Fungal and vascular plant polysaccharide digestion by larvae of Aenetus virescens (Lepidoptera: Hepialidae)

Abstract

Larval feeding by the wood borer Aenetus virescens is characterised by an initial diet of dead wood and fungal fruiting bodies (“litter-phase”) followed by a transition to callus tissue of trees and shrubs for the main period of larval development (“tree-phase). Larvae of both stages exhibit gut activity to laminarin and starch, showing the potential to digest β-(l,3) and α-(l,4) glucans respectively. Although β-(1,3) glucans are rare in vascular plants it is suggested that they may be present in the diet of A. virescens as callose. Gut activity to laminarin and starch was also confirmed for the foliage feeding Wiseana, indicating that the ability to digest β-(l,3) glucans may be widespread in the Hepialidae. Tree-phase gut activity was recorded for galactomannan, very weak activity to carboxymethyl cellulose and no activity to chitin. The litter-phase exhibited very weak activity to chitin, but no activity to carboxymethyl cellulose.

Keywords>:

• Hepialidae
• polysaccharide digestion
• Aenetus virescens
• Lepidoptera
• Mycophagy
• fungivory
• larvae
• fungi