Drosophila: how does it live? How to eradicate it from the house?

We tend to use the singular to talk about the Drosophila fly. In reality, Drosophila is a genus that includes 400 different species recorded in the world. The one that we come across the most and that we would like to get rid of is the Drosophila melanogaster, also called “vinegar fly”. How does she live? And above all, how to eradicate it from the house?

Drosophila, in a few words

To get rid of your enemy, it is better to get to know him.

Why there Drosophila melanogaster does she name it so?

  • drósos, means “nectar, divine liquor, wine”,
  • phílos, “who likes”,
  • melanogaster, “With a black belly”.

Let’s take a closer look at this wine-loving animal with a black belly.

Like all insects, this fly, a few millimeters long, has three pairs of legs and represents the smallest species of Diptera. Its body is light brown and black rings are outlined on its abdomen, in a different way depending on whether it is a male or a female. These eyes are bright red, very characteristic. First African, this fly has spread widely across the world. This is called a “cosmopolitan” species.

After mating, females lay eggs about 0.5 millimeters long in an environment where larvae can feed: rotting fruits or vegetables are perfect for them! About thirty hours is enough for whitish larvae 5 mm long to appear. Only 5 to 6 days later, the larva is able to move and transforms into a pupa which will be succeeded, after metamorphosis, by an adult winged insect. The life cycle of this fly lasts about two weeks at 22 ° C, but the cycle slows down when the temperature is lower.

Drosophila appreciates humidity and light.

Why is she drawn to fruits?

What attracts the Drosophila melanogasteris alcohol. Its preferred environment consists of 6% to 11% alcohol. In its food, alcohol represents up to 4%. If this rate is higher, its mortality increases.

Bacteria and yeast are present on the fruits. They cannot be completely removed by a simple washing. However, if the fruit remains in an environment hot after picking, the microbes multiply. They get inside the fruit through favorable areas, such as stained areas. Inside the fruit, oxygen is lacking. The biochemical process which then occurs is alcoholic fermentation: the fructose is transformed into alcohol (ethanol).

Drosophila also feeds on yeasts, even though these produce toxins that have the role of repelling predators. Drosophila use their olfactory system to locate egg-laying areas, guided by the smell of acetic acid.

How to get rid of fruit flies?

The presence of fruit flies is not appreciated. However, they are not dangerous, not carrying any disease to which we would be susceptible.

The best solution to get rid of fruit flies is to make traps placed in areas where flies seem to be most numerous.

Here is an example of a trap:

  • Take a tin can,
  • Pour about two centimeters of cider vinegar, beer or wine,
  • Place a funnel as a cover, narrow part inside. It can be made of paper,
  • Place adhesive around the perimeter to prevent flies from coming out on the edges,

Another trap can be made with a glass jar in which you place apple cider vinegar, beer or a piece of ripe fruit. The jar is covered with a transparent plastic film in which a few holes are drilled. The fruit flies, attracted inside, will not be able to come out.

Remember to replace the fluid every 2 days.

If the sight of traps turns you off, be sure to choose containers opaque or cover them up so you can’t see what’s inside.

A small cup of water filled with sweet vinegar and dish soap will also work. Flies are attracted to vinegar but cannot fly away because of the dish soap. The flies end up drowning.

How not to attract fruit flies to the house?

The best is probably still not to attract flies. Here are some simple things to do:

  • Do not store too many fruits at the same time that you could not eat quickly,
  • Store fruits and vegetables in the refrigerator or clean them beforehand to slow down the ripening process,
  • Regularly check stored fruits and vegetables. Fruits that are starting to spoil must be eaten without delay,
  • Place the apples and tomatoes apart because they are fruits that give off more ethylene than the others, a molecule that accelerates the ripening of the fruits,
  • Keep your kitchen clean. Waste and compost buckets should be emptied regularly.

Fabrics or papers impregnated with a few drops ofessential oils like those of basil, lavender, lemongrass or cedar, placed near your fruit will act as repellents. It’s up to you to choose the scent you prefer.

A fly yet very useful for research

The Drosophila melanogaster has everything to appeal to researchers: small size, high fertility and adaptability which facilitates its culture in plastic bottles, at low cost in addition. This insect is indeed essential to genetics. It was the American scientist Thomas Hunt Morgan who made him known to the research world and even received the Nobel Prize for Medicine in 1933 for his work using Drosophila.

The insect’s life cycle of around 12 days guarantees researchers 25 generations per year. Enough to study the phenomena of heredity and the role of genes in the construction of the body over a short period of time. This fly shares only 60% of genes with humans; if this does not cover all aspects of the human body, they are nevertheless subjects fundamentals that can be approached: neurobiology, immune system, aging, cancer … There are many areas that this little insect helps to advance!