Indian Journal of Weed Science
Year : 2007, Volume : 39, Issue : 1&2
First page : ( 81) Last page : ( 84)
Print ISSN : 0253-8040.

Host Preference of Neochetina bruchi Hustache and N. eichhorniae Warner towards Leaves and their Aqueous Extracts of Chosen Agricultural and Horticultural Crops

Murugesan A. G., Ruby John, Paulraj M. Gabriel

Manonmaniam Sundaranar University, Sri Paramakalyani Centre for Environmental Sciences, Alwarkurichi-627 412, (Tamil Nadu), India.

Abstract

The water hyacinth weevils, Neochetina bruchi Hustache and Neochetina eichhorniae Warner were studied for their orientation behaviour towards leaves and their aqueous extracts of 18 agricultural and horticultural crops and the host plant Eichhornia crassipes (water hyacinth) under laboratory conditions with the help of a multi-arm olfactometer. Excess proportion index (EPI) was worked out to know the approaching behaviour of the weevils. Both N. bruchi and N. eichhorniae rejected all the crops tested here and preferred water hyacinth only. The EPI values for the leaves of all the crops tested (except paddy and pomegranate) and their extract treatments were only negative, indicating that the weevils rejected the plants. Positive values were obtained in pomegranate (+0.33) and paddy (+0.11) leaf treatments when N. bruchi and N. eichhorniae were used, respectively. In general, extracts were more deterrent to both the weevil species than leaf treatment.

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