Qli

possess a formidable array of long, very sharp-tipped spines. The walking legs are long and slender and splayed out to the side. They lack spray glands.

Amblypygids (Kaestner 1968) live in tropical to subtropical areas (Beck 1968), always under fairly humid conditions, under stones, under bark and in hollow logs, in litter, and so on. They shun light and are well-known cave inhabitants. They occasionally run on the trunks of large trees or even the walls of homes at night, where they search in darkness with their sensitive, antenniform (whiplike) forelegs and snare with their spiny pedipalps. Little more is known of their habits in nature; some laboratory studies have been completed (Weygoldt 1977).

There are two suborders, Pulvillata and Apulvillata (Quintero 1986), each containing several families and many genera, found from the southern United States to the northern half of South America. Among the former, there are nine genera with varied habits. Paracharon and Trichari-nus are small, blind, and live in the nests of ants and termites (Quintero 1986). Other dominant genera are Chirinus in South America and Charinides in the Caribbean (Quintero 1983). The New World species of Apulvillata are placed in five genera: Phrynus, the most widespread, Paraphrynus (Mullinex 1975), Heterophrynus (fig. 4.7b), Acanthophrynus, and Trichodamon (Mello-Leitao 1935). The last is the only New World member of its otherwise Old World family, Damonidae, and is found in Brazil (Quintero 1976).

Phrynus are sometimes much feared by locals for their large size (BL to 2.8 cm, leg span of 20 cm), ugliness, and wrongly suspected venomousness. They are truly harmless creatures. They defend themselves only by pinching and carry no sting or poisonous bite. In this genus, the pedipalpal spines form a kind of basket for catching prey when interposed.

References

Beck, L. 1968. Aus den Regenwaldern am Amazonas II. Natur Museum 98(2): 71-80.

Kaestner, A. 1968. Invertebrate zoology, arthropod relatives, Chelicerata, Myriapoda. Vol. 2. Wiley Interscience, New York.

Mello-Leitäo, C. 1935. Sobre o género Trichodamon M.-L. Inst. Butantan Mem. 10: 297-302.

Mullinf.x, B. L. 1975. Revision of Paraphrynus Moreno (Amblypygida: Phrynidae) for North America and the Antilles. Calif. Acad. Sei. Occ. Pap. 116: 1-80.

Quintf.ro, Jr., D. 1976. Trichodamon and Damonidae, new family status (Amblypygi: Arachnida). Brit. Arachnol. Soc. Bull. 3: 222-227.

Quintero, Jr., D. 1980. Systematics and evolution of Acanthophrynus Kraepelin (Amblypygi, Phrynidae). 8th Int. Cong. Arachnol. (Vienna) Proc. Pp. 341-347.

Quintf.ro, Jr., D. 1983. Revision of the amblypygid spiders of Cuba and their relationships with the Caribbean and continental American amblypygid fauna. Stud. Fauna Curaçao Carib. Is. 196: 1—54.

Quintf.ro, Jr., D. 1986. Revisión de la clasificación de Amblypygidos pulvinados: Creación de subórdenes, una nueva familia y un nuevo género con tres nuevas especies (Arachnida: Amblypygi). 9th Int. Cong. Arachnol. (Panama City) Proc. Pp. 203-212.

Weygoldt, P. 1972. Geisseiskorpione und Geisseispinnen (Uropygi und Amblypygi). Zeit. Kölner Zoo. 15(3): 95-107.

Weygoldt, P. 1977. Coexistence of two species of whip spiders (Genus Heterophrynus) in the Neotropical rain forest (Arachnida, Amblypygi). Oecologia 27: 363-370.

false scorpions

Pseudoscorpionida. Spanish: Quernitos (General). Book scorpions.

False scorpions all possess scorpionlike pedipalps and general shape but differ from those arachnids most conspicuously by their much smaller size (BL of most 2—4 mm) and the lack of a segmented tail. Also missing are the scorpion's characteristic ventral pectines. The fingers of the pedipalps usually contain venom glands open ing at the sharp tips. They also have silk glands, located in the prosoma, with ducts opening at the tip of the chelicera's movable article. Silk is used to make cocoonlike nests about twice the animal's size in which to molt, pass the winter, or oviposit.

There are three suborders, all with members in the Neotropics. The region's fauna is poorly known; Beier (1932) listed about 180 species, to which authorities have since added approximately 400 species; some 100 to 200 more may remain undiscovered (Mahnert pers. comm.). The Amazonian fauna is especially diverse (Mahnert 1979, Mahnert et al. 1986).

Phoresy is practiced by many species in this order, usually only by females, and is apparently important to them as a means of dispersal (Muchmore 1971). The best-known hosts are long-horned beetles, especially the harlequin beetle, under whose elytra several species travel.

The best known of these is Cordylochernes scorpioides, which constructs a "safety harness" of silk on the beetle's abdomen to which they cling when the host flies (Zeh and Zeh 1991). A few pseudoscorpions have become associated with civilization. Cheiridiurn museorurn, Chelifer cancroides (fig. 4.7c), and Withius piger (in Chile) have spread recently from the Old World to South America in grain shipments in which they have secreted themselves to feed on stored product pests.

Pseudoscorpions are typically cryptic, living in soil and litter, under bark, beneath rocks, and in similar retreats. Many are cavernicolous (Muchmore 1972). There are several maritime species, living under stones and shore debris such as driftwood and stranded seaweed and in rock crevices, where they search for prey (Lee 1979).

Courtship and mating are complex behaviors much like those of scorpions. The process begins with a form of dance in which the male stops close to the female, shakes his abdomen, and waves his pincers. He then drops a thread from his ventral genital opening. This hardens into a pedestal (spermatophore) on which he leaves seminal fluid. The female straddles the pillar and draws the fluid into her sexual opening, during which process the male may advance and shake her by the legs to ensure that the fluid becomes detached within her body.

References

Beier, M. 1932. Pseudoscorpionida. Das Tierreich 57: 1-258, 58: 1-294. Lee, V. F. 1979. The maritime pseudoscorpions of Baja California, México (Arachnida: Pseudoscorpionida). Calif. Acad. Sei. Occ. Pap. 131: 1-38.

Mahnert, V. 1979. Pseudoskorpione (Arachnida) aus dem Amazonas-Gebiet (Brasilien). Rev. Suisse Zool. 86: 719-810. Mahnert, V., J. Adis, and P. F. Bührnheim. 1986. Key to the families of Amazonian Pseudoscorpiones (Arachnida). Amazoniana 10: 21-40.

Muchmore, W. B. 1971. Phoresy by North and Central American pseudoscorpions. Rochester Acad. Sei. Proc. 12: 79-97. Muchmore, W. B. 1972. New diplosphyronid pseudoscorpions, mainly cavernicolous, from Mexico. Amer. Micros. Soc. Trans. 91: 261-276.

Zeh, D. W., and J. A. Zeh. 1991. Novel use of silk by the harlequin beetle-riding pseudoscor-pion, Cordylochernes scorpioides (Pseudoscorpionida, Chernetidae). J. Arach. 19: 153-154.

0 0

Post a comment