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Revision of the World species of Xeris Costa (Hymenoptera: Siricidae)
CJAI 28 -- September 25, 2015
doi: 10.3752/cjai.2015.28
http://zoobank.org/References/1360ED3A-8330-43BD-B051-2DDBBBD76AA0
Henri Goulet1, Caroline Boudreault1 and Nathen M. Schiff2
2. Key to species of Xeris
1 A)

Vertex densely pitted and without or almost without smooth surfaces (Fig. B2.1).

 
B)

Maximum distance between outer genal edges shorter than maximum distance between outer edges of eyes (in frontal view outer edges of gena intersected by outer edges of eyes) (Fig. B2.4).

C)

Maximum eye height in lateral view 0.53–0.61 times maximum head height (measured from genal transverse ridge above mandible to top of head) (Fig. B2.6).

D)

Ventral surface of propleuron with clearly impressed meshes of microsculpture between teeth; sculpticells scale-like, dull between pits and teeth (Fig. B2.9).

E)

In female, apical section of sheath without longitudinal ridge between dorsal and ventral edges (Fig. B2.12, insert); sheath with basal section 0.5–0.6 times as long as apical section (Fig. B2.12).

 

[Additional characters. Lateral surface of pronotum with sharply reticulate pattern around one or more pits (Fig. B2.15); ovipositor with a pit on each annulus anterior to teeth annuli and each pit large and extending anteriorly toward preceding annulus as a shallow furrow (Fig. B2.16); sheath with junction of basal and apical sections aligned between annuli 8 and 9 of ovipositor. Note. All known hosts are Cupressaceae. Range. Western United States between Washington and California.]

   
a)

Vertex less densely pitted, with obvious smooth surfaces on outer sides of median furrow (Figs. B2.2 and B2.3).

 
b)

Maximum distance between outer genal edges slightly or very clearly wider than maximum distance between outer edges of eyes, thus, in frontal view, outer edge of gena not intersected by outer edges of eyes (Fig. B2.5).

c) Maximum eye height in lateral view at most 0.54 times maximum head height (measured from genal transverse ridge above mandible) (Figs. B2.7 and B2.8).
d)

Ventral surface of propleuron without or with lightly impressed meshes of microsculpture, shiny between pits and teeth (Figs. B2.10 and B2.11).

e)

In female, apical section of sheath with longitudinal ridge between dorsal and ventral edges (insert in Fig. B2.13, insert); sheath with basal section at most 0.46 times as long as apical section (Figs. B2.13 and B2.14).

 

[Note. Known hosts are almost always Pinaceae except one of the recorded hosts of X. malaisei (Pinaceae and Cupressaceae).]

   
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2(1) A)

Gena dorsal to mandible with broadly rounded and coarsely pitted transverse ridge (Fig. B2.17).

 
B)

Distance between lateral ocellus and nearest eye edge about 1.0 (Fig. B2.19).

C)

Propleuron in ventral view densely pitted (Distance between lateral ocellus and nearest eye edge about 1.0 (Fig. B2.21).

D)

In female, femora black, tibiae and metatarsomere 1 light reddish brown in basal 0.1 (Fig. B2.23).

  [Additional characters. Gena below eye and genal ridge (including adjacent occiput) densely pitted Figs. B2.27 and B2.28; setae on frons and clypeus about twice as long as diameter of lateral ocellus (Figs. B2.27 and B2.28); female sheath with basal section 0.4 times as long as apical section (Fig. B2.29), with abdomen red, and with darkly tinted wings except for clear basal 0.5 of hind wing (Fig. B2.30). Note. The male is unknown, but characters A, B and C probably apply. Range. Southernmost Mexico in the state of Chiapas.]
   
a) Gena dorsal to mandible with sharp and smooth transverse ridge (Fig. B2.18).  
b)

Distance between lateral ocellus and nearest eye edge 1.15–1.50 times distance between inner edges of lateral ocelli (Fig. B2.20).

c)

Propleuron in ventral view not sharply pitted or not pitted, surface in most specimens consisting of few to many isolated teeth ( Fig. B2.22)

d)

In female, femora varying from black to light reddish brown, tibiae and tarsi light reddish brown (Fig. B2.24), or tibiae and metatarsomere 1 black but light reddish brown in at least basal 0.3 (Figs. B2.25 and B2.26).

