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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

Urocerus sah (Mocsáry)

Fig. C26.1, Schiff et al. 2006: 75, 76 (female habitus)
Fig. C26.2 (male habitus)
Fig. C26.3 (map)

Sirex Sah Mocsáry, 1881: 36. Holotype female (HNHM), not examined. Type locality: “Persia”.
Sirex Shach; Mocsáry, 1881 (misspelling).
Urocerus augur sah; Benson, 1943: 41 (change in combination and rank).
Urocerus sah; Smith 1978: 81 (change in combination).


Diagnostic Combination

Both sexes of U. sah are recognized by very few pits on the vertex (without pits except narrowly behind edge of eye, and along postocellar and median furrows). Females also have light reddish brown protarsomeres 2–5, a reddish brown pronotum, and a light reddish brown apical 0.5 of tergum 9. Males also have a large genal spot extending from the ventral margin of eye to the postocellar furrow.

Description

FEMALE

Color. Head capsule almost completely reddish brown except for white spot behind eye extending from ventral edge of eye almost to median furrow of postocellar surface (Fig. B4.13). Maxillary palp and mandible brown or black. Scape and pedicel more or less brown; flagellum light reddish brown and apex of last flagellomere not darkened. Thorax black or brown, but reddish brown on most of dorsal surface of pronotum (Fig. B4.9) and dorsal half of mesepisternum. Coxae black; profemur reddish brown on posterior surface, mesofemur brown at base and gradually shifting to light reddish brown toward apex; and metafemur almost completely black except at extreme apex (Fig. B4.11, hind leg); pro- and mesotibia and tarsi light reddish brown; metatibia in apical 0.7 black and light yellow in basal 0.3 (Fig. B4.11, hind leg); metatarsomere 1 light reddish brown in basal 0.5 and brown in apical 0.5, otherwise tarsomeres 1–5 reddish brown. Fore and hind wings clearly yellow tinted. Abdomen black, but light reddish brown on terga 1, 2 (at least basal 0.5), 8 (basal 0.5), 9 (apical 0.5 dorsally), and 10 (including cornus) (Fig. B4.7).

Head. Vertex not pitted except narrowly behind eye, along postocellar and median furrows, but densely pitted (diameter of pits about 0.2 times that of ocelli) on frons to posterior ocelli (Fig. B4.13).

Thorax. Metatarsomere 2 in lateral view about 2.0 times as long as high, and its tarsal pad about 0.8 as long as ventral length of tarsomere.

Abdomen. Median basin of tergum 9 with base (outlined by two lateral black longitudinal furrows) about 1.7 times as wide as median length, with maximum width about 1.9 times as wide as median length, and with median length about 0.4 times cornus length. Cornus in dorsal view constricted near base, and minimum width of constriction about 0.75 times maximum width subapically. Tergum 8 with microsculpture of sublateral surface (between spiracle and pitted sculpticells on central area) with meshes and sculpticells flat; tergum 9 with dorsal surface lateral to median basin smooth and without meshes, and ventral surface with meshes and flat sculpticells. Sheath. Length as long as fore wing, apical section about 1.5 times as long as basal section. Ovipositor. Lancet with about 34 annuli (annuli in basal 0.5 of lancet outlined but difficult to see); junction of basal and apical section of sheath aligned between 6th and 7th annuli; lancet with about 30 pits. Pits 0.2–0.3 times as long as an annulus, becoming gradually small, and disappearing at base of basal sheath section (lacking on annuli 2–4). Edge of about last 11 annuli before teeth annuli extending as ridge to ventral margin of lancet.

MALE

Color. Head capsule black, except white genal spot extending from about ventral edge of eye to postocellar furrow (Figs. B4.54 & B4.56). Flagellum ranging from black to light reddish brown (usually paler in basal half). Thorax black except for small pale spot at anterodorsal angle. Coxae black; profemur reddish brown on posterior surface, mesofemur brown at base and gradually shifting to light reddish brown toward apex; and metafemur mainly black except in apical 0.25 (Fig. B4.58, hind leg); pro- and mesotibia and tarsi light reddish brown; metatibia and metatarsomere 1 brown or black and narrowly reddish brown at base and apex; metatarsomere 2–5 light reddish brown (Fig. B4.58, hind leg). Abdomen light reddish brown except black on terga 1 (partly or completely), 6–8 or 7 and 8, sterna 2, 6–9 or 7–9 (Fig. B4.60).

Head. Vertex not pitted except narrowly behind edge of eye, and along postocellar and median furrows (Fig. B4.54). Surface ventral to genal white spot scarcely pitted (Fig. B4.56).

Thorax. Metatibia about 6.0 times as long as maximum width. Metatarsomere 1 in lateral view about 5.0 times as long as maximum height (Fig. B4.58).

Taxonomic Notes

Smith (1987) was the first to recognize this adventive species, known from North Africa, Asia Minor, and as far east as Afghanistan. The species as been treated as U. augur sah. More recently, this subspecies has been regarded as specifically distinct from U. augur. Smith (1978) accepted this, especially because U. sah and U. augur are sympatric, at least in Asia Minor. Two subspecies cannot be sympatric; therefore, U. augur and U. sah are specifically distinct.

Biological Notes

Over the years males of U. sah were observed aggregating at the highest spot of Mount Rigaud, Quebec (about 220 m above the plain). On June 15, 2011, 200 to 300 specimens were observed. Although no female were captured, we assume that both sexes mate there.

Hosts and Phenology

Urocerus sah was reared from Pinaceae (Abies sp., Picea sp., and Pinus sp.). No specimens have been reared in North America.

Based on 15 field-collected specimens, the capture dates are June 15, June 22, July 11, August 22 and September 7.

Range

CANADA: QC (Rigaud). USA: NH (Smith 1987: Rocking Co, Newmarket 1 female; Durham).  Urocerus sah, an adventive species, is known from very few localities in eastern North America (Fig. C26.3).

Specimens studied and included for the distribution map: 3 females and 15 males from CNC, DENH, and USNM.