The availability of suitable habitat, i.e. ponds, for this species is largely determined by the soil type. The pattern of ponds shown here closely matches that of boulder clay which forms a band from SW to NE (see maps for Cowslip and Black Byony). Further survey work will probably reveal more sites for this species and it is not clear at present how much of this pattern is due to recorder bias. This species is included in the Suffolk Biodiversity Action Plan.