   
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3(2) A)

Gena below eye and genal ridge (including adjacent occiput) densely pitted (Fig. B2.31, black arrow).

 
B)

Clypeus with setae 1.0–1.5 times as long as diameter of lateral ocellus (Fig. B2.33, red arrow) and vertex quite densely pitted between dorsal edge of eye and occiput outside postocellar area (Fig. B2.33, black arrow).

 
  [Additional characters. Flagellum black (as in Fig. B2.35). Pronotum in dorsal view with a yellowish-white longitudinal band along margin between anterolateral to posterolateral angles (Fig. B2.36). In male, base of metatibia with clearly outlined white spot [not present in other Nearctic species (Fig. B2.38). Abdomen black (Fig. B2.37). Range. Arizona and Colorado in southwestern United States.]  
   
a)

Gena below eye and genal ridge smooth, without or with very few pits (Fig. B2.32, black arrow).

 
b) Clypeus with setae 0.6–0.7 times as long as diameter of lateral ocellus (Fig. B2.32, red arrow), or setae 1.0–1.4 times as long (only X. umbra) (Fig. B2.34, red arrow) and vertex pits scattered between dorsal edge of eye and occiput ouside postocellar area (Fig. B2.34, black arrow).  
   
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4(3) A)

Fore wing with cell C darkly tinted (yellowish brown to dark brown) and with base of stigma on both sides of junction with vein 1r-rs black or somewhat paler (as in Fig. B2.39).

 
B)

Vertex with pits denser (usually touching) and bigger (0.2–0.5 times diameter of lateral ocellus) between dorsal edge of eye and occiput outside postocellar area (Fig. B2.41) or pits as in "b" (Fig. B2.42) and fore wing cell C color as in "A".

   
a)

Fore wing cell C very lightly tinted (yellowish white) and with base of stigma on both sides of junction with vein 1r-rs clearly white or yellowish white (Fig. B2.40).

 
b) Vertex with pits sparser (usually not touching) and smaller (0.05–0.25 times diameter of lateral ocellus) between eye dorsal edge and occiput outside postocellar area (Fig. B2.43).  
    [Range. Europe and Asia.]  
     
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5(4) A)

Vertex between dorsal edge of eye and occiput outside postocellar area with dense (usually touching) and big pits (0.2–0.5 times diameter of lateral ocellus) (Fig. B2.44).

 
B)

Gena with pits between eye outer edge and genal ridge large (0.2–0.4 times diameter of lateral ocellus) (Fig. B2.46).

C)

In female, procoxa black (Fig. B2.48) and flagellum black (as in Fig. B2.50) or partly to completely light reddish brown (Figs. B2.51 and B2.52), or procoxa light reddish brown (Fig. B2.53) and flagellum completely light reddish brown (Fig. B2.52).

D) In female, pronotum in dorsal view black or with a yellowish-white spot at anterolateral corner not extending to posterolateral corner (Figs. B2.54 and B2.55).
E)

In male, pronotum in dorsal view black or black with a yellowish-white anterolateral spot at most extending posteriorly but not reaching posterolateral corner and much narrower posteriorly (Figs. B2.57 and B2.58).

     
a)

Vertex between dorsal edge of eye and occiput outside postocellar area with pits sparse (rarely touching) and smaller (0.2–0.25 times diameter of lateral ocellus) (Fig. B2.45).

 
b)

Gena with pits between eye outer edge and genal ridge smaller (0.05–0.15 times diameter of lateral ocellus) (Fig. B2.47).

c) In female, procoxa light reddish brown (Fig. B2.49) and flagellum black (as in Fig. B2.50).
d) In female, pronotum in dorsal view black with a yellowish-white longitudinal band between anterolateral corner and posterolateral corner (Fig. B2.56).
e) In male, pronotum in dorsal view black with a longitudinal yellowish-white band between anterolateral and posterolateral corners (as in Fig. B2.59).
  [Range. North America.]
   
