Materials and methods
Sample collection
P. manihoti, samples were collected from 28 major cassava-growing areas in 18 of the 77 provinces in northeastern, eastern, central, and western Thailand. Each individual insect sample was placed in a 1.5 ml micro-centrifuge tube containing 95 % ethanol. Furthermore, the geographical position of each collecting site was determined using GPS. Species identification of insect specimens was then confirmed using the identification key of Parsa et al.