EFFECT OF TEMPERATURE ON THE GALL FORMATION AND ON THE SURVIVALITY OF ADULT POUROPSYLLA TUBERCULATA (HOMOPTERA : PSYLLIDAE), A GALLINACEOUS INSECT ON ALSTONIA SCHOLARIS (APOCYNACEAE)

Temperature is the most important abiotic factor affecting development and reproduction of insects. Pauropsylla tuberculata forms pouch galls on the leaves of Alstonia scholaris. It is observed that increase in temperature has direct influence on population built up of P. tuberculata and gall formation. During field study, it was observed that maximum galls are formed in August to October, when temperature (19°C to 32°C) and relative humidity (55 to 93%) remain suitable for the growth and development of P. tuberculata. Minimum infestation occurs from March to June due to increase in temperature up to 40°C and decrease in relative humidity (13 to 48%). Hence, increase in temperature up to 30°C enhance population built up of P. tuberculata and further increase in temperature up to 40°C decrease reproduction and survivality. These data were confirmed by laboratory experimental observations.