Diversity, temporal abundance, foraging behaviour of floral visitors and effect of different modes of pollination on coriander (Coriandrum sativum L.)

Studies on spatial distribution, foraging behaviour of pollinators and effect of different modesof pollination on yield of coriander (Coriandrum sativum) were undertaken at Karnal (Haryana).Coriander flowers were visited by 34 species of insects belonging to 18 families and 8 orders.Apoidea (35.9%), diptera (47.8%) and other hymenoptera (13.2%) were the three major groupscomprising 96.9% of the total visitors. Italian honey bee, Apis mellifera was the most prominentspecies (31.1%) followed by Episyrphus balteatus (19.2%) and unidentified Hymenoptera species(10.2%). Honey bees foraged both for nectar and pollen whereas, dipterans and other speciesfor nectar alone. A. mellifera started foraging early at 09.05 h, peaked from 11.00 to 16.00 hand declined drastically thereafter. A. dorsata peaked at 11.00 h and was not recorded after14.00 h. A. cerana population peaked from 10.00 to 14.00 h and was not recorded after 15.00h. The syrphid and other dipteran flies were present throughout the day with two peaks,first from 07.00 to 11.00 h and another minor peak late in the afternoon from 15.00 to 18.00h. A. cerana had higher foraging rate (15.2 flower-1) than A. mellifera (13.1) and A. dorsata(10.6) and likewise visited more number of plants per minute (3.6, 2.7 and 2.1 min-1,respectively). A meagre yield of 6.3 g plant-1 was recorded in caged plots without honey bees(control). Yields in open and honey bee pollinated plots were 14.0 g each, with an increase of122.2% over without insect pollinated plots. Maximum yield was in plots treated with beeattractant Bee-Q (18.1 g plant-1) which was 187.3% higher over without insect pollinatedplots and 30.0% higher over open pollinated or bee pollinated plots.