Plant science for plant people.

A tropical vine has learned to counterfeit a fig. Heterostemma ficoides opens globe-shaped, closed flowers that copy the fruit of Ficus heterophylla in both form and scent, close enough that the fig's own specialist wasp, a Kradibia, comes flying in.

The wasp gets nothing for the trip. It can't complete its life cycle inside the fake and leaves without reproducing. Meanwhile a small Megaselia fly, an insect nobody scripted into the fig story at all, does the actual pollinating and raises its young inside the flower successfully. It's the first documented case of a plant faking one insect's nursery while genuinely paying a different one.

That gap between who a flower seems built for and who actually turns up runs through the rest of this week's pollinator work. In French blackcurrant orchards, wild bees tracked the volunteer weeds coming up between rows, while hoverflies preferred the deliberately sown flower strips. Across 16 city farms in Havana, plant variety fell roughly 90% as paved cover climbed from 38% to 97%, and small wild bees, ants and hoverflies thinned out with it. Farms that kept something in bloom held onto their visitors anyway, even on a shrinking plot.

So the insect a flower advertises to isn't always the one earning its keep, and the one earning its keep may be a fly you'd never have counted. Food for thought next time you're deciding which plants in a bed are pulling their weight: watch who actually lands, not who's supposed to.