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What Are Harvestmen, a.k.a. Daddy-Long-Legs?

On his current expedition, Ronald Clouse ventures into the jungles of the Philippines to study harvestmen, or daddy-long-legs, of the order Opiliones. By collecting data for phylogenetic analysis, he hopes to learn more about the history of these creatures and the lands they inhabit.

A Jeepney in Manila. Jeepneys are a main type of inexpensive transportation throughout the Philippines. (Photo by Ronald Clouse)
A Jeepney in Manila. Jeepneys are a main type of inexpensive transportation throughout the Philippines. (Photo by Ronald Clouse)

Our decision to leave Panay Island early in the hopes of arranging some other excursions didn’t work so well, and the week spent in Manila saw our plans change almost daily. Dave was able to go to Cavinti, Laguna via a long bumpy motorcycle ride, where he collected some great harvestmen, including two sandokanids. Our trip to Mt. Malindang on Mindanao was called off for safety reasons, as kidnappings in the region continue to be a major threat. Still, the time in Manila may have been a blessing in disguise, as it allowed me the opportunity to communicate with my family just when my father passed away. Not unexpected, but still a sad event, it was good to have a measure of closeness to others via the internet. Now, on June 7th, we are traveling to Mt. Bulusan in the southern end of Luzon, where we will camp and collect for a week. From there we go to Davao City on Mindanao, very close to where the mysterious Cyphophthalmi harvestmen juveniles were collected by Dr. Arvin Diesmos in 2009.

This brings me to an important topic which we should discuss now, which is: What exactly are harvestmen? Called daddy-long-legs in the U.S., they are often called spiders, and many people believe they are dangerous, but both are untrue. Like spiders, harvestmen are arachnids, members of class Arachnida, but they are in a different order from spiders. In fact, harvestmen are not even that closely related to spiders; their closest related arachnids are scorpions.

An Opiliones in the suborder Eupnoi, from Brazil. (Photo by Ronald Clouse)
An Opiliones in the suborder Eupnoi, from Brazil. (Photo by Ronald Clouse)

How can you tell the difference between a harvestman and a spider? The easiest way is to look for a narrow constriction between the front part (with the legs and eyes and mouth) and the rear part. If there is a constriction, it’s a spider. Spiders also make silk, but harvestmen do not.

The only adult member if the Opiliones suborder Cyphophthalmi collected from the Philippines, from Palawan, dorsal view. (Photo credit Harvard University, Cyphophthalmi Checklist, Prof. Gonzalo Giribet. )
The only adult member if the Opiliones suborder Cyphophthalmi collected from the Philippines, from Palawan, dorsal view. (Photo credit Harvard University, Cyphophthalmi Checklist, Prof. Gonzalo Giribet. )

There are three kinds of harvestmen that live in the Philippines. These are in the suborders Eupnoi (the same suborder that contains the long-legged species people see in their basements and around old wood), Laniatores (which have evolved into spectacular forms in South America), and Cyphophthalmi. The last kind live all over the world, deep in humid leaf litter, where they look a lot like little seeds. They are rare in the Philippines, though, known only from four specimens, only one of which is a male. Because they do not normally (or perhaps ever) cross large bodies of water, they are excellent evidence of past land connections.

An Opiliones in the suborder Laniatores, from Brazil. (Photo by Ronald Clouse)
An Opiliones in the suborder Laniatores, from Brazil. (Photo by Ronald Clouse)

Opiliones has been around for over 400,000,000 years, and early fossils look very much like the forms alive today. Follow the video links to see more details about the geologic history of the Philippines and the taxonomy of harvestmen.

The only adult member if the Opiliones suborder Cyphophthalmi collected from the Philippines, from Palawan, lateral view. (Photo credit Harvard University, Cyphophthalmi Checklist, Prof. Gonzalo Giribet)
The only adult member if the Opiliones suborder Cyphophthalmi collected from the Philippines, from Palawan, lateral view. (Photo credit Harvard University, Cyphophthalmi Checklist, Prof. Gonzalo Giribet)

The Philippines, then and now:

What are daddy-long-legs?

Cyphophthalmi Checklist link:
http://giribet.oeb.harvard.edu/Cyphophthalmi/

Read all posts by Ronald Clouse: http://newswatch.nationalgeographic.com/author/ronaldclouse/

Comments

  1. Ronald Clouse
    July 15, 8:42 pm

    Susan, thanks so much for the kind words and sharing these videos with the AMNH volunteers. I hope they are helpful. I know that I didn’t really absorb this history until I had seen it several times from different sources. And then, of course, there’s debate and updating to this timeline as we learn more. What a fascinating part of the world.

    Hello to all my American Museum friends!

  2. Susan Bednarczyk
    New York, NY
    July 14, 11:42 am

    The video showing the techtonic plate movements is brilliant! I hope you don’t mind that I posted it on the American Museum of Natural History volunteer Facebook page. The docents in the Hall of Planet Earth will love it! Thank you for explaining such a complex phenomenon so simply!

  3. Ronald Clouse
    June 23, 12:43 am

    Bill, thank you very much for telling the story of this entrenched misconception. I had heard vague versions of this account but didn’t know the details.

    Lucinda, the audio seems to be fine — it’s just coming over from youtube and sounds OK here — but yes, the captions are pretty rough! Sorry I don’t have any useful technical advice here.

  4. Lucinda Boyd
    SPNC
    June 14, 5:08 pm

    The audio is not coming through, but captions are — such as they are, there is serious potential here to improve artificial speech — on my screen at the moment “be don’t is likes long legs” –

  5. William Shear
    Hampden-Sydney, VA
    June 12, 12:59 pm

    Patrick, the spiders you called “daddy-long-legs” were probably members of the spider family Pholcidae, which do indeed have long legs and are very common in dark spaces like cellars and closets. In fact, in Austrialia, the name “daddy-long-legs” refers to these spiders. This bit of Aussie slang led to a great confusion in the US and Europe. It seems that an Austrialian biologist ran some tests on the venom of a pholcid spider (NOT the one found in the US) and determined that its venom was highly potent. Now these spiders are very small, so they could probably not even penetrate human skin with their fangs, and the amount of venom they could deliver would in any case be minute. However, Australian news reports picked up the story and of course referred tot he spiders as “daddy-long-legs.” An American tabloid reprinted a sensationalized version in which they said that “daddy-long-legs” had the most potent venom of any animal! Of course, in the US, most people call Opiliones “daddy-long-legs!” So those of us who study these animals have spent nearly 2 decades answering questions from the public about the horrible venom of “daddy-long-legs.” Opiliones have no venom glands at all. This makes a point about the use of Latin scientific names, which are unequivocal and refer to one species or group only, and common names, which can be quite different from culture to culture.

  6. Ronald Clouse
    June 12, 9:27 am

    Hi, Patrick. Yes, you are right: in some regions people call certain actual spiders “daddy-long-legs.” There’s another complication, which is that the term “grand-daddy-long-legs” is also being used by some people, for what, I’m not sure. I didn’t get into these additional naming issues, as I don’t entirely understand them myself. Suffice it to say that in general, common names are often a problem. Just this past week a colleague told me that where he comes from people call green bananas “figs!”

  7. Patrick Hoffman
    Oakland, CA
    June 10, 11:43 pm

    I grew up calling a certain type of silk creating, body-constriction having spider a Daddy long-legs. To me and most people I know Harvestmen are completely different than Daddy long-legs. I am guessing this might be a regional thing? I am California born and raised. I am not actually sure what the group of spiders I call Daddy long-legs are beyond just knowing that common name. I guess I should look in to that.