New York City : The American Museum of Natural History ... United States: en_US: dc.title: New Phalangodidae (Phalangida) from the United States. American Museum ...
40-41 40 JOURNAL NEW YORK ENT. SOC. [VOL. II. THE PHALANGIDA OF NEW YORK. By NATHAN BANKS. The State of New York extending from Lake Erie to the Atlantic coast lies in parts of several quite different faunal regions; Viz., the WVestern or Prairie, the Northern or Mountains, and the Atlantic or Southern region.
- Antipredator Defenses
- Endangered Status
- Fossil Record
The Opiliones are known for having exceptionally long legs relative to their body size; however, some species are short-legged. As in all Arachnida, the body in the Opiliones has two tagmata, the anterior cephalothorax or prosoma, and the posterior 10-segmented abdomen or opisthosoma. The most easily discernible difference between harvestmen and spiders is that in harvestmen, the connection between the cephalothorax and abdomen is broad, so that the body appears to be a single oval structure. Other differences include the fact that Opiliones have no venom glands in their chelicerae, so pose no danger to humans. They also have no silk glands and therefore do not build webs. In some highly derived species, the first five abdominal segments are fused into a dorsal shield called the scutum, which in most such species is fused with the carapace. Some such Opiliones only have this shield in the males. In some species, the two posterior abdominal segments are reduced. Some of them are divi...
Many species are omnivorous, eating primarily small insects and all kinds of plant material and fungi. Some are scavengers, feeding upon dead organisms, bird dung, and other fecal material. Such a broad range is unusual in other arachnids, which are typically pure predators. Most hunting harvestmen ambush their prey, although active hunting is also found. Because their eyes cannot form images, they use their second pair of legs as antennae to explore their environment. Unlike most other arachnids, harvestmen do not have a sucking stomach or a filtering mechanism. Rather, they ingest small particles of their food, thus making them vulnerable to internal parasites such as gregarines. Although parthenogenetic species do occur, most harvestmen reproduce sexually. Mating involves direct copulation, rather than the deposition of a spermatophore. The males of some species offer a secretion (nuptial gift) from their chelicerae to the female before copulation. Sometimes, the male guards the...
Predators of harvestmen include a variety of animals, including some mammals, amphibians, and other arachnids like spiders and scorpions. Opiliones display a variety of primary and secondary defenses against predation, ranging from morphological traits such as body armor to behavioral responses to chemical secretions.Some of these defenses have been attributed and restricted to specific groups of harvestmen.
All troglobitic species (of all animal taxa) are considered to be at least threatened in Brazil. Four species of Opiliones are on the Brazilian national list of endangered species, all of them cave-dwelling: Giupponia chagasi, Iandumoema uai, Pachylospeleus strinatii and Spaeleoleptes spaeleus. Several Opiliones in Argentina appear to be vulnerable, if not endangered. These include Pachyloidellus fulvigranulatus, which is found only on top of Cerro Uritorco, the highest peak in the Sierras Chicas chain (provincia de Cordoba) and Pachyloides borellii is in rainforest patches in northwest Argentina which are in an area being dramatically destroyed by humans. The cave-living Picunchenops spelaeusis apparently endangered through human action. So far, no harvestman has been included in any kind of a Red List in Argentina, so they receive no protection. Maiorerus randoi has only been found in one cave in the Canary Islands. It is included in the Catálogo Nacional de especies amenazadas (N...
An urban legend claims that the harvestman is the most venomous animal in the world, but possesses fangs too short or a mouth too round and small to bite a human, rendering it harmless (the same myth applies to Pholcus phalangioides and the cranefly, which are both also called a "daddy longlegs"). This is untrue on several counts. None of the known species of harvestmen has venom glands; their cheliceraeare not hollowed fangs but grasping claws that are typically very small and not strong enough to break human skin.
