!!! I accidentally unpublished this and so I had to republish it !!!

Even better version with changes for the identification of E. discincta and E. adumbrata. Some sentences made more clear and understandable. It is of note that E. nevadensis will soon be synonymized with E. delicata, the taxon will be named Metablapylis nevadensis. Since Johnston 2015 does not recognize E. nevadensis in favor of E. delicata, I would recommend that any of your E. delicata/E. nevadensis observations be identified as E. delicata. Also the range of E. wheeleri is not restricted just to the Colorado Plateau as implied by some statements in this key. More info in V1.0: https://www.inaturalist.org/journal/eleodesthermopolis/87075-v1-0-a-key-to-the-eleodes-species-of-the-united-states-and-canada

Please let me know if the identification given to you with this key seems incorrect. I don’t think this key will work exactly as expected on some occasions since one species can be variable in itself. I will recommend, if you meet a crossroads and you don’t know which option to pick, go down both paths and pick the better outcome.

1 Mesofemora and metafemora dentate or subdentate...2
1’ Mesofemora and metafemora never dentate...4
2 Elytral punctures strongly muricate...E. moesta
2’ Elytral punctures simple or slightly muricate...3
3 Pronotum widest anterior of middle, femoral spines large...E. armata
3’ Pronotum widest at middle, femoral spines small to medium sized...E. femorata
4 Body small pronotum generally cordate and constricted at base, elytra apex not attenuate or caudate, roughly sculptured, distributed across beaches, forests, and mountains...subgenus Blapylis
4’ Body small or large, pronotum usually not cordate although often slightly constricted at base, elytral apex attenuate, caudate or neither, roughly sculptured or not, widespread across all environments...5
5 Legs long with unproportionately small body, robust or not, body often flattened if not robust...6
5’ Legs long or short but with body fairly proportionate, only rarely flattened...23
6 Body generally slender and flattened, pronotal and elytral sculpturing simple (except in E. nigrina)...7
6’ Body, generally robust, never flattened, pronotal and elytral sculpturing complex...19
7 Elytral sculpturing muricate or scabrous...E. nigrina
7’ Elytral sculpturing simple...8
8 Range only in Inyo White Mountains...9
8’ Range widespread...10
9 Profemora with large tooth, anterolateral angles blunt but projected...E. aalbui
9’ Profemora only sinuate, anterolateral angles slightly projected...E. microps
10 Range near Big Bend National Park and the Guadalupe Mountains...11
10’ Range in the Southwest United States excluding Texas and the Guadalupe Mountains...13
11 Range in the Guadalupe Mountains...E. guadalupensis
11’ Range in Big Bend National Park...12
12 Mentum with finger-like process, pronotum subquadrate, widest at middle...E. labialis
12’ Mentum without finger-like process, pronotum widest anterior to middle...E. easterlai
13 Range in the Mohave Desert of California, pronotum usually evenly arcuate...E. californica
13’ Range in Arizona, Utah, and Sonora, pronotum rarely evenly arcuate...14
14 Range in the Sonoran desert or the most western portion of the Arizona-Utah border...15
14’ Range in the Sky Islands or the Colorado Plateau...17
15 Anterolateral angles strongly projected, caves by the most western point of the Arizona-Utah border…E. wynnei
15’ Anterolateral angles not strongly projected, the Sonoran desert…16
16 Short, red setae arising from elytral punctures...E. nevadensis
16’ No setae arising from elytral punctures...E. delicata
17 Body elongate, northern Arizona and southern Utah...18
17’ Body not elongate, Sky Islands in southeast Arizona...E. dissimilis
18 Strial punctures larger than punctures of intervals, restricted to the Grand Canyon...E. leptoscelis
18’ Strial punctures subequal to punctures of intervals, northern Arizona and southern Utah...E. wheeleri
19 Large tubercles present on Elytra...20
19’ Elytra without large tubercules...21
20 Range in Sierra Nevada region...E. granosa
20’ Range near the Four Corners...E. leechi
21 Pronotum evenly tuberculate, range in Oregon...E. spoliata
21’ Pronotum punctate, range widespread...22
22 Antennas robust, body generally more robust...E. hirsuta
22’ Antennas thin, body generally more slender...E. pilosa
23 Size small or sometimes medium, covered in long setae, restricted to coastal California and the Baja peninsula, and the Sonoran desert...24
23’ Size small or large, usually glabrous, if with conspicuous setae then not found in coastal California, nor in the Baja peninsula or the Sonoran desert...29
24 Males with dentate profemora and elytra caudate, Sonoran desert...E. tribulus
24’ Males nor females ever caudate or attenuate, coastal California and the Baja peninsula...25
25 Third antennomere shortened, body smaller...E. littoralis
25’ Third antennomere not shorted, body larger...26
26 Body larger...27
26’ Body smaller...28
27 Setae orange, California and northern Baja peninsula...E. osculans
27’ Setae black or grey, California and northern Baja peninsula...E. ursus
28 Setae black, California and northern Baja peninsula...E. nigropilosa
28’ Setae yellow, Baja peninsula...E. subdeplanata
29 Elytra caudate at least in males and strongly muricate, near Tamaulipas if not caudate, size usually large...30
29’ Elytra caudate or not, but if caudate and muricately punctured then elytra only slightly muricate, elytra can be strongly muricate if not caudate and not near Tamaulipas, size large or small...32
30 Only males caudate with profemora dentate, Tamaulipas...E. fiski
30’ Both males and females caudate with mutic profemora, Four Corners and Sierra Nevada region...31
31 Elytra usually glabrous, rarely with long setae, Four Corners...E. caudifera
31’ Elytra always with long setae, Sierra Nevada region...E. longipilosa
32 Elytral sculpture very rough, elytra always attenuate but never caudate, restricted to California...33
32’ Elytral sculpture variable but if rough then elytra never attenuate, widespread...34
