Bracon singaporensis Szépligeti, 1905

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 : 655-657

Bracon singaporensis Szépligeti, 1905

( Figure 4E–H ) Bracon singaporensis Szépligeti 1905, p. 37 ; Shenefelt 1978, p. 1539.

Variation

Length of forewing of female 2.9–3.1 mm (of male 2.4 mm), and of body 3.3–3.5 mm (of male 2.7 mm); antenna of female with 30 (1) or 31 (1) segments; ovipositor sheath about as long as metasoma and 0.50–0.53 times as long as forewing; male has posterior half of third tergite and most of fourth and fifth tergites dark brown.

Biology

The small subgenus Ophthalmo-bracon Tobias contains parasitoids of Gelechiidae ( Lepidoptera : Gelechioidea) and it is therefore likely that B. singaporensis parasitizes larvae of Gelechiidae feeding on Shorea seeds. However, we have not identified any Gelechiidae spp., but have some Oecophoridae species ( Lepidoptera : Gelechioidea; Table 1) as possible hosts.

Notes

Dr Jenö Papp (Budapest) examined the holotype and kindly informed the first author that the malar space was much shorter than the basal width of the mandible. Therefore, it is obvious that B. singaporensis belongs to the subgenus Ophthalmobracon . It has the dorsolateral carinae of first tergite present (absent in Palaearctic spp.), the middle lobe of mesoscutum densely setose, the body yellowish-brown, but the third and fourth metasomal tergites of female with a pair of dark brown spots (and also sixth tergite in male), the propodeum (except anteriorly) largely and the vertex finely granulate, the ovipositor sheath is about 0.5 times the forewing and about as long as the metasoma and the marginal cell of the forewing reaches about the apex of the forewing ( Figure 4E ). Two species included in this subgenus can be separated because they have the ovipositor sheath distinctly shorter than the metasoma and vein 1-R1 of forewing about as long as pterostigma: the Central Asian B. (O.) nocturnus (Tobias, 1962) and B. (O.) lissothorax (Tobias, 1964) . Bracon singaporensis is similar to the Central and East Palaearctic B. (O.) ophthalmicus Telenga, 1933 , and the Afrotropical B. (O.) kirkpatricki (Wilkinson, 1927) having the ovipositor sheath about as long as the metasoma, but B. ophthalmicus has vein SR1 of the forewing 2.3–3.0 times as long as vein 3-SR (1.3– 1.4 times in B. singaporensis , 1.6–1.9 times in B. kirkpatricki ), no dorsolateral carinae on the first tergite, the third and fourth metasomal tergites completely yellowishbrown and antenna of female with 24–28 segments (30 or 31 segments in B. singaporensis ). In addition, B. kirkpatricki has the forewing membrane (except basally) and the pterostigma medially darkened.

Bracon greeni Ashmead, 1896 , from Sri Lanka is similarly coloured but has the ovipositor sheath about 0.7 times as long as the metasoma, the pterostigma brown, the antenna brownish-black, third tergite about as long as the fourth tergite, the second tergite shagreened to closely punctured and with a weak median carina, vein 3-SR of the forewing about three times as long as vein r and the type series was reared from a host [ Laccifer albizziae (Green) ( Kerriidae ; Coccoidea)] on shrubs and they were not associated with the seeds of trees.

In addition, we examined two males from Shorea acuminata seeds belonging to another species with the mesoscutum largely smooth.

Material examined

One female, ‘‘W. Malaysia, N. Sembilan Pasoh Forest Reserve, 25 January 2002. From Shorea acuminata seeds, Y.F. Ng and Hosaka’’, ‘‘C 13’’, ‘‘Collected from S. acuminata seed (324995)’’ (UKM) ; two females and one male, id., but C 1, C 3 or C 14 ( RMNH) ; two females, id., but 12 January 2002. no. 324995 and B 15 or B 11 ( UKM) ; one male, id., but 25 January 2002, no. 324995 and C 15 ( RMNH) ; one male, id., but 10 December 2001, from Shorea pauciflora seeds, no. 255519 and C 9 ( UKM) ; one female, id., but 1 December 2001, no. 255519 and C 8 ( UKM) ; one female, id., 12 January 2002, from Shorea macroptera seeds, no. 215945 and C 5 ( RMNH) .

Figures

Figure 4. (A–D) Schizoprymnus torreadorides, female, holotype; (E–H) Bracon singaporensis, female, Malaysia, Pasoh Forest; (I–K) Bracon rugulifer, female, holotype. (A) Metasoma, dorsal aspect; (B) scutellum, dorsal aspect; (C, G, I) head, anterior aspect; (D) apex of third tergite, dorsoventral aspect; (E) part of forewing; (F, K) head, dorsal aspect; (H, J) head, lateral aspect. Scale bars: 1.0×(A–D); 1.3×(E, K); 1.8×(F–H); 1.4×(I, J).