Digestive system formation during metamorphosis of Carposina sasakii Matsumura, 1900 (Lepidoptera: Carposinidae)

Abstract

The purpose of this study is to investigate the adaptive mechanism of morphological and structural changes to habits, during the metamorphosis development of Carposina sasakii Matsumura, 1900. Traditional dissection, paraffin section, and scanning electron microscopy techniques were used to study the morphological structure and cytohistology of the digestive system in different developmental stages of C. sasakii by classical comparativemorphology study. In order to adapt to the change of feeding habits from solid in the larva stage to liquid in the adult stage, the digestive tract of C. sasakii reconstructed in the pupal stage. The crop of the foregut transformed from a spherical shape in the larval stage to an enlarged lateral, accessory, bag-like structure beyond middle of pupal stage and in the adult stage. The hindgut transformed from a columnar structure in the larval stage to a dilated rectal sac at the end of the hindgut in the adult stage. The morphological changes of the digestive tract provided the basis for theC. sasakii to adapt to the changes of food habits and environment. In addition, the present study provides a basis for better understanding of pupal reconstruction of digestive tract. It also lays the foundation for the nutritional physiology and co-evolution between C. sasakii at different stages and its host plant, while providing morphological data for the toxicological and pathological research of this significant agricultural pest.