Monarch Danaidae

Danaus plexippus (Linnaeus, 1758)

Description: Wingspan 95-100mm. Males and females are similar. The body is black and spotted with white. The uppersides are reddish-orange with black veins. The margins are black with a double row of small whites spots. The patterning on the underside is similar.

Similar Species: None in Ireland.

Key Identification Features:

Sets:  male upperside male underside

Flight Period: The majority of records in Ireland have been in late Autumn which is the time of year on would expect weather conditions to be most suitable for bringing individuals across the Atlantic.

Status: Very rare vagrant. It was first reported in N. Ireland at Lurgan in July 1964. Four adults were seen in east Down and Belfast between the 12 and 15 October 1995. These last arrivals were part of a large influx of Monarchs to Britain and Ireland in which approximately 150-200 individuals were seen. The weather patterns strongly indicated they had been blown across the Atlantic.

Ecology: This is a North American butterfly which has established populations in other parts of the world including the Canary Islands, and recently southern Spain. The larval foodplants are species of milkweeds Asclepias which are not native to Ireland, so there is no prospect of the species ever becoming established.

World Distribution: A native of North America where the species is well known as a migrant. It has colonised other parts of the world where the foodplant have become established including New Zealand, Australia, Asia and most recently southern Spain.

Bradley & Fletcher number: 1630 Agassiz number: 59.001

Additional information:

UK Butterflies account


 Thompson, R. S. & Nelson, B., 2003 (Oct 2). [In] The Butterflies and Moths of Northern Ireland