Utilization of Waste Materials for Management of Alfalfa Pollinating Megachilid Bees

Hollow waste stems of sarkandas (Arundo sp. and Saccharum sp.) and castor (Ricinus communis L.) cut into small lengths were tried as nesting tunnels for culturing/keeping the wild bee pollinators. Of the four megachild bees, three of them easily accepted these tunnels for provisioning and nesting activities. The provisioning bees were the specialist pollinators of important crops like alfalfa (Medicago sativa L.), pigeon pea (Cajanus cajan Millsp.) and cucurbits. During the study period, three species of megachilid bee were found to nest, reproduce and build their populations in these tunnels. This paper discusses the possibility of harnessing Megachile harayanesis, Chalicodoma rubripes and M. femorata for which various artificial devices were tried. The castor stems and soda straws fixed in the drilled wooden boards/blocks were ultimately found as the most convenient means acceptable to the bees for nest construction, especially in 6 mm internal diameter (I.M). Although tunnels of lower significantly the number of cells constructed per tunnel. Decrease in cell number seemed independent of the tunnel length and the cell length also remained unaffected. If length of the tunnel was taken as the parameter against acceptability by M. haryanaensis, 10 cm tunnels were found to be the most suitable. The nesting behavior of C. rubripes and C. cephalotes as affected by the tunnel characteristics has also been discussed. A comparision for the tripping efficiency has also been drawn among the indigenous megachilid bees and Nomia malanderi and Megachile rotundata. Among them M haryanaensis has been found to be the most efficient.