catalpae

Are Catalpa Worms Poisonous? Ok, if you already know it is a catalpa worm, then it is NOT poisonous, OR venomous. ‘Poisonous’ means something is toxic if it is ingested (eaten). ‘Venomous’ means its bite or sting is dangerous. Catalpa worms eat ONLY catalpa, so it won’t eat if it is not on that tree.