33 Luster shiny and elytral apex acutely attenuate...E. marginata
33’ Luster dull and elytral apex blunt yet still attenuate...E. scabricula (E. acutangula)
34 Body oval shaped, coated in minute setae, coastal Texas and Louisiana...E. veterator
34’ Body shape variable, if small and shaped slightly oval then not found in coastal Texas or Louisiana...35
35 Body small and fusiform...36
35’ Body small or large, shape variable...38
36 Body nearly oval, clothed with minute setae, Great Plains above Texas...E. opaca
36’ Elytra highly punctured and glabrous...37
37 Body more fusiform, central and southern Great Plains...E. fusiformis
37’ Body less fusiform, the Sierra Nevadas to the Rocky Mountains, and the Arizona Sky Islands to British Colombia, northern Great Plains...E. extricata (in part)
38 Size medium to large, elytra usually inflated, wide, large, and rotund or occasionally flattened in E. striolata and some E. subnitens and E. madrensis, elytra only attenuate if also flattened, elytra never caudate...39
38’ Size variable but abdomen rarely inflated, if so, then size is usually small or the elytra are attenuate or caudate...42
39 Elytral striae composed of large conspicuous punctures...E. goryi
39’ Elytral striae without large punctures...40
40 Elytra flattened, always attenuate, south and central Texas...E. striolata
40’ Elytra sometimes flattened, if so then also attenuate, Arizona, New Mexico, and Sonora...41
41 Pronotum more or less parallel sided...E. subnitens
41’ Pronotum evenly arcuate...E. madrensis
42 Size large sometimes medium or small in rare occasions, but always with legs long, sometimes caudate...43
42’ Size usually small, sometimes medium, if so then legs short, never caudate...71
43 Body elongate, sometimes robust, pronotum not all that distinct from elytra, profemora never dentate and never with caudate elytra, punctures always simple except in E. inornata where they are muricate...44
43’ Body fairly variable, sometimes elongate, often robust, pronotum usually quite distinct from elytra, males almost always with dentate profemora, elytra sometimes caudate...48
44 Elytral punctures muricate, tiny inconspicuous setae arising from each one, western Nevada...E. inornata
44’ Elytral punctures simple, glabrous, widespread...45
45 Tarsi with grey spicules in the plantar groove, often with red line running down the length of the elytra, this line never diffuses into black...E. ornatipennis
45’ Tarsi without grey spicules in the plantar groove, if a red line is present along the elytra it diffuses into black...46
46 Profemora strongly sinuate, pronotum widest slightly anterior of middle...E. hepburni
46’ Profemora simple, pronotum widest at middle...47
47 Pronotun wider than long, restricted to California...E. gigantea
47’ Pronotum as wide as long or longer than wide, widespread but not found in California...E. longicollis
48 Elytra never completely smooth (muricate, irregularly punctured, sulcate even if sulci not deep), pronotum sometimes concave, body large, robust, and elytra with carina, if carina absent and body not very robust, then anterolateral angles of the pronotum rounded off, and the pronotum widest anterior of middle...49
48’ Elytra variable, often smooth, pronotum never concave, body variable, and elytra lacking carina, if elytra sulcate then pronotum widest at middle or with acute anterolateral angles...54
49 Pronotum concave...E. suturalis
49’ Pronotum convex...50
50 Elytra with carina...E. acuta
50’ Elytra without carina...51 (E. obscura)
51 Elytra with striae...52
51’ Elytra without striae...53
52 Elytra deeply sulcate...E. obscura sulcipennis
52’ Elytra slightly sulcate...E. obscura obscura
53 Elytra with simple punctures...E. obscura glabrisulca
53’ Elytra with muricate punctures...E. obscura dispersa
54 Elytra with large glabrous costae, intervals minutely hirsute, often coated with white debris, males are caudate, females are sometimes slightly caudate, legs long...E. mirabilis
54’ Elytra variable but without costae, caudate or not...55
55 Pronotum very wide, humeral angles of elytra obsolete, never attenuate...E. grandicollis
55 Pronotum variable, if wide, then elytral apex attenuate at least, humeral angles of elytra not obsolete...56
56 Restricted to California and the Baja peninsula, never having deep sulci...57
56’ Widespread not found in California or the northern Baja peninsula, if found in California then elytra sulcate...63
57 Pronotum two times wider than the head...E. acuticauda
57’ Pronotum less then two times wider than the head...58
58 Pronotum more or less parallel sided, Mohave desert...59
58’ Pronotum not parallel sided, or if so then elytral apex with groove in between both elytra, coastal and inland California…60
59 Tibia strongly curved, profemoral spines blunt, never caudate...E. subcylindrica
59’ Tibia not strongly curved, profemoral spines acute, males caudate...E. mexicana
60 Elytral punctures minute, pronotum nearly parallel sided, although sometimes slightly arcuate, elytral apex with groove in between both elytra…E. discincta
60’ Elytral punctures not minute, or if so then pronotum wide…61
61 Pronotum larger, elytral striae less prominent…E. dentipes
61’ Pronotum smaller, elytral striae more prominent…62
62 Pronotum widest anterior of middle, luster more shiny, elytra with simple punctures, glabrous, striae very clear…E. gracilis distans
62’ Pronotum widest at middle, luster more dull, elytra with muricate punctures and conspicuous setae, striae not clearly defined…E. adumbrata
63 Elytra strongly sulcate…64
63’ Elytra not strongly sulcate…65
64 Pronotum widest anterior to middle…E. hispilabris
64’ Pronotum widest at middle…E. composita
65 Body flattened, elytra and pronotum not too distinctly separated, or elytra remain wide up until their humeral angles…E. knullorum
65’ Body usually not flat, elytra and pronotum clearly separate, if elytra remain wide up until their humeral angles then elytra inflated…66
66 Elytra with muricate punctures…67
66’ Elytra with simple punctures…68
