The butterfly and moth collection includes around 300,000 spread specimens from 20,000 different species. Of these, around 200 taxa are represented by primary types. The butterflies and moths come from all over the world, but especially Europe, Asia, Africa and South America. The local fauna is particularly well-represented, as are the Blues (Lycaenidae) and the Palaearctic owlet moth (Noctuoidea).
An important part of the collection from the 19th century includes around 140 drawers from Friedrich Riggenbach-Stehlin, containing mostly local butterflies and moths from the southern foot of the Jura mountains (Bechburg).
Significant general collections come from Hermann Honegger, Eugen Wehrli (without geometrid moths), Ludwig Paravicini, W. Markl, Otto Gutzwiller, F. Weber and P. Ryhiner.
The following special collections are worthy of mention: Lycaenidae from Ludwig Georg Courvoisier and Henry Beuret, Noctuinae from Arnold Corti, Swiss Microlepidoptera from Johann Müller-Rutz and Afro-tropical Charaxes and Papilionidae from GianCarlo Veronese.