Ecology, Environment and Conservation Paper

EFFICACY OF MENTHA PIPERITA AGAINST SUIDASIA NESBITTI HUGHES (ACARI: SUIDASIIDAE) IN STORED BENGAL GRAM

Poonam Devi, Rachna Gulati, Vivek Srivastava and Deshdip Arya

Abstract

Mentha a member of the Lamiaceae family is recognized for its vital oils, medicinal uses, insecticidal activity and miticidal action. Investigations on the effects of aqueous and methanolic extract of Mentha pipertica on Suidasia nesbitti Hughes (Acari: Suidasiidae) in stored Bengal gram showed 100 % mite mortality at 4% and 8 % of aqueous extract after 45 and 30 days of post treatment. No mites were recovered from Methanolic extract (4% and 8%) within 45 and 15 days of treatment. Amongst the two extracts, methanolic extract was more effective against S. nesbitti because of lower LC50 value (1.15%) than aqueous extract of M. pipertica (1.74%) under direct spray bioassay. With increase in aqueous and methanolic extract concentration from 0.58 %, esterase activity of S. nesbitti increased significantly from 1.13 to 2.73OD m-1 and 1.60 to 3.79 OD m-1, respectively. It showed significantly greater activity of esterase at higher concentrations after 48 h as compared to lower concentrations. The Glutathione-S-transferase activity in S. nesbitti also increased with increase in exposure time of extract. It was 0.005OD m-1 after 24 h which increased to 0.006OD m-1 after 48 h of exposure with aqueous extract and from 0.005 to 0.006 OD m-1with methanolic extract. The Glutathione- S-transferase activity in S. nesbitti also increased with increase in exposure time of aqueous and Methanolic extract of M. pipertica although the increase was non-significant.