Rhagoletis pomonella

Geographic Range

Rhagoletis pomonella are found in the eastern United States and southeastern Canada. More specifically, apple maggots range from Florida to Nova Scotia on the extreme east portion of its range, and from Texas to Alberta on the extreme west.

• Biogeographic Regions
• nearctic nearctic
  • native native

Habitat

Rhagoletis pomonella live primarily in apple orchards (hence the name) and at the edge of deciduous forests.

• Habitat Regions
• temperate temperate
• terrestrial terrestrial

• Terrestrial Biomes
• forest forest

• Other Habitat Features
• agricultural agricultural

Physical Description

Apple maggots have a yellow or orange head, and legs that range in color from bright yellow to gray. The thorax may range from shiny black to tan depending on enviroment, and is crossed by three white lines (in males) or four white lines (in females). These lines blur together at the sides of the thorax. Eyes are red, and the antennae's third segment is larger and more rounded than the other segments. Four dark bars, sometimes "F" shaped, are present on the wings, which lack an apical spot.

• Other Physical Features
• ectothermic ectothermic
• heterothermic heterothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes colored or patterned differently

Development

Fertilized eggs are individually oviposited inside of host fruit. The majority of this fruit is consumed by larvae after hatching. Once the fruit is consumed, larvae drop to the ground and pupate through the winter. In July of the following year adult flies emerge and feed upon leaves and fruit until mating in late August to early September.

• Development - Life Cycle
• metamorphosis metamorphosis

Reproduction

Males perform a courtship dance while the female watches, after which she may choose whether or not to copulate with him. She is attracted by a non-volatile aromatic hydrocarbon pheromone that is yet to be fully identified and classified.

• Mating System
• polygynandrous (promiscuous) polygynandrous (promiscuous)

Males perform a courtship dance while the female watches, after which she may choose whether or not to copulate with him. She is attracted by a non-volatile aromatic hydrocarbon pheromone that is yet to be fully identified and classified. Fertilized eggs are deposited singly into unripened apples (if available) or other fruit plants.

• Key Reproductive Features
• sexual sexual
• fertilization fertilization
  • internal internal
• oviparous oviparous

Fertilized eggs are oviposited in unripe apples or other unripe fruit, which provides food for larvae after hatching. There is no further parental care after oviposition.

• Parental Investment
• no parental involvement
• pre-fertilization
  • provisioning
  • protecting
    • female

Lifespan/Longevity

Behavior

• Key Behaviors
• flies
• diurnal diurnal
• parasite parasite

Communication and Perception

These flies communicate with each other primarily through contact pheromones. Most of these pheromones are either alkanes or alkenes, and they are highly volatile for maximum dispersion. The exception to this is the mating pheromone which has not been classified but is thought to be an aromatic. The flies commonly produce about twenty separate pheromones, although upwards of thirty have been identified.

• Communication Channels
• chemical chemical

• Other Communication Modes
• pheromones pheromones

• Perception Channels
• visual visual
• chemical chemical

Food Habits

Apple maggots infest wild hawthorns, blueberries, and western snowberries. They are well known for their affinity for domesticated apples and are capable of ruining an entire crop.

Adults of this species subsist on scraping particles from the outer surface of leaves and fruit. In non-agricultural areas where apples are unavailable, they prefer blueberry bushes and western snowberries.

• Primary Diet
• herbivore herbivore
  • folivore folivore
  • frugivore frugivore

• Plant Foods
• leaves
• fruit

Predation

Flies of the family Tephritae have a well studied ability to mimic primary predator's territorial behavior. Zonosemata vittigera , a member of the same family as R. pomonella , will wave its wings at an attacking spider in a display that closely matches this spiders intraspecific territorial display. In the majority of cases, this display will cause the attacking spider to back off, not wishing to fight what it sees as another spider over its terrritory.

Ecosystem Roles

Economic Importance for Humans: Positive

There are no known positive economic benefits derived from this species.

Economic Importance for Humans: Negative

The apple maggot is an agricultural pest capable of decimating entire crops when in sufficient numbers. Even when using aggressive pest control methods are implemented, which may wipe out adult apple maggot populations one year, some pupae do not emerge until the following year making Rhagoletis pomonella very difficult to completely eradicate.

• Negative Impacts
• crop pest

Conservation Status

This species is at no risk of extinction and requires no special protective status.

Additional Links

Encyclopedia of Life

Contributors

Sara Diamond (editor), Animal Diversity Web.

Stuart Nelson (author), Southwestern University, Stephanie Fabritius (editor), Southwestern University.

References

Arnett, R. 1985. American Insects: A Handbook of the Insects of America North of Mexico . New York: Van Nostrand Reinhold Company.

Chapman, R. 1998. The Insects . New York: Cambridge University Press.

Garman, P. 1937. Notes on Breeding the Apple Maggot, Rhagoletis pomonella. Pp. 436-437 in Culture Methods for Invertebrate Animals . New York: Dover Pulications, Inc..

Greene, E., L. Orsak, D. Whitman. 17 April 1987. A Tephritid Fly Mimics the Territorial Displays of Its Jumping Spider Predators. Science , 236: 310-312.

Milne, L., M. Milne. 1980. Apple Maggot Fly (Rhagoletis pomonella). Pp. 675 in The Audubon Society Field Guide to North American Insects . New York: Alfred A. Knopf.