Dr Sami Karjalainen. Author of many insect books (Odonata, Calopterygidae, Orthoptera, Coccinellidae).

The latest book, Suomen hyppyhämähäkit (The Jumping Spiders of Finland, Salticidae), was published in 2022. In Finnish with a preface and short summaries in English.

See inside the book:
http://www.samikarjalainen.fi/hypykki/Suomen-hyppyhamahakit-nayte-lowres.pdf

How to buy the book:
http://www.samikarjalainen.fi/hypykki/howtobuy.html (sorry, sold out!)