Abstract
Larval feeding responses of the two types, i.e. fruit-feeding type (FFT) and Pinaceae-feeding type (PFT) of the yellow peach moth to the host-plant extracts and their sugar components were examined by a filter paper assay. Both larvae responded positively to the 80% MeOH extracts of host plants but not to chloroform, ether and ethyl acetate extracts. FFT larvae refused the 80% MeOH extract of Japanese white pine, and showed no response to that of Himalayan cedar and fir. PFT larvae responded positively to the 80% MeOH extracts of chestnut, young green apple and peach. Seven different sugars were identified from the host plants by HPLC. FFT larvae preferred sucrose to fructcse and gluccse whereas PFT preferred fructose to sucrose and gluccse. FFT larvae responded moderately to sorbitol and inositol but refused maltose and lactose at higher concentrations whereas the PFT larvae showed no response to these sugars. Based on these observations, FFT and PFT appeared to show different response spectra to the host-plant constituents, e.g. sugars, and also to be taxonomically different within the species.
