Siricidae of the Western Hemisphere; Schiff, Goulet, Smith et al.; 2012

Key to genera of Siricidae
Key to Sirex species

Key to Tremex species
Key to Urocerus species

Key to Xeris species

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Key to Xeris Species

1.	A)	Gena in dorsal view with lateral angle not prominent (Fig. B5.1), the maximum distance between outer genal edges thus at most about as wide as maximum distance between outer edges of eyes (Fig. B5.3).
	B)	Maximum eye height in lateral view 0.53–0.61 times maximum head height (measured from genal ridge) (Fig. B5.5).
	C)	Female: tibiae black and tarsi light reddish brown (Fig. B5.8).
	D)	Female: sheath with length of basal section about 0.5 times length of apical section (Fig. B5.11); apical section without longitudinal ridge between dorsal and ventral edges (Fig. B5.11, insert).
	E)	Female: ovipositor with pits on each annulus anterior to teeth annuli at apex (Fig. B5.14) and each pit with anterior end extending toward preceding annulus as a shallow furrow (as in middle and apex Fig. B5.14); sheath with junction of basal and apical sections aligned between annuli 8 and 9 of ovipositor.
			Xeris tarsalis (Cresson, 1880)
–	a)	Gena in dorsal view with lateral angle more prominent (Fig. B5.2); the maximum distance between outer genal edges at least slightly wider than maximum distance between outer edges of eyes (Fig. B5.4).
	b)	Maximum eye height in lateral view at most 0.51 times maximum head height (measured from genal ridge) (Figs. B5.6 & B5.7).
	c)	Female: tibiae and tarsi similar in color: black (Fig. B5.9) or light reddish brown (Fig. B5.10).
	d)	Female: sheath with length of basal section at most 0.46 times length of apical section (Figs. B5.12 & B5.13); apical section with longitudinal ridge between dorsal and ventral edges (insert in Fig. B5.13).
	e)	Female: ovipositor with pit only on apical 5–7 annuli anterior to teeth annuli (very small pit may be present on one or more additional annuli anteriorly) (Fig. B5.15); each pit with anterior end sharp and round, and shorter than 0.5 times annulus length (as in apex Fig. B5.15); sheath with junction of basal and apical sections aligned between 2 and 3, 3 and 4, or 4 and 5 annuli.
			. . . . . . . . 2

2(1).	A)	Wings darkly tinted over most or all of surface (Fig. B5.16).
2(1).			. . . . . . . . 3
–	a)	Wings very lightly tinted or clear except for lightly tinted apical 0.25 (Fig. B5.17).
–			. . . . . . . . 5
		[Note. Some specimens of X. indecisus could key through either alternate of this couplet.]

3(2).	A)	Gena below eye and genal ridge (including adjacent occiput) densely pitted (Fig. B5.18).
	B)	Gena with transverse ridge dorsal to mandible, broadly rounded and coarsely pitted (Fig. B5.20).
	C)	Female: legs black (Fig. B5.22).
	D)	Female: sheath with basal section 0.4 as long as apical section (Fig. B5.24).
			Xeris tropicalis Goulet, n. sp.
		[Note. Male not known, but characters A and B will help recognizing it.]
–	a)	Gena below eye and genal ridge (including adjacent occiput) with or without a few pits, the surface shiny (Fig. B5.19).
	b)	Gena with transverse ridge dorsal to mandible narrow, sharp and mainly smooth (Fig. 5.21).
	c)	Female: at least tibiae and tarsi light reddish brown (Fig. B5.23).
	d)	Female: sheath with basal section at most 0.35 times as long as apical section (Fig. B5.25).
			. . . . . . . . 4

4(3).	A)	Gena narrow, its maximum length from eye to genal ridge at most 0.50 times as long as maximum eye length (Fig. B5.26).
	B)	Female: coxae and femora black (Fig. B5.28).
	C)	Female: flagellum brown or black in basal 0.3, gradually becoming light reddish brown in apical 0.6 (Fig. B5.30).
			Xeris morrisoni (Cresson, 1880)
–	a)	Gena wide, its maximum length from eye to genal ridge at least 0.50 times as long as maximum eye length (Fig. B5.27).
	b)	Female: coxae brown usually becoming reddish brown apically, and femora light reddish brown (Fig. B5.29).
	c)	Female: flagellum entirely light reddish brown (Fig. B5.31).
			Xeris indecisus (MacGillivray, 1893) [in part]
		[Note. Only females with reddish brown abdomen have darkly tinted wings and all are from southwestern United States or South Dakota.]

