Syntomernus shoreatus 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 : 665-667

Syntomernus shoreatus van Achterberg and Ng , sp. nov.

( Figures 5H,I , 6A )

Holotype

Female, length of body 2.9 mm, length of forewing 3.0 mm.

Head

Antenna with 26 segments, scapus short, ovoid and apically truncate, length of third segment 1.4 times fourth segment, third, fourth and penultimate segments 2.8, 2.0 and 2.0 times their maximum width, respectively; length of maxillary palp 0.7 times height of head (in paratype, not well visible in holotype); face slightly convex, finely granulate but medially triangular area smooth; clypeus flattened and largely smooth and ventral rim protruding and below lower level of eyes ( Figure 5H ); frons slightly convex laterally and nearly flat medially, largely superficially granulate with short median groove in front of anterior ocellus; vertex distinctly convex (distinctly protruding above upper level of eye in lateral view), smooth (except for some punctures) and sparsely medium-sized setose; OOL: diameter of posterior ocellus: POL 7: 4: 3; in dorsal view length of eye 1.7 times temple; eye glabrous; temples smooth and slightly narrowed behind eyes; length of malar space equal to basal width of mandible; height of eye 2.9 times length of malar space; occipital flange small.

Mesosoma

Distinctly depressed, length of mesosoma 1.9 times its height; side of pronotum and mesopleuron smooth, except for with some punctures and faint microsculpture; metapleuron smooth and its flange medium-sized; mesoscutum densely setose, smooth except for punctulation, shiny; notauli absent posteriorly, anteriorly smooth; scutellar sulcus medium-sized and distinctly crenulate; scutellum flat, smooth but anteriorly with some punctures; metanotum with short median carina, not protruding; propodeum flattened, without protuberance near spiracle, weakly oblique (but in one paratype moderately oblique), smooth, its median carina present posteriorly, but anterior half of propodeum largely absent.

Wings

Forewing. Angle of 1-SR with C+SC+R about 60 ° ( Figure 6A ); r: 3-SR: SR1 10: 18: 65; 2-SR: 3-SR: r-m 19: 18: 11; r-m largely sclerotized; cu-a vertical.

Hind wing. cu-a nearly vertical; M+CU: 1-M: 1r-m 10: 27: 6; 1r-m twice as long as vein 2-SC+R; 1-M rather curved; surroundings of cu-a evenly setose.

Legs

Hind coxa smooth; tarsal claws moderately robust and with a wide and ventrally straight lobe; length of femur, tibia and basitarsus of hind leg 3.5, 6.0 and 5.0 times their maximum width, respectively, fourth hind tarsal segment about as long as wide; hind tibia 0.8 times as wide as hind femur; fore tibia with an irregular row of short pegs; hind tibial spurs 0.48 and 0.52 times as long as hind basitarsus, hind basitarsus distinctly compressed.

Metasoma

Length of first tergite 0.8 times its apical width, dorsolateral carinae strongly developed, its surface smooth but dorsoapical elevation rugose, flat part of median area with shallow and narrow smooth median groove, lateral area medial-sized and distinctly crenulate ( Figure 5I ); second tergite with small and smooth mediobasal area, with shallow longitudinal lateral depression, a weak median carina and remainder largely rugose except anteriorly ( Figure 5I ); second metasomal suture wide medially, deep and coarsely crenulate; third tergite 0.8 times as long as second tergite, without median ridge or carina, rugulose and a weakly crenulate subapical transverse groove, 3.6 times as wide as long medially ( Figure 5I ); fourth to sixth tergites mainly coriaceous and with subapical transverse groove, rather weakly convex behind basal groove; sixth tergite weakly concave posteriorly; second to sixth tergites with acute lateral margin and following tergites retracted; length of ovipositor sheath 0.75 times as long as forewing and 1.6 times metasoma, sheath moderately setose, apex of ovipositor normal, with medium-sized nodus and with minute but distinct ventral teeth; hypopygium triangular apically and just surpassing apex of metasoma.

Colour

Yellowish-brown; antenna (but scapus and pedicellus largely brown), telotarsi apically, apical rim of propodeum, first tergite narrowly laterally, second metasomal suture and basal fifth and apex of ovipositor sheath dark brown; pterostigma basally yellowish brown; most of veins and remainder of pterostigma brown; wing membrane subhyaline.

Variation

Length of forewing of female 2.7–3.2 mm, of male 2.1–2.2 mm and of body of female 2.6–3.5 mm and of male 2.6 mm; antenna of female with 24 (1), 25 (1) or 26 (1) segments, and of male 24 (1) segments; length of ovipositor sheath 0.75–0.92 times forewing; smooth sublateral basal areas of second tergite may be more developed than in holotype; medially apex of metasoma of male dark brown; ovipositor sheath completely dark brown or only basally and apically; subapical transverse grooves of third and fourth tergites of female may be dark brown; body more or less depressed, length of mesosoma 1.2–1.9 times as long as its height.

Biology

A parasitoid of larvae in seeds of Shorea acuminata , Shorea lepidota , Shorea leprosula and Shorea parvifolia . Emergence from earlier aborted fruits suggests that Syntomernus shoreatus may attack Nanophyes shoreae and/or Nanophyinae sp. ( Figure 1C ).

Distribution

West Malaysia.

Notes

The new species differs from the only other described species in the genus, Syntomernus pusillus Enderlein, 1920 , from China (Taiwan) by having the lobe of the outer hind tarsal claw straight ventrally (slightly concave in S. pusillus ), the hind tibia 0.8 times narrower than the hind femur (0.6 times), the ovipositor sheath 0.7–0.9 times as long as the forewing (0.4–0.5 times), the temples slightly narrowed behind eyes (strongly narrowed), the fourth metasomal tergite rather weakly convex (strongly convex), and the second tergite with shallow sublateral grooves (without sublateral grooves).

Material examined

Holotype female, ‘‘W. Malaysia, N. Sembilan Pasoh Forest Reserve , 3 September 2002, from Shorea leprosula seeds, Y.F. Ng and Hosaka’ ’, ‘‘Collected (214678)’’, ‘‘C 24’’, ‘‘ Centre for Insect Systematics, Universiti Kebangsaan Malaysia’ ’ ( UKM) . Paratypes (five females and two males): one female, id., but 5 August 2002, C 25 and no. 23366 ( RMNH) ; one female, id., but collected from Shorea parvifolia seeds (no. 184538), C 10 and 10 December 2001 ( UKM) ; one male, id., but no. 274222 and C 12 ( UKM) ; one female, id., but collected from Shorea acuminata seeds (no. 435018) and C 11 ( UKM) ; one female, id., but collected from Shorea lepidota seeds (no. 184598), C 2 and 27 June 2002 ( RMNH) ; one female, id., but no. 334880, B 20 and 6 June 2002 ( RMNH) ; one male, id., but collected from Shorea parvifolia seeds (no. 184538), B 18 and 10 December 2002 ( RMNH) .

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).

Figure 6. (A) Syntomernus shoreatus, female, holotype; (B–H) Ascogaster cornifera, female, holotype. (A, B) Part of forewing; (C) metasoma, dorsal aspect; (D) propodeum and metasoma, lateral aspect; (E), head, lateral aspect; (F) clypeus; (G) hind leg; (H) area between antennal sockets, anterior aspect. Scale bars: 1.0×(A–E, G); 2.3×(F, H).