Sihag, R.C.Nidhi2018-05-172018-05-172011http://krishikosh.egranth.ac.in/handle/1/5810046398Insects are associated with flowering plants since their evolution on the earth. While some of them act as their pests, others are either pollinators or parasites and predators of the pests. Although a variety of insects frequent the entomophilous (insect pollinated) crop blossoms for their food rewards (nectar and pollen), only bees belonging to the genus Apis outnumber others and are efficient pollinators. Plums are richest sourse of antioxidants, they provide protection against diseases. The study was made on floral biology and phenology, diversity, relative abundance and pollinating efficiencies of insects visiting the blossoms of three different varieties of plum and the role of different modes of pollination in fruit set of the three varities of plum. Flowering habit of all the three varieties of this study viz. Alu Bokhara, Titron and Kala-Amritsari was similar. Floral structure was studied under dissecting microscope revealed the presence of perigynous condition in the flowers of plum. Abundance of insect visitors studied at hourly and weekly intervals which was maximum during peak flowering period of this plant. Twelve insect species visited the crop of plum; out of these five species i.e. Apis dorsata, A.mellifera, A.florea, A.cerana and Dipterans were the main pollinators.Among the hymenopterous insects, Apis.mellifera visited maximum number of flower per minute, followed by A.cerana, A.dorsata, A.florea and Dipterans Among all the insect visitors, Apis dorsata remained active for the longest duration on plum flower followed by, A.mellifera, A.cerana A.florea and Dipterans respectively. Out of the three varieties Titron was the most prefered variety by the insect visitors followed by Kala-Amritsari and Alu-Bokhara.Pollinating efficiencies of the pollinators were derived on the basis of their abundance, foraging rate, mean activity duration and loose pollen grains on the body of insect. Among the five insect pollinators Apis dorsata came out to be on the first place and seemed to be the best pollinator of this crop .Other pollinators with relatively lower ranking in descending order of pollinating efficiency were A.mellifera, A.cerana A.florea.Studies on fruit set parameters revealed that plum flowers were highly benefited from insect visits, and insect pollination greatly enhanced its fruit set. Crop without insects produced very low fruit set. It was further revealed that plum is a cross-pollinated and entomophilous plant.The structure shape and fertility status of the flower clearly revealed that it has honeybee pollinated flowers and mellitophily pollination syndrome existed in plum.ennullThesis