Rosa
Guides
Diplolepis
gall wasps, rose gall wasps
Diplolepis is a genus of gall-inducing wasps in the family Diplolepididae, most commonly associated with roses (Rosa spp.). These small wasps are notable for inducing complex, often conspicuous galls on their host plants through chemical manipulation of plant tissues. The genus includes both sexual and parthenogenetic species, with some like D. rosae reproducing primarily by thelytokous parthenogenesis. Diplolepis species exhibit intricate life cycles involving alternation between sexual and agamic generations, and their galls support diverse communities of parasitoids and inquilines.
Diplolepis californica
leafy bract gall wasp
Diplolepis californica is a cynipid gall wasp that induces distinctive club-shaped bud galls on wild roses (Rosa species) along the Pacific coast of North America. The species was originally described as Rhodites californicus by Beutenmüller in 1914 and later transferred to Diplolepis. Its galls are characterized by flat, leafy lobes projecting from the main gall body—structures that resemble aborted leaflets and distinguish this species from other rose gall wasps. Each gall contains multiple larval chambers, indicating communal development within a single gall structure.
Diplolepis nervosa
Spiked Pea Gall Wasp
Diplolepis nervosa is a gall wasp in the family Diplolepididae that induces distinctive spiked pea galls on wild roses (Rosa species). Like other members of its genus, it exhibits an alternation of generations with both sexual and parthenogenetic phases. The species is native to Europe and has been introduced to North America, where it has become established. The galls it produces are among the most recognizable of rose galls due to their characteristic spiny, pea-like appearance.
Diplolepis polita
Spiny Leaf Gall Wasp
Diplolepis polita is a gall wasp in the family Cynipidae, first described by William Harris Ashmead in 1890. The species induces distinctive spherical, spiny galls on the leaves of wild roses, primarily Rosa acicularis and Rosa arkansana, in spring and early summer. Originally known only from western North America west of the Rocky Mountains, it has demonstrated host flexibility by colonizing the introduced domestic shrub rose Rosa rugosa in urban environments. This host shift provides insight into the vagility and host specificity of cynipid wasps.
Diplolepis rosae
Mossy Rose Gall Wasp, Rose Bedeguar Gall Wasp, Robin's Pincushion Gall Wasp
A gall-inducing wasp in the family Diplolepididae that forms distinctive mossy, pincushion-like galls on wild roses, primarily Rosa canina and Rosa arvensis. The species is notable for its predominantly parthenogenetic reproduction, with fewer than 5% males in most populations. Females lay up to 60 eggs in developing rose buds, inducing chemically-driven plant tissue distortion that creates the characteristic bedeguar gall. The wasp has been introduced to North America alongside cultivated roses.
Periclistus
Periclistus is a genus of micro-hymenopteran gall wasps (Cynipidae) comprising at least 17 described species. These wasps are obligate inquilines that occupy galls induced by other cynipid genera on plants in the rose family (Rosaceae), particularly roses (Rosa). Unlike gall inducers, Periclistus species have lost the ability to initiate galls but retain the capacity to modify existing gall tissue, inducing nutritive tissue for their own larvae. The genus exhibits a phylogenetic divide between Palaearctic and Nearctic clades, with host specificity ranging from specialists to generalists across different species.
Phylloecus trimaculatus
Rose Shoot Sawfly
Phylloecus trimaculatus, commonly known as the rose shoot sawfly, is a stem sawfly in the family Cephidae. Adults emerge in late April and oviposit inside the stems of Rosa and Rubus species. Larvae feed within host stems throughout the summer before dropping to the ground to overwinter. The species occurs from southern Canada through the eastern United States to the Great Plains.
Rabdophaga rosacea
rose rosette gall midge, rose rosette midge
Rabdophaga rosacea is a gall midge in the family Cecidomyiidae that induces distinctive rosette galls on native roses (Rosa spp.). The species was first described by Ephraim Porter Felt in 1908 from specimens collected in Manitoba, Canada. The galls form on terminal buds, creating tightly packed leafy rosettes with a central cavity that houses the developing midge larvae. The genus name derives from Greek roots meaning 'rod-eater', while the specific epithet refers to its rose hosts. A 2014 taxonomic proposal suggested transferring this species to the broadly defined genus Dasineura, though both genera remain within the tribe Dasineurini.
Trichapion roseae
Trichapion roseae is a small weevil in the family Brentidae, formerly placed in the family Apionidae. It is associated with plants in the genus Rosa (roses), with adults and larvae feeding on various parts of the host. The species is native to the Palearctic region and has been introduced to North America. It is recognized by its elongated rostrum and association with rose hosts.