The story itself, set in a 'GenerationX' mindset of hard core industrial music, spiked collars, black lipstick and nailpolish, skinheads with multiple piercings dressed in all black, - - most of it set in dim, dark, grim and depressing settings - ... and in the author's description..."A fun world for the sick-o masochists, those inscrutable pervs who enjoy pain and injury enough to allow some equally psychopathic hornbug get his or her giggles by producing squeals of torment and agony using this junk" (referring to the different array of toys used by practitioners of this lifestyle)

This is the only reference to "hornbug" I've found. Hope it helps

So many words for the concept!

Horn"bug` (?), n. (Zoöl.) A large nocturnal beetle of the genus Lucanus (as L. capreolus, and L. dama), having long, curved upper jaws, resembling a sickle. The grubs are found in the trunks of old trees.
(just to get that out of the way)
Ergo: stays hidden, is nocturnal, likes decay


From Harriet Beecher Stowe's "Uncle Tom's Cabin", Chapter IV:

"And so ye telled Tom, did ye? O, Lor! what young uns will be up ter! Ye crowed over Tom? O, Lor! Mas'r George, if ye wouldn't make a hornbug laugh!"

From Ms Stowe's "Poganuc People", Chapter X:

"Well, if ever I see such young 'uns!" said Nabby, flaming carnation color over the fire as she took off the cakes.
"That Bill is saassy enough to physic a hornbug. I never see the beat of him!"

**"physic", here, means "to heal".


Also, keep in mind that "Ya such a hornbug" is not standard construction so the translation has to be equally off.

Je n'arrive pas à situer vraiment ce que peut être un "hornbug" sans le contexte qui amène ce "compliment"... Néanmoins, je pense à:

dans le sens "dépravé": "t'es malade!" "t'es tout un malade!" qualifie (au Québec) toute personne au comportement discutable, tordue, vicieuse ou psychotique.

dans le sens dérangeant: casse-pied