Biodiversity of odonates in rice eco-system, Titabar, Assam
Rituraj Saikia, Himangshu Mishra, Anjumonee Devi and D.K. Saikia
The present study was conducted at Farmers field near Regional Agricultural Research Station, Titabar, main rice bowl of the district Jorhat, Assam. Visual count and catch per unit effort was adopted to record the odonate diversity in the rice field. 68 individuals of odonate belonging to 14 species, equal number of species were recorded from each sub-order, Zygoptera and Anisoptera. The study revealed more number of damselfly population (40) than the dragonfly (28). Vegetative growth of rice crop support more number of Odonates (17 damselfly and 10 dragonfly) followed by reproductive (15 damselfly and 10 dragonfly) and ripening stage (8 damselfly and 8 dragonfly). The most dominant damselfly and dragonfly species were Ceriagrion coromandelianum and Diplacodes trivialis with 11 and 10 individuals respectively. Diversity of damselfly (1.73) was greater than dragonfly (1.42) same as in case of richness and evenness index in vegetative stage. But dragonfly diversity (1.75) was more than damselfly (1.55) as in richness and evenness index particularly when the crop was at reproductive stage. The ripening stage of rice crop support more or less similar diversity of damselfly (1.32) and dragonfly (1.30) with richness and evenness index (1.44, 1.92 & 0.95, 0.81) respectively.