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FIGURE 1. Harvestmen are among the most fascinating of animals. Science fiction could not come up with a more remarkable critter. Worldwide, there are 37 families of Harvestmen. Eighteen species are reported from Texas.

   
 

 

FIGURE 2. The Harvestmen’s most striking characteristic is their legs. Not only are those legs long but they are delicate. Note that the specimen shown above is missing one leg.

   
 

 

FIGURE 3. Harvestmen have only one pair of eyes. Their two eyes are mounted on top of their head, which looks like a small pedestal above their torso. Each eye looks somewhat outward, oriented sideways. These eyes only scan above their body, and can detect a moving object several feet away.

   
 

 

FIGURE 4. Harvestmen serve dual roles as predators (preying on a variety of insects and other arthropods) and also as scavengers (feeding on fungi, fecal matter, etc.).

   

Quick Facts

Common Name:

Harvestmen & Daddylonglegs

Other Common Names: Daddy longlegs, Daddy-Long-Legs, Harvest-Spiders, Shepherd Spiders and Grandfather Graybeards

Genus / Species:

Opiliones spp.

Size: Average body length is 5/16 of an inch. Average length including leg span can exceed 6 inches

Type of Beneficial:

Insect predator; also a scavenger

Beneficial Stage(s):

Both adults and immatures are predators

Prey:

Generally carnivorous, feeding on live invertebrate prey including aphids, beetles, caterpillars, earthworms, flies, mites, small slugs, snails and spiders.

Occurrence:

Not common in Galveston County. More widespread in other parts of Texas especially wooded areas, under rocks or logs, caves and similar sheltered areas

Mounted Specimen?

Yes (mounted specimen for viewing available in insect collection at County Extension Office)

 

How many times has a woodland picnic been disrupted by an odd looking, eight-legged creature scampering across your lunch? More than likely that creature was a Harvestman.

In the old days, it was believed that daddy-long-legs could find lost cattle. If one picked it up by 7 of its 8 legs, the free leg would point in the direction of the cattle. Another myth was that if you killed a daddylonglegs, it would rain the next day.

Harvestmen are among the most fascinating of animals. Science fiction could not come up with a more remarkable critter. Worldwide, there are 37 families of Harvestmen. Eighteen species are reported from Texas. Members of only one family, Phalangiidae, are properly (i.e., according to entomologists) referred to as “daddylonglegs” or “daddy longlegs” or “daddy-long-legs.”

The name Harvestmen comes from their being seen in late summer and fall at harvest time. Other common names include harvest-spiders, shepherd spiders (because of the way males guard females during egg-laying) and the Native Americans call them grandfather graybeard, meaning "Feet of Hairs."

In Germany, they are called afterspinnen (pseudo-spiders) and zimmermaenner (carpenters) and the French names are similar: faucheux, faucheurs, translating to haymaker or reaper. The common name, daddylonglegs, is also used (and confused) with crane flies (Tipulidae) and cellar spiders (Pholcidae).

Harvestmen are members of the class Arachnida, which also includes spiders, scorpions, mites and ticks. But they are not spiders, similar to the way that butterflies are insects, but they are not beetles.

Like all arachnids, Harvestmen do have 4 pairs of legs, a fang-like mouthpart called "chelicerae," and 2 antennae-like appendages near the mouth called "pedipalps." Most Harvestmen have very long legs, though there are some short-legged species that look very similar to mites.

There are vast differences between Harvestmen and spiders. Harvestmen have two eyes versus the spiders' six or eight. Unlike spiders (that have 2 body segments, which are distinct and separated), the head, thorax and abdomen of the Harvestmen are a compact oval body and appear fused (as with mites and ticks). Next, spiders have venomous fangs.

Harvestmen have no venom glands or silk glands (they do not spin webs or build nests). Harvestmen do have a pair of scent glands that secrete a peculiar smelling fluid when disturbed. Most importantly, Harvestmen pose absolutely no danger to humans.

Harvestmen are relatively long and, in some species, quite sturdy. Their typical body length is about 5/16 of an inch. However, with the Harvestmen’s leg span, they can exceed over 6 inches. Like humans, Harvestmen have only one pair of eyes. Their two eyes are mounted on top of their head, which looks like a small pedestal above their torso. Each eye looks somewhat outward, oriented sideways. These eyes only scan above their body and can detect a moving object several feet away.

Differentiation between male and female is seen in size, color and proportions of the appendages. Usually the male's body is smaller, shorter and more brilliantly colored than that of the female; however, the female's markings tend to be more distinct. Males have longer legs, as well as more distinct granulations and spines.

The Harvestmen’s most striking characteristic is their legs. When spotting a harvestman, its body is surrounded with eight long legs that range from 1-to2 inches in length. (If the human torso was the size of theirs, proportionally-sized legs would extend over a span of 40-to-50 feet.)

Not only are those legs long but they are delicate. Their legs are as fine as those of water striders, but Harvestmen cannot penetrate the surface of water for the water’s surface tension traps their feet. Harvestmen do not raise their bodies much above the ground when walking. They carry it low with the middle part of their legs high in the air.

