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HISTORIC
OVERVIEW OF PAST CONGRESSES OF ARACHNOLOGY AND OF THE CENTRE INTERNATIONAL
DE DOCUMENTATION ARACHNOLOGIQUE (C.I.D.A.)
Otto Kraus:
Zoologisches Institut und Museum, Universitat Hamburg, Martin-Luther-King-Platz
3, D-20146 Hamburg, Germany
ABSTRACT. In
1959, Hermann Wiehle encouraged junior colleagues to arrange a
meeting for arachnologists. This was held in 1960 at the University
of Bonn, Germany, and is counted as the first in the senes of
international congresses. After a second conference, held just
one year later in Saarbrucken, Germany, a third truly international
congress followed in 1965 in Frankfurt am Main. On this occasion,
Max Vachon presented his idea to form what was later called the
C.I.D.A. This institution was formally established at the occasion
of the 4th congress, held in Paris in 1968. Detailed information
on the origins, the series of congresses, and the C.I.D A. up
to 1968 is presented.
The Journal of
Arachnology 27:3-6
THE
GENUS ATTIDOPS (ARANEAE, SALTICIDAE)
G.B. Edwards:
Curator, Arachnida & Myriapoda, Florida State Collection of
Arthropods, Division of Plant Industry, RO. Box 147100, Gainesville,
Florida 32614-7100 USA
ABSTRACT.
The genus Attidops is resurrected from Ballus based on
its strongly excavate cymbial tip, transverse embolar groove,
flatter carapace with extended postocular area, and single retromarginal
cheliceral tooth, which indicate a closer relationship to the
genus Admestina. The type species, Ballus youngii
Peckham & Peckham 1888, again transferred, becomes Attidops
youngi (Peckham & Peckham). Two new species, Attidops
nickersoni (sister species to A. youngi) and Attidops
cutleri, are described. Icius cinctipes Banks 1900,
previously transferred to Ballus, becomes a new combination,
Attidops cinctipes (Banks). Lectotypes and paralectotypes
are designated for Ballus youngii and Icius cinctipes.
The genus is recorded from south-central Canada, eastern U.S.
and eastern Mexico.
The Journal of
Arachnology 27:7-15
A
NEW DISEMBOLUS (ARANEAE, LINYPHIIDAE) FROM CAPE COD, MASSACHUSETTS
AND LONG ISLAND, NEW YORK
Robert L. Edwards:
Research Associate, United States National Museum, Box 505, Woods
Hole, Massachusetts 02543 USA
ABSTRACT.
Disembolus bairdi new species is described from the coastal
region of northeastern United States. Notes on the habitat, natural
history and its associated spiders are provided.
The Journal of
Arachnology 27:16 18
SINOPODA,
A NEW GENUS OF HETEROPODINAE (ARANEAE, SPARASSIDAE) FROM ASIA
Peter Jager:
Institute for Zoology, Johannes Gutenberg-University, Saarstr.
21, 55099 Mainz, Germany
ABSTRACT.
Sinopoda new genus (Araneae, Sparassidae, Heteropodinae) is
described from Asia It is recognizable only from genital characters.
At present, the new genus comprises 25 species from Japan Korea,
China, Thailand, Malaysia and east India. Heteropoda campanacea,
H. forcipata, H. hamata, H. koreana, H. Iicenti, H. marsupia (?),
H minschana, H. serrata, H. shennonga, H. stellata and
Panaretidius microphthalmus are placed in Sinopoda
new genus. Relationships to other heteropodine genera are discussed.
The Journal of
Arachnology 27:19-24
CARBINEA,
A NEW SPIDER GENUS FROM NORTH QUEENSLAND, AUSTRALIA (ARANEAE,
AMAUROBIOIDEA, KABABININAE)
Valerie Todd Davies:
Queensland Museum, P.O. Box 330O, South Brisbane, Australia
ABSTRACT.
The distnbution of four species of Carhinea new genus in
the Wet Tropics region of northern Queensland documents the species'
richness and local endemism. The new species are C. Iongiscapa,
C. breviscapa, C. wunderlichi and C. robertsi. They
are placed in the sub-family Kababininae which is removed from
the Amphinectidae (Davies 1995) as there is evidence that it does
not belong there. The placement of this clade remains problematical.
The Journal of
Arachnology 27:25-36
SPIDERS
OF THE GENUS HEPTATHELA (ARANEAE, LIPHISTIIDAE) FROM VIETNAM,
WITH NOTES ON THEIR NATURAL HISTORY
Hirotsugu Ono:
Department of Zoology, National Science Museum, 3-23-1 Hyakunin-cho,
Shinjuku-ku, Tokyo, 169-0073 Japan
ABSTRACT.
Spiders of the family Liphistiidae collected from northern Vietnam
are taxonomically studied. Two new species of the genus Heptathela
are described under the names, H. abca (from Yen Bai) and
H. cucphuangensis (from Cuc Phuong National Park). Some
natural history and zoogeographic notes of the new species are
given.
