Bracalba plana 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 : 12-14

Bracalba plana Burks sp. n. Figures 12-13Morphbank17

Description.

Female. Body length 2.75-3.13 mm (n=3). Color of antenna beyond radicle: mostly dark, ventral parts of pedicel apex, A4-A12 variably lighter. Radicle color: lighter than scape. Number of claval segments with ventral gustatory sensilla: 7. Number of ventral gustatory sensilla on A6: 2.

Ocular setae: short and dense. Frontal depression: with many irregularly transverse rugae. Smooth depression extending dorsolaterally from antennal foramen: present. Dorsal clypeal margin: absent between antennal foramina. 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: 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: weakly rounded anteriorly. Sculpture of posteromedian area of mesoscutum: densely foveolate. Lateral margin of dorsal axillar area: triangularly expanded or with posterior tooth, broadest posteriorly. Mesoscutellar sculpture: sparsely foveolate, with large smooth interspaces. Metascutellum in dorsal view: semicircular. Dorsal surface of metascutellum: flat. Femoral depression: centrally smooth, peripherally foveolate. Leg color: coxae dark, leg becoming gradually lighter apically. 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: without bend. Posterolateral margins of metasomal terga: without protrusions. T5 median carina: absent. Longitudinal sculp tural septa on T5: weak, blunt and hardly raised. Transverse sculptural septa on T5: about as strong as the longitudinal septa. T5 setae: directed posteriorly, arising from anterior edge of sculptural mesh. T6: as broad or broader than long. T6 laterotergite: overlapped by rim from S6. S4 median carina: absent. Transverse sculptural septa on S5: about as strong as the longitudinal septa. S5 setae: directed posteriorly, arising from anterior edge of sculptural mesh. Lateral carinae of S6: absent. Apex of S6: without notch.

Males. Body length 2.75-3.00 mm (n=2). Flagellomere length: A3 1 –1.2× as long as broad, most others transverse. T7: flat and posteriorly truncate.

Diagnosis.

Female. A6 with 2 large ventral sensilla; 2 mandibular teeth; anterolateral corner of dorsal pronotal area weakly rounded anteriorly; metascutellum trapezoidal with a broad apex, flat dorsally; metasomal bend absent; T4-T6 without median carina, S4-S6 without median carina; T6 broader than long; S6 without apical notch. This species is very similar to Bracalba globosa , but differs mainly in having a shorter, more flat metascutellum and shorter flagellomeres in males.

Etymology.

Latin adjective, referring to the flat mesoscutum, mesoscutellum, and metascutellum of most specimens of this species.

Link to distribution map.

http://hol.osu.edu/map-full.html?id=302159

Material examined.

Holotype, female: AUSTRALIA: NT, Centre for Zone Research (CSIRO), Alice Springs, XI-1992, malaise trap, Austin & Dangerfield, OSUC 230804 (deposited in SAMA). Paratypes: AUSTRALIA: 5 females, 3 males, OSUC 148706, 238115, 238168, 238170 (CNCI); OSUC 230802-230803, 230805-230806 (WINC).

Comments.

Most specimens have a flat mesoscutum and mesoscutellum, but these features were not constant within this species nor in others of the genus.