Druon ignotum

This species is widely distributed in central and eastern North America.[1][2] Larvae induce galls on white oaks, including bur oak, swamp white oak, overcup oak, and post oak.[3]

Like many oak gall wasps, this species has two generations per year - one asexual (or agamic) and one sexual, with each generation producing distinct galls.[2] Galls of the agamic generation are small, ovoid, and occur in clusters along veins on the underside of leaves.[2] They are covered by woolly cream- or pink-colored hair that becomes brown over the winter and sometimes wears away.[2][4] Females emerge from these galls early in spring and oviposit in the buds of host oak trees.[2] This induces the galls of the sexual generation, which are small ovoid cells within buds and young shoots; they cause little or no externally visible deformity.[2] Both male and female adult wasps emerge from these galls and mate, with mated females then ovipositing on the underside of oak leaves, inducing the galls of the agamic generation.[2]

This species was first described by Homer Franklin Bassett as Cynips ignota in 1881 and has been included in various genera before its recent placement in Druon.[5][2]

• Data related to Druon ignotum at Wikispecies
• Media related to Druon ignotum at Wikimedia Commons