127th Meeting – November 1994

Deceit in the Forest Canopy: The ravishing Lady Slipper orchid & the naive hoverfly

A talk and slide presentation by Hans Bänziger

The talk, illustrated by a fine collection of vivid slides showing minute detail and punctuated by the unique and educational humor of Hans, went like this:

The Lady Slipper is a deceptive flower, inducing insects to pollinate her without offering nectar as a reward. It entices insects into its inner reaches with a brilliantly reflective but fake honeydew-like pad sporting an almost luminous green wart mimicking a perch. The unwary hoverfly which attempts to alight upon this oily little knob promptly falls into the toe of the slipper and is unable to fly out. Entrapped, it slowly and laboriously climbs out the back along the sole, collecting a bit of viscous amber-colored pollen on its back as it leaves this temporary prison to somewhere someday-soon be en­trapped by another Lady Slipper and pollinate her internal parts.

To accumulate this knowledge and these superb slides of Lady Slippers and hoverflies, Hans has, over many years, been required to risk life and limb in the name of scientific exploration, including: learning the ancient art of bow [63 lb.] and arrow in order to loop nylon string & rope over tree limbs 20-30 meters above the forest floor and thereupon ascend to new heights, and long hours of observation, film and note taking as well as consummate patience - and he has even taken photos of himself performing these courageous feats. But it's all worth it, particularly for the audience, which learns that:

·        Lady Slippers grow in the most outrageous places - rock faces and lofty tree limbs

·        They are poached and sold cheaply in the market and are thus getting harder to find

·        There are over 70 species of Lady Slipper in Southeast Asia and 10 in Thailand,

pollinated by six species of hoverflies

·        A lot of Darwin's theory of evolution was based on his observation of orchids

In trenchant summary, Hans concluded something like this: Man expends great effort in killing insects, when the majority of plants depend on them for pollination. Pests, however, soon adapt and recover. The Lady Slipper, on the other hand, has been using hoverflies at their own expense, for her benefit, for thousands of years, without them ever calling her bluff.

"When will Man become as wise as a flower?"