OFF Facts & Photos
Gary J. Steck, Gary.Steck@freshfromflorida.com, Florida Department of Agriculture & Consumer Services, Division of Plant Industry
ORIENTAL FRUIT FLY FACTS
Economic Importance
One of the world's most important and widespread pests in the fruit fly complex is the oriental fruit fly, Bactrocera spp. Economic loss caused by this species is extensive in Hawaii, China and other Asian countries.
Life History & Habits
Typically, oriental fruit fly eggs hatch in 1 to 3 days. Ideal conditions for incubation are 80 degrees F. and 70 percent relative humidity. Eggs are laid within the host fruit or vegetable. Cool weather prolongs the life cycle, which would probably be about 30 days in Florida during the warm months.
Oriental fruit fly larvae develop through three stages or "instars", with 3 to 4 days for each stage. The mature larvae reach about 2/5 inch (10 mm) long. They are off-white with black mouth hooks and light brown posterior spiracles. The larvae feed and develop inside the host material, making it unfit for human consumption. Larval feeding usually results in premature fruit drop.
The larvae drop from the host fruit or vegetable, burrow into the soil (½ to 2 inches deep) and enter the pupal stage. The pupal cases are light to dark tan. They remain in the soil for 10 to 12 days until the adults emerge. Ideal conditions for pupae are 75 to 80 degrees F. and 70 to 80 percent relative humidity; below about 50 degrees F. no development takes place.
The adult oriental fruit fly emerges from its pupal case and digs its way through the soil, usually in the early hours of sunlight when the relative humidity is high. During their first week as adults, flies search out food sources such as honey-dew, nectar, decomposing fruit, or bird droppings. During this stage the adult flies frequently disperse away from the area where they emerged from the soil, often several miles.
The fly reaches sexual maturity within approximately 8 to 12 days, and seeks the opposite sex. The female is attracted to its potential mate by a pheromone (chemical attractant) released by the male oriental fruit fly. Multiple matings may occur.
The adult oriental fruit fly is approximately 6 to 8 mm long, or slightly larger than the common housefly, with a narrow yellowish-brown band along the edge of its wings. The thorax (middle body part) is mottled on the upper portion with black or brown and yellow spots and stripes. The abdomen is yellowish with a black T-shaped mark. The female has a serrated-tip ovipositor, which penetrates the host fruit or vegetable and deposits eggs inside. She may lay as many as 3,000 eggs, but usually 1,200 to 1,500 eggs in an average life span. The adult fly usually lives from 1 to 3 months (but up to a year in cool climates).
Hosts
Preferred hosts, in Florida include calamondin, kumquat, sour orange, Surinam cherry, grapefruit, mango, peach, white sapote, plum, pear, roseapple, cattley guava and guava. However, known hosts number about 140 species, among which many occur in Florida.
![Oriental fruit fly, Bactrocera sp. [complex], adults](images/off.jpg)
![Oriental fruit fly, Bactrocera sp. [complex], adults](images/off5.jpg)
![Oriental fruit fly, Bactrocera sp. [complex], closeup](images/offcloseup.jpg)
![Oriental fruit fly, Bactrocera sp. [complex], adults](images/offserveral.jpg)
Oriental fruit fly, Bactrocera sp. [complex], adults
Photography credits: Jack Kelly Clark, University of California Cooperative Extension and Jeffrey Lotz, FDACS/DPI.
Date revised: May 25, 1999 |
