“Daddy Long Legs are one of the most poisonous spiders, but their fangs are too short to bite humans. But if they could, they would be deadly.”
Have you heard this common myth? This creature has long held on to this untrue legacy. While the Daddy Long Legs or Harvestman is in the Order of arachnids, having eight legs, so do scorpions, mites and ticks. True spiders have two segments or body parts; the cephalothorax (Greek for head-body) and the abdomen or gut. The abdomen of true spiders also has spinnerets for producing silk for web making. Daddy Long Legs (of the Order Opiliones) have a fused cephalothorax and abdomen, or a single body part, and do not possess spinnerets. They do not produce silk and webs. If you see one in a web it has probably fallen victim to a true spider. Other differences are that Opiliones have no venom glands in their chelicerae (mouth parts), where true spiders have both fangs and venom.
Daddy Long Legs or Harvestman are opportunistic, and may eat other small insects but their primary diet is that of a decomposer, eating dead plants and fungi and sometimes dead animal material. That is why you will find them under dead logs and in other dead forest and garden debris. Since they lack venom glands, fangs or any other mechanism for chemically subduing their food, they do not have poison and, by the powers of logic, cannot be poisonous from venom.
How do Daddy Long Legs defend themselves from their predators? There are two ways besides outrunning them. First, in their limited arsenal of self-defense is the art of distraction. If a leg is lost (some species may have the ability to throw off their legs) the separated leg will twitch for a few minutes. Some species’ legs have been recorded to twitch for up to an hour. The twitching is an adaptation designed to hold the attention of the predator while the Daddy Long Legs escapes to safety. A final defense found in some types of Daddy Long Legs is their ability to secrete a substance with a strong odor from their abdomen to discourage the predator. This secretion may be poisonous if eaten. I could not find any studies on how many or much of this substance a mammal would have to consume to be affected.
In summary, you are safe to capture and observe Daddy Long Legs to your heart’s content and should not suffer any negative consequences, as long as you do not eat them! –By Robin Lee, Education Programming Coordinator