The smooth elytra of adult Colorado potato beetle, Leptinotarsa decemlineata, make this insect difficult to make efficiently for long-term field studies. Enamel paint marks fell off rapidly, and after 28 days, 25010 of marked beetles had lost all four original marks. Use of small paper labels glued to the elytra after an acetone wash and sanding pretreatment was the most effective method for long term marking of individual beetles. Mortality in labeled laboratory-reared and field-collected beetles did not increase when compared to unmarked beetles.
Caprio, Michael A.; Miller, Deborah; and Grafius, Edward
"Marking Adult Colorado Potato Beetles, Leptinotarsa Decemlineata (Coleoptera: Chrysomelidae) Using Paper Labels,"
The Great Lakes Entomologist, vol 23
Available at: https://scholar.valpo.edu/tgle/vol23/iss1/4