Gall
Galls are plant growths caused by the action of insects. Two main types of galls are of commercial importance: Turkish galls ("Aleppo galls") and Chinese galls ("jagged galls, Gallae chinensis").
Turkish galls are formed on the "gall oak"(Quercus infectoria OLIV.) by oviposition of the gall wasp(Cynips tinctoria HARTIG; Fam. Cynipidae) on the vegetation point of the sprouting buds. They are spherical growths in which the insect larvae grow well protected for about six months.
Chinese galls are caused by the bite of the aphid Aphis sinensis BELL. (Fam. Aphididae, Rhynchota). They parasitise in northern India, China and Japan on trees belonging to various sumac species (mainly Rhus semialata MURR.; Anacardiaceae). In contrast to the previous ones, these galls are irregular in shape, but serve the same purpose.
So-called "Japanese galls" are of lesser importance.