By looking at tansy beetles in museum collections, we know that you used to be able to find them in many more places.
Museum specimens come with data – information on when and where they were collected and this is often kept with the specimen itself and on a digital catalogue.
The museum collection at Leeds Museums and Galleries has a number of tansy beetles and tansy plants and we can use them to help scientists research topics such as the impact of environmental or climate change, changes to the animals’ morphology (for example getting smaller or larger, or egg cases getting thinner or thicker) and to identify areas for habitat restoration. If we know that a species used to be present in a certain area, then we can work to re-introduce that species to help with its survival. This is especially important with endangered species such as the tansy beetle.