Disentangling the path of pollinator attraction in temporarily colored flowers

Samuel Boff,Jessica Amaral Henrique,Josué Raizer,Anna Friedel

doi:10.1007/s42690-020-00323-4

Abstract

Plants may use different strategies to attract pollinators in long distance (e.g. floral display) and in short distance (e.g. ratio between differentially colored flowers) scales. The Verbenaceae Lantana canescens Kunth is a wide spread species in open sites of the Brazilian Pantanal wetland. Individuals of this generalist species can produce a variable number of open inflorescences with yellow and white flowers that are organized in whorls. In this study we tested the hypothesis that increased floral display (long distance attraction) and the ratio between yellow and white flowers (short distance attraction) enhances the number of pollinator species and individuals. We observed flower visitors and calculated floral parameters in 38 plots of 1 m2 each, that contained a varying number of flowering L. canescens individuals. Non-metric multidimensional scaling and Bray-Curtis distances were used to account for flower visitor composition and the relative visitation rate, respectively. We used a structural equation model to test the power of each predictor variable on the visitation rate and a covariance analysis to disentangle the effect of each independent variable on the frequency of plant-pollinator interactions. We found that the number of flower visitors and the visitation rate increased with increasing number of inflorescences. Disentangling long and short distance attraction indicated that the number of inflorescences (per plot) and the number of yellow flowers (yellowing effect) contributed most to flower visitation at long and short distance, respectively.

Highlights

Flowering plant species differ in floral trait combinations and trait complexity and use these as strategies to attract pollinators for reproduction (Endress 1996)
We hypothesized that i) higher number of inflorescences increases the number of floral visitors as well as the visitation rate since a higher number of flowers may represent a greater source of resources. ii) visitation rate increases with increasing number of yellow flowers iii) bees visit more flowers in the sun than in the shade
We collected a total of 185 flower visitors on L. canescens inflorescences during 380 min of observations (0.43 visitor min −1); 163 of them belonged to the group of Apidae (Apis mellifera Linnaeus and Ceratina aff. morrensis Strand, 1910), 20 specimen were other hymenopterans and two specimen were dipterans

Summary

Introduction

Flowering plant species differ in floral trait combinations and trait complexity and use these as strategies to attract pollinators for reproduction (Endress 1996).

Present address

Materials and methods

Results

Discussion

Compliance with ethical standards