When Hugo Deans were just 8 years old, he saw what he initially believed to be seed surrounding an ant colony. Hugo’s father Andrew is a professor of entomology at Penn State University. Other kids might have made a similar remark and nothing would have come of it, but Andrew understood Hugo had noticed something significant. Further research indicated that ant-wasp partnerships are not exclusive to Marvel movies.
Deans Senior wondered what the wasp galls were doing near the ants’ nest after realizing Hugo’s “seeds” were actually wasp galls. A publication published in American Naturalist as a result of the further investigation has revealed that wasps are utilizing oak trees as middlemen to obtain ant protection for their larvae.
More than a thousand different wasp species deposit their eggs on leaves and manipulate the plant to produce a gall that shields the eggs and larvae from predators and the environment. This gall is most likely created by injecting something into the leaf. The preferred target is oak leaves.
Deans were also aware that many plants use ants in a method known as “myrmecochory” to spread their seeds. These plants develop elaiosomes, which are seed apexes, to provide their offspring room while preventing eating. The elaiosomes, as opposed to the seeds themselves, are appetizing to ants and are eaten in the nest.
In myrmecochory, Deans said, “plants get their seeds disseminated to an enemy-free region, and ants get a little amount of nutrition when they consume the elaiosomes. The phenomenon was initially observed over a century ago and is frequently used as a plant-insect interaction example when teaching biology to students.
Deans surmised that the ants were consuming the caps after noticing that the galls near the nests were missing the caps that were typically present in this species. Deans and the other authors looked into it. In the end, this led researchers to the conclusion that gall wasps manipulate oak trees to generate galls before moving on to manipulate ants to bring the galls back to their nests, according to Deans.
Unknown is whether the advantage of spending the winter in an ant colony is to receive additional protection from predators or to avoid becoming wet. In any case, Deans declared that “This multi-layered connection is mind-blowing.” The researchers were able to prove it, however, by discovering galls safely stored in the ant nests after the caps had been consumed and by photographing ant behavior around the galls.
Studies showed that the ants regard seeds and galls similarly, however they avoid uncapped galls because they are equally attracted to the caps and to elaiosomes. According to a chemical examination of the caps, they contain fatty acids that are comparable to those found in the majority of the dead insects that the ants consume.
The writers are interested in learning how the practice developed because they are scientists. Have ants been returning seeds to their nests for a while, and wasps have noticed they can cash in by driving oak trees to produce delectable crowns on top of the galls? Or perhaps Hugo accidentally discovered the original, with myrmecochory being a copy created to capitalize on an ant behavior induced by the wasps.
Given that the first is simpler and has been around for a century, it would seem more logical, but the authors are not so sure. Myrmecochory is only found in a few plants, and it may represent a relatively recent evolutionary development. A grant has been given to the authors to support additional research on the issue.
Hugo told Penn State’s media department, “I want to be different…unique…when I grow up,” as opposed to following in his father’s footsteps, as is common among children who have participated in scientific research at similar ages.