67 Punctures of elytra arranged in rows, elytral apex attenuate or caudate…E. tenuipes
67’ Punctures of elytra irregular, elytral apex only sometimes attenuate…E. sponsa
68 Elytra inflated and strongly convex…69 (E. spinipes)
68’ Elytra not inflated…70
69 Elytra more or less parallel sided, western Texas to Arizona…E. spinipes macrura
69’ Elytra ventricose, southern Texas…E. spinipes ventricosa
70 Male metatibia sinuate, males caudate, females strongly attenuate, strial punctures not abnormally large…E. eschscholtzii eschscholtzii
70’ Metatibia not sinuate, elytral apex only slightly attenuate, striae composed of rows of moderately sized punctures…E. gracilis gracilis
71 Elytra with conspicuous setae…72
71’ Elytra glabrous, or only with short inconspicuous setae…75
72 Size larger, northern Arizona and southern Utah…E. halli
72’ Size smaller, generally around the Great Basin and the Great Sand Dunes of Colorado…73
73 Distributed only in the Great Sand Dunes National Park…E. hirtipennis
73’ Distributed around the Great Basin…74
74 Setae brownish…E. letcheri
74’ Setae yellowish…E. aspera
75 Elytra flat and widened, about the same width as pronotum, sides sometimes slightly rounded or with carina…76
75’ Sides of elytra rounded evenly, generally elongate or circular…80
76 Body covered with minute setae…E. tricostata
76’ Body glabrous…77
77 Elytral sculpturing rough, luster generally dull, striae vague to absent…E. neomexicana
77’ Elytra with clear striae, luster shiny…78
78 Elytra with deeply impressed striae…E. pedinoides
78’ Elytra with slightly impressed striae…79 (E. wenzeli)
79 Punctures of elytra fine but easily noticeable…E. wenzeli speculicollis
70’ Punctures of elytra extremely fine and minute…E. wenzeli wenzeli
80 Both elytra with at least three large smooth costae…E. parowana
80’ Either elytra without large costae…81
81 Body smaller, elytra with tubercules, papillae, or numerous, irregular, simple punctures, elytral sculpturing never with only muricate or scabrous punctures…82
81’ Body slightly larger, sometimes small, but without tubercules, papillae or numerous, irregular, simple punctures, elytral sculpturing can consist of only muricate or scabrous punctures…86
82 Elytra covered in irregular simple punctures, body usually robust, sometimes slender, vaguely fusiform, the Sierra Nevadas to the Rocky Mountains, and the Arizona Sky Islands to British Colombia, northern Great Plains...E. extricata (continuation)
82’ Elytra with complex sculpturing, body robust or slender, Pacific coast…83
83 Thorax and abdomen fairly proportionate, elytra with papillae or with tubercules forming rugae, California…84
83’ Abdomen disproportionately large, elytra tuberculate at least laterally, Pacific coast…85
84 Elytra papillose…E. papillosa
84’ Elytra tuberculate with transverse rugae…E. corvina
85 Pronotum wider than long, arcuate…E. granulata
85’ Pronotum subquadrate and near parallel sided…E. subtuberculata
86 Outer protibial spur enlarged…E. debilis
86’ Outer protibial spur unmodified…87
87 Body small, robust, and without complex sculpturing, punctures minute, pronotum evenly arcuate and only slightly smaller than abdomen…E. arcuata
87’ Body larger, robust or not, sculpturing variable, pronotum significantly smaller than abdomen…88
88 Longer protibial spur extending to almost to the third tarsomere…89
88’ Longer protibial spur extending only to apex of the first tarsomere…91
89 Elytral sculpturing very complex, abdomen large, and pronotum strongly arcuate, Pacific Northwest…E. humeralis
89’ Elytral sculpturing variable, punctures muricate, usually elongate, sometimes robust, pronotum evenly arcuate, Sierra Nevadas to the Rocky Mountains, and the Grand Canyon to Idaho…90 (E. rileyi)
90 Elytra shiny with prominent striae…E. rileyi reducta
90’ Elytra dull without very prominent striae…E. rileyi rileyi
91 “…longer protibial spur tapering from base to apex”…E. carbonaria (see Thomas 2012 for subspecies key)
91’ “…longer protibial spur parallel sided in basal half then tapering to a point at apex”…92
92 Elytral punctures irregular, San Francisco region…E. quadricollis
92’ Elytral punctures organized in rows, southeast Arizona…E. anthracina

Another improved version, showing the “synonymization” of E. delicata and E. nevadensis, this improved key also adds for the identification of different forms of E. nigrina. Still I will say, E. rileyi could have issues, and while I did add E. anthracina’s subspecies I do not believe them to be all that distinct, same goes for E. wenzeli’s. If an outcome seems wrong, let me know and I’ll see what the problem is, and if you can’t decide between two paths, my advice would be to take both and compare outcomes. More info in V1.0: https://www.inaturalist.org/journal/eleodesthermopolis/87075-v1-0-a-key-to-the-eleodes-species-of-the-united-states-and-canada

1 Mesofemora and metafemora dentate or subdentate...2
1’ Mesofemora and metafemora never dentate...4
2 Elytral punctures strongly muricate...E. moesta
2’ Elytral punctures simple or slightly muricate...3
3 Pronotum widest anterior of middle, femoral spines large...E. armata
3’ Pronotum widest at middle, femoral spines small to medium sized...E. femorata
4 Body small pronotum generally cordate and constricted at base, elytra apex not attenuate or caudate, roughly sculptured, distributed across beaches, forests, and mountains...subgenus Blapylis
4’ Body small or large, pronotum usually not cordate although often slightly constricted at base, elytral apex attenuate, caudate or neither, roughly sculptured or not, widespread across all environments...5
5 Legs long with unproportionately small body, robust or not, body often flattened if not robust...6
5’ Legs long or short but with body fairly proportionate, only rarely flattened...22
6 Body generally slender and flattened, pronotal and elytral sculpturing simple (except in E. nigrina)...7
6’ Body, generally robust, never flattened, pronotal and elytral sculpturing complex...18
7 Elytral sculpturing muricate or scabrous...E. nigrina (in part)
7’ Elytral sculpturing simple...8
8 Range only in Inyo White Mountains...9
