Drosophila melanogaster

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)

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)

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., April 1, 1943; Raven and Johnson, 1999)

  • 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., April 1, 1943)

  • Average age at sexual or reproductive maturity (female)
    1 weeks
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    7 days
    AnAge
  • Average age at sexual or reproductive maturity (male)
    1 weeks
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    7 days
    AnAge

Lifespan/Longevity

  • Average lifespan
    Status: captivity
    0.3 years
    AnAge

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)

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: Positive

This species is widely used in scientific research. (Patterson, et al., April 1, 1943; Raven and Johnson, 1999)

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)

Conservation Status

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., April 1, 1943; Raven and Johnson, 1999)

Contributors

Sara Diamond (editor), Animal Diversity Web.

Conrad Miller (author), Southwestern University, Stephanie Fabritius (editor), Southwestern University.

Glossary

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

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Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

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Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

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Neotropical

living in the southern part of the New World. In other words, Central and South America.

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Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

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agricultural

living in landscapes dominated by human agriculture.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chaparral

Found in coastal areas between 30 and 40 degrees latitude, in areas with a Mediterranean climate. Vegetation is dominated by stands of dense, spiny shrubs with tough (hard or waxy) evergreen leaves. May be maintained by periodic fire. In South America it includes the scrub ecotone between forest and paramo.

cosmopolitan

having a worldwide distribution. Found on all continents (except maybe Antarctica) and in all biogeographic provinces; or in all the major oceans (Atlantic, Indian, and Pacific.

crepuscular

active at dawn and dusk

diurnal
  1. active during the day, 2. lasting for one day.
drug

a substance used for the diagnosis, cure, mitigation, treatment, or prevention of disease

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

frugivore

an animal that mainly eats fruit

herbivore

An animal that eats mainly plants or parts of plants.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

internal fertilization

fertilization takes place within the female's body

introduced

referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

oceanic islands

islands that are not part of continental shelf areas, they are not, and have never been, connected to a continental land mass, most typically these are volcanic islands.

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

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oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

scrub forest

scrub forests develop in areas that experience dry seasons.

semelparous

offspring are all produced in a single group (litter, clutch, etc.), after which the parent usually dies. Semelparous organisms often only live through a single season/year (or other periodic change in conditions) but may live for many seasons. In both cases reproduction occurs as a single investment of energy in offspring, with no future chance for investment in reproduction.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

suburban

living in residential areas on the outskirts of large cities or towns.

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

urban

living in cities and large towns, landscapes dominated by human structures and activity.

year-round breeding

breeding takes place throughout the year

References

Demerec, .. 1950. Biology of Drosophila. New York: John Wiley and Sons, Inc..

Lutz, F. 1948. Field Book of Insects. New York, NY: G. P. Putnam's Sons.

Manning, .. Nov 20, 1999. "The Drosophila Virtual Library" (On-line). Accessed February 16, 2000 at http://ceolas.org/fly/.

Patterson, J., W. Stone. 1952. Evolution in the Genus Drosophila. New York: Macmillan Co..

Patterson, J., R. Wagner, L. Wharton. April 1, 1943. The Drosophilidae of the Southwest. Austin, TX: The University of Texas Press.

Raven, .., .. Johnson. 1999. Biology, Fifth Ed.. Boston: WCB/McGraw-Hill.

Wilson, .. October,1999. "Fruit Fly(Drosophila)" (On-line). Accessed February 16, 2000 at http://agri.gov.ns.ca/pt/hort/organic/ptor9705.htm.