Bioassay of some aqueous plant extracts against leaf and fruit scarring beetle, Nodostoma subcostatum (Jacoby)

Abstract

Aqueous extracts of three medicinal plants viz., Nyctanthes arbor- tristis (Sewali), Sapindus saponaria (Monisal) and Azadirachta indica (Neem) was evaluated in the laboratory against leaf and fruit scarring beetle, Nodostoma subcostatum (Jacoby) to determine its effect on adult mortality. The direct spray method was used in the laboratory at concentrations of 2, 4 and 6 per cent. Among the three plant extracts Sapindus saponaria was more effective against N. subcostatum than other plant extract with the lowest LC50 value (3.91) followed by Azadirachta indica (3.95) and Nyctanthes arbor- tristis (4.21). The present study reports that among three botanicals Sapindus saponaria has the most effective insecticidal activity to reduce the N. subcostatum followed by Azadirachta indica and Nyctanthes arbor- tristis. Thus, these plant extracts may be utilized as potential insecticides for the management of leaf and fruit scarring beetle of banana.