.

Adult: Several days later the adult fly emerges out through the anterior end of the puparium. The adult fly appears light in color, with unexpanded wings and long abdomen. After the passage of a few hours, the fly's body color turns darker. The wings are expanded and the abdomen gets a round shape. These newly emerged fruit flies are lured towards light. In the next 2 days, these adult flies become sexually active and begin to perform the mating dance to woo the female flies. The female can store enough sperm after single insemination, which they can use to fertilize many more eggs in the future. The adults mate and the female flies lay their eggs on a suitable substrate.

Under ideal conditions, fruit flies' life cycle should not exceed a period of 8 days. The large number of eggs a female can lay and the short lifespan, explains how within two or three days we find the room filled with scores of frenzy fruit flies. As the population numbers rises, the havoc created is unbearable, which is when people frantically look for ways for getting rid of them.