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).