Tropical cucumbers in the genus Gurania
are the home of Blepharoneura flies. Gurania plants begin their life as males, then
switch to be females!
Early in life the vine
invests energy in climbing high and capturing as much light as possible. During this
time only male flowers are produced.
When the plant has grown
high enough and big enough, the end of the vine stops creeping upwards
and hangs down loose. On the end of the loose vine female flowers
can finally grow.
Why do female Gurania
flowers hang loose? The bats that disperse the fruit find
it via echolocation. If the fruit didn't hang loose in an open space,
the bats wouldn't be able to find it.
(above) Male inflorescence with a Blepharoneura fly
(below) Hanging female flowers