Doryctobracon anneae Wharton

Wharton, Robert & Norrbom, Allen L., 2013, New species and host records of New World, mostly Neotropical, opiine Braconidae (Hymenoptera) reared from flower-infesting, stem-galling, and stem-mining Tephritidae (Diptera), ZooKeys 349, pp. 11-72 : 20-22

Doryctobracon anneae Wharton sp. n. Figs 11-16

Type locality.

Mexico, Morelos, Lago de Zempoala.

Type material.

Holotype. Female (UNAM), first label, first line: MEXICO: Morelos second line: Lago de Zempoala third line: 23-25.ix.1991 fourth line: A. L. Norrbom, #57 Second label, first line: reared ex. capitulae second line: Dahlia imperialis third line: Roezl. (91M16) Third label, first line: reared ex puparium second line: Gymnocarena mexicana third line: ( Tephritidae ).

Paratypes: 3 males, 8 females, same data as holotype (USNM, TAMU). 1 male, 3 females, same data as holotype but reared ex. capitulae Dahlia merckii Lehm. (91M12A) (USNM, TAMU). 2 males, 5 females, 1 sex unknown (partly emerged from puparium), Morelos, Km 9-10 between Huitzilac and Lago de Zempoala, hollow on right, 22.ix.1991, A. Norrbom, reared ex capitulae Dahlia merckii (91M12), reared ex puparium Gymnocarena mexicana (USNM, TAMU). 3 males, 3 females, Michoacan, 2-4 km N. Angangueo, 4-5.ix.1991, A. L. Norrbom, reared ex. capitulae Dahlia imperialis (91M16B), reared ex. puparium Gymnocarena mexicana (USNM, TAMU, UNAM).

Description.

Eyes in dorsal view not or only slightly bulging beyond temples, temples not receding. Eye in lateral view 1.55-1.75 (male) and 1.7-1.9 (female) × longer than temple. Malar space large, greater than basal width of mandible, 0.45-0.6 × eye height. Clypeus sinuate, distinctly protruding as a lobe medially on ventral margin. Antenna with 41-47 flagellomeres; first flagellomere 0.8-0.9 × length of second, 1.5-1.75 × longer than wide; second flagellomere 1.75-2.0 × longer than wide. Mesosoma 1.3-1.4 × longer than high, 1.35-1.45 × higher than wide, 1.8-1.9 × longer than wide. Pronotum dorsally a broad, flat plate with weakly crenulate, shallow transverse groove near posterior margin, usually with small dimple-like depression dorsal-medially within groove; pronotum laterally with shallow, sinuate vertical groove, carinately margined on anterior side over dorsal 0.25; roughly elliptical area near middle of posterior-ventral margin delineated by very weakly crenulate groove. Notaulus virtually absent, represented primarily by a band of setae extending from anterior-lateral margin of mesoscutum to broad, shallow, median depression at posterior margin. Propodeum densely setose and punctate, with a pair of broadly rounded carinae extending anteriorly from median boss at posterior margin, carinae never extending to anterior margin, usually reaching midpoint; pleural carina often absent, sometimes weakly indicated on posterior 0.4-0.5. Metapleuron densely setose and punctate. Fore wing 2RS 1.3-1.6 × longer than 3RSa. T1 1.05-1.1 (male) and 1.15-1.3 (female) × longer than apical width, apex 1.9-2.3 (male) and 2.25-2.4 (female) × wider than base; T1 dorsal carinae parallel-sided, usually extending to level of spiracle as distinctly elevated ridges, then gradually weakening, not reaching posterior margin; spiracle posteriorad midpoint. Ovipositor 3.1-3.2 × and ovipositor sheath 2.6 × longer than mesosoma; ovipositor without subapical dorsal node. Head black; antenna, legs, ventral 0.6-0.4 of mesosoma, tegula, extreme base of T1 and ovipositor sheath dark brown, palps brown; mesosoma dorsally usually (90%) and metasoma entirely yellow-orange. Body length 3.8-6.0 mm; wing length 4.2-6.6 mm; mesosoma length 1.4-2.25 mm, with smallest male considerably smaller than smallest female.

Diagnosis.

This species is easily separated from the species of Opius s.l. treated below by the short second submarginal cell, with 3RSa much shorter than 2RS, and from all but Opius taramegillae by the complete absence of an occipital carina. The virtually absent notaulus separates Doryctobracon anneae from nearly all other species of Doryctobracon . The notaulus is also relatively poorly developed in Doryctobracon homosoma (Fischer), but the latter has an orange head and a bright yellow spot around the stigma on the otherwise infumate fore wing.

Biology.

All available specimens were reared from the tephritid Gymnocarena mexicana ( Aczél) infesting flower heads of the asteraceans Dahlia imperalis and Dahlia merkii Lehm. Most of the host puparia from which the wasps emerged are stored in gelatin capsules on four separate pins. A few are associated with the individual wasps that produced them. Host records are detailed in Norrbom (2006: 223). Data on a few of the labels indicated that at least some of the parasitoids emerged from their hosts one year after the flower heads were collected. Flies in all four samples were heavily attacked by this opiine, with parasitism rates of 85.7, 80.0, 87.5, and 66.7% for collections 91M16, 91M12A, 91M12, and 91M16B, respectively.

The apex of the ovipositor is narrower in Doryctobracon anneae relative to species such as Doryctobracon crawfordi , which may indicate an earlier host stage attacked but may also be a reflection of the differences in host habitat (fruit vs flower head).

Etymology.

This species is named after Anne Wharton, deceased, wife of the senior author.

Remarks.

This new species differs substantially from the species of Doryctobracon known as parasitoids of fruit-infesting Tephritidae by the near absence of notauli. Nevertheless, the wing venation and shape of the head and clypeus clearly place this species within Doryctobracon . Doryctobracon anneae belongs to the Doryctobracon crawfordi species group characterized by the propodeal sculpture reduced to a pair of median carinae emanating from the posterior margin of the propodeum.

There is variation in the color pattern among the specimens available for study and although they were reared from two different host plants, specimens from Dahlia imperialis exhibited the maximum extent of variation. Ten percent of the specimens, representing two males and one female, all reared from Dahlia imperalis , have a dark mesoscutum while all others are completely pale. Two specimens, also from Dahlia imperalis , have the mesosoma ventrally much less extensively dark, with the tegula only partially brown.