8’ Range widespread...10
9 Profemora with large tooth, anterolateral angles blunt but projected...E. aalbui
9’ Profemora only sinuate, anterolateral angles slightly projected...E. microps
10 Range near Big Bend National Park and the Guadalupe Mountains...11
10’ Range in the Southwest United States excluding Texas and the Guadalupe Mountains...13
11 Range in the Guadalupe Mountains...E. guadalupensis
11’ Range in Big Bend National Park...12
12 Mentum with finger-like process, pronotum subquadrate, widest at middle...E. labialis
12’ Mentum without finger-like process, pronotum widest anterior to middle...E. easterlai
13 Range in the Mohave Desert of California, pronotum usually evenly arcuate...E. californica
13’ Range in Arizona, Utah, and Sonora, pronotum rarely evenly arcuate...14
14 Range in the Sonoran desert or the most western portion of the Arizona-Utah border...15
14’ Range in the Sky Islands or the Colorado Plateau...16
15 Anterolateral angles strongly projected, caves by the most western point of the Arizona-Utah border…E. wynnei
15’ Anterolateral angles not strongly projected, the Sonoran desert…E. delicata (E. nevadensis)
16 Body elongate, northern Arizona and southern Utah...17
16’ Body not elongate, Sky Islands in southeast Arizona...E. dissimilis
17 Strial punctures larger than punctures of intervals, restricted to the Grand Canyon...E. leptoscelis
17’ Strial punctures subequal to punctures of intervals, northern Arizona and southern Utah...E. wheeleri
18 Large tubercles present on Elytra...19
18’ Elytra without large tubercules...20
19 Range in Sierra Nevada region...E. granosa
19’ Range near the Four Corners...E. leechi
20 Pronotum evenly tuberculate, range in Oregon...E. spoliata
20’ Pronotum punctate, range widespread...21
21 Antennas robust, body generally more robust...E. hirsuta
21’ Antennas thin, body generally more slender...E. pilosa
22 Size small or sometimes medium, covered in long setae, restricted to coastal California and the Baja peninsula, and the Sonoran desert...23
22’ Size small or large, usually glabrous, if with conspicuous setae then not found in coastal California, nor in the Baja peninsula or the Sonoran desert...28
23 Males with dentate profemora and elytra caudate, Sonoran desert...E. tribulus
23’ Males nor females ever caudate or attenuate, coastal California and the Baja peninsula...24
24 Third antennomere shortened, body smaller...E. littoralis
24’ Third antennomere not shorted, body larger...25
25 Body larger...26
25’ Body smaller...27
26 Setae orange, California and northern Baja peninsula...E. osculans
26’ Setae black or grey, California and northern Baja peninsula...E. ursus
27 Setae black, California and northern Baja peninsula...E. nigropilosa
27’ Setae yellow, Baja peninsula...E. subdeplanata
28 Elytra caudate at least in males and strongly muricate, near Tamaulipas if not caudate, size usually large...29
28’ Elytra caudate or not, but if caudate and muricately punctured then elytra only slightly muricate, elytra can be strongly muricate if not caudate and not near Tamaulipas, size large or small...31
29 Only males caudate with profemora dentate, Tamaulipas...E. fiski
29’ Both males and females caudate with mutic profemora, Four Corners and Sierra Nevada region...30
30 Elytra usually glabrous, rarely with long setae, Four Corners...E. caudifera
30’ Elytra always with long setae, Sierra Nevada region...E. longipilosa
31 Elytral sculpture very rough, elytra always attenuate but never caudate, restricted to California...32
31’ Elytral sculpture variable but if rough then elytra never attenuate, widespread...33
32 Luster shiny and elytral apex acutely attenuate...E. marginata
32’ Luster dull and elytral apex blunt yet still attenuate...E. scabricula (E. acutangula)
33 Body oval shaped, coated in minute setae, coastal Texas and Louisiana...E. veterator
33’ Body shape variable, if small and shaped slightly oval then not found in coastal Texas or Louisiana...34
34 Body small and fusiform...35
34’ Body small or large, shape variable...37
35 Body nearly oval, clothed with minute setae, Great Plains above Texas...E. opaca
35’ Elytra highly punctured and glabrous...36
36 Body more fusiform, central and southern Great Plains...E. fusiformis
36’ Body less fusiform, the Sierra Nevadas to the Rocky Mountains, and the Arizona Sky Islands to British Colombia, northern Great Plains...E. extricata (in part)
37 Size medium to large, elytra usually inflated, wide, large, and rotund or occasionally flattened in E. striolata and some E. subnitens and E. madrensis, elytra only attenuate if also flattened, elytra never caudate...38
37’ Size variable but abdomen rarely inflated, if so, then size is usually small or the elytra are attenuate or caudate...41
38 Elytral striae composed of large conspicuous punctures...E. goryi
38’ Elytral striae without large punctures...39
39 Elytra flattened, always attenuate, south and central Texas...E. striolata
39’ Elytra sometimes flattened, if so then also attenuate, Arizona, New Mexico, and Sonora...40
40 Pronotum more or less parallel sided...E. subnitens
40’ Pronotum evenly arcuate...E. madrensis
41 Size large sometimes medium or small in rare occasions, but always with legs long, sometimes caudate...42
41’ Size usually small, sometimes medium, if so then legs short, never caudate...71
42 Body elongate, sometimes robust, pronotum not all that distinct from elytra, profemora never dentate and never with caudate elytra, punctures simple or muricate/scabrous...43
42’ Body fairly variable, sometimes elongate, often robust, pronotum usually quite distinct from elytra, males almost always with dentate profemora, elytra sometimes caudate...48
43 Elytral punctures simple…45
43’ Elytral punctures not simple…44
44 Anterolateral angles strongly projected, elytral punctures with tiny inconspicuous setae arising from each one...E. inornata
44’ Anterolateral angles not projected or only slightly projected, elytral punctures glabrous…E. nigrina (continuation)
