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common name: South American fruit fly
scientific name: Anastrepha fraterculus (Wiedemann) (Insecta: Diptera: Tephritidae)

Introduction - Synonyms - Distribution - Description - Hosts - Selected References

Introduction (Back to Top)

This species is of great economic importance because of the wide variety of plants that it attacks and its extensive distribution. In most of South America, it probably is the most important species of Anastrepha. Despite its importance, it has no accepted common name. It has been called the South American fruit fly, but this is an inappropriate name because the species, as currently understood, occurs also throughout most of Central America northward to southern Texas. There is increasing evidence that what has been considered for many years to be a species, which varies widely throughout its range, is a species complex that represents two or more species, and possibly several biological rates, the Brazilian population being the true A. fraterculus described by Wiedemann.

Synonyms (Back to Top)

Anastrepha fraterculus was described in the genus Dacus by Wiedemann (1830), based on specimens from Brazil. Anastrepha fraterculus is a species complex that has not yet been studied in sufficient detail to permit a clear separation of the included species. Members of this species have also been known as:

Tephriitis mellea Walker
Trypeta unicolor Loew
Trypeta fraterculus (Wiedemann)
Dacus fraterculus Wiedemann
Anthomyia frutalis Weyenbergh
Anastrepha soluta Bezzi (as fraterculus var.)
Anastrepha peruviana Townsend
Anastrepha brasiliensis Greene
Anastrepha pseudofraterculus Capoor
Anastrepha costarukmanii Capoor
Anastrepha scholae Capoor
Acrotoxa fraterculus (Wiedemann)

(From White and Elson-Harris 1994)

Alan Stone (1942) believed A. fraterculus to be a highly variable species ranging from Texas to central South America, and he identified specimens from peach and guava as A. fraterculus. However, he further stated that populations occurring from Texas to Argentina eventually may be found to represent a complex of species rather than a single one.

Dr. R.H. Foote (personal communication) stated that he believes there are at least four biologically distinct populations included in the A. fraterculus complex. There are several other species of Anastrepha which closely resemble the A. fraterculus complex, so that there is great difficulty in determining specific limits. Further biological and taxonomic studies, including sampling populations throughout the range of this complex and in association with various fruit hosts, are needed to resolve these questions. Evidently, all forms of this complex attack economically important plants.

Distribution (Back to Top)

The range of Anastrepha fraterculus is continental America from the Rio Grande Valley of Texas to Argentina, and the islands Trinidad and Tobago. There are records from Chile, but it is not established there (White and Elson-Harris 1994). This species has been trapped in abundance in Texas throughout the year, the peak of its occurrence being in January, with a smaller peak in August; it is least abundant there in March, April and May (Stone 1942).

Description (Back to Top)

Adults: Adult identification is based primarily on the female, as male specimens in most cases are still indeterminable. It may be possible eventually to determine males, but much work must be done, even to associate sexes, before this can be accomplished. Steyskal (1977) presented a good pictorial key to species of Anastrepha.

The following description of A. fraterculus is based primarily on Stone (1942). This species is a small to rather small fruit fly with a yellow brown coloring. The mesonotum is 2.75–3.3 mm long and also yellow brown. The humerus, median stripe widened posteriorly anterior to acrostichal bristles and barely including these bristles, lateral stripe from transverse suture to the bright yellow scutellum. A a small diffuse scutoscutellar black spot may or may not be present. The pleura is yellow and yellow brown. The metanotum and postscutellum are rather broadly blackened laterally. The macrochaetae is yellow brown to black, with the pile yellow brown. Sternopleural bristle is slender.

The wing is 5.35–7.2 mm long, and the bands are yellow-orange and brown. As already stated, adult forms currently recognized within the A. fraterculus complex show substantial variation in the wing pattern. In the Brazilian form costal band typically touching S band and V band typically separated from S band.

Baker (Baker et al. 1944) considered the Mexican form distinct from A. fraterculus, noting differences between Brazilian and Mexican forms. He observed that the Brazilian A. fraterculus possesses wing markings that differ from those of the Mexican form. The inverted V is separated from the main pattern, the wing thus resembling that of Anastrepha distincta Greene. The Mexican form has the inverted V connected with the main pattern, the wing thus resembling that of Anastrepha obliqua (MacQuart). However, occasional specimens occur in South America in which the inverted V is connected, and some specimens have been found in Mexico, usually males, in which the connection fades out.

Figure 1. Right wing. Drawing by Division of Plant Industry.

Figure 2. Various wing forms. Drawing by Division of Plant Industry.

The ovipositor sheath is 1.65–2.1 mm long, and is stout, tapering apically. The spiracles are about 0.7 mm from the base. The rasper is a rather small patch of hooks in 4 or 5 rows. The ovipositor itself is 1.5–1.95 mm long and stout, with a base distinctly widened, and the tip narrowed beyond end of oviduct and before serrate portion. The serrations are blunt and rounded, extending little more than half length of tip, sometimes less.

The ovipositors, too, differ slightly among specimens. Baker (1944) noted that those of the Mexican specimens vary very slightly from one host to another but that those from all hosts appear more tapered at the tip than do those of A. fraterculus from Brazil, and the opening seems slightly farther from the distal extremity.

Figure 3. Ovipositor of typical form from Brazil. Drawing by Division of Plant Industry.

