Seasonal Incidence of Gall Forming Psyllid Pseudophacopteron tuberculatum, Crawford Infesting Alstonia scholaris R. Brown at Bhubaneswar, Odisha

The present study was undertaken in Bhubaneswar on a popular ornamental tree Alstonia scholaris (L.) R. Br. during. October 2016 to May, 2018. The psyllid, Pseudophacopteron tuberculatum attack gives ugly appearance for which it fails to serve the original purpose. The study revealed that maximum percentage branch infestation was recorded during the month of October in 2nd fortnight (86.18%) followed by 1st fortnight of November (83.51%). Lowest branch infestation was recorded during 1st fortnight of April (57.04%). Maximum percentage leaf infestation was recorded in 1st fortnight of October (88.31%) followed by 2nd fortnight Alstonia leaves infested with galls of October (88.10%). The 1st and 2nd fortnight of November also witnessed high leaf infestation. The lowest infestation recorded was 66.20% during the 1st fortnight of March followed by 66.83% during 2nd fortnight of February. Maximum no. of galls were found to be 67.2 on an average during the 2nd fortnight of October. There was a positive and significant correlation (both at 5% and 1%) found between percent RH with all the infestation parameters. A negative but significant correlation was found between mean maximum temperature and basic sunshine hour (BSH) with all the infestation characters as mentioned above.