Key to Monolepta pallidula species group from Taiwan

1. Antenna wider (Figs. 29, 35), antennomeres 4–10 about 4.0 times longer than broad at apex; black lateral margin of elytron abbreviated near apex ....................................................................................................................................... 2

- Antenna slender (Figs. 13, 26), antennomeres 4–10 about 5.5–6.2 times longer than broad at apex; body color variable, elytron entirely yellowish-brown (Fig. 1), or yellowish-brown and with black lateral margin (Figs. 2–4), or entirely black (Figs. 5–6) ............................................................................................................................................ 3

2. Black lateral margin of elytra from base to basal 2/5 (Figs. 7–8); lateral margin of median lobe not extending posterior in middle, without a deep groove at middle in ventral view .... ......................................... M. sauteri Chûjô, 1935

- Black lateral margin of elytra from base to basal 4/5 (Figs. 9–10); median lobe extending posterior at middle, with a deep groove at middle in ventral view ................................................................................. M. kuroheri Kimoto, 1966

3. Tibia yellowish-brown (Figs. 1–2) ...................................................................................... M. gracilipes Chûjô, 1938

- Tibia black or blackish-brown (Figs. 3–6)........................................................................... M. tsoui Lee, new species