1. Stingless bees live in populous colonies that vary in size from a few hundred individuals to tens of thousands, although information on actual colony size is limited. Determining colony sizes using easily measurable biological parameters are important steps to understanding their life histories and ease their utilization and keeping. The objectives of this study were to determine the colony size of five Amazonian stingless bee species (Melipona flavolineata, Melipona fasciculata, Scaptotrigona aff. postica, Frieseomelitta longipes and Plebeia minima), and to identify biological parameters that covary with colony size. 2. The number of brood cells, adult bees, and food stocks were counted under laboratory conditions, alongside field assessments of egg-laying rate and external activity of adult workers. To identify covariates of colony size, the number of adult bees was regressed against the number of brood cells, egg-laying rate, external activity of adult workers, and food stocks, and the best Candidate models were ranked using the Akaike Information Criterion. 3. Mean (± s.d.) adult population sizes were: 1,046 ± 185 in M. flavolineata; 593 ± 300 in M. fasciculata; 7,404 ± 1,391 in S. aff. postica; 2,425 ± 1,000 in F. longipes; and 405 ± 254 in P. minima. We showed that the external activity is the biological parameter, after the number of brood cells, that presents the best relationship with the number of adult bees, which can be easily evaluated in the field.

Floral plantings are promoted to foster ecological intensification of agriculture through provisioning of ecosystem services. However, a comprehensive assessment of the effectiveness of different floral plantings, their characteristics and consequences for crop yield across global regions is lacking. Here we quantified the impacts of flower strips and hedgerows on pest control and pollination services in adjacent crops using a global dataset of 529 sites. Flower strips, but not hedgerows, enhanced pest control services in adjacent fields by 16% on average. However, effects on crop pollination and yield were more variable. Our synthesis identifies several important drivers of variability in effectiveness of plantings: pollination services declined exponentially with distance from plantings, and perennial and older flower strips with higher flowering plant diversity enhanced pollination more effectively. These findings provide promising pathways to optimize floral plantings to more effectively contribute to ecosystem service delivery and ecological intensification of agriculture in the future.