If you have less than 30HP, find Hester Gilk in Cor Noth.

Keep saying Insect to her until her reply mentions them. Now say patterns.

She will start rambling about some bugs that stole her patterns and request that you find them for her. Leave Cor Noth and start killing Baby Spiders, Centipedes and Ants in the surrounding areas (it can be 1 or two screens out) until one of them drop a pattern.

Return it to Hester Gilk and she will reward you with a random Robe of the Disciple.