Utetes

I am aware of only one species of Utetes (Utetes anastrephae to Florida) that has been successfully introduced outside its native range for biological control. Other species have also been introduced but either not released or not recovered following release (most notably Utetes africanus to Italy and more recently to France and USA for biological control of olive fly). This is in sharp contrast to several species of Fopius , Diachasmimorpha , and Psyttalia that have been successfully introduced to Hawaii and other parts of the world.

Utetes is cosmopolitan, with about one-fourth of the described species having been reared from fruit-infesting Tephritidae. Rhagoletis is an important host in the Nearctic and Palaearctic Regions, while Anastrepha and Tomoplagia have been recorded as hosts of several Neotropical species. Members of the Dacini (Subtribes Dacina and Ceratitidina) are hosts of species in Australia and the Afrotropical Region.

Psyttalia is the only genus with more species that have been reared from frugivorous tephritids. While the only known hosts of Psyttalia are members of the family Tephritidae, there are several species of Utetes that are known to attack hosts in other dipteran families, with at least two species (including Utetes ruficeps (Wesmael)) developing on leaf-mining Anthomyiidae. It is through species such as Utetes ruficeps and Utetes truncatus (Wesmael) that evolution of host shifts between fruit-infesting and leaf-mining flies can be explored.

occipital carina variable, present laterally and extending dorsally more than half height of head in most species, absent in the Neotropical Utetes anastrephae (Viereck) species group (= Bracanastrepha ). labrum in nearly all species broadly exposed beneath short, truncate or crescentic clypeus (Fig. 1: africanus, and Fig. 2: bianchii_); clypeus usually evenly protruding, more rarely with clypeus flattened. first flagellomere slightly longer than second. propleuron always without oblique carina dorsad propleural flange. Notauli usually deep, sculptured to unsculptured, but usually very short, confined to anterior-lateral 0000510">margin in most species (Fig. 3: africanus and Fig. 4: perkinsi), rarely a little longer (Fig. 5: bianchii_), never complete to midpit (1, 2). midpit (1, 2) often long, deep, and narrowly tear-drop shaped. postpectal carina absent. hind tibia dorso-posteriorly with distinct basal carina (Figs 6&7). 0000351">fore wing (Fig. 8: richmondi_) with second submarginal cell (1, 2) relatively long; m-cu arising distinctly distad 2RS. 0000400">hind wing (Fig. 9: richmondi_) with RS nearly always absent basally, represented at most by a weak crease distally; m-cu absent. Second metasomal tergum unsculptured beyond petiole in most species, though sculptured in a few Southeast Asian species. ovipositor varying from very short to nearly equal in length to 0000015">abdomen, never as long as in Diachasmimorpha and Doryctobracon. Differential coloration of subapical abdominal segments suggests the presence of large abdominal glands in many if not most of the species of Utetes. One of the species included in Utetes by Fischer (1987), Opius froggatti Fullaway, has been reared from tephritids and needs to be mentioned here. This species superficially resembles Utetes in several respects, including loss of hind wing RS and m-cu, but lacks the diagnostic carina at the base of the hind tibia. Fischer (1987) placed several species with froggatti in his Opius (Utetes) froggatti species group and the resemblance of the members of this group to the species of Utetes needs to be further explored to determine if the similarities represent a sister-group relationship or merely convergence.

Utetes is readily characterized by the presence of a sharp ridge or carina located basal-medially on the hind tibia (Figs 1&2). The type species of both Bracanastrepha and Nipponopius have this feature and the two genera are therefore now included in Utetes (Wharton 1988, 1997). The species of Utetes reared from fruit are also generally characterized by having the origin of RS+M widely separated from the parastigma relative to species in other genera (1RS 0.3-0.6 × 1M). Also, many (but not all) have a large, elliptical to transverse pit mid-dorsally on the pronotum. As in Psyttalia_, the labrum is broadly exposed below the shortened 0000212">clypeus.

The species of Utetes that attack fruit-infesting Tephritidae were generally included in the genus Opius prior to about 1990, though Tobias (1977) and Tobias and Jakimavicius (1986) included Utetes as a subgenus of Xynobius. Neotropical species lacking an occipital carina have often been placed as a separate genus Bracanastrepha, as noted in the section on Identification of Species. Utetes is worldwide in distribution.

Synonyms:
Bracanastrepha Brèthes, 1924
Nipponopius Fischer, 1963.
See Wharton (1997) for further information.