When living as a parasite in the intestines of ants, it appears that the tapeworm Anomotaenia brevis has injected antioxidants and other proteins that help the ants remain youthful and healthy.
Being parasitized by a tapeworm is often detrimental; however, for the Temnothorax nylanderi ant, it seems to be different. If a member of this species consumes woodpecker droppings while still a larva and becomes infected with the Anomotaenia brevis tapeworm, it may live up to three times longer than its healthy counterparts, and potentially even longer, as reported by Science Alert on June 17.
Healthy ants take on the role of workers, transporting infected ants around, caring for them, and feeding them. These pampered “patients” rarely leave the nest.
In a recent study published on the bioRxiv database, a team of experts led by entomologist Susanne Foitzik at Johannes Gutenberg University in Germany sought to explain this peculiar lifestyle.
Temnothorax nylanderi Ant. (Photo: Wikimedia).
While the tapeworm resides in the ant’s intestines, it seems to inject antioxidants and other proteins into the hemolymph (the fluid in the circulatory system of arthropods, analogous to blood). The research team is not yet clear on what specific effects these proteins have on health, but it is likely that they contribute to keeping infected ants young and “fresh.”
Throughout the lifecycle of the Anomotaenia brevis tapeworm, ants are not its final host. They will eventually live in the bodies of woodpeckers as adults, meaning they gain certain benefits by keeping the ants looking youthful, healthy, and appetizing. Consequently, the ants may become breakfast for the birds.
In 2021, Foitzik and her colleagues discovered that while Temnothorax nylanderi ants infected with the tapeworm lived quite comfortably, the healthy members of the colony paid the price. They bore the burden of caring for the “patients” and died much earlier. The worker ants’ focus on caring for the infected ants, while neglecting the queen, could disrupt the entire colony.
In the new study, the team once again compared infected ants with healthy ones, meticulously observing the proteins in the hemolymph. They found that the tapeworm’s proteins constituted a significant portion of the proteins flowing through the ants’ hemolymph, with two of the most abundant proteins being antioxidants.
Other proteins may explain why infected ants receive preferential treatment. The researchers identified a large amount of vitellogenin-like A protein, which is not produced by the parasite but rather by the ants themselves. This protein is involved in regulating labor division and reproduction within ant societies. The research team suggests that somehow, this protein influences the behavior of the ants, tricking the healthy ones into favoring the infected ones.
However, scientists are still unclear whether the tapeworm actively manipulates the gene expression of proteins like vitellogenin-like A or if this is merely a byproduct of the parasitic infection process. They plan to continue researching the proteins of the parasite to gain a better understanding of how they affect the behavior, appearance, and lifespan of the ants.
