Eva Gfrerer

Abstract

Floral scent is among the key mediators in plant-insect interactions and often more important for pollinator attraction than visual cues. The common woodland plant Arum maculatum L. (Araceae) has a sapromyophilous pollination strategy and deceives its two main pollinators Psychoda phalaenoides L. and Psychoda grisescens TONN. (Diptera, Psychodidae) by emitting a urineous and faecal scent that chemically mimics the moth flies’ mating and/or oviposition site. Interestingly, the sex ratio and species composition of trapped Psychoda differ among populations north and south of the Alps. Thus, my thesis aims to ascertain the cause of the species/sex variation in pollinators and to investigate if and how local pollinator adaptation may have influenced geographic floral scent patterns of Arum maculatum. Floral scents will be analysed by gas chromatography–mass spectrometry, and compounds being physiologically and behaviourally active in P. phalaenoides and P. grisescens by gas chromatography coupled to electroantennographic detection. Reciprocal transplantation experiments will reveal the environmental and genetic effects on inflorescence scent and show whether plants are locally adapted.