Larry Lyons: Is the daddy long-legs spider dangerous?

Published 8:18 pm Tuesday, July 13, 2010

lyonsMy man cave, otherwise known as workshop, is a large pole building. I call it my workshop but in reality it belongs to spiders and I’m just an intruder.

Spider webs and egg sacs hang from everything that isn’t moved or swept daily. I see all types of spiders but the ones I most often encounter are daddy long-legs. Not surprising, for daddy long-legs are one of the most common spiders found around our houses and outbuildings.

When I decided to do this week’s column on them I figured it would be a pretty easy, slam-dunk topic. As usual, though, that wasn’t the case.

There are actually two entirely different creatures that look very much alike and both of which are commonly referred to as daddy long-legs. In addition, there are a ton of different species within these two groupings. To avoid tedium I’ll just deal in generalities and treat the two groups as wholes.

One of the commonly encountered daddy long-legs isn’t even a true spider. They’re called harvestmen. They can’t spin silk so don’t have webs. They have no venom or hollow fangs to inject it which all spiders do (though most just produce a minor annoyance to humans).

They are opportunistic feeders, eating everything from carrion to decaying vegetation and live insects. They have the classic daddy long-legs look with the tiny body and extremely long, thread-like legs. The key to their identity is their body is a pill-shaped disc, not two segments like spiders.

The other almost identical appearing daddy long-leg is a real spider which also carries other names such as cellar spider, house spider and vibrating spider. They spin a messy, irregular, tangled web in dark undisturbed areas, often in cellars, closets, attics and behind furniture and cabinets. These guys are bad dudes in the spider world for they aggressively prey on other spiders as well as insects.

Their web isn’t sticky but the irregular structure traps prey long enough for the daddy long-legs to administer the coupe-de-grace. They even take on other spiders with very potent venom like hobo spiders and some members of the black widow family. The name vibrating spider comes from their ruse of rapidly vibrating other spider’s webs to imitate a caught prey. When the host spider appears, BAM. They can be distinguished from the harvestmen daddy long-legs by their segmented, two part body.

The fact that the daddy long-legs spider preys on other highly venomous spiders may be the basis of the wide spread legend that daddy long-legs have the most potent spider venom of all but it’s fangs are too short or weak to puncture human skin. This same legend is attached to harvestmen, probably because most folks can’t tell one from the other. It’s obviously a myth with harvestmen for they have no venom. As for the daddy long-legs spider, surprisingly, very little is known in this regard.

They do have very short fangs but so, too, does the potentially deadly brown recluse. We know they also have venom but that’s about the extent of our knowledge. Since there hasn’t been problems with daddy long-legs spider bites, the only way to test it’s potency on humans would be to milk the venom and inject it into a human. A lack of volunteers has precluded this one.

Well, not entirely. It appears that the only ones to venture near there, of all people, were the hosts of the TV program, Mythbusters. One of them stuck their arm into a cage seething with daddy long-legs spiders and let them have their way. One did eventually bite and it only produced a short term, mild burning sensation. However, this was just a one time, anecdotal incident which science gives no credence to.

There is no record whatsoever of any ill effects from a daddy long-legs spider bite. Also, recent research shows their venom is relatively weak on its prey. With no scientific or even anecdotal basis, I’ll call this myth busted. It’s likely this legend came from the assumption that since daddy long-legs prey on other highly venomous spiders their venom must be even more potent yet. In reality, they’re probably just faster.

Carpe diem.

Larry Lyons writes a weekly outdoor column for Leader Publications.
He can be reached at larrylyons@verizon.net.