Losing the bees and other pollinators would make life difficult, as we’d also lose most of the flowering plants we rely on both for food and our green environment.
The vital service that pollinators provide has been drawn into focus by concern about the honeybee‘s alarming decline in many parts of the world—a focus of National Pollination Week, which takes place June 16 to 22. (See “The Plight of the Honeybee.”)A Masdevallia orchid’s aroma is irresistible to a fly. Photograph by Christian Ziegler, National Geographic
But honeybees are just one of about 20,000 known species of bee, and we shouldn’t forget the wild army of other pollen carriers out there.
The plants themselves certainly don’t, as the extravagant ruses they use to draw flies, wasps, moths, bats, and others to their flowers prove. Here are some surprising facts about the pollinators and pollinated that keep our world humming. (Read more about pollinators in National Geographic magazine.)
Orchids Are Sneaky
While most orchids employ the conventional lures of nectar, fragrant perfumes, and colorful blooms, this diverse group is notable for some strange and devious fertilization strategies.
Duping insects into trying to have sex with them is one—a phenomenon known as pseudocopulation.
Flowers of the mirror orchid (Ophrys speculum) do this by mimicking both the appearance and female sex pheromones of a particular wasp species. (See some pictures of sneaky orchids.)
The male wasp, having been drawn by the orchid’s alluring scent, makes frenzied attempts to mate with its flowers. For its efforts, the insect gets a pollen sac to the head—comically, it looks like it has picked up a bulbous pair of yellow antennae.
Thus marked, the unrequited wasp flies off and, if all goes according to plan, will repeat its mistake.
Another orchid, Dendrobium sinese, pulls an even more elaborate scent-mimicking trick by smelling like a frightened bee.
The rare Chinese species replicates the whiff of a bee’s alarm pheromone, which attracts the bee-eating hornet that pollinates its flowers.
Moths and Orchids Evolved Together
While moth species greatly outnumber those of bees or butterflies, they mostly work the pollinator night shift, and their services are often overlooked. (See more pictures of pollinators.)
“It’s a real gap in our knowledge,” said Jeff Ollerton, a professor of biodiversity at the University of Northampton in the U.K., who studies plant-pollinator interactions.
But Charles Darwin, during his own flower-pollination studies, was clever enough to identify a moth without anyone ever having seen it.
Orchid specimens Darwin received from the Indian Ocean island of Madagascar included a species—Angraecum sesquipedale—with a nectar spur longer than any known Madagascan insect could possibly feed from.
Darwin predicted that the orchid was pollinated by a moth with an 11-inch-long (28 centimeter) tongue. More than 40 years later, in 1903, that moth, Xanthopan morganii, was finally revealed.
The relationship is a striking example of co-evolution: As the orchid elongated its spur to ensure that the head of the nectar-seeking moth rubbed the flower’s pollen, the moth elongated its tongue to reach the nectar. As each continued to adapt in response to the other, these adaptations got ever more extreme.
Interestingly, there’s a Madagascan orchid (Angraecum longicalcar) with an even longer nectar spur measuring 15.75 inches (40 centimeters), which means there must be another as-yet undiscovered moth out there with an even longer tongue.
Plants Mimic Rotting Flesh
After bees, flies—especially hoverflies (aka flower or syrphid flies)—are among the most important pollinators of agricultural crops.
For instance, chocolate lovers have midges to thank for their vice: These flies are the sole pollinators of the cocoa tree, according to Ollerton.
But in attracting flies, many plants ditch the flowery approach, as their often bizarre and pungent blooms testify. Take the nausea-inducing corpse flower, Rafflesia arnoldii, a species that boasts the world’s largest flower and smells like rotting carrion to attract flies. (Read more about the corpse flower.)
But Ollerton’s favorite fly attractors are the ceropegias.
“Here you have a large genus of plants [some 180 species] that as far as we know is exclusively pollinated by very small flies, on average less than two millimeters in length,” Ollerton said.
Typically climbing plants, ceropegias have flowers with petals that are fused at the tips to form tubular traps.
To entice the insects, ceropegias have a scent laden with the promise of dung or some rotting animal, plant, or fungus that the flies lay their eggs on. (See more of National Geographic’s flower pictures.)
“A few are vile smelling, but others have sweet or fruity smells, no apparent smell at all, or smell of dead insects,” Ollerton said.
The flies are held captive for 24 hours by downward-pointing hairs that line the inner surface of the petal tube.
The hairs then collapse, and the flowers go from vertical to horizontal, allowing the tiny pollinators to escape, Ollerton added.
Longest-Tongued Mammal Is a Pollinator
Pollinators needn’t be insects, of course. Birds, lizards, and mammals also play their part, including a bat that follows the evolutionary example of Darwin’s moth.
Discovered in cloud forests in Ecuador in 2005, the tube-lipped nectar bat (Anoura fistulata) has the longest tongue, relative to body length, of any known mammal.
The tiny mammal stores the 3.5-inch-long (9 centimeter) tongue—more than one and a half times the length of the bat’s body—in its ribcage.
The extraordinary organ marks the bat as the exclusive pollinator of a nectar-rich plant called Centropogon nigricans.
Fortunately for us, plants and their pollinators are full of surprises. The crucial thing is that we allow them to keep buzzing along together.