Three Cheers for Fungus Gnats!

Bees, butterflies, bats, and birds... Most of us are all too familiar (and thankful) for their roles as plant pollinators. However, there are some unsung heroes of this niche and one of them are the often overlooked fungus gnats.

Pollinators, for good reason, are one of the largest selective pressures on flower evolution. As flowers evolve to cater to a specific kind of pollinator, be it a bird, a bee, or even fungus gnats, we refer to it as a pollinator syndrome. I have been enchanted by the flowers of the genus Mitella ever since I stumbled across them. As you can see in the picture, they are generally saucer shaped and have snowflake-like appendages protruding from their rim. I wondered, what kind of pollinator syndrome would produce such delicate beauty?

A quick search in the literature turned up a paper from a team of botanists based out of the University of Idaho. The paper outlines work done across a wide range of genera in the Saxifragaceae family. They looked at flower morphology and, through hours of field observation, found a common theme in many species. Those with small, white, saucer-shaped flowers, such as those of Mitella pentandra, all seem to be pollinated by fungus gnats. Fungus gnats are themselves quite small and their larvae live in moist soils, feeding on fungi. As it turns out, the adults are avid pollinators of many plant species and because of this, some species, like M. pentandra, have evolved a pollinator syndrome with them.

The research team also found a strong correlation between fungus gnat flowers and habitat type. They all seemed to be tied to moist forest habitats. This is because moist forests are the only place fungus gnats can live. Plants in drier habitats rarely come into contact with fungus gnats and therefore have no selective pressures to cater to these insects.

I love it when general observations based on aesthetics lead to a deeper understanding of what is going on outside.

Photo Credit: Four Corners School of Outdoor Education (http://bit.ly/1jmNLDR)

Further Reading:
http://bit.ly/1VFiHY4