Ideoblothrus descartes is a species of pseudoscorpion in the Syarinidae family.

It was described in 1991 by Australian arachnologists Mark Harvey and Karen Edward.

The specific epithet descartes refers to the type locality.

[1] The species occurs in the Kimberley region of North West Australia.

The type locality is beneath rocks, near a freshwater seep in vine thicket habitat, on Descartes Island, at the mouth of Admiralty Gulf.