The role of floral strips on arthropod population dynamics in rice ecosystem

Floral strips at field margins are well known to attract and support natural enemies of insect pest populations to reduce pest pressure in agroecosystem. While the benefits of floral strips have been widely studied in many crops, their role in rice-based ecosystems remains largely unexplored. We performed a field experiment using four rice varieties to investigate the role flower species Rongon (Ixora coccinea), Allamanda (Allamanda cathartica), Hasnahena (Cestrum nocturnum) and Madhobilota (Hiptage benghalensis) established as floral strips adjacent to rice plot on arthropods population dynamics. Herbivorous and predatory arthropods were sampled from each plot every seven days from vegetative to reproductive maturity. Arthropods communities were categorized according to taxonomic groups. Data on pollinator attraction towards floral species were recorded through visual count. Rice bug and rice stem borer infestation and yield parameters were also recorded. The abundance and diversity of Orthopterans, Hemipterans and Dipteran were reduced significantly with floral strips than control plot. Coleopterans population also decreased with floral strips but species-specific. The predatory Arachnids population increased with flower strips suggested that addition of flower resources benefits predators over control. Principal component analysis summarized that flower species distinctly separated arachnids and pollinators communities. Rice stem borer (% whiteheads) and rice bug (%) infestation also reduced with flower strips than control but differed among varieties. Dry grain weight increased with floral strips than control plot across varieties. This research has wider application to promote conservation biological control to reduce insecticides application for the management of herbivorous insects in rice agroecosystem.