Seasonal Occurrence of Major Pests of Sarpagandha in Mild Tropical Plain Zone of Arunachal Pradesh, India

Sarpagandha [Rauvolfia serpentina (L.) Benth. Ex Kurz], a critically endangered perennial medicinal plant, well known for its bioactive compound reserpine is infested by two major pests, scale insect, Saissetia coffeae (Walker) and mite, Tetranychus ludeni Zacher; reporting for the first time from the mild tropical plain zone of Arunachal Pradesh. During the period of study for two consecutive years (2021 and 2022) the two pests remained active throughout the year. Maximum population of S. coffeae and T. ludeni was recorded during January-February and July-August respectively. The population of scale insect showed a significant negative correlation with the mean atmospheric temperature (r= -0.673 and r= -0.749) and total rainfall (r= -0.778 and r= -0.684) during both the years. Throughout the study period, the mite population exhibited a significant negative correlation with total rainfall (r= -0.770 and r= -0.798).