45 Tarsi with grey spicules in the plantar groove, often with red line running down the length of the elytra, this line never diffuses into black...E. ornatipennis
45’ Tarsi without grey spicules in the plantar groove, if a red line is present along the elytra it diffuses into black...46
46 Profemora strongly sinuate, pronotum widest slightly anterior of middle...E. hepburni
46’ Profemora simple, pronotum widest at middle...47
47 Pronotun wider than long, restricted to California...E. gigantea
47’ Pronotum as wide as long or longer than wide, widespread but not found in California...E. longicollis
48 Elytra never completely smooth (muricate, irregularly punctured, sulcate even if sulci not deep), pronotum sometimes concave, body large, robust, and elytra with carina, if carina absent and body not very robust, then anterolateral angles of the pronotum rounded off, and the pronotum widest anterior of middle...49
48’ Elytra variable, often smooth, pronotum never concave, body variable, and elytra lacking carina, if elytra sulcate then pronotum widest at middle or with acute anterolateral angles...54
49 Pronotum concave...E. suturalis
49’ Pronotum convex...50
50 Elytra with carina...E. acuta
50’ Elytra without carina...51 (E. obscura)
51 Elytra with striae...52
51’ Elytra without striae...53
52 Elytra deeply sulcate...E. obscura sulcipennis
52’ Elytra slightly sulcate...E. obscura obscura
53 Elytra with simple punctures...E. obscura glabrisulca
53’ Elytra with muricate punctures...E. obscura dispersa
54 Elytra with large glabrous costae, intervals minutely hirsute, often coated with white debris, males are caudate, females are sometimes slightly caudate, legs long...E. mirabilis
54’ Elytra variable but without costae, caudate or not...55
55 Pronotum very wide, humeral angles of elytra obsolete, never attenuate...E. grandicollis
55 Pronotum variable, if wide, then elytral apex attenuate at least, humeral angles of elytra not obsolete...56
56 Restricted to California and the Baja peninsula, never having deep sulci...57
56’ Widespread not found in California or the northern Baja peninsula, if found in California then elytra sulcate...63
57 Pronotum two times wider than the head...E. acuticauda
57’ Pronotum less then two times wider than the head...58
58 Pronotum more or less parallel sided, Mohave desert...59
58’ Pronotum not parallel sided, or if so then elytral apex with groove in between both elytra, coastal and inland California…60
59 Tibia strongly curved, profemoral spines blunt, never caudate...E. subcylindrica
59’ Tibia not strongly curved, profemoral spines acute, males caudate...E. mexicana
60 Elytral punctures minute, pronotum nearly parallel sided, although sometimes slightly arcuate, elytral apex with groove in between both elytra…E. discincta
60’ Elytral punctures not minute, or if so then pronotum wide…61
61 Pronotum larger, elytral striae less prominent…E. dentipes
61’ Pronotum smaller, elytral striae more prominent…62
62 Pronotum widest anterior of middle, luster more shiny, elytra with simple punctures, glabrous, striae very clear…E. gracilis distans
62’ Pronotum widest at middle, luster more dull, elytra with muricate punctures and conspicuous setae, striae not clearly defined…E. adumbrata
63 Elytra strongly sulcate…64
63’ Elytra not strongly sulcate…65
64 Pronotum widest anterior to middle…E. hispilabris
64’ Pronotum widest at middle…E. composita
65 Body flattened, elytra and pronotum not too distinctly separated, or elytra remain wide up until their humeral angles…E. knullorum
65’ Body usually not flat, elytra and pronotum clearly separate, if elytra remain wide up until their humeral angles, then elytra inflated…66
66 Elytra with muricate punctures…67
66’ Elytra with simple punctures…68
67 Punctures of elytra arranged in rows, elytral apex attenuate or caudate…E. tenuipes
67’ Punctures of elytra irregular, elytral apex only sometimes attenuate…E. sponsa
68 Elytra inflated and strongly convex…69 (E. spinipes)
68’ Elytra not inflated…70
69 Elytra more or less parallel sided, western Texas to Arizona…E. spinipes macrura
69’ Elytra ventricose, southern Texas…E. spinipes ventricosa
70 Male metatibia sinuate, males caudate, females strongly attenuate, strial punctures not abnormally large…E. eschscholtzii eschscholtzii
70’ Metatibia not sinuate, elytral apex only slightly attenuate, striae composed of rows of moderately sized punctures…E. gracilis gracilis
71 Elytra with conspicuous setae…72
71’ Elytra glabrous, or only with short inconspicuous setae…75
72 Size larger, northern Arizona and southern Utah…E. halli
72’ Size smaller, generally around the Great Basin and the Great Sand Dunes of Colorado…73
73 Distributed only in the Great Sand Dunes National Park…E. hirtipennis
73’ Distributed around the Great Basin…74
74 Setae brownish…E. letcheri
74’ Setae yellowish…E. aspera
75 Elytra flat and widened, about the same width as pronotum, sides sometimes slightly rounded or with carina…76
75’ Sides of elytra rounded evenly, generally elongate or circular…80
76 Body covered with minute setae…E. tricostata
76’ Body glabrous…77
77 Elytral sculpturing rough, luster generally dull, striae vague to absent…E. neomexicana
77’ Elytra with clear striae, luster shiny…78
78 Elytra with deeply impressed striae…E. pedinoides
78’ Elytra with slightly impressed striae…79 (E. wenzeli)
79 Punctures of elytra fine but easily noticeable…E. wenzeli speculicollis
70’ Punctures of elytra extremely fine and minute…E. wenzeli wenzeli
80 Both elytra with at least three large smooth costae…E. parowana
80’ Either elytra without large costae…81
81 Body smaller, elytra with large tubercules, papillae, or large, numerous, irregular, simple punctures, elytral sculpturing never exclusively with only muricate or scabrous punctures…82
81’ Body slightly larger, sometimes small, but almost always without tubercules, and never with papillae or large, numerous, irregular, simple punctures, elytral sculpturing can occasionally consist of only muricate or scabrous punctures, or small tubercules…86
