Bracon nitidisoma van Achterberg and Ng, 2009

Achterberg, C. van, Hosaka, T., Ng, Y. F. & Ghani, Idris B. A., 2009, The braconid parasitoids (Hymenoptera: Braconidae) associated with seeds of Dipterocarpaceae in Malaysia, Journal of Natural History 43 (11 - 12), pp. 635-686 : 657-659

Bracon nitidisoma van Achterberg and Ng , sp. nov.

( Figure 5C–G )

Holotype

Female, length of body 4.1 mm, length of forewing 3.3 mm.

Head

Antenna with 33 segments, densely, short and rather bristly setose, scapus ovoid and apically truncate, length of third segment 1.3 times fourth segment, third, fourth and penultimate segments 2.4, 1.8 and 1.7 times their maximum widths, respectively; length of maxillary palp 0.6 times height of head; face slightly convex, strongly shiny and smooth; clypeus moderately convex dorsally and smooth, its ventral rim lamelliform, protruding and medially above lower level of eyes ( Figure 5E ); frons slightly convex but distinctly concave anteromedially, largely punctulate and setose with short median groove in front of anterior ocellus; vertex distinctly convex (distinctly protruding above upper level of eye in lateral view), smooth and largely glabrous (with some setae); hypoclypeal depression 0.6 times wider than face; OOL: diameter of posterior ocellus: POL 18: 7: 11; in dorsal view length of eye 2.2 times temple; eye largely glabrous; temples smooth and rather directly narrowed behind eyes; length of malar space 0.8 times basal width of mandible; height of eye 4.3 times length of malar space; occipital flange narrow.

Mesosoma

Length of mesosoma 1.4 times its height; side of pronotum smooth and ventral third less sclerotized and paler than dorsally; mesopleuron and pleural sulcus smooth; metapleuron smooth and its flange medium-sized; mesoscutum largely glabrous but medioposteriorly and scutellum distinctly setose, smooth except for punctures near notauli posteriorly, shiny; notauli smooth, shallowly impressed posteriorly; scutellar sulcus medium-sized and sparsely crenulate; scutellum flat, smooth and dorsolaterally densely setose; metanotum with short median carina, not protruding; propodeum convex, without protuberance near spiracle, oblique, smooth (except for a few oblique rugae posteriorly and a few punctures), its median carina complete, but weakly developed anteriorly.

Wings

Forewing. Angle of 1-SR with C+SC+R about 75 ° ( Figure 5C ); r: 3-SR: SR1 9: 17: 41; 2-SR: 3-SR: r-m 15: 17: 10; SR1 reaching wing apex; 1-SR+M bent subbasally; r-m largely sclerotized; cu-a vertical; CU1b short.

Hind wing. cu-a distinctly reclivous and surrounded by setae; with one subbasal anterior bristle; M+CU: 1-M: 1r-m 11: 33: 7; 1-M distinctly widened basally; 1r-m 1.5 times as long as vein 2-SC+R; 1-M slightly curved.

Legs

Hind coxa largely smooth; tarsal claws moderately slender and with a medium-sized and ventrally straight lamelliform lobe; lengths of femur, tibia and basitarsus of hind leg 3.3, 7.0 and 4.8 times their maximum width, respectively; fourth hind tarsal segment 1.5 times as long as wide; hind tibia 0.6 times as wide as hind femur and rather compressed; fore tibia with a regular longitudinal row of long bristly setae; hind tibial spurs 0.4 and 0.5 times as long as hind basitarsus, hind basitarsus weakly compressed.

Metasoma

Length of first tergite 0.8 times its apical width, dorsolateral carinae strongly developed, its surface smooth but anterior twothirds of dorsoapical elevation coarsely rugose, flat part of median area with shallow median groove, lateral area wide and largely smooth ( Figure 5G ); second tergite with small and smooth mediobasal area connected to a median carina, with pair of shallow longitudinal sublateral depressions, and remainder largely very coarsely rugose except narrowly anteriorly and posteriorly ( Figure 5G ); second metasomal suture wide medially, deep and sparsely crenulate; metasoma constricted at level of second suture ( Figure 5G ); third tergite 0.85 times as long as second tergite, without median ridge or carina, or subapical transverse groove, sublongitudinally rugose except posteriorly, 2.6 times as wide as long medially ( Figure 5G ); fourth to eighth tergites smooth, flattened behind basal groove; eighth tergite truncate posteriorly; second to sixth tergites without distinct acute lateral margin; length of ovipositor sheath 0.65 times as long as forewing and 0.9 times as long as metasoma, sheath with moderately long setae, apex of ovipositor normal, with small nodus and minute but distinct ventral teeth; hypopygium triangular apically and not surpassing apex of metasoma.

