Bracalba tridentata Burks

Burks, Roger A., Masner, Lubomir, Johnson, Norman F. & Austin, Andrew D., 2012, Taxonomic revision of Bracalba Dodd (Hymenoptera, Platygastridae s. l.), a parasitoid wasp genus endemic to Australia, ZooKeys 236, pp. 1-53 : 38-40

Bracalba tridentata Burks sp. n. Figures 62-65Morphbank 30

Description.

Female. Body length 5.12-5.38 mm (n=3). Color of antenna beyond radicle: entirely dark. Radicle color: same as scape. Number of claval segments with ventral gustatory sensilla: 7. Number of ventral gustatory sensilla on A6: 1.

Ocular setae: long and sparse. Frontal depression: with many irregularly transverse rugae. Smooth depression extending dorsolaterally from antennal foramen: present. Dorsal clypeal margin: arched, interrupted by broad median carina. Clypeal median carina: present. Ventral clypeal margin: with a small median point. Mandibular color: dark basally and at teeth, becoming lighter reddish brown between these areas. Mandibular teeth: three, but middle tooth tiny. Smooth area obliquely posterior to lateral ocellus: present. Genal sculpture: deeply reticulate-rugose with some septa much stronger than others, forming distinct rows differing in height.

Dorsal pronotal area: not set off by carina ventrally. Anterolateral corner of dorsal pronotal area: truncate anteriorly. Sculpture of posteromedian area of mesoscutum: densely foveolate. Lateral margin of dorsal axillar area: with a semicircular expansion, broadest near midlength. Mesoscutellar sculpture: densely foveolate. Metascutellum in dorsal view: trapezoidal with broad apex, or elongate-trapezoidal but with incised apex. Dorsal surface of metascutellum: apex protruding dorsally. Femoral depression: crossed by 4-6 dorsal carinae, 7-8 ventral carinae interrupted by central smooth area. Leg color: yellowish-brown except for dorsal external part of coxae and sometimes tarsomeres 2-5. Anterior corner of lateral propodeal carina: flat, without tooth. Posteromedial corner of lateral propodeal area: protruding posteriorly.

Metasoma color: black to dark reddish brown. Median lobe of T1: with 7 or more longitudinal carinae. Metasoma at middle of T4: with metasomal bend and abrupt transition in sculpture. Posterolateral margins of metasomal terga: without protrusions. T5 median carina: absent. Longitudinal sculptural septa on T5: strong, sharply raised. Transverse sculptural septa on T5: about as strong as the longitudinal septa. T5 setae: not directed posteriorly, arising from center of sculptural mesh. T6: as broad or broader than long. T6 laterotergite: overlapping S6. S4 median carina: absent. Transverse sculptural septa on S5: weak or absent, much weaker than the longitudinal septa. S5 setae: not directed posteriorly, arising from center of sculptural mesh. Lateral carinae of S6: not meeting apically. Apex of S6: with notch.

Male. unknown.

Diagnosis.

Female. A6 with 1 large ventral sensillum; middle mandibular tooth present but much smaller than the others; metascutellum broadly trapezoidal and with a broadly truncate apex that may have a conspicuous median notch; metasomal bend strong; sculpture posterior to metasomal bend distinctly different from that anterior to it, with very weak transverse septa and strong longitudinal septa; T6 about as long as broad; S6 with apical notch. This species is very similar to Bracalba hesperia , but S6 in that species does not have an apical notch. It is also similar to Bracalba sparsa , but that species has a unique metasomal bend and metascutellar shape.

Etymology.

Latin adjective, named for the usually 3-pronged pattern formed apically by dark cuticle on T6.

Link to distribution map.

http://hol.osu.edu/map-full.html?id=302164

Material examined.

Holotype, female: AUSTRALIA: SA, 32km N Renmark, Amalia Dam, xeric mallee scrub, MT 4, ROM 2000041, Bookmark Biosphere Reserve, 33°53'S, 140°43'E, 263m, 15.II-15.IV.2000, malaise trap, D. C. Darling, OSUC 238113 (deposited in SAMA). Paratypes: AUSTRALIA: 2 females, OSUC 238114, 238116 (CNCI).