Fruit flies part 1: Introduction to Drosophila

Fruit flies are an excellent food for many surface feeding killifish, closely resembling their natural diets in the wild. They are easy to culture, quickly, cheaply and in large numbers. Fruit flys are rarely available in pet shops, but are widely available online, and very much worth trying, even if you don't bother culturing them on an ongoing basis.

What is a fruit fly?

Fruit flies are small flies that live on and around decaying fruit and vegetation. They occur worldwide, except the very coldest regions. The species most familiar to scientists, aquarists and herpetologists are in the genus Drosophila which literally means 'dew-lover' in Greek. Also known as 'bar fly' or 'vinegar fly', these little flies are commonly found around waste bins, bars, orchards etc, and they are widely used in laboratories as research animals. The species we feed to our fish however, have been bred to have shorter 'vestigial' wings, and as such can not fly. These are typically from two species Drosophila melanogaster and Drosophila Hydei.

Why fruit flies?

Although dealing with highly mobile flies can be trickier than with worms, there are some great reasons to consider culturing them.

• Nutritious - all fish can be trained to eat flies, but surface feeders love them. Not only are they relished by the fish, but they also have a high fibre content, and are therefore a great contrast to the fattier foods such as worms and beef heart. They are also typically disease-free, unlike some aquatic livefoods.
• Prolific An adult fly can lay 20+ eggs in a day. Once you get the hang of it, fruit flies are easy to maintain, and at 25 deg. centigrade the development of Drosophila melanogaster takes just 9 days.
• Availability - unlike collected livefoods, cultured Drosophila are available all year round.
• Flightless flies available - fruit flies have been studied in laboratories for very many years, and a lot is known about the humble fruit fly. Over the course of these studies, geneticists line-bred many strains of fly, including vestigial-winged, and even wingless flies. These are the flies typically cultured by hobbiests.

Drosophila larvae in a typical culture

Drosophila larvae climb up the walls of their vials and chrysalise

Drosophila pupae

Drosophila life cycle

Adult flies lay a lot of eggs. A single female can lay over 20 eggs in a day, and can store sperm within her body for up to two weeks, to lay fertilized eggs at will.

Eggs take 23 hours to hatch at 25 deg C. Once they do hatch, the larvae bury into the media and grow. They will stay as larvae for five days, in which time they undergo three moults.

Eventually they will start to climb the sides of the vial, and when fully grown will settle near the top, and form a chrysalis. The change from maggot to fly takes around three days, but again, is temperature dependent.

The image to the right shows a newly formed chrysalis with the lava's segments still visible (1), an older chrysalis with the fly clearly visible. The red dots are its eyes (2) and an empty chrysalis from which a fly will have hatched (3).

Once the flies have emerged they must be moved to new vials, as there is now no food suitable for them in the old vials.

Fruit fly cultures for sale

Golden Hydei Fruit Fly Culture + 1 Just Add Flies 4 Dart Frog Food Reptile Food

Etters, Pennsylvania, 173**, UNITED STATES OF AMERICA

$25

The product is a Golden fruit fly culture kit + 1 additional container of just-add-flies food designed for dart frogs and reptiles. Produced by the brand Crazy Frog Lady, this product provides a convenient and natural way to feed your pets. The fruit flies are a nutritious food source for many reptiles and amphibians, promoting healthy eating habits and reducing the need for processed diets. With this product, you can easily maintain a steady supply of live insects for your pets to enjoy
... view on ebay

Repashy SuperFoods Superfly 17 6 oz. (1 1 lb) Jar Fruit Fly Culture Media

Seminole, Florida, 337**, UNITED STATES OF AMERICA

$42

Repashy SuperFoods Superfly 17 6 oz. (1 1 lb) Jar Fruit Fly Culture Media
Repashy SuperFoods SuperFly 17 6 oz (1 1 Lb) Jar FRUIT FLY CULTURE MEDIAItem Details
Additional FeaturesFruit Fly Culture Media with Enhanced Nutritional ValueAge Range DescriptionAll Life StagesAnimal Food Diet TypeVegetarianBrand NameRepashyBreed RecommendationInstant Formula for Drosophila Culture, Fruit Fly Culture MediaContainer TypeTubDate First AvailableJune 6, 2024FlavorCinnamonItem FormPowderItem Weight1 1 ... view on ebay

TC INSECTS Turkish Glider Fresh Fruit Fly Culture Live Feeders for Dart Frogs

Huntsville, Texas, 773**, UNITED STATES OF AMERICA

$8

Turkish Gliders Fruit Flies
These will be fresh cultures! with Super Swarm Media!
These Turkish Gliders Fruit Flies are extremely prolific and make an excellent feeder insect for small reptiles, amphibians, baby arachnids, and other tiny insect-eating pets. Their smaller adult size makes them a great choice for young animals or species that need a more manageable feeder
Each culture is raised in a 32oz cup using our Super Swarm Media, a premium blend formulated to support strong ... view on ebay

!!MELANOGASTER COMBO PACK!! - Flightless Fruit Fly Culture - LIVE FEEDER INSECT

Cleveland, Georgia, 305**, UNITED STATES OF AMERICA

$70

??PLEASE READ BEFORE PURCHASING??
(WHAT YOU RECEIVE)
-------------------------------------------------------------------------------------
Name: Drosophila melanogaster (x1 CULTURE)
"Golden" Drosophila melanogaster (x1 CULTURE)
Sizes: Flies, Larva & Eggs
Count: 50+ Per Culture (will produce prolifically)
Sex: M / F
WITH EXTREME TEMPS THERE WILL ONLY BE
LIVE ARRIVAL GUARANTEE WHEN UPGRADE TO
EXPRESS MAIL OR IN TEMPS BETWEEN 0 - 85F
(CULTURE ... view on ebay

WINGLESS DROSOPHILA MELANOGASTER AND HYDEI FRUIT FLIES CULTURES 32oz.

Wheeling, Illinois, 600**, UNITED STATES OF AMERICA

$15

WINGLESS DROSOPHILA MELANOGASTER FRUIT FLY CULTURE 32oz
DROSOPHILA HYDEI FRUIT FLY CULTURE 32oz
Wingless Drosophila Melanogaster Fruit Fly Culture is ideal to feed, praying mantis, small frogs, small reptiles and amphibians
Fruit flies' cultures generally keep at 70F - 78F temperature. Humidity 60-80%
Drosophila Hydei Fruit Fly Culture is also ideal for praying mantis, small frogs, small reptiles and amphibians
They are a bit large than D. melanogaster. Fruit flies' ... view on ebay