 Figure 2. Tetramerous tarsus. |
 Figure 3. Pseudotetramerous tarsus. |
1. |
Fourth tarsomere scarcely reduced (pentamerous), subequal to third and attached in normal manner to end of third (fig.2); apical palpomere of maxillary palp cylindrical, not transverse or triangular; mentum strongly transverse (fig.4) | 3 | — |
Fourth tarsal tarsomere strongly reduced (pseudotetramerous), not more than half length or width of third, attached mediodorsally to third (fig.3); apical palpomere of maxillary palp strongly transverse or triangular; mentum not transverse (fig.5,6) | 2 |
Figure 2. Tetramerous tarsus. |
Figure 3. Pseudotetramerous tarsus. |
 Figure 4. Megalodacne sp. |
 Figure 5. Tritoma sp. |
 Figure 6. Triplax sp. |
2(1). |
Elytra non-striate, confusely punctate with large black punctures; prothorax at base but little more than half as wide as greatest common elytral width; size large, 12 mm or more in length (Erotylinae) | Gibbifer |
— |
Elytra regularly striate-punctate; prothorax at base subequal to greatest common elytral width; size small, 8 mm or less in length (Tritominae) | 5 |
3(1). |
Large forms, 9 mm or more in length; black, elytra bearing two reddish fasciae; body largely impunctate (Megalodacninae) | Megalodacne |
— |
Small forms, 6 mm or less in length; elytra without fasciae; body distinctly punctate (Dacninae) | 4 |
4(3). |
Mesosternum extremely short and transverse, about ten times wider than long; prosternum bearing raised, triangular plateau which almost attains prosternal apex; elytron red with black spots | Microsternus |
— |
Mesosternum not more than three times as wide as long; prosternum without such plateau; elytra black or brow, frequently with orange spots | Dacne |
5(2). |
Pronotal angle pores large and conspicuous, umbilicate (fig.7); apical palpomere of maxillary palp bearing distinct brush at apex (fig.6) | 6 |
— |
Pronotal angle pores small, inconspicuous, simple (fig.8); apical palpomere of maxillary palp without apical brush, postmandibular lobes poorly developed, usually not visible | 7 |
Figure 6. Triplax sp. |
 Figure 7. Triplax sp., large pore |
 Figure 8. Tritoma sp., small pore |
6(5). |
Apical palpomere of maxillary palp strongly transverse; body without dorsal pubescence | Triplax |
— |
Apical palpomere of maxillary palp squared, not transverse; body strongly punctured and pubescent | Hirsutotriplax |
7(5). |
Pronotum and elytra bicolored, bearing complex black pattern on lighter background | Ischyrus |
— |
Pronotum unicolored, elytra unicolored or black with basal red spots | 8 |
8(7). |
Prosternal lines long, either incurved anteriorly or meeting at prosternal apex (fig. 5); elytron immarginate basally; body relatively broadly oval or egg-shaped | 9 |
— |
Prosternal lines short, not or scarcely extending in front of inner coxal edges (as in fig. 6); elytron often margined basally; body elongate-elliptical | 10 |
Figure 5. Tritoma sp. |
Figure 6. Triplax sp. |
9(8). |
Eyes coarsely faceted, relatively large and protuberant (fig.9) | Pseudischyrus |
— |
Eyes finely faceted, relatively small (fig.10) | Tritoma |
 Figure 9. Tritoma sp. |
 Figure 10. Pseudischyrus sp. |
10(8). |
Head and pronotum reddish yellow to bright orange-red | Mycotretus |
— |
Head and pronotum entirely black | Haematochiton |