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Siricidae (Hymenoptera: Symphyta: Siricoidea) of the Western Hemisphere
CJAI 21, July, 2012
doi: 10.3752/cjai.2012.21
Nathan M. Schiff, Henri Goulet, David R. Smith, Caroline Boudreault, A. Dan Wilson, and Brian E. Scheffler

Genus Siricosoma Forsius

Fig. C33.1 (female habitus)

Siricosoma Forsius 1933: 173. Type species: Siricosoma tremecoides Forsius 1933: 174, by original designation. Smith 1978: 64.


We studied only one female and we assumed that the following character states apply to both sexes except for those sex-specific characters like the ovipositor and its sheath.

Head. Minimum distance between eyes as long as maximum height of eye (Fig. B1.13), distance between inner edges of antennal sockets about 3.7 times as long as distance between outer edge of antennal socket and nearest edge of eye (Fig. B1.13), distance between inner edges of lateral ocelli subequal to distance from outer edge of posterior ocellus to the nearest edge of eye (Fig. B1.13); maximum eye height 1.6 time as high as its maximum length. Head with setae sharp at apex. Antenna flattened dorsoventrally, with 23 flagellomeres; and flagellomere 1 in lateral view 1.2 times as long as flagellomere 2 (Fig. C33.2).

Thorax. Mesoscutum entirely finely pitted (Fig. C33.1). Fore wing with vein 2r–m joined to cell 2M (as in Fig. B1.71), with the vein 2r–m present, with vein 1cu–a closed to vein M (joining vein Cu in the basal 0.2 between veins 1m–cu and M), and vein M markedly curved (Fig. B1.9), with cell 2R1 0.4 times as long as cell 3R1, with vein 2r-rs joining stigma near middle, with stigma gradually attenuated to apex even after junction with vein 2r-rs (as in Fig. B1.25), with vein 2A along the wing posterior edge for 0.6 times cell length (Fig. B1.7), with vein Sc as well as Sc1 and Sc2 in basal 0.4, and without vein 3A. Hind wing without anal cell, with hamuli present equally basal and apical to junction with veins R1 and C, with vein 1r–m slightly longer than vein M, and with vein M curved.

Abdomen. Female. Tergum 9 with median basin with numerous setae, each seta on raised base. Cornus 2.3 times as long as median basin length, parallel sided, not constricted near base (Fig. B1.21), and cercus about as long as 0.5 width of ovipositor sheath (Fig. B1.19). Sheath. Length of basal section 1.25 times as long as apical section; length of sheath 0.8 times as long as fore wing length, its apical section without teeth dorsoapically, but with teeth on lateral surface in apical 0.25 (Fig. B1.19). Ovipositor. Lancet with annuli only in apical 0.25, and each annulus with wide and prominent ventral tooth along edge, with small pit anteriorly and sharp ridge posteriorly, with small and narrow dorsal tooth attenuating posteriorly, and with a deep trough in between (Fig. B1.19).


Only one species is known, S. tremecoides Forsius from the Malay Peninsula. We have examined one female (AEI) from Pasoh Forest Reserve, Nigri S. [probably the state of Nigri Semiblan], Malaysia, collected on June 26, 1979 in a forest by P. and M. Becker.