Someone at Brazil’s Butantan Institute was sifting through a collection of spiders when they discovered the ornamental one.

Only a few millimeters long, the spider had pale beads neatly stuck to its body, like a tiny pearl necklace.

But it wasn’t just a decoration. It was a parasite larva. They called in a tick expert. Butantan InstituteRiccardo Bassini Silva knew immediately what he was looking at. The larvae of the mite attach themselves to the spider and feed on it.

That alone is rare in Brazil. What happened next was even more surprising. The larvae did not match anything previously known in this country.

After the researchers examined them closely using microscopes and scanning techniques, they confirmed that this was a brand new species, which they named Araneothrombium brasiliensis.

meet Araneothrombium brasiliensis

Brazil has amazing diversity types of spidersHowever, recorded cases of mites parasitic on spiders are surprisingly rare. Until now, only one spider-parasitic mite has been recorded in this country, and it belongs to an entirely different family.

So this discovery is the second recorded in Brazil and the first time this particular tick family has been found in Brazil. It also expands the known range of this genus. araneothrombiumwas only recently described in Costa Rica in 2017.

The finding of this group in Brazil strongly suggests that it is likely spread to many more regions. Neotropics More than scientists have ever been able to document.

In other words, mites may not be rare in nature. It is rare in the scientific record because few researchers have investigated it in sufficient detail.

Parasites that disappear with age

The mite itself is small, about half a millimeter in size, and the spider host is not much larger. In the larval stage, the parasite is just a moving speck.

The researchers found them attached to young spiders from three different families, which were visibly engorged and heavily swollen after feeding. Of note, only mite larvae were found, and no adults. That’s to be expected with this group.

“In the case of this group of mites, it is not uncommon for many parasitic species to be known only through their larvae, because as adults they become free-living predators, living in the soil and preying on small insects and even other mites, making them very difficult to find,” Bassini-Silva said.

in fact, larva Represents the parasitic stage of the life cycle. When the mite matures, it leaves the spider and returns to the soil.

They lead completely different lives there, so it’s very difficult to link parasites and predators unless researchers capture the species at the right time.

Caves and hidden parasites

The infested spiders were collected in and near caves in Piñeirar, Rio de Janeiro state.

This detail is noteworthy because the only known spider parasite in Brazil is the mite. Charletonia Lochaiwas also discovered in similar circumstances.

It’s not necessarily that caves are the “source” of these parasites. Rather, it suggests that these environments may be good hunting grounds for researchers looking to find more examples, or at least to find locations where these interactions can be preserved and noticed later.

Araneothrombium brasiliensis attack

these Araneothrombium brasiliensis The larva does not try to bite off the hardest part of the spider’s body. Instead, target the petite, or narrow “waist” that connects the front (where the eyes and mouthparts are) to the abdomen. Why there? Because it’s basically a weak link.

“This is the most vulnerable area for the spider, as the rest of the spider is rich in chitin, forming an exoskeleton that is difficult for the mite’s fangs to penetrate,” Bassini-Silva said.

They feed on fluids like lymph that circulate through their bodies. arthropod. Therefore, they fix themselves in places that are easy to access.

The fact that the host was a boy also makes sense. Young spiders are generally more at risk and less able to defend themselves, so opportunistic parasites may be better able to target them.

Are these mites technically “spider parasites”? Probably not. Although this new species was discovered in spiders, researchers do not think it is exclusive to spiders.

Some closely related mites feed on more than one type of arthropod. The early Brazilian species Charletonia Lochaiare not picky – they have been observed parasitizing insects from at least two different orders.

So Araneothrombium brasiliensis It could be a spider specialist, or it could be a generalist that also uses other hosts. At the moment, there is definitely evidence that they are using spiders, and the rest is still up in the air.

Uncover the secrets of the collection

This wasn’t discovered during a dramatic jungle expedition. The spider sat in my collection for years. Dani was there the whole time and didn’t notice until someone found the “necklace.”

it’s a good memory museum collection It’s not dead storage. It is full of undiscovered information, especially regarding small organisms and strange relationships such as parasitism.

And Brazil is basically a treasure trove for this kind of work. “With over 3,000 species of spiders alone, Brazil has tremendous potential to discover new parasitic mites,” Bassini-Silva says.

Therefore, if one small spider in the drawer can reveal a brand new species of parasite, perhaps many more surprises await us, not only in the forest, but already sleeping on the shelves.

This research International Acharology Journal.

Image credit: Ricardo Bassini Silva

—–

Like what you read? Subscribe to newsletter We bring you fascinating articles, exclusive content, and the latest updates.

Please check it out earth snapThis is a free app provided by. Eric Ralls and Earth.com.

—–