Tag: new spider

Right under our noses: A novel lichen-patterned spider found on oaks in central Spain

It happened again, a previously unknown spider species, whose home is a strongly humanised European country, appears to have been quietly and patiently waiting to get noticed until very recently.

Living on the trunks of oaks in Spain, the new species would have probably been spotted decades ago, had it not been for its sophisticated camouflage, which allows the small arachnid to perfectly blend with the lichens naturally growing on the tree.

Going by the name Araneus bonali, the new species was discovered on isolated trees at the borders of cereal fields by the scientists Eduardo Morano, University of Castilla-La Mancha, and Dr Raul Bonal, University of Extremadura. Their study is published in the open access journal ZooKeys.

Curiously enough, this is the same habitat, where the team found another new spider in 2016.

“How many new species remain unknown in these isolated oaks that once formed vast forests now becomes one even more intriguing question,” say the researchers.

“Anyone going for a walk around any village or park in central Spain would have been close to the new species. However, noticing it requires not only curiosity, but also a good sight, as its lichen-like colours make up an excellent mimicry.”

Lichens growing on an oak trunk at the study site in central Spain.

The similarity between the adults and the lichens that cover the oak trunks they inhabit is remarkable. Meanwhile, the greenish juveniles live amongst the green new shoots in the oak canopy until they reach maturity.

Whether the spider uses its mimicry to avoid predators or rather surprise its prey remains open for further investigation.

The description of this new species that belongs to the popular group of orb-weavers once again stresses the need of working harder on completing the list of spiders living in the Old World, such as the countries in the Mediterranean basin – a region that certainly keeps more taxonomic surprises up his sleeve.

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Original source:

Morano E, Bonal R (2018) Araneus bonali sp. n., a novel lichen-patterned species found on oak trunks (Araneae, Araneidae). ZooKeys 779: 119-145. https://doi.org/10.3897/zookeys.779.26944

Out of the darkness: A new spider found deep within an Indiana cave

Lead author Marc Milne in the Stygian River Cave and a male specimen of the newly described Islandiana lewisi 

Spiders are ubiquitous within our forests, fields, and backyards. Although you may be used to seeing the beautiful yellow and black spiders of the genus Argiope in your garden, large ground-scurrying wolf spiders in your yard, or spindly cellar spiders in your basement, this new sheet-web-building spider is probably one you haven’t seen before. The reason is that it’s known from a single cave in the world, Stygeon River Cave, in southern Indiana.

The University of Indianapolis assistant professor, Dr. Marc Milne, described the rare species in the open access journal Subterranean Biology with the help of a University of Indianapolis alumnus, Elizabeth Wells, who illustrated the spider for the manuscript.

Sheet weavers, also known as dwarf spiders or money spiders, are minute creatures growing no larger than a few centimetres in length, which makes them particularly elusive. Their peculiar webs are flat and sheet-like, hence their common English name.

Female of the new species Islandiana lewisi

The new spider, Islandiana lewisi, is an homage. Milne was shown the spider by a fellow scientist, Dr. Julian Lewis, who noticed the critter on one of his many cave expeditions. In appreciation for his help, Milne and Wells named the spider after Lewis.

This is the fifteenth species in its genus (Islandiana) and the fifth known to live exclusively in caves. It has been over 30 years since the last species has been added to this group.

At about 2 mm in size, Islandiana lewisi is thought to feed on even smaller arthropods, such as springtails living in the debris on the cave floor. It is unknown when it reproduces or if it exists anywhere else. The spider is likely harmless to humans.

The collectors of the spider, Milne and Lewis, described the hostile conditions within the cave, which the new species calls home: “because the cave floods from time to time, the insides were wet, muddy, slippery, and dangerous to walk on without the proper equipment.”

Milne and Lewis found the spider in small, horizontal webs between large, mud-caked boulders in the largest room in the cave. It was collected in October 2016 with the permission of the landowner.

Milne hypothesized that he had collected something special, stating, “I didn’t know what the spider was at first, I just thought it was odd that so many were living within this dark cave with no other spider species around.”

After returning to the lab and inspecting the spider under a microscope, Milne initially misidentified the species. However, when he re-examined it months later, he realized that the species was indeed new to science.

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Original source:

Milne MA, Wells E (2018) A new species of spider (Araneae, Linyphiidae, Islandiana) from a southern Indiana cave. Subterranean Biology 26: 19-26. https://doi.org/10.3897/subtbiol.26.25605