Harvestmen are a scientifically neglected group. Description of new taxa has always been dependent on the activity of a few dedicated taxonomists. Carl Friedrich Roewer described about a third (2,260) of today's known species from the 1910s to the 1950s, and published the landmark systematic work Die Weberknechte der Erde (Harvestmen of the World) in 1923, with descriptions of all species known to that time. Other important taxonomists in this field include:Pierre Latreille (18th century)Carl Ludwig Koch, Maximilian Perty (1830s-1850s)L. Koch, Tord Tamerlan Teodor Thorell (1860s-1870s)Eugène Simon, William Sørensen (1880s-1890s)James C. Cokendolpher, Raymond Forster, Jürgen Gruber, Reginald Frederick Lawrence, Jochen Martens, Cândido Firmino de Mello-Leitão (20th century)Gonzalo Giribet, Adriano Brilhante Kury, Tone Novak (21st century). Since the 1990s, study of the biology and ecology of harvestmen has intensified, especially in South America.
Harvestmen are ancient arachnids. Fossils from the Devonian Rhynie chert, 410 million years ago, already show characteristics like tracheae and sexual organs, indicating that the group has lived on land since that time. Despite being similar in appearance to, and often confused with, spiders, they are probably closely related to the scorpions, pseudoscorpions, and solifuges; these four orders form the clade Dromopoda. The Opiliones have remained almost unchanged morphologically over a long period. Indeed, one species discovered in China, Mesobunus martensi, fossilized by fine-grained volcanic ash around 165 million years ago, is hardly discernible from modern-day harvestmen and has been placed in the extant family Sclerosomatidae.
The Swedish naturalist and arachnologist Carl Jakob Sundevall (1801–1875) honored the naturalist Martin Lister (1638–1712) by adopting Lister's term Opiliones for this order, known in Lister's days as "harvest spiders" or "shepherd spiders", from Latin opilio, "shepherd"; Lister characterized three species from England (although not formally describing them, being a pre-Linnaeanwork).
The interfamilial relationships within Opiliones are not yet fully resolved, although significant strides have been made in recent years to determine these relationships. The following list is a compilation of interfamilial relationships recovered from several recent phylogenetic studies, although the placement and even monophyly of several taxa are still in question. The family Stygophalangiidae (one species, Stygophalangium karamani) from underground waters in North Macedoniais sometimes misplaced in the Phalangioidea. It is not a harvestman.
Despite their long history, few harvestman fossils are known. This is mainly due to their delicate body structure and terrestrial habitat, making them unlikely to be found in sediments. As a consequence, most known fossils have been preserved within amber. The oldest known harvestman, from the 410-million-year-old Devonian Rhynie chert, displayed almost all the characteristics of modern species, placing the origin of harvestmen in the Silurian, or even earlier. A recent molecular study of Opiliones, however, dated the origin of the order at about 473 million years ago (Mya), during the Ordovician. No fossils of the Cyphophthalmi or Laniatores much older than 50 million years are known, despite the former presenting a basal clade, and the latter having probably diverged from the Dyspnoi more than 300 Mya. Naturally, most finds are from comparatively recent times. More than 20 fossil species are known from the Cenozoic, three from the Mesozoic, and at least seven from the Paleozoic.
In the United States, research in the Order Phalangida (Order Opil- iones) has been concerned primarily with taxonomy, as seen in the contri- butions by C. Ril. Weed, N. Banks, C. R. Crosby, and others. Tlle phalangids of some states have been studied systematically, notably those of New York (Bishop, 1919) and Ohio (Walker, 1928).
United States. Specimens have been examined from northern Michigan southward t o northern Florida. It has been reported from parts of Canada (Edgar, 1966; Bishop, 1949), but the total northern extension of its range is not well known . Some museum specimens labeled L. politum from New York, New Hampshire and Maine belong to L. bracchiolum.
7. Respiration by means of tracheae with spiracles located on the second abdominal segment. Within the order Opiliones, there are three suborders as follows: I. Cyphophthalmi: mite-like forms. Species are known from the states of Washington and Florida, without known species between. No cave forms are known in the United States. II.
↑Banks, N. (1893b) The Phalanginae of the United States. The Canadian Entomologist, 25(8), 205–211. ↑ Banks, N. (1900a) New genera and species of American Phalangida. . Journal of the New York Entomological Society, 8(3), 199