Parasitoids of Fruit-Infesting Tephritidae

The name hildagensis is based on a misreading of the locality label on the holotype, which is correctly written as Hidalgo Nat. Park, not “Hildago Nat. Park” as given by Fischer (1964) in the original description. In the original description, hildagensis is included in a key to the subgenus Biosteres, but the subgeneric name was not included in the heading for the species description. This species was transferred to Diachasmimorpha on the basis of fore and hind wing venation, the morphology of the labrum, clypeus, and mandible, and the well-developed notaulus and midpit, all shown in the figures above under the diagnosis section. A detailed description of Diachasmimorpha is provided in Wharton (1997). Inclusion of D. hildagensis in the Diachasmimorpha mexicana species group is based on the greatly reduced occipital carina, sinuate anterior margin of the pronotum ventral-laterally, and the body and wing coloration.

Both D. hildagensis and D. mexicana were described from single male specimens collected in the state of Mexico and the Distrito Federal, respectively, and unassociated with either hosts or host plants. Both have relatively small eyes, but are readily separated from one another on the basis of head coloration. Associating the name hildagensis with the many dark-headed specimens available for study, however, has been considerably more challenging. Reared material, representing over 50 specimens kindly made available to us by Allen Norrbom, Martin Aluja, and Juan Rull, provides clear evidence of sexual dimorphism in eye size as well as variation in ovipositor length associated with different hosts and host plants. This material has been especially critical for understanding color patterns and associating males with females. Based primarily on eye size and body size, the holotype of D. hildagensis is closest to the series of three specimens listed above under “other specimens examined,” that emerged from puparia of O. latifrons infesting fruits of S. brachycarpum.

Opius (Biosteres) hildagensis Fischer, 1964: 12, 20-22. Holotype male in AEIC (examined).
Biosteres (Parasteres) hildagensis: Fischer 1967a: 5 (generic transfer).
Parasteres hildagensis: Fischer (1971): 33 (generic transfer); Fischer 1977: 880-883 (key, redescription).
Diachasmimorpha hildagensis: Wharton et al. (2012): 36-43 (generic transfer).

Holotype male. Eye in dorsal view (Fig. 3) as long as temple, temples neither receding nor expanded beyond eyes; eye in lateral view (Fig. 2) 1.3 x longer than temple. Frons irregularly rugulose along midline between antenna and median ocellus. Clypeus (Fig. 4) 2.8 x wider than high. Occipital carina distinct near base of mandible, short, not extending dorsally to ventral margin of eye. Antenna with 46 flagellomeres; first flagellomere 1.25 x longer than wide. Pronope (Fig. 3) deep, large, interrupting posterior crenulate groove middorsally. Notauli (Fig. 5) deep anteriorly, reaching anterior-lateral margin of mesoscutum and extending posteriorly about 0.5 x distance to deep, elongate midpit. Precoxal sulcus (Fig. 2) distinctly crenulate throughout, nearly extending to anterior margin of mesopleuron. Propodeum (Fig. 6) rugose, areola extending over posterior 0.6 but largely obscured by sculpture. Fore wing (Fig. 7) 2RS 0.95 x length of 3RSa; m-cu distinctly postfurcal. T1 with dorsal carinae weakly converging, widely separated at posterior margin, gradually weakening posteriorly. Meso- and metasoma orange, tegula black, head dark brown to black except narrow yellow-orange band along epistomal sulcus extending to and through malar sulcus and small orange spot on vertex adjacent eye; legs black except extreme base of hind coxa irregularly orange, joint between femora and trochantelli reddish orange, mid and hind tarsi dark brown. Body length about 4.3 mm, fore wing length 4.5 mm, mesosoma length 1.8 mm.

Specimens reared from Oedicarena latifrons (Wulp) vary as follows relative to the holotype: clypeus length/height ratio 2.6-2.8; eye/temple ratio, lateral view, 1.3-1.4 (males), 1.55 (female); antenna with 46-48 flagellomeres; 2RS/3RS ratio 0.95-1.0; ovipositor sheath 2.5 times longer than the mesosoma (Fig. 8); mesosoma length 1.85-1.9 mm (male), 2.0 mm (female); one male with T1 dorsal carinae absent over posterior 0.5 and mandible, clypeus, face, and hind coxa more extensively orange; female with outer surface of hind coxa completely pale (dark medially), mandible, clypeus and lower part of face more extensively pale than in holotype.

This species is slightly larger and has a smaller eye than both of the similarly-colored species Diachasmimorpha martinalujai Wharton and D. norrbomi Wharton. Based on the single female reared from O. latifrons, D. hildagensis also has a much longer ovipositor than D. norrbomi. The ovipositors of D. hildagensis and D. martinalujai are similar in length. In D. hildagensis and D. martinalujai, the notaulus consistently extends anteriorly to the margin of the mesoscutum (Fig. 2) whereas in D. norrbomi, the notaulus usually does not (Fig. 10). Color variation in the specimens reared from O. latifrons is similar to that in the paratype series of D. martinalujai and D. norrbomi. Both D. hildagensis and these two more recently described species are similar in having the head mostly dark in contrast to the orange heads of D. mexicana and D. sanguinea, the other two members of this species group. The holotype of D. hildagensis exhibits subsurface discoloration on the metasoma, but the tergites are all entirely orange.

Type locality: Mexico, State of Mexico, Hidalgo National Park.

Other specimens examined: 2 females, 1 male, Mexico, Mexico, Rt 890, km 9, 6 km W Lago Zempoala, 2.×.1991, A.L. Norrbom, reared from Oedicarina latifrons infesting fruits of Solanum brachycarpum (91M14B) (TAMU, USNM).

This species was originally described from a single male specimen without any associated biological information. Specimens fitting this description (Wharton et al. 2012) have been reared from Oedicarena latifrons (Wulp) infesting fruits of Solanum brachycarpum Correll. See Norrbom et al. (1988) for host data associated with this collection: the valid name (as of 2013) for the host plant is Solanum iopetalum (Bitter) Hawkes.