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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
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Key to Sirex - Females
1. A) Metafemur black (Fig. B2.1).  
   
a) Metafemur light reddish brown (Fig. B2.2).  
  [Doubtful specimens from Alaska and Yukon key out through both parts of the couplets]  
   
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2(1). A) Metatarsomere 2 4-5 times as long as high (Fig. B2.3).  
B) Sheath with basal section relative to apical portion less than 0.8 (Fig. B2.5).
C) Ovipositor with more than 38 annuli.
  [Additional character. Fore wing vein 3A clearly present.]
   
a) Metatarsomere 2 1.5-3.5 times as long as high (Fig. B2.4).  
b) Sheath with basal section relative to apical portion greater than 0.9  (Fig. B2.6).
c) Ovipositor with fewer than 37 (usually 29-31) annuli.
   
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3(2). A) Tibiae and tarsi reddish brown (Fig. B2.7).  
B) Ovipositor with 13-18 annuli outlined by annulus line only (Fig. B2.11) followed more distally by 23-28 annuli with pits before teeth annuli (Fig. B2.9); 10–15 annuli (anterior to teeth annuli at apex of ovipositor) each with a ridge extending from pit to ventral margin (Fig. 2.9).
C) Sheath with basal section relative to apical section less than 0.53 (if between 0.53 and 0.61, use only A and B) (See Fig. B2.5 for measurements).
   
a) Tibiae and tarsi dark brown or black (Fig. B2.8).  
b) Ovipositor with all annuli before apical teeth annuli with pits (Fig. B2.12); 5–7 annuli (anterior to teeth annuli at apex of ovipositor) each with a ridge from pit to ventral margin (Fig. B2.10).
c) Sheath with basal section relative to apical section greater than 0.61 (if between 0.53 and 0.61, use only a and b) (See Fig. B2.5 for measurements).
   
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4(2). A) Abdomen mostly reddish brown and abdominal segment 10 entirely light reddish brown (Fig. B2.13).  
B) Gena behind eye with a weakly outlined ridge (rounded and not sharp) (Fig. B2.16).
C) Ovipositor pits (if necessary, remove apical section of sheath to see pits) 0.2 times as long as an annulus near middle or aligned with base of apical section of sheath (Fig. B2.18), and tibiae black and tarsi reddish brown.
  [Additional character. Fore wing vein 3A present and extended along posterior wing margin. Ovipositor with very small pits at base.]
   
a) Abdomen black (Fig. B2.14), or mostly reddish brown and abdominal segment 10 with cornus black at least apically (Fig. B2.15).  
b) Gena behind eye without ridge (Fig. B2.17).
c) Ovipositor pits (if necessary, remove apical section of sheath to see pits) 0.12 times as long as an annulus (Figs. B2.20 & B2.21), or 0.3-0.7 times as long as an annulus near middle or aligned with base of apical section of sheath (Fig. B2.19), or if as C then tibiae light reddish brown.
   
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5(4). A) Metatarsomere 2 with tarsal pad slightly shorter than ventral length of tarsomere (Fig. B2.22).  
B) Ovipositor without pits in basal 0.4-0.5 or pits very small at base (Fig. B2.24).
C) Tibiae and tarsi light reddish brown (Fig. B2.26) and abdomen black with dark blue metallic reflections (Fig. B2.29), or tibiae and tarsi completely black (one specimen from Alaska).
D) Specimen from Alaska, Yukon, north of central Alberta and probably northernmost British Columbia.
  [Additional character. Head dorsally with diameter of pits 0.15-0.25 that of lateral ocellus.]
   
a) Metatarsomere 2 with tarsal pad about half as long as ventral length of tarsomere (Fig. B2.23).  
b) Ovipositor with medium to large pits on all annuli before teeth annuli (Fig. B2.25).
c) Tibiae and tarsi black (Fig. B2.27), or light reddish brown (Fig. B2.28) and most of abdomen reddish brown (Fig. B2.30).
d) Specimen clearly south or east of region described in D.
   
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6(5). A) Fore wing darkly tinted (Fig. B2.31a) or clear with darkly tinted bands near middle and apex (Fig. B2.31b).  
   
a) Fore wing clear and slightly yellow tinted (Fig. B2.32).  
   
