Pollination ecology in Centrosema brasilianum (L.) Benth. (Fabaceae: Papilionoideae): bee size influences pollen deposition

Abstract

Here, were observed the interaction between Centrosema brasilianum (Fabaceae, Papilionoideae) and their floral visitors and quantified pollen removal and visitor traits. Aims: for to determine whether the behavior, quantity, and location of deposited pollen on the body of visiting bees differs according to the body size of bees. Methods: the morphological and behavioral attributes of floral and bees observed in interaction were measured in 20 individuals of C. brasilianum. The place of deposit and the amount of polinic charge in each bee were identified. The relationship between the attributes of the interactants and of pollen deposited was determined using simple linear models. Results: Bee behavior and pollen deposition on the body varied according to bee body size. Larger-sized bees with long tongues raised floral keels during visits and pollen deposition occurred on their heads and dorsal surfaces. Smaller individuals with short tongues did not raise the keel, and pollen was deposited on the dorsal surface, but mostly over the wings. Additionally, larger bees had twice as many pollen grains deposited on their body surfaces than smaller bees. Conclusions: we assumed that larger bees may provide a more effective pollination service than smaller bees in C. brasilianum. Implications: Future evaluations should be conducted that include more morphological and behavioral attributes in a larger sample number, which would provide a more nuanced understanding of pollination efficiency, the relationship between different behaviors and body sizes of bees, and the consequences of differential pollen deposition on the reproductive success of C. brasilianum.