He did not explain how the bee collects the nectar. The effects of these visits on the flowers was not mentioned. The pollination requirements of crotalaria are not too well understood. However, self-fertilization does not occur unless the stigmatic surface is rubbed against an insect's body, and lack of pollinators probably helps to explain why in parts of India few flowers set seed. A study of the effect of pollinating insects on the volume of seed produced by the different species of crotalaria and also on the germination of the seed would be of interest.
Honey bees seem to be suitable pollinators.