Abstract: As an important part of insects, nocturnal species have evolved some sensory mechanisms adapted to their habitats. It is generally believed that nocturnal insects mainly rely on olfaction and mechanical perception to explore habitats, and the visual system has been degraded or lost. In recent years, with the application of new biological technologies such as infrared night vision, electroretinogram (ERG) and optic nerve, breakthroughs have been made in visual and ecological research of insects. Since 2002, it has been successively found that some nocturnal insects such as moths, bees and dung beetles had evolved a remarkable capacity of dimlight vision, and can see brightness, color, shape, size, contrast, polarized light and motion at night (light intensity lower than 0.3 lx) as in bright day, showing an immense potential for visually regulating behaviors in nocturnal insects. In addition, the pupil, focal length, rod and pigment particles of compound eyes of these nocturnal insects have evolved some morphological and physiological characteristics to improve the optical sensitivity and to adapt to the dim-light environment at night. Since the study of dim-light vision and the mechanisms of visual adaptation in nocturnal insects is still in its infancy with a focus on flower-visiting or fecal-feeding insects, the research of the following aspects should be streagthened: (1) the dim-light vision in major nocturnal agricultural pests; (2) the optical structure characteristics of atypical superposition compound eye and the mechanisms of its adaptation to dim-light environment; (3) the mechanisms of visual adaptation in nocturnal insects in response to dim-light environment; and (4) the development of new pest control technology based on dim-light vision in nocturnal insects.

Key words: Nocturnal insects, dim-light vision, color vision, visual navigation, compound eye, opsin