White grubs (Coleoptera: Scarabaeidae) on fruit crops: Emerging as pests of economic importance

Abstract

White grubs (Coleoptera. Scarabaeidae) are polyphagous pests with a wide host range including several commercially important crops. Surveys conducted in different parts of the country covering six states (Assam, Himachal Pradesh, Punjab, Kerala, Karnataka, Uttar Pradesh) during 2015-18 reveled the occurrence of white grubs on major fruit crops like mango, grapes, pomegranate, guava, apple, peach and plum in considerable proportions. Though white grub adults and larvae are known to be pests of fruit crops, they were considered as minor pests. However, the survey results indicate that in the recent past, white grubs are causing considerable damage ranging from 15-40% in different fruit crops and diversity of species occurring also has widened. While young plantations of guava and pomegranate suffered root damage resulting in death of 10-25% plants, other crops were defoliated by adult beetles. White grubs encountered during these surveys mainly belonged to 11 species under six genera viz., Holotrichia, Anomola, Maladera, Schizonycha, Adoretus and Popillia. Emergence of white grubs, once considered to be minor or sporadic pests of fruit crops, necessitates regular surveillance and documentation to implement timely management practices.