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6(5) A)

Abdomen reddish brown (Fig. B2.60), or black and matching state of following characters (Fig. B2.61).

 
B) In female, flagellum partly or completely light reddish brown (Figs. B2.62 and B2.63).
C) In female, fore wing completely to mainly darkly tinted (Fig. B2.65), or with darkly tinted central and apical bands (old specimens maybe bleached and difficult to evaluate for this feature) (Fig. B2.66).
D) In male, metatibia black or with an indistinct reddish-brown or brown spot at base (Figs. B2.68 and B2.69).
 

[Range. North America.]

   
a)

Abdomen black (as in Fig. B2.61).

 
b)

In female, flagellum black (as in Fig. B2.64).

c) In female, fore wing clear or with very lightly tinted central and apical bands (as in Fig. B2.67).
d)

In male, metatibia clearly yellowish white at base (as in Fig. B2.70).

  [Range.Morocco (Rif), Western Himalaya.]
   
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7(6) A)

In female, coxae, trochanters and femora black (Fig. B2.71).

 
B) In female, flagellum brown or black in basal 0.3, gradually becoming light reddish brown in apical 0.7 (Fig. B2.73).
C)

Gena narrow, its maximum length from eye to genal ridge 0.40–0.50 times as long as maximum eye length (Fig. B2.76).

  [Range. Arizona and Colorado in southwestern United States.]
   
a)

In female, coxae mainly black to mainly reddish brown, trochanters and femora light reddish brown (Fig. B2.72).

 
b)

In female, flagellum brown or black in basal 0.7 and light reddish brown in apical 0.3 (Fig. B2.74), or completely light reddish brown (Fig. B2.75).

c)

Gena wide, its maximum length from eye to genal ridge 0.50–0.70 times as long as maximum eye length (Fig. B2.77).

   
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8(7) A)

Abdomen black (Fig. B2.78).

 
B)

In female, flagellum light reddish brown in apical 0.3 (rarely completely light reddish brown) (Fig. B2.80).

  [Range. Forested regions of western Canada and United States.]
   
a)

Abdomen reddish brown (Fig. B2.79) and

 
b)

In female, flagellum completely light reddish brown (Fig. B2.81).

   
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9(6) A)

In female, fore wing with darkly tinted central and apical bands (Fig. B2.82).

 
 

[Note. Males of X. indecisus and X. degrooti are indistinguishable. Only X. indecisus is recorded from southern British Columbia, Washington, northern Idaho, Montana, western Oregon, and California. In the central portion of the Rocky Mountain ranges both species are sympatric.]

   
a)

In female, fore wing completely darkly tinted (Fig. B2.83).

 
 

[Note. Specimens from at least South Dakota and probably those from Wyoming, Utah, eastern Nevada, Colorado, New Mexico and Arizona could belong to X. degrooti. However, both species may be sympatric in this region. Neither males nor females could be distinguished morphologically despite a remarkable 9% difference between their barcodes.]

   
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10(6) A)

Clypeus in lateral view with setae about 0.6–0.7 times as long as diameter of lateral ocellus (Fig. B2.84).

 
B) In female, coxae mainly light reddish brown (Fig. B2.86).
 

[Range. Morocco, Tizi-Ifri and Talasse N'Tane.]

     
a)

Clypeus in lateral view with setae about 0.7–1.2 times as long as diameter of lateral ocellus (Fig. B2.85).

 
b) In female, coxae black (Fig. B2.87).
   

[Range. High elevations in Pakistan, India, Nepal and China.]

     
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11(5) A)

In female, sheath with basal section more than 0.27 times length of apical section (if 0.25–0.27, use characters B and C) (Fig. B2.88).

 
B)

In most females, tergum 10 with meshes of microsculpture lightly impressed on laterobasal angle in dorsal view (Fig. B2.90).

C)

In most females, abdominal tergum 9 in lateral view with meshes of microsculpture clearly impressed with scale-like sculpticells on surface posterior to and above lateral furrow, thus surface slightly dull (Fig. B2.92).