82 Elytra covered in irregular simple punctures, body usually robust, sometimes slender, vaguely fusiform, the Sierra Nevadas to the Rocky Mountains, and the Arizona Sky Islands to British Colombia, northern Great Plains...E. extricata (continuation)
82’ Elytra with complex sculpturing, body robust or slender, Pacific coast…83
83 Thorax and abdomen fairly proportionate, elytra with papillae or with tubercules forming rugae, California…84
83’ Abdomen disproportionately large, elytra tuberculate at least laterally, Pacific coast…85
84 Elytra papillose…E. papillosa
84’ Elytra tuberculate with transverse rugae…E. corvina
85 Pronotum wider than long, arcuate…E. granulata
85’ Pronotum subquadrate and near parallel sided…E. subtuberculata
86 Outer protibial spur enlarged…E. debilis
86’ Outer protibial spur unmodified…87
87 Body small, robust, and without complex sculpturing, punctures minute, pronotum evenly arcuate and only slightly smaller than abdomen…E. arcuata
87’ Body larger, robust or not, sculpturing variable, pronotum significantly smaller than abdomen…88
88 Longer protibial spur extending to almost to the third tarsomere…89
88’ Longer protibial spur extending only to apex of the first tarsomere…91
89 Elytral sculpturing very complex, abdomen large, and pronotum strongly arcuate, Pacific Northwest…E. humeralis
89’ Elytral sculpturing variable, elytra muricate or tuberculate, body usually elongate, sometimes robust, pronotum evenly arcuate, Sierra Nevadas to the Rocky Mountains, and the Grand Canyon to Idaho…90 (E. rileyi)
90 Elytra shiny with prominent striae…E. rileyi reducta
90’ Elytra dull without very prominent striae…E. rileyi rileyi
91 “…longer protibial spur evenly tapering to a point from base to apex”…E. carbonaria (see Thomas 2012 for subspecies key)
91’ “…longer protibial spur parallel sided in basal half then tapering to a point at apex”…92
92 Elytral punctures irregular, San Francisco region…E. quadricollis
92’ Elytral punctures organized in rows, southeast Arizona…93 (E. anthracina)
93 Size larger, elytral punctures less fine…E. anthracina anthracina
93’ Size smaller, elytral punctures more fine…E. anthracina lustrans

This is version 2.0 instead of 1.4 because I believe that this key is improved to the point that most Eleodes (outside of Blapylis) in the U.S. and Canada can be identified with it, which was still in question in the previous version. The main change is a major improvement in the Litheleodes and Melaneleodes section at the bottom, some species were still very likely to be misidentified with the previous version since making a reliable key was tough, but, I think I’ve nailed it, or am nearly there. For more information see V1.0: https://www.inaturalist.org/journal/eleodesthermopolis/87075-v1-0-a-key-to-the-eleodes-species-of-the-united-states-and-canada-outdated

1 Mesofemora and metafemora dentate or subdentate...2
1’ Mesofemora and metafemora never dentate...4
2 Elytral punctures strongly muricate...E. moesta
2’ Elytral punctures simple or slightly muricate...3
3 Pronotum widest anterior of middle, femoral spines large...E. armata
3’ Pronotum widest at middle, femoral spines small to medium sized...E. femorata
4 Body small pronotum generally cordate and constricted at base, elytra apex not attenuate or caudate, roughly sculptured, distributed across beaches, forests, and mountains...subgenus Blapylis
4’ Body small or large, pronotum usually not cordate although often slightly constricted at base, elytral apex attenuate, caudate or neither, roughly sculptured or not, widespread across all environments...5
5 Legs long with unproportionately small body, robust or not, body often flattened if not robust...6
5’ Legs long or short but with body fairly proportionate, only rarely flattened...22
6 Body generally slender and flattened, pronotal and elytral sculpturing simple (except in E. nigrina)...7
6’ Body, generally robust, never flattened, pronotal and elytral sculpturing complex...18
7 Elytral sculpturing muricate or scabrous...E. nigrina (in part)
7’ Elytral sculpturing simple...8
8 Range only in Inyo White Mountains...9
8’ Range widespread...10
9 Profemora with large tooth, anterolateral angles blunt but projected...E. aalbui
9’ Profemora only sinuate, anterolateral angles slightly projected...E. microps
10 Range near Big Bend National Park and the Guadalupe Mountains...11
10’ Range in the Southwest United States excluding Texas and the Guadalupe Mountains...13
11 Range in the Guadalupe Mountains...E. guadalupensis
11’ Range in Big Bend National Park...12
12 Mentum with finger-like process, pronotum subquadrate, widest at middle...E. labialis
12’ Mentum without finger-like process, pronotum widest anterior to middle...E. easterlai
13 Range in the Mohave Desert of California, pronotum usually evenly arcuate...E. californica
13’ Range in Arizona, Utah, and Sonora, pronotum rarely evenly arcuate...14
14 Range in the Sonoran desert or the most western portion of the Arizona-Utah border...15
14’ Range in the Sky Islands or the Colorado Plateau...16
15 Anterolateral angles strongly projected, caves by the most western point of the Arizona-Utah border…E. wynnei
15’ Anterolateral angles not strongly projected, the Sonoran desert…E. delicata (E. nevadensis)
16 Body elongate, northern Arizona and southern Utah...17
16’ Body not elongate, Sky Islands in southeast Arizona...E. dissimilis
17 Strial punctures larger than punctures of intervals, restricted to the Grand Canyon...E. leptoscelis
17’ Strial punctures subequal to punctures of intervals, northern Arizona and southern Utah...E. wheeleri
18 Large tubercles present on Elytra...19
18’ Elytra without large tubercules...20
19 Range in Sierra Nevada region...E. granosa
19’ Range near the Four Corners...E. leechi
20 Pronotum evenly tuberculate, range in Oregon...E. spoliata
20’ Pronotum punctate, range widespread...21
21 Antennas robust, body generally more robust...E. hirsuta
21’ Antennas thin, body generally more slender...E. pilosa
22 Size small or sometimes medium, covered in long setae, restricted to coastal California and the Baja peninsula, and the Sonoran desert...23
