Key to the Guinea-Bissau species of Arsinoe

1. Elytra with thin transverse microreticulation; each elytron with a large yellow humeral spot extending since the 3 rd to the 8 th intervals and a large, irregular subapical yellow spot extending since 1 st to 7 th intervals, giving a clearly trimaculate appearance to the elytra (Fig. 1 in Facchini 2011); legs yellowish; male genitalia as in Facchini (2011, Figs. 7a–b)............................................................................................. Arsinoe triguttata Facchini, 2011

- Elytra without transverse microreticulation................................................................. 2

2. Head with strong longitudinal furrows on the sides above and near the eyes (Fig. 1a); pronotum strongly transverse (1.8–1.9 times as wide as long), lateral sides very large and heavily wrinkled posteriad; male genitalia as in figures 2a–b............................................................................................. Arsinoe aguiari n. sp.

- Head with few and slight longitudinal furrows on the sides above and near the eyes................................. 3

3. Elytra with two pairs of yellowish spots, one subhumeral sub-rounded extending from the 3 rd –4 th to 7 th intervals, and other subapical rounded extending from 1 st –2 nd to 4 th intervals; legs with femurs and tibiae yellowish, knees and tarsi blackish.............................................................................. Arsinoe flavosignata (Gory, 1833)

- Elytra with two pairs of yellowish spots, one subhumeral oblique extending from the 3 rd interval to the 8 th interval, dented anteriad in the 5 th (part), 6 th and 7 th (part) intervals and posteriad in the 4 th interval, and other subapical joined by the suture, extending from 1 st –5 th intervals, strongly dented anteriad in the 3 rd interval and posteriad in the suture-1 st interval and 4 th interval; legs totally blackish................................................ Arsinoe laevigata Basilewsky, 1970