Dart Den - Care Sheet


Care sheet provided by : Anonymous - Various internet sources .

Life Cycle of the Fruit Fly

1994 Woodrow Wilson Biology Institute

There are four stages in the life cycle of the fruit fly: egg, larva, pupa, and adult. At a typical classroom temperature (21 C), Drosophilla Hydei will produce new adults in two weeks; eight days in the egg and larval stages, and six days in the pupal stage. The life span of a fruit fly may be several weeks.
Twenty-four hours after the egg is laid, the larva hatches. The larva has two molting periods, during which the cuticle, mouth, hooks, and spiracles are shed. The larva is called an instar during the periods of growth before and after molting. Thus, the fruit fly has three instars. The puparium develops from the third instar which becomes hard in texture and dark in color.

The puparium is where metamorphosis takes place. Just before the adult fly emerges from the puparium, the pupa darkens. Approximately 24 hours before the adult fly emerges, one can see the folded wings and the pigment of the eyes if one looks closely through the puparium.

Upon completion of metamorphosis, the adult forces its way through the operculum (anterior end) of the puparium. Initially the fruit fly appears light in color with a long abdomen and unexpanded wings. In just a few hours the fly gets darker in color, rounder in the abdomen and extends its wings.

Approximately 48 hours after emerging from the puparium, it is possible for females to start laying eggs. However, there are only 12 hours that a female can be considered virgin after emerging as an adult. After reaching this maturity, the flies are fertile for life. A female fruit fly can store sperm after a single insemination and use it for many reproductions; therefore it is important to use virgin females for genetic crosses.

Various Media Mixtures

RECIPE A

8 bananas

1/4 cup sugar

rolled oats (oatmeal)

1 packet bakers yeast

Put banana and sugar in blender and mix until the banana is liquefied. Mix in oatmeal until it becomes firm, but still moist. Put mixture in wide mouth quart canning jars. Add a few granules of bakers yeast to the surface and add about 30 fruit flies. Cap the jars with a paper towel folded in fourths held on with a rubber band. Substitution with other types of fruit also works.

Variation, use the following ingredients:

1 cup banana (about 2 bananas)
1 cup apple sauce
1 Tablespoon vinegar
2 cups oat meal

RECIPE B

1 cup water

1 tablespoon cornmeal

1 teaspoon powdered agar

1 tablespoon molasses

1/8 teaspoon calcium propionate (optional)

1 package bakers yeast

Mix all ingredients except yeast, then heat until boiling. Quickly pour mixture into clean culture jars. Cap and let cool to room temperature. This mixture can be stored in the refrigerator with a tightly capped lid until ready for use. When ready to use, sprinkle a couple granules of baker's yeast on the surface and add fruit flies. Calcium propionate is a mold inhibitor used in bread.

RECIPE C

baker's yeast

brewer's yeast

instant potato flakes

tegosept (methylparaben)

To prepare dry culture media, mix 1 part brewer's to 10 parts instant potato flakes by weight. When ready for use, mix 4 grams of the mold inhibitor, tegosept (methylparaben), to 1 gallon of hot water. Let cool and add an equal amount of water to the dry culture media (by volume). When the mixture solidifies, add a couple of granules of baker's yeast to the surface and add fruit flies. Calcium propionate may be used as a substitute for tegosept.