Larger pollinators deposit more pollen on stigmas across multiple plant species – a meta-analysis

Abstract

1. Many insect species provide essential pollination services. However, the amount of pollen deposited onto a stigma when visiting a flower (“single visit pollen deposition”, SVD) can vary greatly among taxa depending on morphological traits of pollinators. Further, SVD is commonly measured using one of two methods (‘static’: waiting for an insect to visit a flower present on plant, and ‘active’: removing the flower and presenting it to a flower visitor) that may also differ in their effectiveness.

2. To gain a more comprehensive understanding of how SVD compares among pollinators, we conducted a hierarchical meta-analysis using data from 28 studies identified by a systematic review. These contained SVD data for 94 bee and 33 fly taxa (hereafter “wild pollinators”), across 30 plant species from which we included 127 observations. In the analysis of each study, we used the western honey bee (Apis mellifera) as a comparator species.

3. Wild pollinators deposited more pol...