Histomorphological modifications in the alimentary canal of the fruit sucking moth, Othreis materna (Linn.) (Lepidoptera:Noctuidae) in relation to phytophagous and fruit sucking habits

In the larva of fruit sucking moth, O. materna in accordance with the phytophagous feeding habit, the pharyngeal, pyloric and ileac intima bears fine spines facing the lumen while these cuticular structures are lacking in the adult which are adapted to the fruit sucking habit. The rectal pads are present in the anterior and the middle region of the rectum in larva and adult respectively. In the larvae the total length of the alimentary canal is always equal to the body length and maintain the ratio 1:1 while in the adult it is longer than the body length at the ratio of 1:1.08. The progressive growth factor in relation to the gut is often changing in successive larval instars. The relative growth rate of the alimentary canal was reduced in the last instar larva.