Morphology of the Mouthparts of Ladybeetle Vibidia duodecimguttata (Coleoptera: Coccinellidae), with Emphasis on Their Sensilla.

Mouthparts are the feeding organs of insects, which play vital roles in the feeding process. The morphology of insect mouthparts has greatly evolved according to different foods and feeding habits. Therefore, studying the structure of the mouthparts is the key to understanding their feeding mechanisms. Vibidia duodecimguttata is an important biological control agent for powdery fungus. In this study, the fine morphology of the mouthpart of V. duodecimguttata was studied by scanning electron microscopy. The basic components of mouthpart of V. duodecimguttata are similar to those of other ladybeetles, while the specific morphology of each part is different. In total, six kinds of sensilla were identified on mouthpart, and twelve types of sensilla were divided according to their morphology, length and distribution. In addition, two kinds of glandular structures were also found, namely perforated plates and cuticular pores. Finally, the morphological differences between mycetophagous and other feeding habits ladybeetles were compared, and the function of each kind of sensilla was discussed, which may establish a solid foundation for further understanding of the feeding mechanism of ladybirds.