Abstract: 【Aim】 Superposition eyes play significant roles in the evolution of compound eyes of insects. The study aims to elucidate the type and structural features of compound eyes of nocturnal Manulea affineola, attempting to fill a gap in the compound eye research in the Arctiinae, to expand the characteristic data of the compound eyes of nocturnal insects, and to provide evidence for exploring the variation trend of superposition eyes and the evolution of compound eyes. 【Methods】 The ultrastructure of adult compound eyes of M. affineola was observed using light and transmission electron microscopy. 【Results】 The adult compound eyes of M. affineola possess clear zones, which are formed by electron-lucent cytoplasm of six secondary pigment cells. The ommatidium has eight retinula cells, one of which is short and only located at the base of ommatidium. Within the clear zone, seven retinula cells gather into a bundle, which distally connects with the proximal end of the crystalline tract but does not form a rhabdom. Beneath the clear zone the seven retinula cells form a centrally-fused rhabdom. The rhabdoms display approximately square transverse profiles in the ommatidia in the dorsal rim area of the compound eye, whereas in the rest ommatidia they assume multi-branched transverse profiles. 【Conclusion】 The adult compound eyes of M. affineola are of the superposition eyes. The square rhabdoms in the dorsal rim area of the compound eye are likely related to the polarization sensitivity of insects.

Key words: Lepidoptera, Erebidae, Arctiinae; Manulea affineola, ommatidium, clear zone; superposition eye