I have to admit that this creature was not in my garden, but found by my husband underneath the loose bark of an oak tree he was about to saw to slaps.
There was another one in a more brownish colour.
Are these really Book scorpions?
As far as I understand, the thin line over the back of these creatures identifies them as Book scorpions. There are also a lot of different varieties among Book scorpions, but it needs an expert to identify them exactly. Book scorpions are one of many different pseudo scorpions.
What do Book scorpions eat?
What is very good to know is that book scorpions are helper insects. They also live in our living space and eat house dust mites and dust lice. Other than that they also eat wood lice, mites, fruit flies and springtails.
How do Book scorpions breed?
After a courtship dance the male sets a spermatophore on the ground and pulls the female above it.
The black Book scorpion is a female with its brood pouch underneath her abdomen. Apparently the brood pouch is made from secretion in which the female caries the embryo’s. The embryo’s are fed with her body’s own nutrient solution. The eggs are laid in specially woven incubators.
Information mainly found on: http://www.biologie-seite.de/Biologie/B%C3%BCcherskorpion