Bug Blog

Flatworms Vs. Harvestmen in the Forests of Brazil

Deep in the forests of Brazil a battle is waging between flatworms and harvestmen. In case you didn’t know, harvestmen are also known as daddy longlegs, and are not classified as spiders, but are actually another member of the arachnid family. Now, most would think that the harvestmen would be able to win these fights hands down. I mean what kind of self respecting arachnid loses to a worm? However, the most logical conclusion is not always the correct one. In the war raging between flatworms and harvestmen in Brazil, it is the flatworm that more often than not ends up the victor of these fights. What kind of worm is capable of beating an arachnid in a life and death battle?

In a recent study researchers from the Universidade de Sao Paulo, M. S. Silva. R. H. Willemart and F. Carbayo, observed these fights between flatworms and harvestmen to try and better understand the dynamics of these fights. In this particular study the researchers were observing the Cephaloflexa bergi flatworm, which use the mucus they emit from the their skin to catch their prey. To start the researchers observed the battles waged between these two creatures in their natural forest habitat. Strangely enough, they found that the flatworms tended to win these fights. In order to better understand why this is the case, the researchers then took brought specimens of both the flatworm and harvestmen back to their lab to study further.

During the course of their research the team found that the flatworms were actually the aggressors in these fights. Upon approaching a harvestman the flatworms would swing the tip of their body at one of the harvestmen’s legs, the mucus secreted from their skin causing the harvestmen to get stuck to the flatworm. As the harvestman struggles to escape, the flatworm nabs another of its legs. They even end up hogtying some unfortunate harvestmen, glueing all of their legs together. The basic strategy was to incapacitate the harvestmen enough so that they could then eat their captured prey. Of course, the flatworms are not always the victors. Harvestmen have sharp spines covering their legs, which some would use to injure the attacking flatworm, sometimes cutting them clean in half, allowing the harvestman to flee to safety.

Do you know of any other insects like the flatworm that are able to somehow defeat other insects/arachnids in fights that you would normally think they would lose?