There are 2 varieties of fruit flies that are best for feeding tarantulas. The vestigial winged flies have short stunted wings and cannot fly. Therefore, the flies cannot escape and have to walk all over the substrate, making it easy prey for the babies to attack. Another type is those without wings. This type have a disadvantage: they will develop functional wings if the temperature get too high.

RAISING FRUIT FLIES

Fruit flies can be raise with a bare minimum of equipment. Any sort of bottle or jar can serve as a container. It is best to sterilize the bottles with boiling water, to prevent any growth of mold or fungus that might grow later on. Place the containers in a warm place as Fruit flies thrive best in higher temperaures.

LIDS

The jars must have lids, to prevent the flies from escapeing and also to prevent wild fruit flies from entering. The best lid is made from a plug of cotton wool or plastic foam inserted snugly into the opening. This arrangement allows air circulations and also prevent the wild flies from entering.

FEEDING THE FLIES

The flie should be fed with comercial dried potato flakes. Mix equal parts of potato flake with water to form a paste & sprinkle some bakers yeast on top. Tha paste shuld be 1" deep and should be thick so that it doesn't run if the bottle topples.