R. CHELSIA*, K. MANJULA, P.N. HARATHI AND M. GURIVI REDDY

Department of Entomology, S.V. Agricultural College, ANGRAU, Tirupati-517 502.

ABSTRACT

The pathogenicity test of unformulated entomopathogenic fungal isolate Bb. Cd (Beauveria bassiana) (Balsamo) Vuillemin isolated from Chandragiri village were conducted against third instar Spodoptera litura (Fabricius) larvae maintained at three different temperatures viz, 15°C, 25°C and 35°C under laboratory conditions, resulted in comparatively higher larval mortalities of 80.00 per cent at 25ºC. At 35ºC, relatively lower mortalities of 66.67 per cent were recorded. Lower temperatures favoured conidial spore germination, growth and infection on larvae. Conversely, at 15ºC shorter incubation period was taken for the fungi to infect and cause larval mortality. The rate of pupation and normal adult emergence were inversely proportional to the larval mortality and Entomopathogenic fungi virulence.

KEYWORDS: Beauveria bassiana, pathogenicity, Spodoptera litura, different temperatures.