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7(6). A) Gena in lateral view (Fig. B2.33) and in dorsal view (Fig. B2.35) with most pits relatively larger and 0–1 diameters apart (only a few pits farther apart).  
B) Ovipositor pits near base (e.g., annuli 3–5) as long as pits of middle annuli or pits aligned with base of apical sheath section (0.3 or more than 0.37 times as long as annulus) (Fig. B2.37).
   
a) Gena in lateral view (Fig. B2.34) and in dorsal view (Fig. B2.36) with most pits relatively smaller and 1–3 diameters apart (rarely, pits touching).  
b) Ovipositor pits near base (e.g., annuli 3–5) shorter (about 0.25 as long as annulus) than pits of middle annuli or pits aligned with base of apical sheath section (about 0.3 times as long as annulus) (Fig. B2.38).
   
    [Note. Adults of this species exist in two color forms. The dark-legged form keys out here. The pale-legged form keys out in couplet 13.]  
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8(7). A) Metatarsomere 2 in lateral view about 1.5 times as long as high (Fig. B2.39), and ventral tarsal pad about 0.5-0.7 times as long as tarsomere.  
B) Mesoscutum with discal pits usually without tooth-like processes except at middle; some processes fused laterally into irregular transverse ridges (Fig. B2.41).
C) Abdomen black.
D) Ovipositor with pits near middle or pits aligned with base of apical section of sheath (if necessary, remove apical section of sheath to see pits) about as long as high and small, their length 0.3 as long as annulus (Fig. B2.43).
   
a) Metatarsomere 2 in lateral view 2.0-2.5 times as long as high (Fig. B2.40), and ventral pad 0.3-0.5 times as long as tarsomere.  
b) Mesoscutum with most discal pits with tooth-like processes; most processes fused in many directions forming a net-like pattern (Fig. B2.42).
c) Abdomen black or mainly reddish brown.
d) Ovipositor with pits near middle or pits aligned with base of apical section of sheath (if necessary, remove apical section of sheath to see pits) 1.4–1.8 times as long as high and their length 0.37–0.45 as long as annulus (Fig. B2.44).
   
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9(6). A) Femora brown.  
B) Mesoscutum with most discal pits with processes; processes usually fused in many directions forming a net-like pattern (Fig. B2.45).
C) Fore wing without vein 3A (Fig. B2.47).
D) Ovipositor with pits (if necessary, remove apical section of sheath to see pits) near middle or aligned with base of apical section of sheath about 3.0 times as long as wide, their anterior end long and furrow-like (Fig. B2.49).
E) Ovipositor thin and long: annulus length divided by ovipositor diameter at annulus between pits 1 and 2 = 1.9–2.4, and between pits 12 and 13 = 1.5–2.1 (Fig. B2.51).
   
a) Femora black though sometimes dark brown dorsally.  
b) Mesoscutum with most discal pits usually mainly round with tooth behind large pits; some processes fused laterally into irregular transverse ridges (Fig. B2.46).
c) Fore wing with vein 3A (Fig. B2.48).
d) Ovipositor with pits (if necessary, remove apical section of sheath to see pits) near middle or pits aligned with base of apical section of sheath 1.2–1.3 times as long as wide, their anterior end not extended as narrow furrow  (Fig. B2.50).
e) Ovipositor thick and short: annulus length divided by ovipositor diameter at annulus between pits 1 and 2 = 1.3, and between pits 12 and 13 = 1.0 (Fig. B2.52).
   
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10(1). A) Abdomen posterior to segment 2 or 3 almost completely reddish brown (Fig. B2.53).  
B) Gena (Fig. B2.55) and vertex (Fig. B2.57) with pits large (diameter 0.3-0.4 times that of lateral ocellus) and dense (on gena and vertex pits 0.0-0.5 pit diameter apart).
C) Metatarsomere 2 1.7 times as long as high (Fig. B2.59).
  [Additional characters. Metatarsomere 2 in ventral view with tarsal pad 0.9 times as long as tarsomere. Sheath with apical section clearly shorter than basal section, their junction aligned between 15th and 16th annuli of ovipositor. Cornus in dorsal view short and clearly angular.]
   
a) Abdomen black with dark blue metallic reflections (Fig. B2.54).  
b) Gena (Fig. B2.56) and vertex (Fig. B2.58) with pits smaller (diameter 0.1-0.25 that of lateral ocellus) and scattered (on gena pits between 4-10 pit diameters apart, and on vertex 2-8 pit diameters apart).
c) Metatarsomere 2 2.0-3.6 times as long as high (Fig. B2.60).
   
