The Forest Research Institute collection includes zoological and botanical specimens.

The zoological specimens (insects) come from the insect collection of the IBL in Sękocin Stary, and their range is worldwide. The collection includes insect specimens belonging to 3 orders:

• representatives of the order LEPIDOPTERA (BUTTERFLIES), which is the richest collection of the IBL in terms of fauna. The oldest part of the collection dates back to the 1920s and 1930s and was mainly established by Józef Schneider
• representatives of the order COLEOPTERA (beetles), the collection includes, among others, the families: Carabidae, Curculionidae, Cerambycidae;
• representatives of the order DIPTERA (MUCHÓWKI), which belong to the youngest part of the collection. The collection of flies began in the 1960s, and the first specimens collected belonged to the family Tachinidae. However, most of the digitized materials are insects collected since the mid-1990s, and the most numerous are species belonging to the following families: Tachinidae, Muscidae, Rhinophoriidae, Sciomyzidae and Syrphidae, and less numerous also from the families Scatophagidae, Anthomyiidae or Caliphoridae and sporadically from several other families of two-winged insects.