Does colour of the central floret in Queen Anne's Lace umbels affect the types of pollinators a racted to them? Researchers: Fiona Hunter (Ph.D.), Donnie Aedy (B.Sc.)
Abstract Background Informa on The Dark Florets
The objec ve of this study is to test whether Daucus carota (ini ally na ve to Europe) was introduced to North America Research has shown that the dark central floret serves an or not there is a difference between the types about 150 years ago. It is highly invasive and tends to spread quickly. D. adap ve role in insect a rac on. Eisikowitch (1980) of pollinators present on Queen Anne’s Lace Carota is a biennial plant that can reach heights of up to 100 cm. They are observed a greater number of Musca flies visi ng dark (Daucus carota) umbels with dark central widely distributed, occur in a variety of habitat types, belong to the Family inflorescences rela ve to the white inflorescences. spots (dubbed “dark flowers”) and umbels Apiaceae, with "bird cage-like" inflorescences. Currently, half of the research Unfortunately the experiments were conducted with only without dark central spots (dubbed “white supports the hypothesis that the dark spot serves as an insect a ractant and one species of fly and therefore only one poten al flowers”). Since the me of Darwin, may be involved in insect mimicry. The other half of the research was pollinator. A Study by Goulson et al. (2009) supported specula on about the role of the central dark inconclusive due to insufficient data. the role of the dark florets as an insect a ractant. spot in the umbels of Queen Anne’s Lace However, a study by Westmoreland and Muntan (1996) (QAL) has been put forth. According to a found that the coloured florets did not serve any purpose paper by Lamborn and Ollerton (2000), in insect visita on. The conclusions of the study were Darwin believed that the modified central Results ambiguous since it failed to control for all variables of flower served no func onal or adap ve seed dispersal and did not examine pollen loads for importance to the species and therefore was individual groups. Lamborn and Ollerton (2000) also did a remnant of an ancestral past. We separated not support the proposed adap ve role of the dark QAL umbels based on the colour of the inflorescences in pollina on but only due to insufficient central flower and collected the insects data. present on each. Although s ll preliminary, we present evidence confirming a significant difference between insect popula on Reproduc on distribu ons on “dark” and “white” flowers. Daucus carota contains hermaphrodi c flowers (making up 95% of its primary umbels) and central staminate Purpose flowers, which also make up most secondary umbels. The central dark flower, if present, is always By solving the great debate of its func on, new hermaphrodi c. Anther matura on occurs before s gma knowledge about the central dark spot and its development in order to maintain a protandrous possible role as an insect a ractant could lead to dichogamy reproduc ve strategy. future developments in cul va on as well as in methods for improving agricultural processes in Conclusion cul vated carrots.
In summary, the dark flowers and light flowers of D. carota do differ significantly with beetles being more Study Design Donnie Aedy (B.Sc.), present on the light flowers and bees and wasps being more present on the dark flowers. Con nued analysis A study site was chosen consis ng of D. carota popula ons in an open grassland will hopefully reveal a significant difference at the species environment. Plants were separated into two dis nct groups dubbed “white level and will prompt and inspire future research in this flowers” and “dark flowers” based on the treatment they receive. A er area. It is strongly believed that this dark central floret treatment, data collec on commenced using basic sweep ne ng procedures for serves a more adap ve purpose than simply being a 5 minutes on each treatment group in the morning (9:30 am) and in the late remnant of a possible ancestral past. a ernoon (5:00 pm). This was done three mes a week for 2 weeks (24 samples). Temperature and Humidity was noted each day. Insects were iden fied to family and later to species (for Hymenoptera, Diptera and Coleoptera) using various techniques. References 1. Eisikowitch, D. (1980). The role of dark flowers in the pollina on of certain umbelliferae. Journal of Natural History. 12:737 – 742. 2. Goulson, D., McGuire, K., Munro, E.E., Adamson, S., Colliar, L., Park, K.J., Tinsley, M.C. and Gilburn, A.S. (2009). Func onal significance of the dark central floret of Daucus carota (Apiacease) L.; Is it an insect mimic? Plant Species Biology. 24:77 – 82. 3. Westmoreland, D. and Muntan, C. (1996). The Influence of dark central florets on insect a rac on and fruit produc on in Wuuen Anne’s Lace (Daucus carota L.). The American Midland Naturalist. 135:122 – 129. 4. Lamborn, E. and Ollerton, J. (2000). Experimental assessment of the func onal morphology of inflorescences of Daucus carota (Apiacease): Tes ng the ‘fly catcher effect.’ Fun onal Ecology. 14:445 – 454.