Eggs: The eggs of A. fraterculus, typical of the genus, are creamy white, elongate, and tapering at the ends, averaging 1.4 mm in length and 0.2 mm in width at the midpoint. The micropylar end is twisted and is subapical rather than apical, characters distinguishing it from many other species of Anastrepha. There is a diamond-shaped sculpturing around the micropylar end, and there is a small tuft of pile at the extreme tip. Emmart (1933) gave a detailed comparison of the eggs of Mexican "A. fraterculus" with those of three other common species of Anastrepha. While location of eggs in fruit is difficult, when they can be obtained, an early identification of the species may be possible when working with several known species. A gravid female inserts her eggs into the fruit of a plant host with an eversible, sclerotized ovipositor.

Figure 4. Eggs of common species of Anastrepha compared to A. fraterculus. Drawing by Division of Plant Industry.

Figure 5. Micropyle. Drawing by Division of Plant Industry.

Larvae: The developing larvae molt three times as they feed and grow. An inactive 4th-instar larval stage within the puparium precedes formation of a pupa. This process may occur within or on the host plant, but pupation occurs in the soil. The mature larva is 8–10 mm in length and 1.5 mm in diameter; pale yellowish white, tapering slightly toward the cephalic end; 11 segments of about equal length in addition to the head; a ventral fusiform area on anterior portion of each of segments 4 to 11. Head small, partly retractile; mouth hooks medium-sized, 1st part rather slender, 1st and 2nd parts black, 3rd part with brown infuscation at base, and remainder of joint hyaline. Anterior spiracles small, yellowish, chitinized, with 15 to 17 small rounded tubules arranged in an irregular row. Posterior spiracles small, located well above medio-horizontal line.

Larvae of the Veracruz population attacking tropical almond possess spiracular processes which resemble those of larvae of A. obliqua from Puerto Rico.

Figure 6. Larva. Drawing by Division of Plant Industry.

Figure 7. Mouth hook of larva. Drawing by Division of Plant Industry.

Figure 8. Anterior spiracle of larva Drawing by Division of Plant Industry.

 

Figure 9. Posterior view of larva (left) and spiracle (right). Drawing by Division of Plant Industry.

Pupae: The pupae are 4.5–6.0 mm long and 2–2.5 mm in diameter. The are cylindrical, with coloring a dull luteous to reddish-yellow or dark red. There are 11 distinct segments. Anterior spiracles are like those of the larva but much darker. The posterior spiracles are medium sized, dark reddish in color, and located in a faintly depressed hexagonal area which is on but mostly below the medio-horizontal line. Greene (1929) gave a detailed description of both larva and pupa, based on material collected in Panama.

Figure 10. Pupa. Drawing by Division of Plant Industry.

Figure 11. Posterior view and spiracles of pupa. Drawing by Division of Plant Industry.

Fruit fly larvae and pupae are difficult to identify to species, and much more research is needed in this area.

Hosts (Back to Top)

In South America, A. fraterculus attacks various fruits including peach, Citrus, guava, Spondia and Eugenia. The Mexican "A. fraterculus" has been reared from peach, guava and rose apple. What appears to be the same thing, or very similar, was reared from tropical almond, but only in the city of Veracruz. Tropical almond is not recorded as a host of A. fraterculus in South America. It may be that the Veracruz population associated with tropical almonds is more closely related to the typical A. obliqua of the West Indies.

Populations of Mexican "A. fraterculus" in northern Mexico occur commonly in the vicinity of Citrus, but no infestation in sour orange or other Citrus has been found in that region. Baker (Baker et al. 1944) noted that attempts to rear the Veracruz form which attacks tropical almond from Spondias were unsuccessful, although Spondias is one of the common hosts of A. fraterculus in South America.

The A. fraterculus complex has been reared from the following:

Annona cherimola, cherimoya, chirimoya, custard apple or cherimalla

Citrus maxima (=grandis), shaddock or pommelo; C. paradisi, grapefruit; C. reticulata, Mandarin orange, Satsuma orange, tangerine; C. sinensis, sweet orange

Coffea arabica, common coffee

Cydonia oblonga, common quince

Dovyalis hebecarpa, kitembilla or Ceylon gooseberry

Eriobotrya japonica, loquat, Japanese medlar or Japanese plum

Eugenia brasiliensis (=dombeyi), Brazil cherry, grumichama or grumixameira; E. uniflora, Surinam cherry, Brazil cherry, Barbados cherry, Cayenne cherry or pitanga

Mangifera indica, mango

Manilkara zapota, sapodilla

Prunus persica, peach

Psidium guajava common guava, yellow guava or apple guava

Pyrus communis, common pear

Spondias mombin, hog plum, yellow mombin or jobo; S. nigrescens; S. purpurea, Spanish plum, red mombin, purple mombin or jocote

Syzygium (=Eugenia) jambos, rose apple or Malabar plum; S. malaccense, Malay apple or rose apple

Terminalia catappa, tropical almond, Indian almond, kamani or myrobalan

Vitis vinifera, wine grape or European grape

Ximenia americana, tallow-wood

Of these food plants the Surinam cherry, peach, and guava seem to be particularly subject to attack. This species also has been reared experimentally from Annona glabra, pond apple; Malus pumila, common apple; and Phyllanthus acidus, Otaheite gooseberry or gooseberry tree.

Selected References (Back to Top)