By Conrad Miller
Geographic Range
Drosophila melanogaster has been introduced to every continent of the world with one exception, Antarctica. On other continents its range is limited only by mountain ranges, deserts, and high lattitudes. (Demerec 1950) The natural range of D. melanogaster is throughout the Old World tropics. Humans have helped to spread Drosophila melanogaster to every other location which it inhabits. (Demerec, 1950; Patterson and Stone, 1952)
Biogeographic Regions:
nearctic
(introduced
); palearctic
(introduced
); oriental
(native
); ethiopian
(native
); neotropical
(introduced
); australian
(introduced
); oceanic islands
(introduced
).
Other Geographic Terms:
cosmopolitan
.
Habitat
Drosophila melanogaster lives in a wide range of habitats. Native habitats include those in the tropical regions of the Old World, but the common fruit fly has been introduced to almost all temperate regions of the world. The only aspects that limit the habitats Drosopila melangaster can live in is temperature and availability of water. The scientific name Drosophila actually means "lover of dew", implying that this species requires moist environments.
The development of this species' offspring is extremely dependent on temperature, and the adults cannot withstand the colder temperatures of high elevations or high latitudes. Food supplies are also limited in these locations. Therefore, in colder climates Drosophila melanogaster cannot survive.
In temperate regions where human activities have introduced Drosophila melanogaster, these flies seek shelter in colder winter months. Many times Drosophila can be found in fruit cellars, or other available man made structures with a large supply of food. (Demerec, 1950)
These animals are found in the following types of habitat:
temperate
; tropical
; terrestrial
.
Terrestrial Biomes:
savanna or grassland
; chaparral
; forest
; rainforest
; scrub forest
.
Other:
urban
; suburban
; agricultural
.
Physical Description
Drosophila mature through complete metamorphosis, as do all members of the order Diptera.
Similar to all insects Drosophila is covered in a chitinous exoskeleton; has three main body segments; and has three pairs of segmented legs.
Adult: The common fruit fly is normally a yellow brown (tan) color, and is only about 3 mm in length and 2 mm in width (Manning 1999, Patterson, et al 1943). The shape of the common fruit fly's body is what one would normally imagine for a species of the order Diptera. It has a rounded head with large, red, compound eyes; three smaller simple eyes, and short antennae. Its mouth has developed for sopping up liquids (Patterson and Stone 1952). The female is slightly larger than the male (Patterson, et al 1943). There are black stripes on the dorsal surface of its abdomen, which can be used to determine the sex of an individual. Males have a greater amount of black pigmentation concentrated at the posterior end of the abdomen (Patterson and Stone 1952).
Like other flies, Drosophila melanogaster has a single pair of wings that form from the middle segment of its thorax. Out of the last segment of its throax (which in other insects contains a second pair of wings) develops a set rudimentry wings that act as knobby balancing organs. These balancing organs are called halteres. (Raven and Johnson 1999)
Larvae are minute white maggots lacking legs and a defined head. (Patterson and Stone, 1952; Patterson et al., 1943; Raven and Johnson, 1999)
Some key physical features:
ectothermic
; heterothermic
; bilateral symmetry
.
Sexual dimorphism:
female larger, sexes colored or patterned differently.
Reproduction
Reproduction in Drosophila is rapid. A single pair of flies can produce hundreds of offspring within a couple of weeks, and the offspring become sexually mature within one week (Lutz 1948).
As in all insect species Drosophila melanogaster lays eggs. The eggs are placed on fruit, and hatch into fly larvae (maggots), which instantly start consuming the fruit on which they were laid (Patterson and Stone 1952).
Male flies have sex combs on their front legs. It has been theorized that these sex combs might be used for mating. However, when these combs are removed it seems to have little effect on mating sucess (Patterson, et al 1943). (Lutz, 1948; Patterson and Stone, 1952; Patterson et al., 1943)
Key reproductive features:
semelparous
; year-round breeding
; sexual
; fertilization
(internal
); oviparous
.
Behavior
The behavior of Drosophila melanogater is simplistic. They are easily drawn towards the smell of any food source, and will mate almost indiscriminately with any individual of the opposite sex.
They have hairs on their backs that are sensitive to air currents; their eyes are sensitive to slight differences in light intensity; and they will instinctively fly away when they sense a shadow or movement (Demerec 1950).
Drosophila melanogaster also have a propensity to fly towards light. If you culture the flies in a tube it is easily noticable that the flies will migrate towards the side of the tube that is nearest to the brightest source of light (Lutz 1948). (Demerec, 1950; Lutz, 1948)
Key behaviors:
flies; diurnal
; crepuscular
; motile
.
Food Habits
As the name implies, the fruit flies lives primarily on plant material. The adults thrive on rotting plants, and fruits; while eggs are usually laid on unripened/slightly ripened fruit, so by the time the larva develop the fruit will have just started to rot, and they can use the fruit that the egg was laid on as their primary source of nutrition. Drosophila are considered major pests in some area of the world for this reason. (Demerec, 1950; Lutz, 1948; Wilson, October,1999)
Plant Foods:
fruit.
Economic Importance for Humans: Negative
Drosophila melanogaster has been known to over winter in storage facilites, where it can consume/ruin vast quatities of food. As stated above, the fruit fly also lays its eggs on unripened fruit, and is considered a pest in many areas. (Demeric 1950, Wilson 1999)
Economic Importance for Humans: Positive
This species is widely used in scientific research. (Patterson et al., 1943; Raven and Johnson, 1999)
Ways that people benefit from these animals:
source of medicine or drug
.
Conservation Status
IUCN Red List: [link]:
Not Evaluated.
US Federal List: [link]:
No special status.
CITES: [link]:
No special status.
We have no text on this topic for this species. Look to the sidebar on the right for some limited information.
Other Comments
Drosophila melanogaster has been studied in genetic research laboratories for almost a century. Because the fruit fly has a short lifespan, a simple genome, and is easily made to reproduce in captivity it is a prime canidate for genetic research. (Patterson, et al., 1943)
In 1910 Thomas H. Morgan used Drosophila to provide the first proof that the chromosomal theory of inheritance is correct. The chromosomal theory of inheritance states that the chromosomes are the carriers of genetic information. Morgan was the first to use Drosophila in genetic reasearch.
In 1913 H. Sturtevant, a student of Morgan created the first genetic maps using Drosophila melanogaster. Since that time the simple genome of Drosophila melanogaster has become very well known, allowing for much of the progression of genetic research.
Drosophila is also widely used by students of biology. (Raven and Johnson 1999) (Patterson et al., 1943; Raven and Johnson, 1999)
For More Information
Find Drosophila melanogaster information at
Contributors
Conrad Miller (author), Southwestern University.
Stephanie Fabritius (editor), Southwestern University.
Sara Diamond (editor), Animal Diversity Web Staff.

