Bracalba intermedia 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 : 19-20

Bracalba intermedia Burks sp. n. Figures 24-27Morphbank20

Description.

Female. Body length 3.25-3.88 mm (n=7). Color of antenna beyond radicle: entirely dark. Radicle color: lighter than scape. Number of claval segments with ventral gustatory sensilla: 6. Number of ventral gustatory sensilla on A6: 0.

Ocular setae: short and dense. Frontal depression: medially smooth, torular triangle sparsely foveolate, or foveolate dorsally, torular triangle foveolate, areas lateral to it with transverse carinae. Smooth depression extending dorsolaterally from antennal foramen: absent. Dorsal clypeal margin: bordering antennal foramina, absent between them. Clypeal median carina: absent. Ventral clypeal margin: convex. 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: reticulate-rugose without any strong carinae.

Dorsal pronotal area: not set off by carina ventrally. Anterolateral corner of dorsal pronotal area: weakly rounded anteriorly. Sculpture of posteromedian area of mesoscutum: foveolate with slightly stronger longitudinal septa. Lateral margin of dorsal axillar area: triangularly expanded or with posterior tooth, broadest posteriorly. Mesoscutellar sculpture: densely foveolate with slightly stronger longitudinal septa. Metascutellum in dorsal view: strongly transverse, subrectangular. Dorsal surface of metascutellum: flat. Femoral depression: centrally smooth, peripherally foveolate. Leg color: coxae, femora (aside from their apices), and at least the last two tarsomeres dark, otherwise yellowish brown. 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 a set of rugae that merge with one another. Metasoma at middle of T4: without bend. Posterolateral margins of metasomal terga: without protrusions. T5 median carina: absent. Longitudinal sculptural 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: longer than broad. T6 laterotergite: overlapping S6. S4 median carina: present. Transverse sculptural septa on S5: weak or absent, much weaker than the longitudinal septa. S5 setae: directed posteriorly, arising from anterior edge of sculptural mesh. Lateral carinae of S6: absent. Apex of S6: without notch.

Male. Body length 2.62-3.25 mm (n=18). Flagellomere length: A3 over 1.5 × as long as broad, most others as long or longer than broad. T7: flat and posteriorly truncate.

Diagnosis.

Female. A6 without large ventral sensilla; 3 mandibular teeth with middle tooth much smaller than the others; metascutellum broad and subrectangular, very short; metasomal bend absent; T4-T6 without median carina, S4-S6 with at least a vague median carina; T6 longer than broad; S6 without apical notch. The antenna and short metascutellum help distinguish it from similar species. It is very similar to Bracalba pinnula , but differs in having a much shorter metascutellum. It is also very similar to Bracalba clavata , but has no distinct metasomal bend and has a longer T6 in females.

Etymology.

Latin adjective, referring to its unusual mixture of characters.

Link to distribution map.

http://hol.osu.edu/map-full.html?id=302155

Material examined.

Holotype, female: AUSTRALIA: WA, via Dwellingup, Yarragil 4P Catchment, 18.II-25.II.1981, malaise trap, A. Postle, OSUC 230811 (deposited in QMBA). Paratypes: AUSTRALIA: 8 females, 23 males, OSUC 148705, 148707-148708, 180713, 238105-238109, 238111, 238179, 238182, 238184-238186 (CNCI); OSUC 230809-230810, 230812, 230814, 238450 (QDPC); OSUC 227572-227578, 230801, 238454, 238457, 384567 (WINC).

Comments.

Bracalba intermedia lacks a metasomal bend, but the three mandibular teeth, elongate metasoma, and sculptural features suggest that it belongs in the laminata group. Specimens from the eastern localities tend to be slightly smaller and have some reduction in sculpture, but are retained in our concept of this species.