Even In the Spider World the Old Adage That the Enemy of My Enemy is My Friend Stands True

It is common knowledge that our ecosystem exists in a delicate balance and that every creature, whether cute or terrifying, serves their purpose. Without even one of these species that delicate balance can be disturbed. Even creatures that seem to be harmful to another species may actually help it in another way. The interactions between different creatures such as plants and spiders can be observed everywhere you look. One such interaction grabbed the attention of Anina Knauer and Florian Schiestl, a professor at the Department of Systematic and Evolutionary Botany of the University of Zurich. They decided to take a closer look at the relationship between crab spiders and a yellow flowering plant called the buckler-mustard.

Crab spiders like to spend their time hiding among the petals of the buckler-mustard flower, laying in wait for a tasty meal to come their way. Scientists previously believed that these spiders harmed the plant, as they will prey upon any insect that comes near the plant, including pollinators. This, of course, also scares away other pollinators from visiting the plant and pollinating it. This doesn’t sound like a spider that is beneficial to the plant in any way. However, a recent study conducted by Knauer and Schiestl revealed a strange phenomenon that scientists had never linked to the crab spider until now.

While it is true that a crab spider sitting on the flower will frighten away bees and other necessary pollinators, they actually help to protect the flower as well. The spiders don’t just eat those important pollinators. They also eat other insects that want to eat the plant, as well as their larvae that like to munch on the flowers or fruit of the plant, which damages the plant and can even kill it. This turns the previous belief that crab spiders are solely detrimental to the plant. The crab spiders actually benefit the plant. They do it so well that the flowers will release more of the floral volatile, which happens to attract both bees and crab spiders, when they are being attacked by florivores. The plant’s cry for help encourages the spiders to come to its rescue where it will find plenty of food to devour in the form of the insects harming the flower. It seems that the saying “the enemy of my enemy is my friend” holds true even in nature.

Can you think of any other relationships between insects/spiders and plants that are similar to this one? Are there other insect “enemies” that also benefit that which they harm?