5(2).	A)	Vertex between eye and postocellar furrows with large, densely spaced pits over most of surface (many pits polygonal) (Fig. B5.32).
	B)	Gena below eye and genal ridge (including adjacent occiput) densely pitted; clypeus, face, frons and vertex with setae about 2.0 times as long as posterior ocellus (Fig. B5.34).
	C)	Female: coxae black and rest of legs light reddish brown (Fig. B5.36).
	D)	Male: metatibia with dorsal edge in lateral view very deeply indented in basal 0.3 (Fig. B5.39).
		[Additional character. Pronotum in dorsal view with broad white longitudinal band along the lateral margin between anterior and lateral angles.]
			Xeris chiricahua Smith, n. sp.
–	a)	Vertex between eye and postocellar furrows with mostly small, more sparsely spaced pits over most of surface (pits round) (Fig. B5.33).
	b)	Gena below eye and genal ridge (including adjacent occiput) with or without a few pits, the surface shiny; clypeus, face, frons and vertex with setae at most as long as posterior ocellus (Fig. B5.35).
	c)	Female: coxae either completely light reddish brown (Fig. B5.37) or brown shifting to reddish brown apically (Fig. B5.38).
	d)	Male: metatibia with dorsal edge in lateral view shallowly indented in basal 0.3 (Fig. B5.40).
			. . . . . . . . 6

6(5).	A)	Gena with white spot behind eye (very rarely absent) not extending to genal ridge (Fig. B5.41).
	B)	Gena with few, small pits between dorsal and ventral limits of genal ridge (Fig. B5.43).
	C)	Female: abdomen black and coxae completely light reddish brown except near articulation of coxa to thorax (Fig. B5.45).
	D)	Female: flagellum black, at most dark brown in apical 0.25 (Fig. B5.48).
	E)	Male: femora mainly or completely light reddish brown (Fig. B5.51).
		[Additional character. Pronotum in dorsal view with broad longitudinal band along lateral margin between anterior and lateral angles.]
			. . . . . . . . 7
–	a)	Gena with white spot behind eye large, extending to genal ridge (Fig. B5.42).
	b)	Gena with numerous, larger pits between upper and lower limits of genal ridge (Fig. B5.44).
	c)	Female: abdomen black and coxae mainly brown laterally, becoming reddish brown near apex (Fig. B5.47) or abdomen mainly reddish brown and coxae reddish brown or procoxae at least brown laterally, becoming reddish brown apically (Fig. B5.46).
	d)	Female: flagellum black, becoming light reddish brown (in specimens with black abdomen) (Fig. B5.49), or completely reddish brown (in almost all specimens with reddish brown abdomen and very rarely with those with black abdomen) (Fig. B5.50).
	e)	Male: femora or at least metafemur completely or almost completely black (Fig. B5.52).
			Xeris indecisus (MacGillivray, 1893) [in part]
		[Note. Females with either black and reddish brown abdomens are found together except in southwestern United States where females with black abdomens have not been recorded.]

7(6).	A)	Female: sheath with basal section less than 0.25 times length of apical section (if 0.25–0.27, use B) (Fig. B5.53).
	B)	Range from mid latitudes of Alberta and British Columbia south to mountains of California and Northern Mexico, and east of cordillera in Alberta and perhaps as far east as north central Saskatchewan.
			Xeris caudatus Cresson 1865
		[Note. Both sexes are difficult to recognize on morphological features, but can be distinguished by the CO1 barcode sequence. The general range is a good indication. This species occurs in the Rocky Mountains westward. East of the Rocky Mountains, in central Alberta, both species occur sympatrically.]
–	a)	Female: sheath with basal section more than 0.27 times length of apical section (if 0.25–0.27, use b) (Fig. B5.54).
	b)	Range from Alberta to Nova Scotia and south east of the prairie region Michigan to Maine.
			Xeris melancholicus (Westwood, 1874)
		[Note. Both sexes are difficult to recognize on morphological features, but can be distinguished by the CO1 barcode sequence. The general range is a good indication. This species occurs east of the Rocky Mountains and is sympatric with X. melancholicus in central Alberta (perhaps as far east as north central Saskatchewan].