TENBM:1998:0073 - Leptinotarsa decemlineata is an invasive pest species. Over the past 30 to 60 years it has rapidly become resistant to all insecticides. Specimens in museums that have a good provenance, showing where and when they were found, are used by scientists to monitor changes in the insect. This specimen is flattened between two pieces of glass to create a slide. Insects are most often pinned to preserve their shape.