RELATIVE INCIDENCE AND ABUNDANCE OF STEM BORER COMPLEX IN RICE GROWING AREAS OF COASTAL ANDHRA PRADESH

Abstract

Random roving survey was carried out for the incidence and relative abundance of different rice stem borers in three coastal districts viz., Vizianagaram, Srikakulam and Nellore of Andhra Pradesh, India during Kharif 2021. The damage was quantified through the dead hearts and white ears symptoms and species through a destructive sampling of the infested tillers. The survey revealed the occurrence of three different species of rice stem borers viz., Yellow stem borer (YSB), Scirpophaga incertulas (Walker), Pink stem borer (PSB), Sesamia inferens (Walker), and Gold fringed stem borer (GFSB) Chilo auricilius (Dudgeon). The damage by stem borers ranged from 10.91 to 14.70 per cent in the surveyed mandals of Srikakulam (Amadalavalasa, Srikakulam and Seethampeta), Vizianagarm (Merakamudidam, Therlam and Garividi) and Nellore (Venkatagiri, Nellore and Dakkili) districts of Andhra Pradesh. Among the stem borers, YSB was the most predominant species, with 84.26 per cent followed by GFSB with 12.41 per cent in Srikakulam and Vizianagaram districts. A high incidence of GFSB, Chilo auricilius (80 %) was noticed in Seethampeta mandal in Srikakulam district, which is a hilly area where sugarcane is grown predominantly. In Nellore district, yellow stem borer is the only species prevalent where mono-cropping and staggered planting of rice throughout the year is practiced where low PSB incidence (3.33 %) was recorded in Venkatagiri mandal of Nellore district. This study clearly brings out the variation in the abundance of rice stem borer complex prevailing in rice-based cropping systems in different districts of Andhra Pradesh.