Burnet moths in Cornwallby John Worth
In the Victoria County History published in 1906 the Five-spot burnet is described as very local whilst the Six-spot Burnet is described as common throughout Cornwall. A century later and a similar situation exists today with the five-spot's restricted distribution and the six-spot relatively common especially along parts of the coasts. The Six-spot has the wider distribution within the UK ranging from the Isles of Scilly to the Outer Hebrides. The Five-spot has two subspecies in Britain, each with a distinct ecology; ssp. palustrella is found on chalk downs and limestone hills in southern England whilst it is ssp. decreta which is found in Cornwall.
Decreta is confined to marshes, wet moorland, damp meadows and occasionally to comparatively dry cliffs. Sites include Marazion Marsh, Goss Moor and Breney Common. It is an indicator species of relatively undamaged wetlands (W. G. Tremewan, 1985).
The distribution of the six-spot is no doubt incomplete because many small colonies probably go unnoticed or unrecorded. For example, a small colony at Roskilly, near Mousehole exists in a narrow area below the road and coast path, but within the splash zone. An area where comparatively few people let alone moth recorders visit.
Both species fly during the day and the graph is constructed from data provided by recorders and shows the flight periods in Cornwall.
Both species broadcast their eggs near the foodplants. In the case of the Five-spot the foodplant is greater bird's-foot trefoil (Lotus pedunculatus) and for the Six-spot it is usually the common bird's-foot trefoil (L. corniculatus), although it has been recorded on greater at the Lizard.
In Cornwall both species pupate in a cocoon, usually exposed on stems of grasses, etc. Some guidebooks state that the Five-spot cocoon is concealed amongst grass and other herbage but this refers to the subspecies palustrella.
Tremewan, W.T. 1985. Zygaenidae. In: Heath, J. and Maitland Emmet, A. (eds.) The Moths and Butterflies of Great Britain and Ireland. Vol. 2. Colchester: Harley Books.
Images can be seen at ukmoths:
- 169 Six-Spot Burnet Zygaena filipendulae (Linnaeus, 1758)
- 170 Five-Spot Burnet Zygaena trifolii (Esper, 1783)