Floral Volatiles in a Sapromyiophilous Plant and Their Importance in Attracting House Fly Pollinators

Abstract

Floral scent in sapromyiophilous plants often consists of complex blends with not only fetid (e.g., sulfides) but also sweet (e.g., terpenoids) volatile organic compounds, and a recent study suggests that both groups of compounds are involved in pollinator attraction. However, little is known about the number and identity of compounds involved in pollinator attraction in these deceptive plants that mimic breeding sites of fly pollinators. In the present paper, we studied flower volatiles of sapromyiophilous Periploca laevigata and their capability to elicit biological responses in one of the pollinator species, Musca domestica. Floral volatiles were collected by dynamic headspace and analyzed by gas chromatography/mass spectrometry (GC/MS), and electrophysiological (GC/EAD) and behavioral assays (two choice olfactometer) were conducted. In the floral scent of P. laevigata, we detected 44 compounds, of which indole, β-caryophyllene, and germacrene D, as well as dimethyl trisulfide, which was present in trace amounts, were electrophysiologically active in the antennae of M. domestica. However, when we evaluated in behavioral experiments the attractiveness of the electrophysiologically active compounds (complete mixture against partial mixtures or against single compounds), we found that indole was the only attractive compound for the flies.

Variation in floral characters, particularly floral scent, in sapromyophilous Stemona species

“…Interestingly, the similar chemicals dimethyl disulfide and dimethyl trisulfide often resulted in different biological responses in saprophilous flies (Zito et al ). Various other compounds, such as p ‐cresol and indole, are potent lures for saprophilous coprophagous flies (Kite et al ; Jeanbourquin and Guerin ; Jürgens et al , ; Shuttleworth and Johnson ; Zito et al ). We propose that the functions of the fetid floral scents emitted by Stemona species identified in our study be tested in the field in future studies.…”

The loss of dispersal on islands hypothesis revisited: Implementing phylogeography to investigate evolution of dispersal traits in Periploca (Apocynaceae)

“…Periploca laevigata is an insect‐pollinated, wind‐dispersed shrub (Zito, Dötterl, & Sajeva, ) that occupies open habitats across southern areas of the Mediterranean region and the Macaronesian islands. It is a common element in island and mainland locations of both areas, showing a nearly continuous distribution of populations across its distribution range (see Figure S1 in Appendix S1).…”

rWind: download, edit and include wind data in ecological and evolutionary analysis

“…In this example, we focus on Periploca laevigata, a Mediterranenan wind-dispersed shrub (Zito et al 2015) found in the southern Mediterranean and west African regions, and on the Macaronesian Islands. Specifically, we compare the genetic structure of northwestern African and Macaronesian populations of P. laevigata obtained by García-Verdugo et al (2017) with wind connectivity between those areas computed with rWind.…”