 

[Range. Recorded from central Alberta to Nova Scotia and south (east of Prairie region) to Minnesota and Maine. This species and X. caudatus are sympatric in the central regions of Alberta and Saskatchewan. Note. Males cannot be recognized on morphological features, but can be distinguished by their barcodes.]

   
a)

In female, sheath with basal section less than 0.25 times length of apical section (if 0.25–0.27, use characters b and c) (Fig. B2.89).

 
b)

In most females, tergum 10 without meshes of microsculpture on laterobasal angle in dorsal view (Fig. B2.91).

c)

In most females, abdominal tergum 9 in lateral view with meshes of microsculpture not well impressed, with sculpticells almost flat and somewhat scale-like on surface posterior to and above lateral furrow, thus surface shiny (Fig. B2.93).

  [Range. Recorded from the Rocky Mountains to the Pacific coast between Alaska and California but also occurring east of the Rocky Mountains in Alberta and Northern Saskatchewan. This species and X. melancholicus are sympatric in the central regions of the above two provinces. Note. Males cannot be recognized on morphological features, but can be distinguished by their barcodes.]
   
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12(4) A)

Pronotum in dorsal view with yellowish-white longitudinal band very smooth between large teeth (Fig. B2.94).

 
B)

Pronotum in lateral view almost entirely without coarse pits (pit base slightly to clearly raised as a tooth or cone and not fused with nearby teeth) (Fig. B2.96).

C)

In female, coxae light reddish brown (Fig. B2.98).

 

[Additional characters. In male, gena with yellowish-white spot large, almost always sharply outlined, and extending to genal ridge but not behind ridge on occiput (Fig. B2.100); hind leg with metafemur reddish brown to completely black, apex of metatarsomere 1 narrowly reddish brown, and in most males, with black central transverse band on metatarsomere 2 (Fig. B2.101). Range. Central Europe.]

   
a)

Pronotum in dorsal view with surface of lateral margin (usually margin yellowish

white) bearing small ridges between large teeth (Fig. B2.95).

 
b)

Pronotum in lateral view with coarse reticulate pits over 0.3–0.9 of surface (Fig. B2.97).

c)

In female, coxae black, at least on outer surface (Fig. B2.99).

   
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13(12) A)

Clypeus with setae 1.0–1.4 times as long as length of lateral ocellus (Fig. B2.102).

 
B)

Metanotum posterior to cenchrus and on lateral 0.5 of metascutellum with fine, isolated pits (Fig. B2.104).

C)

In female, trochanters black, pro- and mesofemur brown, metafemur mostly black, and tarsomeres 1 (in apical 0.5) and all of tarsomeres 2–5 black, tibiae and basal 0.5 of metatarsomere 1 light reddish brown (Fig. B2.106).

D)

In female, tergum 10 in dorsal view with teeth along lateral margin in apical 0.3 very small but larger toward apex (Fig. B2.109).

E) In male, pro- and mesotibiae black or at most clearly or indistinctly yellowish white in basal 0.1 (Fig. B2.111).
  [Additional characters. In female, flagellum black (Fig. B2.113). Range. China, Yunnan.]
   
a)

Clypeus with setae 0.6–0.7 as long as length of lateral ocellus (Fig. B2.103).

 
b)

Metanotum posterior to cenchrus and on lateral 0.5 of metascutellum with coarse, dense and usually polygonal pits (Fig. B2.105).

c)

In female, legs below coxae light reddish brown (Fig. B2.107), or metafemur mostly black, tarsomeres (apical 0.6) and all of tarsomeres 2–5 black, tibiae in basal and apical 0.3 and mesofemur light reddish brown (Fig. B2.108, hind leg).

d)

In female, tergum 10 in dorsal view with teeth along lateral margin in apical 0.3 large (Fig. B2.110).

e) In male, pro- and mesotibia clearly yellowish white in basal 0.5–0.6 and quite sharply separated from black apex (Fig. B2.112).
 

[Note. The male of X. xanthoceros (couplet 17) is unknown. Characters “a” and “b” probably apply.]

