Effect of ultraviolet light on viability of liquid formulation of Lecanicillium lecanii (Zimmermann) Zare and Gams with various adjuvants

The effect of ultraviolet irradiation on the viability of entomopathogenic fungus, Lecanicillium (=Verticillium) lecanii (Zimmerman) Zare and Gams was studied under laboratory conditions at Biocontrol Research Laboratory of Entomology, Mahatma Phule Krishi Vidyapeeth, Rahuri, Maharashtra during 2002–04. The liquid formulation of L. lecanii with different adjuvants, viz., glycerol, Tween-80, Triton-x-100, boric acid, indigo, milk, turmeric and arachid oil were exposed to UV light for different exposure periods of 10, 20, 30, 40 and 50 min. The distance between exposed suspension and UV light source was 0.3 m. The UV rays proved detrimental to the growth and development of L. lecanii. The detrimental effect increased with increase in exposure period. However, glycerol, boric acid and Tween-80 gave good UV protection to L. lecanii, while milk, turmeric and indigo lack the UV protectability.