22’ Size small or large, usually glabrous, if with conspicuous setae then not found in coastal California, nor in the Baja peninsula or the Sonoran desert...28
23 Males with dentate profemora and elytra caudate, Sonoran desert...E. tribulus
23’ Males nor females ever caudate or attenuate, coastal California and the Baja peninsula...24
24 Third antennomere shortened, body smaller and more slender...E. littoralis
24’ Third antennomere not shorted, body larger...25
25 Body larger, pronotum with constriction at base, if missing constriction then setae more dense...26
25’ Body smaller, pronotum lacking constriction at base, setae less dense...27
26 Setae orange, California and northern Baja peninsula...E. osculans
26’ Setae black or grey, California and northern Baja peninsula...E. ursus
27 Setae black, California and northern Baja peninsula...E. nigropilosa
27’ Setae yellow, Baja peninsula...E. subdeplanata
28 Elytra caudate at least in males and strongly muricate, near Tamaulipas if not caudate, size usually large...29
28’ Elytra caudate or not, but if caudate and muricately punctured then elytra only slightly muricate, elytra can be strongly muricate if not caudate and not near Tamaulipas, size large or small...31
29 Only males caudate with profemora dentate, Tamaulipas...E. fiski
29’ Both males and females caudate with mutic profemora, Four Corners and Sierra Nevada region...30
30 Elytra usually glabrous, rarely with setae, Four Corners...E. caudifera
30’ Elytra always with long setae, Sierra Nevada region...E. longipilosa
31 Elytral sculpture very rough, elytra always attenuate but never caudate, restricted to California...32
31’ Elytral sculpture variable but if rough then elytra never attenuate, widespread...33
32 Luster shiny and elytral apex acutely attenuate...E. marginata
32’ Luster dull and elytral apex blunt yet still attenuate...E. scabricula (E. acutangula)
33 Body oval shaped, coated in minute setae, coastal Texas and Louisiana...E. veterator
33’ Body shape variable, if small and shaped slightly oval then not found in coastal Texas or Louisiana...34
34 Body small and fusiform...35
34’ Body small or large, shape variable...37
35 Body nearly oval, clothed with minute setae, Great Plains above Texas...E. opaca
35’ Elytra highly punctured and glabrous...36
36 Body more fusiform, central and southern Great Plains...E. fusiformis
36’ Body less fusiform, the Sierra Nevadas to the Rocky Mountains, and the Arizona Sky Islands to British Colombia, northern Great Plains...E. extricata (in part)
37 Size medium to large, elytra usually inflated, wide, large, and rotund or occasionally flattened in E. striolata and some E. subnitens and E. madrensis, elytra only attenuate if also flattened, elytra never caudate...38
37’ Size variable but abdomen rarely inflated, if so, then size is usually small or the elytra are attenuate or caudate...41
38 Elytral striae composed of large conspicuous punctures...E. goryi
38’ Elytral striae without large punctures...39
39 Elytra flattened, always attenuate, and heavily punctate, south and central Texas...E. striolata
39’ Elytra sometimes flattened, if so then also attenuate, inconspicuous punctures present, Arizona, New Mexico, and Sonora...40
40 Pronotum more or less parallel sided...E. subnitens
40’ Pronotum evenly arcuate...E. madrensis
41 Size large sometimes medium or small in rare occasions, but always with legs long, sometimes caudate...42
41’ Size usually small, sometimes medium, if so then legs short, never caudate...71
42 Body elongate, sometimes robust, pronotum not all that distinct from elytra, profemora never dentate and never with caudate elytra, punctures simple or muricate/scabrous...43
42’ Body fairly variable, sometimes elongate, often robust, pronotum usually quite distinct from elytra, males almost always with dentate profemora, elytra sometimes caudate...48
43 Elytral punctures simple…45
43’ Elytral punctures not simple…44
44 Anterolateral angles strongly projected, elytral punctures with tiny inconspicuous setae arising from each one...E. inornata
44’ Anterolateral angles not projected or only slightly projected, elytral punctures glabrous…E. nigrina (continuation)
45 Tarsi with grey spicules in the plantar groove, often with red line running down the length of the elytra, this line never diffuses into black...E. ornatipennis
45’ Tarsi without grey spicules in the plantar groove, if a red line is present along the elytra it diffuses into black...46
46 Profemora strongly sinuate, pronotum widest slightly anterior of middle...E. hepburni
46’ Profemora simple, pronotum widest at middle...47
47 Pronotun wider than long, restricted to California...E. gigantea
47’ Pronotum as wide as long or longer than wide, widespread but not found in California...E. longicollis
48 Elytra never completely smooth (muricate, irregularly punctured, sulcate even if sulci not deep), pronotum sometimes concave, body large, robust, and elytra with carina, if carina absent and body not very robust, then anterolateral angles of the pronotum rounded off, and the pronotum widest anterior of middle...49
48’ Elytra variable, often smooth, pronotum never concave, body variable, and elytra lacking carina, if elytra sulcate then pronotum widest at middle or with acute anterolateral angles...54
49 Pronotum concave...E. suturalis
49’ Pronotum convex...50
50 Elytra with carina...E. acuta
50’ Elytra without carina...51 (E. obscura)
51 Elytra with striae...52
51’ Elytra without striae...53
52 Elytra deeply sulcate...E. obscura sulcipennis
52’ Elytra slightly sulcate...E. obscura obscura
53 Elytra with simple punctures...E. obscura glabrisulca
53’ Elytra with muricate punctures...E. obscura dispersa
54 Elytra with large glabrous costae, intervals minutely hirsute, often coated with white debris, males are caudate, females are sometimes slightly caudate, legs long...E. mirabilis
54’ Elytra variable but without costae, caudate or not...55
55 Pronotum very wide, humeral angles of elytra obsolete, never attenuate...E. grandicollis
55 Pronotum variable, if wide, then elytral apex attenuate at least, humeral angles of elytra not obsolete...56