   
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14(13) A)

In female, flagellum black (Fig. B2.114).

 
B)

In male, tarsomeres 2–5 light reddish brown (metatarsomere 2 may have an indistinct dark central spot) (Fig. B2.118).

C)

In male, metatarsomere 1 black, but broadly reddish brown at apical margin (Fig. B2.120).

D) In male, metafemur (almost always) and trochanter reddish brown (Fig. B2.122).
 

[Additional characters. Tergum 10 with surface anterior to anus often light reddish brown (Fig. B2.124). Range. Transpalaearctic, mainly in cold temperate and boreal regions.]

   
a)

In female, flagellum light reddish brown in apical 0.3–0.7 (Fig. B2.115, B2.116 and B2.117).

 
b)

In male, at least tarsomeres 5 dark brown or black and usually tarsomeres 2–5 dark brown or black (Fig. B2.119).

c)

In male, metatarsomere 1 black to apex, at most narrowly reddish brown at apical margin (Fig. B2.121).

D)

In male, metafemur and trochanter black (Fig. B2.123).

 

[Note. The male of X. xanthoceros (couplet 17) is unknown. Character “b”, “c” and “d” are likely to apply. Range. Eastern Asia from extreme southeastern Russia to Laos and Taiwan.]

   
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15(14) A)

Pronotum in lateral view with deep and coarse polygonal pits on about 0.9 of surface (Fig. B2.125).

 
B)

In female, flagellum black in basal 0.5 (7 or 8 basal flagellomeres) and light reddish brown apically (Fig. B2.127).

C)

In male, gena with yellowish-white spot large, sharply outlined, and extending to genal ridge and clearly behind ridge on occiput (spot comma-like) (Fig. B2.130).

D)

In male, pro- and mesotarsomeres 1 light reddish brown (Fig. B2.132).

 

[Range. Laos, Huaphan.]

   
a)

Pronotum in lateral view with coarse polygonal pits on posterior 0.5 of surface (as in Fig. B2.126).

 
b)

In female, flagellum black either in basal 0.3 (Fig. B2.129) or in basal 0.7 (Fig. B2.128) and light reddish brown apically.

c)

In male, gena with yellowish-white spot large, sharply (rarely indistinctly) outlined, and extending to genal ridge but not behind ridge on occiput (Fig. B2.131).

d) In male, pro- and mesotarsomeres 1 light reddish brown in basal 0.1–0.8 and black thereafter (Fig. B2.133).
  [Note. The male of X. xanthoceros (couplet 16) is unknown. Character "a" probably applies, but character states "c" and "d" may not apply.]
 

 

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16(15) A)

Pronotum medially in dorsal view with a wide shiny surface and with a deep impression near center (Fig. B2.134, insert).

 
B)

In female, flagellum black in basal 0.7–0.75 (9–10 basal flagellomeres) and light reddish brown apically (Fig. B2.136).

C) In female, last labial paplpomere black (Fig. B2.138).
D)

In female, tergum 8 dull over surface (sculpticells scale-like at or near lateral edge) (as in Fig. B2.140).

  [Additional character. In female, pronotum in dorsal view along lateral margin with a yellowish-white band (usually wide except at high elevation) (Fig. B2.142). Range. China (northeastern region), Japan (Hokkaido and Honshu), Russia (Primorsky Kray), South Korea, and Taiwan (high elevation).]
   
a)

Pronotum medially in dorsal view with a narrow shiny surface and without an impression near center Fig. B2.135).

 
b) In female, flagellum black in basal 0.3 (3 or 4 basal flagellar segments) and light reddish brown beyond flagellomere 4 (Fig. B2.137).
c) In female, last labial paplpomere reddish brown (Fig. B2.139).
d) In female, tergum 8 shiny along most of lateral margin (sculpticells flat or meshes absent) (Fig. B2.141).
  [Note. The male of X. xanthoceros is unknown, characters "16 a", “14c” and “14d” probably applies. Additional characters. In female, pronotum black except for a trace of a pale narrow spot along margin of anterolateral corner (Fig. B2.143). Range. China, Yunnan.]
   

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