On the developmental morphology of the rosette galls of Acacia leucophloea Willd., (Mimosaceae) induced by Thilakothrips hablu Ramk. (Thysanoptera: Insecta)

Abstract

Thilakothrips babuli induces rosette (artichoke) galls on the axillary buds of Acacia leucophloea. As a result of feeding by the building populations of thrips, axillary shoot meristems are destroyed, and primordial palisade tissues of the leaflets and cortical tissues of the shoot axis are transformed into nutritive cells of specialised morphology. Very similar to the galls induced by mites, midges, chalcids, and chloropids, Thilakothrips-induced Acacia galls also have a characteristic morphology, involving the inhibition of elongation of the shoot axis and crowding of maldeveloped leaflets. While describing the cecidogenesis in relation to the biology of the gall maker, an attempt has been made to discuss the morphological convergence among shoot apex galls.