56 Restricted to California and the Baja peninsula, never having deep sulci...57
56’ Widespread not found in California or the northern Baja peninsula, if found in California then elytra sulcate...63
57 Pronotum two times wider than the head...E. acuticauda
57’ Pronotum less then two times wider than the head...58
58 Pronotum more or less parallel sided, Mohave desert...59
58’ Pronotum not parallel sided, or if so then elytral apex with groove in between both elytra, coastal and inland California…60
59 Tibia strongly curved, profemoral spines blunt, never caudate...E. subcylindrica
59’ Tibia not strongly curved, profemoral spines acute, males caudate...E. mexicana
60 Elytral punctures minute, pronotum nearly parallel sided, although sometimes slightly arcuate, elytral apex with groove in between both elytra…E. discincta
60’ Elytral punctures not minute, or if so then pronotum wide…61
61 Pronotum larger, elytral striae less prominent…E. dentipes
61’ Pronotum smaller, elytral striae more prominent…62
62 Pronotum widest anterior of middle, luster more shiny, elytra with simple punctures, glabrous, striae very clear…E. gracilis distans
62’ Pronotum widest at middle, luster more dull, elytra with muricate punctures and conspicuous setae, striae not clearly defined…E. adumbrata
63 Elytra strongly sulcate…64
63’ Elytra not strongly sulcate…65
64 Pronotum widest anterior to middle…E. hispilabris
64’ Pronotum widest at middle…E. composita
65 Body flattened, elytra and pronotum not too distinctly separated, or elytra remain wide up until their humeral angles…E. knullorum
65’ Body usually not flat, elytra and pronotum clearly separate, if elytra remain wide up until their humeral angles, then elytra inflated…66
66 Elytra with muricate punctures…67
66’ Elytra with simple punctures…68
67 Punctures of elytra arranged in rows, elytral apex attenuate or caudate…E. tenuipes
67’ Punctures of elytra irregular, elytral apex only sometimes attenuate…E. sponsa
68 Elytra inflated and strongly convex…69 (E. spinipes)
68’ Elytra not inflated…70
69 Elytra more or less parallel sided, western Texas to Arizona…E. spinipes macrura
69’ Elytra ventricose, southern Texas…E. spinipes ventricosa
70 Male metatibia sinuate, males caudate, females strongly attenuate, strial punctures not abnormally large…E. eschscholtzii eschscholtzii
70’ Metatibia not sinuate, elytral apex only slightly attenuate, striae composed of rows of moderately sized punctures…E. gracilis gracilis
71 Elytra with conspicuous setae…72
71’ Elytra glabrous, or only with short inconspicuous setae…75
72 Size larger, body more robust, northern Arizona and southern Utah…E. halli
72’ Size smaller, body more slender, generally around the Great Basin and the Great Sand Dunes of Colorado…73
73 Distributed only in the Great Sand Dunes National Park…E. hirtipennis
73’ Distributed around the Great Basin…74
74 Setae brownish or blackish…E. letcheri
74’ Setae yellowish…E. aspera
75 Elytra flat and widened, about the same width as pronotum, sides sometimes slightly rounded or with carina…76
75’ Sides of elytra rounded evenly, generally elongate or circular…80
76 Body covered with minute setae…E. tricostata
76’ Body glabrous…77
77 Elytral sculpturing rough, luster generally dull, striae vague to absent…E. neomexicana
77’ Elytra with clear striae, luster shiny…78
78 Elytra with deeply impressed striae…E. pedinoides
78’ Elytra with slightly impressed striae…79 (E. wenzeli)
79 Punctures of elytra fine but easily noticeable…E. wenzeli speculicollis
79’ Punctures of elytra extremely fine and minute…E. wenzeli wenzeli
80 Both elytra with at least three large smooth costae, southern Utah…E. parowana
80’ Both elytra without at least three large costae…81
81 Size small, elytral luster generally shiny, elytra only with conspicuous irregular punctures, never with tubercules…E. extricata (continuation)
81’ Size small to medium, luster variable although generally dull if elytra with irregular punctures, said irregular punctures also smaller, elytra with punctures in rows or irregular, or with tubercules or papillae…82
82 Elytra generally inflated, if not, then elytra more or less parallel sided, usually tuberculate, Pacific Northwest…E. humeralis
82’ Elytra inflated or not, but if with tubercules then elytra not inflated and not parallel sided, if without tubercules then not found in the Pacific Northwest, or if in the Pacific Northwest then pronotum not clearly widest in front of middle…83
83 Elytra with papillae, pronotum wide…E. papillosa
83’ Elytra without papillae…84
84 Elytra with large tubercules…85
84’ Elytra without large tubercules…86
85 Pronotum more or less arcuate and wider than long…E. granulata
85’ Pronotum more or less parallel sided and longer than wide…E. subtuberculata
86 Size small, pronotum evenly arcuate, lateral edges angular instead of rounded, punctures minute…E. arcuata
86’ Size variable, pronotum variable, but if arcuate, then lateral edges rounded…87
87 Luster shiny, elytral punctures large and in rows, outer protibial spur clearly larger than inner protibial spur…E. debilis
87’ Luster variable but usually not too shiny, punctures variable but rarely large, if protibial spurs disproportionate in size, then elytra with small punctures or tubercules…88
88 Longer protibial spur extending to almost to the third tarsomere…89 (E. rileyi)
88’ Longer protibial spur extending only to apex of the first tarsomere…90
89 Elytra shiny with prominent striae…E. rileyi reducta
89’ Elytra dull without very prominent striae…E. rileyi rileyi
90 “…longer protibial spur evenly tapering to a point from base to apex”…E. carbonaria (see Thomas 2012 for subspecies key)
90’ “…longer protibial spur parallel sided in basal half then tapering to a point at apex”…91
91 Elytral punctures irregular, San Francisco region…E. quadricollis
91’ Elytral punctures organized in rows, southeast Arizona…92 (E. anthracina)
92 Size larger, elytral punctures less fine…E. anthracina anthracina
92’ Size smaller, elytral punctures more fine…E. anthracina lustrans