Spiders Secret Love For Pollen
Insects aren’t the only things that get trapped in a spiders’ web. In addition to snaring insect prey, they also catch aerial plankton such as pollen. Everyone knows that spiders are purely carnivorous, eating flies, crickets, and other tasty insects by the droves. So, this extra debris must just be discarded by spiders in favor of the tasty insects also caught in their web. Right? Maybe not.
A recent study found that spiders actually might have a more diverse appetite than we previously believed. Dr. Dirk Sanders with the University of Exeter proved that spiders might not be the absolute predators that we generally believe they are. His study found that some spiders also like a bit of pollen with their insects, with pollen making up a quarter of some spider’s diets. This means that spiders aren’t carnivores, but rather omnivores. Sounds like something from an alternate universe, right?
Dr. Sanders found during his study that orb web spiders (just the common garden variety) don’t just eat pollen along with the insects they catch, but even choose to eat pollen specifically even if insects are available to munch on. The study involved Dr. Sanders and his colleague Mr. Benjamin Eggs from the University of Bern performing numerous feeding experiments on juvenile spiders to find out whether they included plant-based nutrition in their diet.
They concluded that a whole 25 percent of the nutrients they consume is pollen, leaving 75 percent that was made up of various flying insects. The combination of the two gave them all of the essential nutrients they needed, with the spiders that ate both getting optimal nourishment through this mixed diet as opposed to a purely carnivorous one. Scientists already knew that orb web spiders eat their webs when they take them down in order to recycle the silk proteins, and had suggested that it is during this process that they accidentally eat the pollen. However, this was proved to be impossible because of the large size of the grains of pollen, signifying they actively consume them. The significant part of their diet that pollen makes up (25%) also proves that it is not simply consumed by accident, but is in fact a regular part of their diet.
Apparently spiders are omnivores…who knew?
Did you think spiders were solely carnivorous? Can you think of any other seemingly-carnivorous insect predator that also consumes plant material along with their diet of other insects?