Infestation index and damage rating scale for bondar's nesting whitefly (Paraleyrodes bondari Peracchi) infestation in coconut plantations in southern Tamil Nadu

Abstract Surveys were conducted at fortnightly intervals in major coconut gardens across the southern districts of Tamil Nadu, including Thoothukudi, Tenkasi, Tirunelveli, and Kanyakumari, from December 2020 to October 2021, to assess the intensity of damage caused by the whitefly complex in coconut. Paraleyrodes bondari Peracchi, commonly known as Bondar's Nesting Whitefly, poses a significant threat to coconut crops, affecting both yield and overall plant health. During the study a comprehensive Damage Rating Scale was tailored for the assessment of Bondar's Nesting Whitefly infestation in coconut crops. In Thoothukudi district, P. bondari infestation was generally low, except during early December 2020 and March 2021, when the infestation index ranged from 1.01 to 2.00. Tenkasi district saw the infestation index peak at 1.06 in early August 2021, with a low of 0.54 recorded in late July 2021. In Tirunelveli district, the infestation index varied from 1.38 in early December 2020 to 0.14 in late October 2021, while Kanyakumari district reported the highest infestation index of 1.54, categorizing it as medium. This scale aims to provide a standardized and practical tool for growers, researchers, and agricultural practitioners to quantify the extent of damage caused by this particular pest. Keywords: Bondar’s nesting whitefly, damage rating scale, Woolly wax nests, Sooty mold