ECOLOGICAL STUDES OF THE PAUROPSYLLA DEPRESSA CRAWFORD GALLS ON FICUS GLOMERATA ROXB. PLANT LEAVES

Pauropsylla depressa Crawford (Homoptera: Psyllidae) is a gall making insect which forms leaf galls on this tree causing extensive damage to the foliage of the plant. Galls are formed on the dorsal surface of the leaf because upper part of the leaf gets proper sunlight necessary for photosynthesis. Tender leaves are heavily infested. Gall is a cumulative expression of a suit of adaptation achieved by the host plant for accommodating the inducing insect. A gall provides shelter and nutrition to the inducing insect. P. depressa forms monolocular and multilocular galls develop on dorsal side of the leaf and in severe infestation entire leaf turns a agromerated mass. Maximum infestation occurs from August to October and minimum during March to June. A newly formed gall is green in colour but as the gall grows it changes to pale green. Lateron it develops brownish spots. A mature gall turns pinkish due to formation of Some phenolic compound which trap sunlight during winter for keeping proper temperature inside the gall. Newly formed gall measures 2.2 mm in diameter, mature gall measure 10-12 mm in diameter, medium sized 6-8 mm in diameter. Maximum no. of galls were found in the middle area of the tree foliage while minimum no. of galls were found on the bottom of the tree. In the increase in temperature after winter, number of galls increased up to October. Thereafter, on the decrease in temperature after November, no. of galls also decreases up to February. However, one or two galls on a leaf do not interfere much in the photosynthesis but when entire leaf turns gallinaceous and badly distorted this activities is greatly affected.