Food plant, larval bionomics, and diagnosis of the Alpine Silver-Y, Syngrapha ottolenguii (Lepidoptera: Noctuidae)

Information on the biology of the alpine moth, Syngrapha ottolenguii, is very limited. On the main island of Japan, Honshu, we determined a natural host plant of S. ottolenguii to be Empetrum nigrum in alpine fields; the larvae showed a characteristic nocturnal feeding behavior on this plant. During daytime, the moths hid in the lower layer of the dense E. nigrum shrub. S. ottolenguii exhibited a univoltine life cycle with hibernation at the second or third instar larval stage under deep snow, where the temperature stayed stable at 0 °C for about 6 months. They could be reared with a generation time of about 60 days on an artificial diet under 16L–8D at 20 °C. The larva was classified as a monosetose with subventral (SV) setae on the second and third thoracic segments.