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

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

Anaheim, California, 928**, UNITED STATES OF AMERICA

$51

SuperFoods SuperFly 17 6 oz (1 1 Lb) Jar FRUIT FLY CULTURE MEDIA
FRUIT FLY CULTURE MEDIA Our Instant Formula for Drosophila Culture. This Premium Mixture is fortified with Minerals, Trace Elements, Vitamins, and Carotenoids in order to Maximize the Nutritional Value of Fruit Flies when they are Used as Feeders.... more

Flightless Fruit Fly Culture, Drosophila Hydei, 32 oz. from TerraCraft

Eureka, California, 955**, UNITED STATES OF AMERICA

$16

Fresh, healthy fruit fly cultures grown on a premium, nutrient-rich medium for strong growth and reliable production
Each culture is started with a generous number of flies to ensure quick establishment and steady output
Perfect For:
?? Dart frogs & tree frogs
?? Baby chameleons
?? Small geckos (crested, gargoyle, day geckos, leachies)
?? Praying mantises & jumping spiders
?? Betta & nano fish
?? Isopods, springtails, & bioactive tanks love spent ... more

Wondercide Fruit Fly Trap Home + Kitchen

Fort Lauderdale, Florida, 333**, UNITED STATES OF AMERICA

$24

The plant-powered solution to get rid of fruit flies is here! This targeted, self-contained product is your easy tool to keep these annoying bugs away from the fun. Fruit Fly Trap Home + Kitchen is part of the Wondercide 360? Protection System and helps families stay bug-free and worry-free all year long
Ingredients: Water, vinegar syrups, hydrolyzed starch, hydrogenated, malic acid, yeast, ethyl lactate, vitamin E, Sodium Lauryl sulfate
Product Details:
Size: 5 4 fl. oz
Brand: ... more

Wingless Fruit Fly Cultures 2 Pack+ 2 Pack of Hydei Total of 4 CULTURES.

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

$35

This 2 pack of Hydei Fruit Fly cultures + 2 Pack of Wingless is the perfect addition to any reptile or dart frog owner's collection. These cultures provide a nutritious and tasty food source for your pets without the hassle of dealing with live insects. The flies are easy to maintain and will last for several weeks, ensuring that your pets are well-fed and healthy.
With free shipping included, this is a great deal that you don't want to miss out on. Whether you're a seasoned reptile owner or... more

Flightless Fruit Fly Culture Combo (Melanogaster & Hydei) - LIVE FEEDER INSECTS

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

$70

??PLEASE READ BEFORE PURCHASING??
(WHAT YOU RECEIVE)
-------------------------------------------------------------------------------------
Name: Drosophila melanogaster / Drosophila hydei (x2 CULTURES)
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 ... more