Pollinating insects are a crucial part of the health and well-being of our planet. They enable plants to set seed and reproduce,
driving the Earth’s terrestrial ecosystems and providing us with fresh fruits, vegetables, greens, spices, coffee and fiber for clothing (to name a few items we can’t live without). But did you know that pollinator insect populations are steadily declining year after year due to habitat loss, crop monoculture and pesticide use? Even if you are a hardcore carnivore, the animals you eat depend on a variety of insect pollinated plants for food, so their plight affects you, too. In short, if insect populations suffer, the human population will quickly follow suit. The relationships between organisms on our planet is beautifully complex. To illustrate how intertwined these relationships can be, I’d like to tell you the story of a sweet smelling orchid, a love-struck metallic green bee and the Brazil nut tree.
As most people are aware, the deforestation of our planet is rampant, especially in tropical areas. In the Amazon rainforest, areas are sometimes selectively logged and the understory plants are bulldozed or burned, leaving only certain trees standing that might continue to provide income. Since Brazilian nuts are of economical importance, Brazil nut trees are often left alone. Unfortunately, the trees stop producing nuts after the surrounding forest is cleared… but why?
To solve the mystery, we must turn to a very cool group of insects – the orchid bees. Orchid bees (also known as Euglossine
bees) are the main pollinators of orchids that are familiar to orchid enthusiasts: Gongora, Stanhopea, and their relatives. The orchids in this group have perfumed flowers that smell strongly of vanilla, clove, wintergreen and even root beer! The flowers offer no nectar, so female bees collecting food for their young have no interest in them. It turns out that these flowers are pollinated only by male bees, and each species of bee prefers a single species of orchid. So what are the male bees getting out of this? In order to attract a female bee, the male has to smell nice… so he collects perfumed wax from his preferred orchid flower and transfers it to specialized “pockets” on his hind legs. He then flies to a spot attractive to females (such as a big Brazil nut tree with lots of nectar-bearing flowers) and performs a scented mating display with his orchid perfume. This sparks the female bee’s interest and mating occurs, ensuring future generations of orchid bees. And while they’re around, the female bees pollinate the Brazil nut tree so that it may produce seeds (this is the part we eat).
So why doesn’t pollination occur when we leave a Brazil nut tree standing in an otherwise cleared forest? The orchid perfume that the male orchid bees need to successfully mate is nowhere to be found – the orchid plants only live in the shaded understory. No orchid, no bees, no pollination, no Brazilian nuts. This is but one example of countless stories in nature; most of
these intricate relationships are not fully understood and many more have not even been documented.
The same types of relationships occur here in the U.S., and the less plant variety we have, the more our beneficial insect numbers decline. This affects the entire ecosystem (think of how many other animals depend on insects for food; not to mention the plants they pollinate). But never fear – you can do your part to help save this fascinating group of animals! Plant a pollinator friendly garden at home, at school, at the office… no plot of land is too small and every little bit helps. If we spread the word, we can create diverse urban and suburban habitats for all kinds of wildlife. We can reverse the damage we have done and bring the pollinators back! Learn more at: http://www.xerces.org/pollinator-conservation/gardens/.