Flower recognition by nocturnal bees: a study case with cambuci (Campomanesia phaea - Myrtaceae)

• Grant number: 13/26599-6
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Effective date (Start): April 01, 2014
• Effective date (End): July 31, 2014
• Field of knowledge: Biological Sciences - Zoology - Animal Behavior
• Principal Investigator: Isabel Alves dos Santos
• Grantee: Guaraci Duran Cordeiro
• Supervisor: Stefan Dötterl
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Research place: University of Salzburg, Austria
• Associated to the scholarship: 11/06811-5 - Phenology, reproductive biology and pollination of cambuci (Campomanesia phaea - Myrtaceae) and monitoring of associated apifauna, BP.DR

Abstract

Although pollination by bees is an essential ecosystem service, little is known about the attraction of bees to flowers in general, and about the contribution of floral scents contributes to pollinator attraction. For an interaction between a plant and a pollinator to occur, floral signals are essential to attract the pollinators. To attract the floral visitors afar, plants use olfactory and to some extent visual signals. In the case of flowers with nocturnal anthesis, olfactory signals are even more important to attract pollinators from afar, because visual signals became inefficient in the absence of light.The ongoing PhD project aims at assessing the reproductive biology and pollination of Cambuci (Campomanesia phaea - Myrtaceae). This plant is endemic of Atlantic Rainforest and cited as fruit tree of great economic potential in Brazil. The results obtained so far in our study show that C. phaea is self-incompatible and depends on pollinators for fruit set to occur. The bee species Megalopta sodalis, Mydrosoma sp., Ptiloglossa latecalcarata, and Zikanapis seabrai were considered effective pollinators and were one of the most frequent visitors of C. phaea. These bees are nocturnal, flying before the sunrise with little or no light available.Although bees are typically considered diurnal, some groups are nocturnal and fly before sunrise or after sunset. These bees have been underrepresented in most bee studies because they are active at a time when researchers are not looking for bees. Olfactory signals of the flowers are probably very important for bees to find host plants; The Cambuci anthesis starts around 4:30 am. As soon as the flowers start to open, the female nocturnal bees aforementioned intensely visit them. These observations led to the following question: How do these bees find Cambuci flowers in darkness? Our hypothesis is that floral scents of C. phaea are the signals that guide these bees and help them find the flowers in the dark. To test this hypothesis and to understand the chemical communication between the plant and the nocturnal bees, it is necessary to collect and analyze the scents, and identify which compounds are responsible for bee attraction. We discussed this hypothesis during the visit of Prof. Dr. Stefan Dötterl (University of Salzburg, Austria) to our laboratory in last October. The Prof. Stefan Dötterl is an expert in the field of chemical ecology of pollination on the subject ecological chemical and the use of this as tool to study in insect plant interaction. He agreed that the study system is very interesting and proposed a collaboration to test this hypothesis and study for the first time the chemical communication between nocturnal plants and nocturnal bee pollinators. The compounds emitted by Cambuci flowers will be sampled in the morning immediately after opening and then 3-4 hours after the beginning of anthesis. These samples will be analyzed with the Dr. Stefan Dötterl at the University of Salzburg using the methods of GC-MS (gas chromatography-mass spectrometry). In Austria, Guaraci Duran Cordeiro will not only analyze the collected samples and prepare on the basis of these results synthetic scent samples for biotests in Brazil, but be generally trained in chemical-ecological techniques and attend ongoing research projects. Back to Brazil, the synthetic scent samples prepared in Salzburg will be tested in field bioassays for attractiveness to nocturnal bees.The knowledge acquired in the internship at the University of Salzburg with Dr. Dötterl, and its application in Brazil, will expand greatly the biological data about the main pollinators of Cambuci and contribute to the understanding of the mechanisms of pollinator attraction. As a next step, the data obtained may be used to manipulate the attractiveness of Cambuci for bees to increase fruit production in agricultural systems. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

RACHERSBERGER, MELANIE; CORDEIRO, GUARACI D.; SCHAEFFLER, IRMGARD; DOETTERL, STEFAN. Honeybee Pollinators Use Visual and Floral Scent Cues to Find Apple (Malus domestica) Flowers. Journal of Agricultural and Food Chemistry, v. 67, n. 48, p. 13221-13227, DEC 4 2019. (13/26599-6)

CORDEIRO, G. D.; PINHEIRO, M.; DOETTERL, S.; ALVES-DOS-SANTOS, I.. Pollination of Campomanesia phaea (Myrtaceae) by night-active bees: a new nocturnal pollination system mediated by floral scent. Plant Biology, v. 19, n. 2, p. 132-139, MAR 2017. (13/26599-6, 11/06811-5)