In Southern and Appalachian speech, a devil’s darning needle is a folk name for a dragonfly - rooted in old superstitions about dragonflies sewing up snakes or people.
★ This name reflects an old superstition that dragonflies would sew up the mouths of liars or snakes - giving them their "needle" reputation. ★
Origin and Etymology
Recorded widely in Southern/Appalachian and European folklore. The name "devil’s darning needle" appears in print from the 1800s and spread to rural America, especially the South, where it blended with local myths about snakes and sewing.
Usage Notes
Devil’s darning needle - folk name for a dragonfly with a superstition attached.
Created by The Hillbilly Dude, this site is a growing field guide to culture, speech, memory, and meaning - rooted in Appalachia but reaching across the world. Every slang word, saying, accent and story is gathered from first-hand experience and trusted sources. The goal: preserve authentic voices and share them with writers, learners, and culture lovers everywhere - with a little humor thrown in here and there. Read more...
I love these old long ones like 'devil’s darning needles,' but this one in particular I've only ready. 
