Interactions between oil-collecting bees and Krameria grandiflora (Krameriaceae) with emphasis on the role of specialized floral traits in the mutual fit

Author(s)

Carneiro, Liedson Tavares ; Danny Silva Andre, Camila Barbara ; Takahasi, Adriana ; Alves-dos-Santos, Isabel

• Document type: Journal article
• Source: ARTHROPOD-PLANT INTERACTIONS; v. 13, n. 2, p. 14-pg., 2019-04-01.

Abstract

Oil-producing flowers have evolved specialized traits along with the ability to secrete oil as reward, leading to the expectation of a narrow relationship between floral architecture and oil-collecting behaviours of pollinators. Krameriaceae flowers have a showy calyx and a less conspicuous dimorphic corolla modified into a pair of elaiophores that secrete the oil, and a group of petaloid petals that, among oil-collecting bees, are used by only Centris (Centridini) during the oil gathering. A manipulative experiment consisted of excising these floral parts to test the prediction that these structures contribute to successful oil gathering by the bees and plant reproduction. We surveyed the oil-collecting bees associated with the Krameria grandiflora A. St.-Hil. across its distribution range and performed the experiment in populations associated with two different oil-collecting bee taxa-Caenonomada (Tapinotaspidini) and Centris, the main pollinators. Although predicted to mediate the floral mechanical fit with Centris, the absence of the petaloid petals had a neutral effect on both oil-gathering behaviour and seed set, when comparing Caenonomada and Centris. A negative effect on these responses was found when the elaiophores were excised, indicating that these glands have greater importance than the petals related to the mutual fit between flowers and pollinators. However, the petaloid petals seemed to function jointly with the sepals in pollinator attraction. When the sepals were excised, only Centris behaviour was affected, but not that of Caenonomada, indicating potentially divergent selective pressures on the calyx. In addition, we provide a novel oil host plant for several oil-collecting bees. (AU)

• FAPESP's process: 13/00181-5 - Geographic mosaic structure of the interaction between Krameria Loefl. (Krameriaceae) species and oil collecting bees
• Grantee: Liedson Tavares de Sousa Carneiro
• Support Opportunities: Scholarships in Brazil - Doctorate