Bracalba sparsa 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 : 34-36

Bracalba sparsa Burks sp. n. Figures 55-59Morphbank28

Description.

Female. Body length 3.37-4.00 mm (n=6). Color of antenna beyond radicle: reddish-brown, darker at scape apex, pedicel, and A3. Radicle color: lighter than 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 irregular rugae indicating large foveae. Smooth depression extending dorsolaterally from antennal foramen: present. Dorsal clypeal margin: forming a complete connection between antennal foramina medially. Clypeal median carina: absent. Ventral clypeal margin: with a small median point. Mandibular color: dark basally and at teeth, becoming lighter reddish brown between these areas. Mandibular teeth: two, separated by narrow incision. Smooth area obliquely posterior to lateral ocellus: present. Genal sculpture: reticulate-rugose without any strong carinae.

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 but tapering to narrow apex. Dorsal surface of metascutellum: apex protruding dorsally. Femoral depression: crossed by rounded carinae. Leg color: entirely reddish. Anterior corner of lateral propodeal carina: flat, without tooth. Posteromedial corner of lateral propodeal area: protruding posteriorly.

Metasoma color: mostly reddish, variably dark at T4 bend, T5-T6, with variable smaller dark areas elsewhere. 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: with tooth-like protrusions. T5 median carina: absent. Longitudinal sculptural septa on T5: strong, sharply raised. Transverse sculptural septa on T5: weak or absent, much weaker than 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: present. 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. Body length 3.5 mm (n=1). Flagellomere length: A3 over 1.5 × as long as broad, most others as long or longer than broad. T7: arched and posteriorly concave.

Diagnosis.

Female. A6 with 1 large ventral sensillum; 2 mandibular teeth; metascutellum subtrapezoidal but strongly tapering to a narrow truncate apex; metasomal bend expressed as a raised hump with posterior metasomal segments not tilted downwards; sculpture posterior to metasomal hump with strong longitudinal and transverse septa; T4-T6 without longitudinal carina; T6 broader than long; S4-S6 with longitudinal carina; S6 with apical notch.

Etymology.

Latin participle meaning “scattered,” recalling the sparsely distributed setae of this species.

Link to distribution map.

http://hol.osu.edu/map-full.html?id=302162

Material examined.

Holotype, female: AUSTRALIA: WA, Toodyay, 31.X.1979, R. M. Bohart, OSUC 231798 (deposited in WAMP). Paratypes: AUSTRALIA: 4 females, 3 males, OSUC 230821 (ANIC); OSUC 148703, 238204-238206, 238208 (CNCI); OSUC 55870 (OSUC).

Comments.

Bracalba sparsa represents a distinctive element within the genus, with its unique metasoma and unusual metascutellum.