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11(10). A) Head posterodorsally with setae each with or without small pit at base (Fig. B2.61).  
B) Mesoscutum with most discal pits mainly round with tooth behind larger pits, giving a rasp-like pattern; few processes fused laterally into irregular transverse ridges (Figs. B2.63 & B2.64).
C) Metatarsomere 2 with tarsal pad 0.3–0.4 as long as tarsomere (Fig. B2.66).
D) Ovipositor pits (if necessary, remove apical section of sheath to see pits) near middle or pits aligned with base of apical section of sheath at least 0.5 as long as annulus length (Fig. B2.68).
  [Additional character. Metatarsomere 5 black or dark brown.]
   
a) Head posterodorsally with setae with large, clearly outline pit at base (Fig. B2.62).  
b) Mesoscutum with most discal pits with processes; processes usually fused in many directions forming a net-like pattern (Fig. B2.65).
c) Metatarsomere 2 with tarsal pad 0.4–0.5 or 0.8 times as long as tarsomere (Fig. B2.67).
d) Ovipositor pits (if necessary, remove apical section of sheath to see pits) near middle or pits aligned with base of apical section of sheath 0.1–0.4 times as long as annulus (Figs. B2.69-B2.71).
   
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12(11). A) Tibiae light reddish brown and their dorsal surface almost always with dark blue with metallic reflections (Fig. B2.72).  
  [Additional characters. Ovipositor pits near middle or aligned with base of apical section of sheath (if necessary, remove apical section of sheath to see pits) 1.5–2.0 times as long as wide and 0.3–0.4 times as long as length of annulus (Fig. B2.71). Fore wing clear, faintly yellow tinted, and without dark bands at middle and apex.]
   
a) Tibiae completely light reddish brown (Fig. B2.73).  
   
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13(12). A) Fore wing clear with dark bands at center and apex or completely darkly tinted (Fig. B2.74).  
B) Metarsomere 5 completely black (Fig. B2.76).
C) Metatarsomere 2 with tarsal pad about 0.5 times as long as ventral length of tarsomere (Fig. B2.78).
D) Ovipositor pits near middle portion or aligned with base of apical section of sheath 1.5-2.0 times as long as wide and 0.3-0.4 as long as length annulus (Fig. B2.80).
   
    [Note. This species has two color forms: the pale-legged form keys out here, and the dark-legged form in couplet 7.]  
a) Fore wing clear, faintly yellow tinted, and with at most a dark band at apex (Fig. B2.75).  
b) Metarsomere 5 entirely light reddish brown or almost black in apical half (Fig. B2.77).
c) Metatarsomere 2 with tarsal pad about 0.8 times as long as ventral length of tarsomere (Fig. B2.79).
d) Ovipositor either without pits in basal 0.4–0.5, or pits present, almost as long as wide, and at most 0.25 times as long as annulus length (Figs. B2.81 & B2.82).
   
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14(13). A) Ovipositor pits near middle or pits aligned with base of apical section of sheath 0.15–0.25 as long as annulus and present even on annulus 2 but much smaller than pits at middle; ovipositor annulus lines clearly outlined in basal 0.3–0.4 (Fig. B2.83).  
  [Additional character. Lancet with length of annulus 10 1.27–1.85 times as long as width of ovipositor at this annulus.]
   
a) Ovipositor pits near middle portion or pits aligned with base of apical section of sheath 0.0–0.14 times as long as annulus and pits absent in basal 0.4–0.5 of ovipositor; ovipositor annulus lines in basal 0.3 weakly outlined near dorsal edge or not outlined at all (Fig. B2.84).  
   
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15(14). A) Sheath with basal section relative to apical section less than 0.87 (if between 0.87-1.0, use only B and C).  
B) Lancet with length of annulus 10 greater than 1.82 times as long as width of ovipositor at this annulus (if between 1.76-1.82, use A and C) [based on 26 specimens, we found no values below 1.85] (Fig. B2.85).
C) Cornus usually long (about 2.0 times as long as wide) and broad in basal half (Fig. B2.87).
   
a) Sheath with basal section relative to apical section greater than 1.0 (if between 0.87–1.0, use b and c).  
b) Lancet with length of annulus 10 less than 1.76 times as long as width of ovipositor at this annulus (if between 1.76–1.82, use a and c) [based on 40 specimens, we found no values above 1.77] (Fig. B2.86).
c) Cornus usually short (about 1.5 times as long as wide) and narrow in basal half (Fig. B2.88).