Fruit Flies
Tephritidae
Description 5
For terms see Morphology of Diptera and Tephritidae glossary
Tephritids are small to medium-sized (2.5–10 mm) flies that are often colourful, and usually with pictured wings, the subcostal vein curving forward at a right angle. The head is hemispherical and usually short. The face is vertical or retreating and the frons is broad. Ocelli and cellar bristles are present. The postvertical bristles are parallel to divergent. Two to eight pairs of frontal bristles are seen (at least one but usually several lower pairs curving inwards and at least one of the upper pairs curving backwards). In some species, the frontal bristles are inserted on a raised tubercle. Interfrontal setulae are usually absent or represented by one or two tiny setulae near the lunula. True vibrissae are absent, but several genera have strong bristles near the vibrissal angle. The wings usually have yellow, brown, or black markings or are dark-coloured with lighter markings. In a few species, the wings are clear. The costa has both a humeral and a subcostal break. The apical part of the subcostal is usually indistinct or even transparent and at about a right angle with respect to the basal part. Crossvein BM-Cu is present; the cell cup (posterior cubital cell or anal cell) is closed and nearly always narrowing to an acute angle. It is closed by a geniculated vein (CuA2). The CuA2 vein is rarely straight or convex. The tibiae lack a dorsal preapical bristle. The female has an oviscape.
The larva is amphipneustic (having only the anterior and posterior pairs of spiracle). The body varies from white to yellowish or brown. The posterior end of pale-coloured species is sometimes black. The body tapers at the anterior. The two mandibles sometimes have teeth along the ventral margin. The antennomaxillary lobes at each side of the mandibles have several transverse oral ridges or short laminae directed posteriorly. The anterior spiracles (prothoracic spiracles) end bluntly and are not elongated. Each has at least three openings or up to 50 arranged transversely in one to three groups or irregularly. Each posterior spiracle (anal spiracle) lacks a clearly defined peritreme and each has three spiracular openings (in mature larvae). These are usually more or less horizontal, parallel and usually bear branched spiracular hairs in four tufts.
Ecology 5
The larvae of almost all Tephritidae are phytophagous. Females deposit eggs in living, healthy plant tissue using their telescopic ovipositors. Here, the larvae find their food upon emerging. The larvae develop in leaves, stems, flowers, seeds, fruits, and roots of the host plant, depending on the species. Some species are gall-forming. One exception to the phytophagous lifestyle is Euphranta toxoneura (Loew) whose larvae develop in galls formed by sawflies.The adults sometimes have a very short lifespan. Some live for less than a week. Some species are monophagous (feeding on only one plant species) others are polyphagous (feeding on several, usually related plant species).
The behavioral ecology of tephritid fruit flies is of great interest to biologists. Some fruit flies have extensive mating rituals or territorial displays. Many are brightly colored and visually showy. Some fruit flies show Batesian mimicry, bearing the colors and markings of dangerous arthropods such as wasps or jumping spiders because it helps the fruit flies avoid predation, though the flies lack stingers.
Adult tephritid fruit flies are often found on the host plant and feeding on pollen, nectar, rotting plant debris, or honeydew.
Natural enemies include the Diapriidae and the Braconidae.
Sources and Credits
- (c) Katja Schulz, some rights reserved (CC BY), https://www.flickr.com/photos/treegrow/38892900454/
- (c) C. Mallory, some rights reserved (CC BY-NC), uploaded by C. Mallory
- (c) Nikolai Vladimirov, some rights reserved (CC BY-NC), uploaded by Nikolai Vladimirov
- (c) Katja Schulz, some rights reserved (CC BY), https://www.flickr.com/photos/treegrow/39427601562/
- (c) Wikipedia, some rights reserved (CC BY-SA), https://en.wikipedia.org/wiki/Tephritidae
