Colastes fritzeni, Achterberg & Shaw, 2008

Achterberg, C. van & Shaw, M. R., 2008, A new subgenus of the genus Colastes Haliday (Hymenoptera: Braconidae: Exothecinae) for species reared from bracket fungi, with description of two new species from Europe, Journal of Natural History 42 (27 - 28), pp. 1849-1860 : 1854-1857

Colastes fritzeni sp. nov.

( Figures 3A–E )

Holotype, female, length of body 3.3 mm and of forewing 3.2 mm.

Description

Head. Antenna with 26 segments, third antennal segment 1.4 times fourth segment, length of third, fourth and penultimate segments 4.8, 3.3 and 2.0 times their width, respectively ( Figures 3B, C ); length of maxillary palp 1.2 times height of head; length of eye in dorsal view 1.9 times temple; OOL: diameter of ocellus: POL57:3:5; vertex smooth and conspicuously setose; frons smooth and with a shallow median groove anteriorly; face transversely rugulose medially (except dorsally) and rugulosegranulate laterally; malar space only granulate; clypeus with some transverse striae and rugulae; hypoclypeal depression half as wide as face; ventral part of occipital carina visible in anterior view of head; length of malar space 1.3 times basal width of mandible; occipital flange rather wide ( Figure 3B ); malar suture obsolescent; mandible distinctly twisted apically and with convex striate outer side.

Mesosoma. Length of mesosoma 1.6 times its height; pronope absent except for an indistinct sculptured depression; side of pronotum smooth dorsally, with a triangular depression and remainder coarsely rugose; mesosternum with a widely crenulate and deep median sulcus and sublaterally superficially crenulate (but smooth posteriorly); mesopleuron smooth, but densely vermiculate-rugose antero-dorsally; precoxal sulcus absent; metapleuron vermiculate-rugose; notauli complete, rather wide and coarsely crenulate, medio-dorsally with coarse rugae; middle lobe and anteriorly lateral lobes of mesoscutum densely setose; scutellar sulcus wide and deep, with some distinct carinae; scutellum weakly convex, setose and largely smooth, but distinctly rugose medio-posteriorly; surface of propodeum coarsely rugose-reticulate, with an irregular median carina but without an areola posteriorly.

Wings. Forewing: r slightly widened and 0.9 times width of pterostigma; pterostigma elongate ( Figure 3A ); r:3-SR:SR1510:24:52; 1-CU1:2-CU151:2; 2-SR:3-SR:rm517:24:11; m-cu antefurcal and converging to 1-M posteriorly; cu-a short and first subdiscal cell strongly widened apically ( Figure 3A ); CU1b much shorter than vein 3-CU1. Hind wing: m-cu present, antefurcal; M+CU:1-M: 1r-m519:22:10.

Legs. Hind coxa densely rugose laterally and dorsally; hind femur densely and long setose and largely rugose, except postero-laterally ( Figure 3D ); hind tibia densely setose and striate except dorsally; tarsal claws simple, setose, but with some short bristles basally; fore tarsus as long as tibia, tibia with a row of bristly setae; length of femur, tibia and basitarsus of hind leg 3.4, 8.6 and 5.6 times their width, respectively; hind tibial spurs 0.20 and 0.15 times as long as hind basitarsus.

Metasoma. Length of first tergite 1.2 times its apical width, its surface strongly longitudinally striate ( Figure 3E ), its dorsal carinae remain separated; dorsope medium-sized; laterope absent, with glymma slightly impressed and crenulate; second tergite smooth but widely finely striate basally; ovipositor straight; length of ovipositor sheath 0.48 times as long as forewing (and 3.4 times as long as first tergite).

Colour. Black; scapus (but dorsally darkened), pedicellus largely and annellus yellowish-brown; antennal sockets, small lateral patch of frons and metasoma ventrally more or less dark brown; remainder of antenna and pterostigma dark brown; palpi, tegulae, seventh and eighth metasomal tergites and legs pale yellowish, but apical third of hind tibia and most of hind tarsus infuscate; parastigma and veins rather dark brown; wing membrane subhyaline.

Variation

Length of body 2.6–3.9 mm (female) or 1.6–2.9 mm (male), and of forewing 2.7– 3.7 mm (female) or 1.7–2.9 mm (male); antenna of female with 25 (3), 26 (2) or 28 (2) segments, of male with 20 (1), 21 (2), 23 (2), 24 (4), 27 (2) or 28 (1) segments; shape of pterostigma of male similar to that of female; small males tend to have the hind leg (and to a lesser degree fore and middle legs) largely dark brown, especially hind coxa and tibia and their sculpture is less developed; vein 3-SR of forewing 1.4–2.0 times as long as vein 2-SR; length of ovipositor sheath 0.48–0.52 times as long as forewing. One male with the same data as the holotype is excluded because it is extremely small (forewing 1.3 mm), antenna with 18 segments, mesoscutum with few setae and first subdiscal cell of forewing narrow and subparallel-sided.

Biology

Several times reared from bracket fungi in which Dorcatoma species were breeding in the apparent absence of other possible hosts.

Distribution

Finland.

Material examined

Holotype female: ‘‘ Finland: Ta: Valkeakoski, S of Lotilanjärvi. 61.26 ° N / 24.00 ° E, ex? Phellinus ignarius (s.l.)/ Betula with Dorcatoma punctulata , coll. 8 April 2006, em. April- June [20]06 (indoors), N. R. Fritzén & I. Österblad’’ (NMS). Paratypes (6 females + 14 males): 2 females + 7 males, same data as holotype (NMS, RMNH); 1 female, id., but ex Phellinus tremulae /Populus tremulus with Dorcatoma lomnickii and D. dresdensis (NMS) ; 1 female, id., but with D. punctulata and Cis alni (NMS) ; 2 males, id., but ex? Phellinus ignarius (s.l.)/ Betula with Dorcatoma dresdensis (NMS, RMNH) ; 1 male, id., but ex Phellinus pini on Pinus sp. (NMS); 1 female + 4 males: ‘‘ Finland: Om: Lohtaja, Korteperänräme. 63.91 ° N / 23.47 ° E, [ex] Phellinus ignarius (s.l.)/ Betula with Dorcatoma dresdensis , coll. February 2006, em. ca April [20]06 (indoors), N. R. Fritzén’’ (NMS, RMNH); 1 female, ‘‘ Finland: Oa: Korsholm, Jungsund. 63.18 ° N / 21.58 ° E, [ex] Fomes fomentarius with Dorcatoma dresdensis , [coll.] 2006, Ika Österblad’’ (NMS).

Note

It is a pleasure to name this species after one of the collectors of the holotype, Mr N. R. Fritzén (Sund), who reared important series of Braconidae from bracket fungi in Finland .

Figures

Figure 3. (A–E) Colastes (Fungivenator) fritzeni, holotype, female; (F) Colastes (Colastes) braconius Haliday, Belgium, near Antwerp, female. (A) Part of forewing; (B, F) head, lateral aspect; (C) apex of antenna; (D) hind leg; (E) first metasomal tergite, dorsal aspect. Scales: 1.0×scale bar (A); 1.5×(B); 1.9×(C); 1.1×(D); 1.3×(E); 2.0×(F).