Bracalba pinnula 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 : 28-30

Bracalba pinnula Burks sp. n. Figures 43-46Morphbank25

Description.

Female. Body length 3.37-3.75 mm (n=7). Color of antenna beyond radicle: entirely dark. Radicle color: lighter than scape. Number of claval segments with ventral gustatory sensilla: 7. Number of ventral gustatory sensilla on A6: 1, or 2.

Ocular setae: short and dense. Frontal depression: with many strong transverse carinae, sparsely foveolate at torular triangle. 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: three of roughly equal size. 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: with a semicircular expansion, broadest near midlength. Mesoscutellar sculpture: densely foveolate. Metascutellum in dorsal view: trapezoidal with broad apex. Dorsal surface of metascutellum: flat, or convex. Femoral depression: centrally smooth, peripherally foveolate. Leg color: coxae and femora dark, but tibiae, tarsi, and sometimes 2nd trochanters 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: with metasomal bend and abrupt transition in sculpture. 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: as broad or broader than long. T6 laterotergite: overlapping S6. S4 median carina: present. 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.

Male. Body length 2.75-3.13 mm (n=4). 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 with 1 or 2 large sensilla; 3 mandibular teeth of approximately equal length; metascutellum trapezoidal with a broad and truncate or slightly concave apex; metasomal bend present but very weak; sculpture posterior to metasomal bend with longitudinal and transverse septa of about equal height and hardly differing from those anterior to the bend; T4-T6 and S4-S5 without median carina; S4 sometimes with a slight median carina; T6 longer than broad; S5 with longitudinal septa not stronger than transverse septa; S6 without apical notch. Bracalba pinnula has only a very slight metasomal bend, and therefore it can easily be confused with those species that lack the bend. It differs from most of these species in that the fore wings reach to the middle of T4, and from Bracalba intermedia in having a long and trapezoidal metascutellum.

Etymology.

Latin noun, meaning "a small fin." This is considered to be a noun in apposition to the generic name.

Link to distribution map.

http://hol.osu.edu/map-full.html?id=302158

Material examined.

Holotype, female: AUSTRALIA: WA, WA122401, 7km N Stirling Range National Park, 34°19'S, 118°11'E, 900ft, 24.XII.1994, malaise trap, L. S. Kimsey & R. B. Kimsey, OSUC 231797 (deposited in WAMP). Paratypes: AUSTRALIA: 12 females, 11 males, OSUC 149756 (AEIC); OSUC 230822-230824, 367508, 367512-367519 (ANIC); OSUC 148700, 231780-231781 (CNCI); OSUC 238452 (QDPC); OSUC 179086, 179088-179089, 231794-231796 (UCDC).