Tuesday, June 22, 2021

Not All Pollinators Are Bees

A bee completely covered in a flower's yellow pollen.Most people learn from a young age that bees are pollinators, and we need them to maintain our food supply. While all that is true (bees are the number-one pollinator after all), they are by far not the only creatures out there pollinating the world.  In fact, there are myriad pollinators at work keeping things going. Sometimes these pollinators are responsible for a specific plant species so their essential work can be overlooked by the world in general. Other times, the way they move through their lives makes them surprising pollinators. In honor of Pollinator Week this week, I’d like to introduce you to some of these lesser-known pollinators.

Chocolate Midges (Theobroma cacao)

A close-up of a cacao flower with a chocolate Midge inside it.
These two words shouldn’t go together – most people like chocolate and loath midges. But if you want chocolate, you’ll have to come to appreciate these particular midges because without them you wouldn’t have your favorite chocolate treat. This midge is the only pollinator of the cacao plant, from which we get our chocolate. They have come to this special job due to several unique circumstances: The cacao plant cannot self-pollinate, and the flowers of this plant are small (dime-sized), with intricate petals that curl down and overlap each other, creating a maze that most insects cannot enter. Also, the blooms either have no smell or an unpleasant one, so they are not particularly attractive to insects. Added to all that, for a long time the thought was that they did not have provide nectar for insects. But, upon microscopic inspection, they found the nectaries on the stems and at the base of the flowers. Why microscopic nectaries? For the little bitty flies that have made it their business to care for the plant, of course. Chocolate midges do not do well in the large-scale farming situation needed to supply the world’s near-insatiable demand for chocolate, so growers have had to resort to hand-pollination but that is not without its drawbacks. Growers and scientists are working hard to find a solution that can replace or subsidize all the efforts of one little midge. Read more about this cool little insect here.
A brown Honey Possum sitting on an orange flower.
Honey Possums (Tarsipes rostratus)

This adorable Australian creature serves as an important pollinator for a number of native Australian plant species. A mouse-sized marsupial, the Honey Possum does not actually eat honey. Instead, it lives on a diet of nectar and pollen, the only marsupial to do so. These cute little guys need up to 7mL of nectar a day and have long bristly tongues that are perfectly adapted to retrieve what they need from the flowers. They mostly spend their time scampering around in trees with their mouths and bodies dusted with pollen. This foraging behavior works perfectly to spread the pollen of their host plants. Honey Possums live in southwestern Western Australia. Their habitat was much broader at one point, but they’ve lost ground due to wildfires and human encroachment. Luckily, there are dedicated conservationists working to keep this unique species around (read more here). Australia is also home to another super-cute mammalian pollinator – the Sugar Glider. These nocturnal animals have become popular in the exotic pet trade in recent years, but they are not domestic animals and should not be kept in captivity. They should remain in the wild, pollinating like the Honey Possum.

A Snow Pool Mosquito on a Bog Orchid. It has two yellow balls of pollen on his head. Photo by Kylie Riffell.
Snow Pool Mosquitoes (Aedes communis) –

I know – “Mosquitoes? As Pollinators?”, but the answer is “Yes!”. For one thing, mosquitoes don’t live on blood. This is a common misconception, but the fact is that only females draw blood and that is solely for the purpose of enriching their eggs. The males, and non-egg-laying females will take advantage of the nutrition found in flower nectar. A visit to the nectar bar often results in pollen becoming attached and then distributed as the mosquito moves away. This behavior has been fine-tuned in one mosquito species, the Snow Pool Mosquito. These guys are pretty widespread across northern parts of the US and one particular native orchid species relies on them for pollen distribution. The Blunt-Leafed Bog Orchid (aka One Leaved Rein Orchid) is a pretty but unassuming flower that these mosquitoes have chosen to care for. The Snow Pool Mosquito will climb right into the orchid to partake of the nectar found on the floral spur and as it laps it up, pollen becomes attached to its eyes and head. As they move away with their new pollen hats, they look like they have devil horns. Granted, this is a small insect in an obscure environment, but it goes to show that even the heavily demonized mosquito can have an essential wildlife function.

A Blue-Tailed Day Gecko with half its body inside a pink flower.
Many Types of Lizards –

With these small reptiles scampering all over the world, it’s no wonder they get some pollinating done. But how does this work since these animals don’t have specially designed tongues or masses of pollen-capturing fur? Scientists in New Zealand have figured that out- In the course of their daily activities lizards will get tree sap and honeydew from aphids on their bodies. When they climb into a flower for a little sip of delicious nectar, pollen will adhere to the sticky substances. And, since one flower is never enough, the next sip can result in pollen transfer. In Mauritius, the Blue-Tailed Day Gecko is one of the many species of active lizard pollinators. In fact, lizards appear to be important pollinators in many island ecosystems. It is believed that lizards have had to adapt to limited (or declining) food sources on their island homes and so they’ve turned to calorie-rich flower nectar.

A Sumatran bull elephant peering out of the jungle

Sumatran Elephants – ?

Okay, I’m not really sure about this one but it makes for a good story. Some say that jungle elephants in Indonesia help to spread the pollen of the world’s largest flower, the Rafflesia. Extraordinarily large flowers have extraordinarily large pollen and need extraordinarily large pollinators. Or so the story goes. There is even a word for this kind of pollination – Elephophily. If any of this is truly true, it could be part of why these flowers are so very rare. 

A short cartoon of pollinators visiting plants, from which crops grow.
Everything in the natural world serves a purpose and even the smallest of creatures means the world to some other living thing. Humans are the only beings on Earth that don’t seem to appreciate this; let’s help change this.  

Take Care.

Submitted by Pam






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