Colour

Yellowish-brown; antenna (but scapus and pedicellus largely brown), telotarsi apically, third tergite largely, and ovipositor sheath dark brown; pterostigma and most of veins blackish-brown; wing membrane subhyaline.

Variation

Length of forewing of female 3.1–3.5 mm and of male 2.7–3.1 mm; length of body of female 3.7–4.5 mm and of male 3.1–3.7 mm; antenna of female with 31 (1), 32 (2) or 33 (3) segments, of male with 33 (1) or 35 (1) segments; length of ovipositor sheath 0.61–0.65 times forewing; third metasomal tergite largely rugose to largely smooth; fourth and following tergites of male dark brown.

Biology

Parasitoids of larvae in seeds of Shorea pauciflora and Shorea leprosula . Emergence from earlier aborted fruits suggests that Nanophyes shoreae and/or Nanophyinae sp. might be the hosts ( Figure 1B ).

Notes

Among the approximately 65 described Oriental species in the genus Bracon the new species is similar to Bracon pallidenotatus Cameron, 1910 , and Bracon sumatranus Cameron, 1910 , because of the medium-sized ovipositor sheath, the largely smooth face, the distinctly sculptured second metasomal tergite and blackish pterostigma. However, B. pallidenotatus Cameron has a patch of the mesoscutum and on the mesopleuron, the mesosternum and the metasoma largely black, the first to sixth metasomal tergites punctate and the hind tibia largely dark brown. Bracon sumatranus Cameron has the body dorsally largely black, the ovipositor sheath about 0.8 times as long as the metasoma and the third to fourth metasomal tergites striate.

Material examined

Holotype female, ‘‘W. Malaysia, N. Sembilan Pasoh Forest Reserve , 22 August 2002, from Shorea leprosula seeds, Y.F. Ng and Hosaka’ ’, ‘‘Collected (453550)’’, ‘‘B 15’’, ‘‘ Centre for Insect Systematics, Universiti Kebangsaan Malaysia’ ’ ( UKM) . Paratypes (10 females and four males): one female, id., but 2 September 2002, B 21 and no. 204560 ( RMNH) ; one female, id., but 13 December 2001, collected from Shorea pauciflora seeds, no. 245184 and C 20 ( UKM) ; one male, id., but 10 December 2002 and B 14 ( UKM) ; one male [?], id., but B 2 ( UKM) ; one male, id., but 24 December 2001 and C 16 ( UKM) ; one female, id., but 25 December 2001 and C 7 ( RMNH) ; one female, id., but no. 265226 and C 23 ( RMNH) ; one male, id., but 10 December 2001 and C 19 ( RMNH) ; two females, id., but from Malaise trap at 50-ha plot, 9 June 2002, Y.F. Ng and Ruslan ( UKM, RMNH) ; one female, id., but 22 June 2002 ( RMNH) ; one female, id., but 13 July 2002 (in logged area) ( UKM) ; one female, id., but 50-ha plot and 20 July 2002 ( RMNH) ; one female, id., but 22 October 2002 ( UKM) .

Figures

Figure 1. (A) Occurrence of Schizoprymnus spp. A character indicates aborted timing of an individual wasp examined. M, Schizoprymnus mesocaudus; T, Schizoprymnus torreadoroides; ¤, Nanophyes shoreae (Coleoptera: Apionidae); m, Nanophyinae sp. (Coleoptera: Apionidae); e, Alcidodes dipterocarpi (Coleoptera: Curculionidae); Δ, Alcidodes humeralis; *, Andrioplecta shoreae (Lepidotera: Tortricidae); MAC, Shorea macroptera; PAU, Shorea pauciflora; LEPI, Shorea lepidota; PAR, Shorea parvifolia; ACU, Shorea acuminata; MAX, Shorea maxwelliana; LEPR, Shorea leprosula. The number following the tree code stands for flowering event; 1 indicates Flowering 2001, 2 indicates Flowering 2002. For example, ACU2 stands for Shorea acuminata in Flowering 2002.

Figure 5. (A, B) Bracon rugulifer, female, holotype; (C–G) Bracon nitidisoma, female, holotype; (H, I) Syntomernus shoreatus, female, holotype. (A, C) Part of forewing; (B, G, I) first to third metasomal tergites, dorsal aspect; (D) head, dorsal aspect; (E, H) head, anterior aspect; (F) head, lateral aspect. Scale bars: 1.0×(A); 1.3×(B, C); 1.4×(D–G); 1.8×(H, I).