One fly to rule them all: Flies are the key pollinators of the High Arctic

Date: September 28, 2016

Source: Swedish University of Agricultural Sciences (SLU)

Forget the view of the Arctic as an icy desert devoid of life. The Arctic summer is buzzing with insects -- and here as everywhere else, plants rely on them for pollination. But who are the insects driving the pollination services across the Arctic? A new study finds the biggest heroes among the most modest of animals: small flies related to our common house fly. This finding offers cause for concern, as arctic fly abundances are declining as the Arctic continues to warm.

Some flies are more important than others

Researchers from Finland, Sweden, Denmark and Canada have focused on a single but common arctic plant: the mountain avens (Dryas). They first recorded what insects visited the flowers of avens at 15 sites in northeast Greenland, then returned to score the seed set of these flowers. The results were clear: the more of the house fly -like flies (family Muscidae) that were present, the more flowers set seed. And even among these flies, a single super-hero emerged: what best explained seed set was the abundance of a single fly, Spilogona sanctipauli.

A new use for fly paper

To record the insects visiting a plant, the researchers invented a new solution. "Instead of staring on flowers for hours, waiting to see who sat down on them, we constructed self-trapping flowers," explains Mikko Tiusanen, lead author of the study. "For this, we used something very similar to fly paper -- the sticky traps used to catch e.g. insect pest in green houses. In our case, we cut this sticky paper into natural-looking flowers, and hid them among the real flowers."

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