Males
1. Summed number of spines in pectinifers 37-50; forewing creamy white ................ mojavella
Summed number of spines in pectinifers 11-33; forewing white or rarely tan ....................... 2
2. Aedeagus less than or equal to 0.025 mm in minimum cross section .................................... 3
Aedeagus bigger than or equal to 0.030 mm in minimum cross section ................................ 5
3. Antennal integument brown ....................................................................................... baccatella
Antennal integument yellow, sometimes with darker apical segment ..................................... 4
4. Aedeagus 1.7 - 2.0 mm long ....................................................................................... maderae
Aedeagus 2.7 - 3.0 mm long .............................................................................. carnerosanella
5. Hindwings white or very light grey ............................................................................ rostratella
Hindwings with at least apical region darker, often solid dark brown-grey ............................ 6
6. Aedeagus bigger than or equal to 0.06 mm in minimum cross section .................................. 7
Aedeagus less than or equal to 0.05 mm in minimum cross section ..................................... 11
7. Aedeagus > 2.2 mm long ........................................................................................... corruptrix
Aedeagus < 1.8 mm long ......................................................................................................... 8
8. Summed number of spines in pectinifers 25-27; hindwing white with darker apical region ................................................................................................................................................. elatella
Summed number of spines in pectinifers 13-20; hindwing dark brown to grey ................... 9
9. Lower base of valva to pectinifer 1.15-1.30 mm, lower base of valva to apex 1.50-1.70 mm; forewing white, hindwings dark brown ........................................................................... superficiella
Lower base of valva to pectinifer 0.95-1.15 mm, lower base of valva to apex 1.35-1.50 mm; forewing sometimes with tan scales, hindwings light with grey areas ............................................. 10
10. Aedeagus diameter 0.07-0.08 mm; forewings often with tan scales ........................... intermedia
Aedeagus diameter 0.09-0.10 mm; forewings without tan scales ....................................... cassandra
11. Distinctive crescent-shaped bend on valva present below pectinifer ........................................ 12
Crescent replaced by gently curved edge below pectinifer ....................................... treculeanella
12. Crescent less than or equal to 0.05 mm wide and < 0.1 mm deep; pectinifers with more than or equal to 21 spines ............................................................................................................... altiplanella
Crescent > 0.05 mm wide, > 0.1 mm deep; pectinifers rarely with >18 spines .......... yuccasella
Females
1. Tentacles rudimentary or wholly absent ..................................................................................... 2
Tentacles fully developed ........................................................................................................... 3
2. Apophyses posteriores < 6 mm long, signa > 1.1 mm in diameter ............................ intermedia
Apophyses posteriores > 8 mm long, signa < 1.0 mm in diameter ............................. corruptrix
3. Hindwings white or very light grey, general habitus an all-white moth ..................................... 4
Hindwings grey or brown in part or their entirety ...................................................................... 5
4. Antennal integument yellow ................................................................................... carnerosanella
Antennal integument brown or dark brown .................................................................. rostratella
5. Keel on ovipositor >0.06 mm, signa > 1.2 mm in diameter ...................................................... 6
Keel on ovipositor less than or equal to 0.04 mm, signa less than or equal to 1.2 mm in diameter (usually much less) ............................................................................................................................................................. 8
6. Very prominent ovipositor keel 0.06-0.07 mm in height, signa 1.2-1.3 mm in diameter, hindwings light with darker apical region, never uniformly dark brown ................................................................................. elatella
Ovipositor keel 0.07-0.09 mm in height, signa 1.3-1.7 mm in diameter; hindwings uniformly brown or dark brown or grey with darker apical region ...................................................................................................................... 7
7. Signa 1.30-1.50 mm in diameter; hindwings uniformly brown or dark brown .......... superficiella
Signa 1.45-1.70 mm in diameter, hindwings light with darker grey apical region .......... cassandra
8. Signa 0.9-1.2 mm in diameter ....................................................................................... yuccasella
Signa less than or equal to 0.8 mm in diameter ........................................................................... 9
9. Signa less than or equal to 0.45 mm in diameter, apophyses posteriores > 7.5 mm in length; hindwings dark greyish brown ..... baccatella
Signa more than or equal to 0.55 mm in diameter, apophyses posteriores less than or equal to 7.3 mm (usually far less); hindwings dark brown or otherwise ............. 10
10. Antennal integument yellow, with apical segment often darker ...................................... maderae
Antennal integument brown or dark brown .............................................................................. 11
11. Serrated ovipositor keel 0.030-0.035 mm in height, half that of ovipositor diameter .... altiplanella
Serrated ovipositor keel so low that teeth appear to arise from ovipositor surface .................... 12
12. Apophyses posteriores < 5.9 mm in length; forewing white ..................................... treculeanella
Apophyses posteriores > 6.6 mm in length; forewing creamy white ............................ mojavella
