Key to Xanthonia species of Texas

1 Tooth of profemur large (Figs 21–22); large species, length 3.8–6.1 mm; apex of median lobe of male genitalia long and narrow, apex acute not incised (Figs 27–31)....................................................................... 2

- Tooth of profemur moderate in size to minute or nearly obsolete (Figs 23–26); small species, length 2.1–4.0 mm; apex of median lobe of male genitalia narrow or broad, truncate or incised (Figs 32–54, 64–75)................................ 3

2 Elytra appearing mottled due to clumping of variable darker and lighter hairs and usually variably alternating light and dark brown coloration of integument (Fig 10).................................................. 1. X. vagans (LeConte)

- Elytra of uniform brownish coloration, hairs uniformly pale brownish and integument of uniform medium brown color (Fig 11)...................................................................... 2. X. marquai Riley & Quinn n. sp.

3 Tooth of profemur moderate (Fig 23); venter and legs dark brownish, elytral dark brown with darker pattern (Figs 6, 15)................................................................................ 3. X. picturata Weisman n. sp.

- Tooth of profemur minute to obsolete (Figs. 24–26); color of venter, legs and elytra, and elytral pattern variable.......... 4

4 Ridge on lateral margins of abdominal ventrites III–V minutely denticulate (Figs 17–19)............................. 5

- Ridge on lateral margins of abdominal ventrites III–V entire, uniformly sharp (Fig 20).............................. 7

5 Median lobe of male genitalia truncate apically (Figs 36–38); punctation of elytral disc subseriate, formed into more-or-less distinct rows; elytra usually without pattern of dark maculae or if present (rarely), ground color is light reddish brown [eastern Texas]......................................................................... 4. X. villosula (Melsheimer)

- Apex of median lobe of male genitalia with conspicuous median incision; punctation of elytral disc confused to subseriate; elytral pattern variable [central and western Texas]........................................................... 6

6 Elytra with distinct pattern of dark maculae (Fig 2, 55), ground color dark brown; apex of median lobe narrowed with moderately deep median incision (Fig 40–43); setae arising from elytral intervals erect and long, imparting bristly appearance; larger, length 2.8–3.4 mm [mountainous regions of western Texas]........................... 5. X. dentata Staines & Weisman

- Elytra without distinct pattern of dark maculae, ground color light reddish brown; apex of median lobe with broad moderately deep median incision (Fig 34); setae arising from elytral intervals reclining, moderate in length, not imparting an especially bristly appearance; smaller, length 2.1–2.7 mm [central Texas]........................ 6. X. parva Riley & Quinn n. sp.

7 Elytral setae dense, all setae appressed, of near uniform length and curvature and with seta emerging from punctures slightly shorter than those emerging from interstitial areas; tip of median lobe with deep, narrow, parallel-sided incision (Fig 45)................................................................................. 7. X. hirsuta Weisman n. sp.

- Elytral setae distinctly duel with setae emerging from punctures shorter, lying nearly flat against elytral surface, strongly curved, and setae emerging from interstitial areas long, reclining and weakly curved; tip of median lobe variable, but not as above............................................................................................... 8

8 Elytra uniformly medium brown, immaculate; larger, length 3.5–4.0 mm; punctation of elytral disc subseriate; median lobe long, broad throughout length, with deep angular apical incision (Fig 67)............... 8. X. angulata Staines & Weisman

- Elytra either uniformly dark reddish brown or medium to pale brownish usually with variably developed pattern of dark maculae (Figs 3–4, 6–8); smaller, length 2.5–3.5 mm; punctation of elytral disc subseriate to confused; median lobe variable, but not as above............................................................................................ 9

9 Abdominal ventrites and most of metasternum dark, nearly black; dorsum uniformly dark reddish brown lacking dark pattern or pattern barely discernable; median lobe (Figs 51–52).................................. 9. X. nitida Weisman n. sp.

- Abdominal ventrites and most of metasternum medium to pale brownish; dorsum pale to medium brown usually with variably developed pattern of darker maculae..................................................................... 10

10 Apex of median lobe of male genitalia broad with broad rounded deep incision (Figs 47–48); femora pale; elytral pattern when well developed as in figures 8 and 76............................................... 10. X. texana Weisman n. sp.

- Apex of median lobe narrowed with narrow shallow incision; knee of leg or apex of femora often vaguely darker than remain- der of leg........................................................................................... 11

11 Apex of median lobe of male genitalia with lobe on each side blunt (Figs 53); femora without dark spot at midlength; elytral pattern as in figures 7 and 77 [central Texas].......................................... 11. X. querci Weisman n. sp.

- Apex of median lobe of male genitalia with lobe on each side acute (Figs 74); femora often with conspicuous dark spot at midlength; elytral pattern as in figures 3 and 78 [northeastern Texas]...................... 12. X. furcata Staines & Weisman