Survey for Root Grub Incidence and their Natural Enemies In Arecanut Gardens in Shimoga District

Areca nut is a major commercial crop in Shimoga district. The field experiment was conducted in arecanut garden at three taluks (Sagara, Hosanagara and Thirthahalli) of Shimoga district during 2012–2013 Karnataka, India. Survey in three taluks (Sagara, Hosanagara and Thirthahalli) revealed that, Thirthahalli showed higher larval count (3.38 grubs per palm) compared to Sagara and Hosanagara taluks and also revealed that L. lepidophora was a predominant species in all root grub infested areas of Shimoga district. In all the three talukas (Sagar, Hosanagar and Thirthhalli) the larval population had highly significant negative relationship with the rainfall. The activity of scoliid wasps was more during April and May and was found to decline during other months. It was confirmed that Colpacampsomeris nr. indica (Saussure) is the species that has been observed as an ectoparasite of root grubs.