The Grandaddy longlegs are here! (May 28, 2007)

Awww, yeah, it's summer time in Lausanne. The weather is warm, and the lakeside is crowding up. Half the time it is still cold, but that makes it even better: now I only have to do laundry half as often. How much better does it get?

At the same time, I am now finding grandaddy longlegs everywhere in my apartment. Lausanne is normally low on the bugs, but I guess it changes during the summer.

I do not mind these creatures too much, because they are terrified of humans, plus they move slow and are easy to squoosh. Still, I would prefer to have less of them, so I will have to open the windows a little less often.

In looking for the above Wikipedia link, I ran across a lot of cool stuff about these creepy leggy creatures. For example, they do not make their own webs -- they do not even have silk glands! -- so any time you see them in a web they must have stolen it. In fact, biologists do not even call these creatures "spiders". They are arachnids, but not spiders. A real spider not only makes webs, but has eight eyes instead of two.

The web stealing is just the beginning of it. These guys are real jerks of the animal kingdom. I ran across a great short paper online where two guys are very proud to have photographic evidence of--get this--a longlegs stealing food out of the web from another spider. It's from the Journal of Arachnology, which appears to be legitimate.

Even aside from the subject of the paper, it's a funny read in other ways. For example, the authors spend a lot of effort arguing over whether the observed behavior counts as "kleptoparasitic". I guess the authors are angling for some kind of position in intellectual history, which is an interesting part of how research works. You would love to be the guy that discovered kleptoparasitic behavior in grandaddy longlegs. Or something; I did not follow the argument closely, as I do not care about the intellectual history of arachnids.

Also amusing is how much page space they spend on ridiculous amounts of detail. I guess they never know what part will turn out to be significant to a future arachnophile, so they put it all in anyway. Reading this, my respect is increased for all those silly "fake" science projects we did in grade school. Check it out:

The harvestman and spider were observed in nature without touching or altering subjects, and were photographed by the senior author. The observations were made at Reserva Municipal da Mata de Santa Genebra, Campinas, state of São Paulo, Brazil (22 44 S, 47 06 W) on 26 September 1992 at about 2000 h. The temperature was about 25 C, relative humidity was 60%, and the day was cloudy.

Here is the punchline of the report. Check out the writing style. It's scientific stuffiness, mixed with psycho-thriller novel.

The harvestman was first detected on a tree trunk about 20 cm from the spider. The spider was holding the prey (a moth partially wrapped in silk) with its chelicerae (Fig. 1). The harvestman slowly approached the spider, until it touched the spider with its first and second pairs of legs (Fig. 2). The harvestman touched the spider again three or four times. Meanwhile, the spider stood motionless. After 1-2 minutes, the harvestman suddenly moved over the spider, which dropped the prey and backed up about 3-4 cm. Because the harvestman also moved back slightly (ca. 1-2 cm), the prey was now located between the two arachnids (Fig. 3). Just a few seconds later, the harvestman started moving towards the prey, while the spider turned around and moved away (Fig. 4). The harvestman eventually picked the prey up with its pedipalps, and remained at the spot handling the prey (maybe already eating it) for several minutes afterwards.

By the way, in case longlegs seem like scary kings of the jungle, the paper also offers the tidbit that, "One of the main predators of goniosomatine harvestmen is the ctenid spider Ctenus fasciatus (Mello-Leitão 1943), which preys mainly on adult and subadult harvestmen." If there is a king of the bug world, it's not longlegs.

Lex Spoon