Dual personalities:

Not all ‘daddy longlegs’ are spiders

Wednesday, December 9, 2009

— Arkansas is home to two animals that share the name daddy longlegs, but are very different creatures, said John Hopkins, extension entomologist for the University of Arkansas Division of Agriculture.

“Both are in the class Arachnida, which includes scorpions, spiders, harvestmen, mites, ticks and several other less well known organisms,” he said.

Daddy longlegs No. 1, is better known as the “harvestman” and sometimes “granddaddy longlegs.” It belongs to the order Opiliones.

“Most harvestmen species have eight very long legs attached to a compact, oval, pill-like body that ranges from onesixteenth of an inch to a half-inch in length,” Hopkins said. “The harvestman’s body actually consists of a combined head and thorax, broadly joined to a distinctly segmented abdomen.”

The two-eyed animal lays eggs in the soil that will hatch the following spring.

“Offspring can live one to two years in locations where temperatures do not drop below freezing,” he said. “Most are predators and feed on live insects; while others feed on dead insects and plant juices.”

Contrary to urban myth, these daddylonglegs aren’t venomous and lack fangs to bite.

Daddy long legs No. 2 is commonly known as a “cellar spider,” and is a true spider.

“It has eight relatively, long, thin legs and, like all spiders, the body has two distinct regions, a cephalothorax and an abdomen,” Hopkins said, adding that unlike the other daddy longlegs, the spider version has eight eyes to the harvestman’s two.

Cellar spiders deposit their eggs in a ball tightly bound in silk.

“This egg sack is then carried in the female’s jaws until the eggs hatch,” he said.

Cellar spiders are generally found in dark, undisturbed areas where they spin loose, irregular webs.

When prey hits the web, “cellar spiders actively shake the web to further entangle the prey,” Hopkins said. The spider injects venom to pre-digest the prey.

“However, there is no scientific reference to any cellar spider biting a person or causing any detrimental reaction and no evidence exists to implicate the cellar spider as being hazardous to man,” he said.

“You don’t need to be afraid of either and unless they’re a particular nuisance to you, just sit back and enjoy the wonders of nature,” Hopkins said.

News, Pages 10 on 12/09/2009