Notes on Two Migrant Moths from the Faroe Islands, Agrotis segetum (L.) and Noctua orbona (Hfn) (Lepidoptera, Noctuidae): Fráboðan um tveir ferðanáttfirvaldar, Agrostis segetum (L.) og Noctua orbona (Hfn) (Lepidoptera. Noctuidae)

Abstract

On 21 June 1996, a male Agrotis segetum (L.) was caught at Oyrarbakki on northern Eysturoy and, on 7 July 1997, a female Noctua orbona (Hfn.) was caught at Nesvík on northern Streymoy. The two moth species had not been recorded previously in the Faroe Islands. In both cases, their presence coincided with influxes of other migratory lepidoptera species to the area. Temperature conditions, the direction and flow rates of the air currents both at sea level (s.l.) and at 850 hPa (1500 m a.s.l.) during the migratory periods of each indicated that both species were transported by air currents, probably at altitudes of 1000 m a.s.l. Reference to meteorological "backtrack" data showed that Agrotis segetum was transported from western Europe westward via a high-pressure area over the British Isles, while the Noctua orbona was transported eastward from central Europe via a low-pressure area again over the British Isles.