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The distribution of pollen upon the insect-visitors to three species of Viola is described and correlated with their feeding and cleaning behaviour. Visitors adopt one of two basic positions while feeding. In the prone position the insect alights on the anterior petal and probes for nectar so that its dorsal surfaces contact the floral genitalia. The supine position may be adopted after alighting on the anterior petal when the insect rotates so that it is virtually standing on its head. While probing for nectar from this position it is the ventral surfaces which contact the floral genitalia. Bumblebees adopt either feeding position; many large solitary bee species almost invariably adopt the supine one while large hoverflies always feed from the prone position. The behaviour of short-tongued visitors tends to be highly individual with respect to contact with the floral genitalia and many body surfaces may be involved. The varying activities of insect-visitors while feeding result in the deposition of pollen at different locations on the integument. Consequently insect-borne pollen is presented to the stigma in various ways and there is a spectrum of pollination effects: medium and long-tongued nectar-seeking insects tend to be systematic cross-pollinators while short-tongued or pollen-gathering species tend to be chance cross- or self-pollinators. The cleaning behaviour of insect-visitors strongly influences pollination as it removes much integumental pollen. Two requirements of the pollen deposition mechanism are postulated: that pollen should be placed (a) in a position not occupied by foreign pollen and (b) in a position irregularly or inefficiently cleaned. There were no positions which were free of foreign pollen throughout the visitor-species. On the other hand, violet pollen was found to be concentrated at locations inaccessible to the cleaning mechanism. [ABSTRACT FROM AUTHOR]

Presents a study conducted to determine the amount and distribution of pollen on the bodies of honeybees and bumblebees. Method of collection of bees for the experiment; Predominant pollens on the bodies of bees leaving their hives; Comparative analysis between behaviors of pollen-gatherer and nectar-gatherer bees.

Studies the foraging behavior of honeybees and bumblebees on blackcurrant, raspberry and strawberry flowers as of 1968. Effect of pollination by insects on the yield and quality of fruits of the three crops; Measure recommended to increase fruit pollination; Reason for more numbers of bumblebees than honeybees on blackcurrants; Crop which attracted the bees the most; Effect of temperature on the amount of strawberry pollen collected by bees.

Focuses on pollinating efficiency of honeybees and bumblebees when visiting red clover flowers. Relationship between the number of florets visited by honeybees and seeds set; Difference between pollinating efficiency of honeybees and different species of bumblebees when both enter the florets; Number of florets visited per head by pollen and nectar gatherers.