Key to the species of Stenolis
1. Spots of pubescence on prothorax and elytra yellow or whitish-yellow............................................ 2
- Spots of pubescence on prothorax and elytra blackish, whitish, grayish, or brownish................................. 5
2. Occiput with median longitudinal yellowish line, this line continuous on pronotum (Fig. 1).... S. polygramma (Bates, 1872)
- Occiput and middle of pronotum without longitudinal lines.................................................... 3
3. Each side of pronotum with broad longitudinal line, continuous on sides of elytra, from base to apex (Fig. 2).......................................................................................... Stenolis gilvolineata sp. nov.
- Each side of pronotum with narrow longitudinal line, not continuous on elytra; each elytron with three to eight rounded spots.................................................................................................... 4
4. Each elytron with eight rounded spots, lacking short longitudinal yellow line behind humerus (Fig. 4)................................................................................................ Stenolis flavoguttata sp. nov.
- Each elytron with three or four rounded spots and short longitudinal line behind humerus (Fig. 6).................................................................................................. Stenolis xanthostigma sp. nov.
5. Pubescence predominantly grayish, with well-defined black spots on elytron...................................... 6
- Pubescence black, brownish, or brownish-gray, with spots of other color......................................... 9
6. Apical half of elytron with well-defined black belt, projecting forward in suture, sometimes with small subquadrate black mark on external side of basal third (Fig. 3).............................................. S. angulata (Fabricius, 1801)
- Apical half of elytron with well-defined black belt and several black spots on basal and distal half, or with lateral black patch projecting forward from apical black belt................................................................. 7
7. Pronotum with a minute round median round spot near anterior and posterior margins; elytron with transverse black belt on apical third and several rounded and elongated black spots on anterior and posterior half (Fig. 7)................................................................................................. Stenolis calligrama (Bates, 1872)
- Pronotum with longitudinal black median patch and two lines on each side of middle; elytra with transverse black belt on api- cal third, projecting forward by suture and by margins........................................................ 8
8. Basal half of elytron mainly covered with grayish-white pubescence in compact patch, with internal and external margins cov- ered with black pubescence (Fig. 8).................................................. Stenolis tavakiliani sp. nov.
- Basal half of elytron with interrupted longitudinal lines of grayish and black pubescence (Fig. 5).................................................................................................... Stenolis inclusa (Bates, 1885)
9. Elytron with large dark-brown area located on disk at mid-length or slightly behind mid-length...................... 10
- Elytron with different pattern of spots and coloration........................................................ 11
10. Elytron with dark-brown subquadrate area on disk at about mid-length (Fig. 9)............. Stenolis pulverea (Bates, 1881)
- Elytron with dark-brown area located laterally behind humeral angle, and trapezoidal dark area on disk, close to suture margin (Fig. 10)............................................................ S. theobromae (Lara & Shenefelt, 1964)
11. Elytron with numerous grayish-white rounded spots on entire surface.......................................... 12
- Elytron with other pattern of spots...................................................................... 13
12. Elytron with 20 spots, almost all rounded and similar in size (Fig. 11)..................... S. vigintiguttata (Bates, 1885)
- Elytron with more than 20 spots, some of them rounded and of different sizes, three larger spots near external margin (Fig. 12)................................................................................. S. multimacula sp. nov.
13. Pronotum with four rounded spots near posterior margin.(Fig. 13).............................. S. giesberti sp. nov.
- Pronotum without rounded spots........................................................................ 14
14. Pronotum with narrow longitudinal white median line, continuous or interrupted................................. 15
- Pronotum with grayish or blackish longitudinal median line.................................................. 16
15. Scape very long, its apex exceeding base of elytron, slightly enlarged in apical third; conspicuous white mark present in middle of elytra (Fig. 14)..................................................................... S. marcelae sp. nov.
- Scape shorter, its apex reaching posterior margin of prothorax, not enlarged on distal third; elytrona with narrow grayish-white longitudinal lines and winged-form posterior area on disk (Fig. 15).......................... Stenolis nearnsi sp. nov.
16. Frons and genae densely covered with grayish pubescence; basal ¾ of femora with light-brown integument (Fig.16).................................................................................... Stenolis laetifica (Bates, 1872)
- Frons and gena covered with sparse dark-brown pubescence; femoral integument dark brown (Fig. 17)............................................................................................ Stenolis polytaenia (Bates, 1885)