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Department of Entomology, S.V. Agricultural College, ANGRAU, Tirupati-517 502.
An extensive roving survey was conducted in different sugarcane growing districts of Andhra Pradesh at different cane developmental stages at bimonthly intervals during 2023-2024. Three shoot borers viz., Early shoot borer, Chilo infuscatellus, Inter nodal borer Chilo sacchariphagus indicus and Top shoot borer, Scirpophaga excerptalis were recorded from 60 farmer fields in four districts viz., Vizianagaram, Anakapalle, Krishna and Tirupati districts of Andhra Pradesh. Relative abundance and Diversity indices were calculated for each district based on population of shoot borers to understand the species composition of shoot borers in Andhra Pradesh. Vizianagaram recorded highest mean relative abundance of ESB (60.50%). While, Anakapalle recorded highest mean relative abundance of INB and TSB (40.20, 50.20). Anakapalle district recorded highest Shannon- Wiener index (1.01), Simpson index of Diversity (00.56) and Pielou’s evenness index (00.91) indicating the species richness and evenness as more number of three shoot borer species were collected here. Based on the diversity indices it could be concluded that the sugarcane shoot borers exhibited uniform distribution and higher diversity in Anakapalle district and aggregate distribution type and lowest diversity in case of Krishna, Vizianagaram and Tirupati districts of Andhra Pradesh.
KEYWORDS: Diversity indices, Distribution, Simpson index, Shannon-Wiener index Species richness and Evenness.