Saurbh Soni ¹, P. K. Mehta ¹, R. S. Chandel ¹

Affiliations
1 Department of Entomology, CSK Himachal Pradesh Krishi Vishvavidyalya, Palampur - 176062, Himachal Pradesh, IN

Abstract

Brahmina coriacea (Hope) is the most widely distributed and destructive species of white grubs having potential to inflict 40-50 per cent yield losses to potato in Himachal Pradesh. The efficacy of two local isolates of Beauveria brongniartii (KH I and KH II) was evaluated against grubs of B. coriacea by dip treatment and oral feeding methods. Against first and second instar grubs, KH I in dip treatment proved to be highly effective, whereas for third instar grubs, KH I through oral feeding showed higher virulence. The LC₅₀ values for first instar grubs for KH I and KH II were 2.55×10⁵ conidia/ml and 2.80×10⁵ conidia/ml in dip treatment, whereas in oral feeding method, the LC₅₀ values were 7.27×10⁵ conidia/ml and 9.69×10⁵ conidia/ml, respectively. Against second instar grubs, LC₅₀ values calculated were 2.91×10⁵ conidia/ml and 3.98×10⁵ conidia/ml for KH I and KH II in dip treatment, whereas corresponding values through oral feeding method were 5.36×10⁵ conidia/ml and 8.82×10⁵ conidia/ml. LC₅₀ values for third instar grubs were 4.47×10⁵ conidia/ ml and 4.88×10⁵ conidia/ml for KH I and KH II in dip treatment, whereas through oral feeding, LC₅₀ values were 3.03×105 conidia/ml and 5.14×10⁵ conidia/ml for KH I and KH II, respectively.

Keywords

Brahmina coriacea, Beauveria brongniartii, Himachal Pradesh, Potato, Susceptibility.

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