Multichambered-gall
Guides
Diplolepis spinosa
many-spined twig gall wasp
Diplolepis spinosa is a cynipid gall wasp native to North America that induces large, conspicuous, multichambered stem galls on wild and domestic roses. The species has been documented on Rosa blanda, Rosa acicularis, and Rosa rugosa, and has recently become established on domestic roses in central Canada. Its galls are among the most visible in grassland habitats across the continent. The wasp exhibits complex gall development involving eggs deposited in slits between leaf primordia near bud tips, with larvae inducing separate chambers within spherical stem galls.