Cecidogenesis of Leaf Galls of Str ychnos nux-vomica (Loganiaceae) induced by the Jumping Plant Louse Species Diaphorina truncata (Homoptera: Psylloidea: Psyllidae)
[Entwicklung der an Strychnos nux-vomica (Loganiaceae) durch die Blattfloh-Art Diaphorina truncata hervorgerufenen Blattgallen (Homoptera: Psylloidea: Psyllidae)]
Balakrishna, Pisupati; Raman, Anantanarayanan
Diaphorina truncata Crawford 1924 induces roll galls on the leaves of Strychnos nux-vomica Linnaeus (Loganiaceae) in the W' coastal plains of S' India. Gravid ♀♀ of D. truncata colonise and oviposit on the abaxial surfaces of differentiated leaves of S. nux-vomica. Feeding activity of the first instar larvae on the mesophyll tissue initiates gall development, evident as wrinkles. In 10-12 days, with the growth of the inhabiting larvae, the leaf turns more-intensely curled. Mature larvae feed on the phloem strands and consequently the vasculature of the galled leaf breaks down. In 25-30 days, the leaf crumples due to distortion of cells and desiccation, and the galled leaf abscises, synchronising with the moulting of the L5 into adults. To supplement these observations, changes in the primary and some secondary plant metabolites of the host leaf during cecidogenesis have been estimated. These changes are related to the nutrition and biology of the psyllid species.