Harvestmen

Harvestmen (Opiliones), also known as "Daddy Long-legs" or "Grand Daddy Long-legs", are a common arachnid, related to spiders. There are thousands of individual species in the order opiliones, of which more than 100 are native to North America. Their shared common names reflect the fact that they walk on very long, spindly legs and are most commonly seen around harvest time in the fall.

Folk legend claims that they are the most venomous spider in the world, but in truth they are non-venomous. They also have no fangs or silk glands, combine the cephalothorax and abdomen into a single body section, and have only two eyes. Harvestmen are generally harmless, though they may emit an unpleasant odor if bothered. The response helps to guard against predation by birds.

They sometimes gather in large masses. Their senses are enhanced by tiny receptors in their legs, concentrated in the second pair, which they can use to hear, smell, taste, and even detect light and shadow while "feeling" around.

Female harvestmen tend to have proportionally larger bodies and shorter legs. They "molt" from their exoskeletons every 10 days or so.

Opiliones are considered beneficial for gardens, as their diet consists of slugs, aphids, mites, and small spiders.

Harvestmen are commonly confused with cellar spiders.

References

• Order Opiliones - Harvestmen at bugguide.net - Accessed 1 July 2015
• Daddy Longlegs (Harvestmen) at the Missouri Department of Natural Resources - Accessed 1 July 2015