Andrew Proudfoot, REGUA Volunteer, reports on research work at REGUA.

“The two men in the middle drop in on Caio Missagia (right) who, helped by his friend Juan, is working towards a doctoral thesis on the intricate relationship between Heliconia spathocircinata, three Hummingbirds (Violet-capped Woodnymph, Reddish Hermit and Saw-billed Hermit) and a Hoverfly (Syrphidae) and Soldierfly (Stratiomyidae) species.

Who benefits, who loses and by how much?    Heliconia needs pollination visits from the hummingbird and could provide a plentiful nectar reward.   Larvae of the two fly species are kleptoparasites, gorging on the sugary tissues deep within the protected bracts of the plant’s familiar boat-shaped flowers.   If only those paired bracts were more open, marauding ants might rid the flower of its freeloading flies.

The Amazonian species has no hiding place for Diptera larvae and perhaps it has no trouble supplying its pollinators with nectar. Natural selection could have driven the development of a less enclosed host plant flower. As the Heliconia provides less resource for the hummingbirds, what is the impact on pollinator behaviour and fitness? Fewer birds are recorded visiting infected flowers.

As yet, Caio has no clear answers to these important questions and whether or not Heliconia spathocircinata might be pushed to control these unwelcome freeloaders? An unfolding story; at REGUA we await the next instalment with excitement!”

Andrew Proudfoot