Pot beetles are a fascinating and charismatic group of leaf beetles that are very rare in Scotland! The Spotting Pot Beetles project has been raising awareness of Pot beetles through workshops and surveys.
Pot beetles are amazing insects within the leaf beetle family (Chrysomelidae). These beetles get their common name from the protective shell-like ‘pot’ that the larvae live in, created using their own droppings. The other key feature of these beetles is that the head of the adults is hidden under their bulging pronotum, which is the source of the scientific name for the genus Cryptocephalus meaning ‘hidden head’.
There are currently 19 species of Cryptocephalus pot beetles in the UK, however many of these have suffered declines in their distribution and are now quite rare. This project has successfully run surveys to assess known sites in Scotland for the Ten-spotted pot beetle (Cryptocephalus decemmaculatus) and Six-spotted pot beetle (Cryptocephalus sexpunctatus); both of which are priority species on the Scottish Biodiversity List.
Ten-spotted pot beetle (Cryptocephalus decemmaculatus) is yellow with black spots and is typically found in damp, deciduous woodland and is specifically associated with willow (Salix species) and birch (Betula species). This species of beetle has an extremely localised distribution in the UK with only a single known site in England. In Scotland, this species has historic records at five sites, although it has been recorded at only two of these since 1980, and only one of these (in Perthshire) has multiple records and detailed location information. In July 2017, several adults were recorded at Black Wood at Rannoch with the help of volunteers.
Six-spotted pot beetle (Cryptocephalus sexpunctatus) is reddish-yellow with black spots and has been found on a number of plant species including Aspen (Populus tremula), Crack willow (Salix fragilis), Hawthorn (Crataegus monogyna) and young oak (Quercus species). This species has an extremely localised distribution in the UK with only one known site in Scotland and one known site in England that has had no sightings since 2003. In June 2017, two adults were recorded from young birch saplings at Kirkconnell Flow, near Dumfries with the help of 12 volunteers!
Additionally, two other species of pot beetle were recorded during the two surveys. Two adults of the Nationally Scarce Two-spotted pot beetle (Cryptocephalus bigutattus) were recorded at Kirkconnell Flow in June 2017. The Black birch pot beetle (Cryptocephalus labiatus) was recorded at Black Wood at Rannoch during the survey in July 2017.