1. Research
2. Behavior
3. Cellar Spiders

EN60CH09-Giribet ARI 27 November 2014 14:47 Evolutionary Biology of Harvestmen (Arachnida, Opiliones) Gonzalo Giribet1,∗ and Prashant P. This is the first comprehensive treatment of a major order of arachnids featuring more than 6,000 species worldwide, familiar in North America as daddy-longlegs but.

TAXONOMY KINGDOM: Animalia PHYLUM: Arthropoda CLASS: Arachnida ORDER: Opiliones (harvestmen) Other Names: daddy-long-legs, opilionids, shepherd spiders, granddaddy-long-legs, reapers WHAT IS A HARVESTMEN? Harvestmen are members of the class Arachnida, which also includes, and. Like all arachnids, harvestmen have 4 pairs of legs, fang-like mouthparts called 'chelicerae,' and 2 antennae-like appendages near the mouth called 'pedipalps.' They have no antennae. Most Kentucky harvestmen have very long legs, and these species are usually called 'daddy-long-legs.' Some harvestmen have short legs and look very similar to mites, but these species are rarely seen in Kentucky. Harvestmen are often confused with spiders, but harvestmen are not true spiders.

Spiders have 2 body segments (cephalothorax and abdomen) that are distinct and separated. On harvestmen the 2 body segments appear fused into a single large body segment (as with mites and ticks).

Also, spiders have venomous fangs, whereas the fangs of harvestmen have no venom glands. SIZE: Body length up to about 1/4' for Kentucky harvestmen LIFE CYCLE Like all arachnids, harvestmen have incomplete metamorphosis. This means that young harvestmen hatch from eggs and look like tiny versions of the adults. They molt (shed their skin) as they grow larger. Most harvestmen in Kentucky live for about a year.

Females lay eggs by the hundreds in moist soil. ECOLOGY The biology and ecology of harvestmen is poorly known. Most harvestmen species are found in moist, shady environments. Some harvestmen live deep in caves, while others are found in basements or in the deep shade of woods or plant growth. Regardless of where they live, they are usually active in darkness or in the shade. Some harvestmen search methodically over the ground and on plants for slow-moving or dead insects, insect eggs, earthworms, and decaying plant material.

Harvestmen are often seen sitting motionless on the upper sides of leaves, like the one shown below, perhaps waiting in ambush for soft-bodied insect prey. Harvestman on leaves (B. Newton 2003) Although they resemble spiders, harvestmen do not have venomous fangs or silk glands. Some species, however, have glands on the sides of their bodies that can secrete bad-tasting and bad-smelling defensive chemicals which help protect them from predators. Harvestmen are sometimes eaten by birds, large spiders, and predatory insects like assassin bugs.

Mites on harvestman leg (B. Newton 2003) Mites are common parasites on all kinds of arthropods, including many insect and spider species. Click to read a brief summary of a scientific study concerning mites and daddy-long-legs. PEST STATUS Harvestmen are sometimes a nuisance around buildings where they congregate by the dozens, but they are not harmful to humans, animals, buildings, or crops. COMMON KENTUCKY HARVESTMEN DADDY-LONG-LEGS: Leiobunum genus FAMILY: Leiobunidae Genus: Leiobunum As mentioned above, long-legged harvestmen species are usually called ' Daddy-Long-Legs.' Many of the daddy-long-legs encountered in Kentucky are in the genus Leiobunum.

Leiobunum daddy-long-legs are almost always present around trees, shrubs, or any thick vegetation in Kentucky during warm months. They are also common around buildings, especially barns, sheds, and similar structures. Pictured below are two common Leiobunum species. The one on the left is probably Leiobunum vittatum, a species that occurs over much of the eastern United States. Daddy-long-legs, Leiobunum sp. Bessin 2000) COLLECTING & PHOTOGRAPHY During warm months, harvestmen are extremely common on the shady sides of buildings, underneath eaves, in crawl spaces, and on trees, and they are found in both rural and urban environments. Harvestmen can be easily collected by hand, but take care not to break off any legs.

Harvestmen will usually stay still for a photo as long as you don't touch them. These creatures have soft bodies, and should be preserved in alcohol. HARVESTMEN FACTS The legs of harvestmen fall off easily and continue to twitch for some time after removal.

It is believed that this helps the daddy-long-legs escape predators (as when a lizard's tail breaks off). MYTHS - LEGENDS - FOLKLORE You may have heard that 'daddy-long-legs are the most poisonous spiders in the world, but their fangs are too small to bite humans.' This is a widespread myth. It has even been presented as a fact on televised nature programs. Daddy-long-legs are not actually spiders, and they do not have venom glands. For details about this myth, take a look at this from the University of California Entomology Department.

In the old days, it was believed that you could use daddy-long-legs to find your lost cattle. When you wanted to know which direction the herd had wandered to, you could pick up a daddy-long-legs by all of the legs but one, and the free leg would point in the direction of the cattle (or so it was believed). Another myth from the old days: if you kill a daddy-long-legs, it will rain the next day. Original document: 25 May 2004 Last updated: 19 Oct 2006 The Kentucky Critter Files are maintained by Blake Newton, Department of Entomology, University of Kentucky. Contact: //Kentucky Harvestmen.

A harvestman (a male Phalangium opilio), showing the almost fused arrangement of abdomen and cephalothorax that distinguishes these arachnids from. The Harvestmen are eight-legged. Although they belong to the class of, harvestmen are not. They belong to the Opiliones or Phalangids. More than 6,400 species of harvestmen have been discovered, although the real number of species may exceed 10,000. Well-preserved have been found in the 400-million year old of.

Research

The samples found look surprisingly modern. Apparently, the basic structure of the harvestmen has not changed much since then. In some places, harvestmen are known by the name 'daddy longlegs', but this name is also used for two other unrelated arthropods: the ( Tipulidae) and the ( Pholcidae).

Many species are, they eat anything they can find. Most of the time this is small, and some and. Harvestmen are not dangerous to humans.

Behavior

None of the described species has poison glands. They are not 'true' spiders even though they look like spiders in many ways. For example, harvestmen have no venom or silk glands; spiders have these. Contents. Anatomy These arachnids have exceptionally long walking legs, compared to body size, although there are also short-legged species. In harvestmen the two main body sections (the abdomen and cephalothorax) are broadly joined, so that they appear to be one oval structure; they also have no venom or silk glands, unlike true spiders. In more advanced species, the first five abdominal segments are often fused into a dorsal shield called the scutum, which is normally fused with the carapace.

In some species, this shield is only present in males. The second pair of legs is longer than the others and works as antennae.

This can be hard to see in short-legged species. The feeding apparatus (Stomotheca) differs from other arachnids as they are able to eat their food in chunks, without needing to liquefy it. Most species have a single pair of eyes in the middle of their heads, oriented horizontally. However, there are some eyeless species.

Further reading. (2005). Pinto-da-Rocha R. Harvestmen – the biology of Opiliones. Harvard University Press.

Pinto-da-Rocha R. Third species of Guasiniidae (Opiliones, Laniatores) with comments on familial relationships. Journal of Arachnology 31: 394-399. Shultz, Jeffrey W. Phylogeny of Opiliones (Arachnida): an assessment of the 'Cyphopalpatores' concept.

Cellar Spiders

Journal of Arachnology 26: 257-272. Other websites.