Scientists have discovered a 47-million-year-old fossil fly with a bloom full of pollen.
This finding is the first direct evidence that some species of ancient tangle-veined flies were once fed on the microspores of several different species of subtropical plants.
“The rich pollen content we found in the fly’s stomach indicates that flies were already feeding and transporting pollen 47 million years ago and shows that it played an important role in the pollen distribution of several plant taxis, ”says botanist Fridgeir Grímsson from the University of Vienna, Austria.
When most people think of a pollinator, they think of a bird, bee or butterfly. Few consider the fly, even though it is generally acknowledged that the second most important is insect pollination.
Today, thin flies with short tongue-like structures called proboscises have been viewed as potential pollen carriers. In fact, only modern nemestrinids with long courtship appendages have ever been observed feeding on tubular plants, and even then, only on nectar.
The new fossil, found in an old quarry near Frankfurt, Germany, represents a new species of ancient, short-proboscid fly (Hirmoneura messelense) that seems to have been a pollination opportunity.
The authors believe that this pollinating beast may have even produced bees.
Fossil records showing direct pollen feeding are rare, but the last food of this fly is remarkably well preserved. Under the microscope, his gut and stomach show traces of pollen from at least four plant families, including water willow and virgin ivy, which may grow around the edges of an old lake forest.
Fossil fly and its gut and stomach contents. (Senckenberg)
The researchers can see long hair – also known as setae – on the thorax or abdomen of the fly. Although no pollen has been found on these hairs, the fact that these long braids are present suggests that they may also carry pollen when the fly has kicked from flower to flower.
Unlike other flies that visit flowers with long proboscises, which usually go over plants to feed on, this particular fly may have landed on flower tops, “before it caught pollen from anthers ”, the team writes. In fact, the fly’s proboscis is so short, it’s not even visible. Researchers believe it is hidden inside the insect’s head.
The flowers he eats are usually tightly packed together, which would have allowed the beast to walk between them easily – eating one food after another.
Three unknown species of pollen in the fly’s clump also suggest that it would eat a mixture of parent plants grown nearby.
“The fly apparently avoided long flights between food sources and sought pollen from closely related plants,” explained Grímsson.
Fossil pollen from the stomach of the fly. (Fridgeir Grímsson)
Although modern flies visiting flowers are not as effective at carrying pollen as bees, they make up for it through large numbers. The study of these pollinators has long been neglected and there are few studies between them.
This new discovery supports an old notion that flower-visiting flies could be at least as important as some pollinating bees – perhaps even more so. The fact that we found pollen in the stomach of an old fly indicates that this may have been an important part of the insect as far back as Jurassic.
“The delicate tangle-veined fly presented here is clearly fed on angiosperm pollen and, as a result, represents the first direct evidence of a pollinivorous nemestrinid,” the authors note. completion.
The study was published in Conventional biology.