Usually leisurely in their movements, they can move rapidly with the body swung below the pumping "knees.” When disturbed, they stand on six legs and wave the second pair in the air, sensing their surroundings.

Harvestmen’s seven-jointed legs are extremely unique. Their extremely sensitive tips are used to explore its path, serve as shock-absorbers so that the torso moves along evenly, search for food and warn of danger. The front pair of legs is the shortest—three-jointed mouth organs with the third joint forming the finger of a claw. Underneath the claw is a pair of small pincers used to grasp, tear and stuff food into its mouth, to fight other Harvestmen and to frequently clean its legs.

The second pair of legs is longer than the others and works as antennae or sense organs, playing a role comparable to a human’s eyes, nose and tongue. The fourth pair is next in length.

Harvestmen have two measures of protection. One is that the Harvestmen’s legs are easily detached from its body (as when a lizard's tail breaks off), serving as a means of protection from predators. Because they are all leg, a predator will likely grab onto a longer one instead of the juicy middle leg. A leg easily becomes detached, further confusing its prey. The detached leg can continue twitching movements for some time (anywhere from one minute to an hour)—distracting a predator while the harvestman escapes.

This twitching continues because there is a pacemaker-like organ located in the ends of the first long segment (femur) of their legs. This "pacemaker" send signals via the nerves to the muscles to extend the leg and then the leg relaxes between signals.

Their other defensive strategy is the art of stench. When disturbed, a pair of scent glands (outside ducts near the base of the first pair of legs) produces two secretions. One is a milky liquid with a foul odor. Not only does a predator smell this rank fluid, but gives it warning that Harvestmen must taste terrible. The second secretion is a clear one to lay a trail, which may be followed by other Harvestmen.

Like all arachnids, Harvestmen have incomplete metamorphosis. They mate in late summer and autumn, copulating readily upon meeting and they meet often. After the male drives away rivals, he forms a kind of umbrella over the female while she deposits her eggs. Females lay a few eggs at a time using an ovipositor that can be extended to a great length. This is repeated until she becomes an empty shell, ultimately dropping hundreds of eggs in the soil, under stones, in some crevice, or rotten wood.

Harvestmen eggs hatch in spring. The young look like white miniatures of the adults, but soon they darken. About every ten days, until they reach maturity, they molt. The harvestman splits open its body case (exoskeleton) and drags its long legs out of the old skin—a process taking around 20 minutes. In the northern part of the United States, most Harvestmen die in the fall after eggs are laid, but in southern states, they hide under organic matter through the winter.

Although seen during the day, Harvestmen are primarily night prowlers and solitary in habit. Sometimes several will form a tangled mass of bodies and legs and remain immobile unless prodded into activity. If you are lucky, you may even see two males joust upon meeting.

Mostly, a harvestman is found sitting motionless on the upper sides of leaves, waiting to ambush a soft-bodied insect. During warm months, Harvestmen are extremely common on the shady sides of buildings, underneath eaves, in crawl spaces and on trees, both in rural and urban environments. They are especially common in wooded areas, under rocks or logs and even caves. They like moist, shady environments and can will live in basements.

Harvestmen are considered to be predators and scavengers and eat a wide variety of food, preferring insects and other arthropods (dead or alive), as well as vegetable matter and juices. Adults usually begin foraging at twilight. They're generally carnivorous, feeding on live invertebrate prey. A harvestman will eat little ants on a crumb of bread and then eat part of the crumb. Food is never a problem, ranging from aphids, beetles, caterpillars, earthworms, flies, mites, small slugs, snails and spiders, to fecal matter and fungi. Watch one eat and notice how after each meal it cleans each leg, drawing them, one at a time through its jaws.

These unusual arachnids make an interesting subject for study and Harvestmen can be easily collected by hand. Carefully capture several. Don't worry about their curling up and becoming immobile. They will become active again once they are in a larger space. Place them in a glass-covered terrarium or 18"x12"x6" box. Cover the floor with a half-inch of earth or coarse sand and be sure to provide water or the Harvestmen will soon die. Do this with dampened blotters, thus avoiding that problem with water surface tension. Change the blotters regularly to minimize mold. Finally, add some leaves for hiding places. Harvestmen will survive on tidbits of bread, butter and fatty meat as well a few tasty insects thrown in for good measure.

Whether you know them as Harvestmen or Daddylonglegs, they are not pests, but very beneficial and medically harmless members of the class Arachnida. Granted, they can sometimes be a nuisance if there are dozens congregated, but remember they are not harmful to humans, animals, buildings, or crops. Large spiders eat Harvestmen along with other predatory insects like assassin bugs. Birds are among its enemies and some species are threatened by the invasion of non-native fire ants.

Beneficials in the Garden & Landscape is an Earth-KindTM program coordinated through Extension Horticulture at Texas A&M University. Earth-Kind uses research-proven techniques to provide maximum gardening and landscape enjoyment while preserving and protecting our environment.

 

This web site is maintained by Master Gardener Laura Bellmore, under the direction of William M. Johnson, Ph.D., County Extension Agent-Horticulture & Master Gardener Program Coordinator.

All digital photographs are the property of  the Galveston County Master Gardener Association, Inc. (GCMGA) © 2002-2006 GCMGA - All Rights Reserved.