The Journal of
Arachnology 27:37-43
ON
THE PHYLOGENETIC RELATIONSHIPS OF SISICOTTUS HIBERNUS (ARANEAE,
LINYPHIIDAE, ERIGONINAE)
Jeremy Zujko-Miller:
Department of Biological Sciences, The George Washington University,
Washington, D.C. 20052, and Department of Entomology, National
Museum of Natural History, NHB-105, Smithsonian Institution, Washington,
D.C. 20560
ABSTRACT.
Carorita hiberna NEW COMBINATION, a species with many putative
autapomorphies known from one sex and few specimens, is transferred
from Sisicottus. This transfer is based on a modified version
of a cladistic analysis of erigonine relationships by G. Hormiga
which incorporated 43 spider taxa scored for 73 characters. The
modified analysis features 46 taxa scored for 74 characters. The
resulting cladogram placed C. hiberna sister to C. Iimnaea,
the type species of Carorita. It is concluded that C.
hiberna is better placed in Carorita than in either
a new monotypic genus or in Sisicottus. Carorita hiberna
is redescribed and the monophyly of Carorita as currently
circumscribed is discussed.
The Joumal of
Arachnology 27:44-52
TOWARDS
A PHYLOGENY OF ENTELEGYNE SPIDERS (ARANEAE, ARANEOMORPHAE, ENTELEGYNAE)
Charles E. Griswold
(1), Jonathan A. Coddington (2), Norman I. Platnick
(3) and Raymond R. Forster (4):
(1) Department of Entomology, California Academy of Sciences,
Golden Gate Park, San Francisco, California 94118 USA;
(2) Department of Entomology, National Museum of Natural History,
NHB-105, Smithsonian Institution, Washington, D.C. 20560, USA;
(3) Department of Entomology, American Museum of Natural History,
Central Park West at 79th Street, New York, New York 10024 USA;
(4) McMasters Road, R.D. 1, Saddle Hill, Dunedin, New Zealand
ABSTRACT.
We propose a phylogeny for all entelegyne families with cribellate
members based on a matrix of 137 characters scored for 43 exemplar
taxa and analyzed under parsimony. The cladogram confimms the
monophyly of Neocnbellatae, Araneoclada, Entelegynae, and Orbiculariae.
Lycosoidea, Amaurobiidae and some included subfamilies, Dictynoidea,
and Amaurobioidea (sensu Forster & Wilton 1973) are polyphyletic.
Phyxelidinae Lehtinen is raised to family level (Phyxelididae,
NEW RANK). The family Zorocratidae Dahl 1913 is revalidated. A
group including all entelegynes other than Eresoidea is weakly
supported as the sister group of Orbiculariae.
The Joumal of
Arachnology 27:53-63
HYPOTHESES
FOR THE RECENT HISPANIOLAN SPIDER FAUNA BASED ON THE DOMINICAN
REPUBLIC AMBER SPIDER FAUNA
David Penney:
Invertebrate Zoology, Manchester Museum, University of Manchester,
Oxford Road, Manchester M13 9PL United Kingdom
ABSTRACT. The
Dominican Republic amber fossil spider record is examined and
hypotheses generated concerning the Recent Hispaniolan spider
fauna which is, at present, poorly known. The families Cyrtaucheniidae,
Microstigmatidae, Nemesiidae, Ochyroceratidae, Tetrablemmidae,
Palpimanidae, Hersiliidae, Symphytognathidae s.l., Anapidae,
Mysmenidae, and Hahniidae, known ffom the fossil, but not Recent,
fauna are predicted to be components of the Recent fauna of Hispaniola.
Based on a terrestrial invertebrate species longevity of less
than ten million years, the presence of endemic and non-endemic
species, and the assumption that Hispaniola has suffered no major
ecological disruption that would cause the amber lineages to become
extinct, the following hypotheses are made: Filistatidae and Desidae
colonized Hispaniola after the Miocene amber formation; Drymusidae,
Amaurobiidae, and Deinopidae were present on Hispaniola dunng
the Tertiary, but avoided capture, or have yet to be found in
the amber; and Scytodidae, Oecobiidae, Uloboridae, Dictynidae
and Clubionidae have colonized Hispaniola since the Miocene amber
formation but these families, which were present on Hispaniola
dunng the period of amber formation, contain undiscovered endemic
species.
The Joumal of
Arachnology 27:64-70
AN
ADAPTIVE RADIATION OF HAWAIIAN THOMISIDAE: BIOGEOGRAPHIC AND GENETIC
EVIDENCE
Jessica E. Garb:
Zoology Department, University of Hawaii at Manoa, Honolulu, Hawaii
96822
ABSTRACT. The
Hawaiian Thomisidae are noted for being extremely species rich,
as well as diverse in morphology and ecology This exceptional
diversity led early systematists to place the species into several
genera with cosmopolitan distributions It has been recently suggested
that these species compose a single large adaptive radiation,
Species-area relationships for all thomisid species and for Misumenops
EO, Pickard-Cambridge 1900 (Thomisidae) species for various island
areas were generated, Further, a phylogenetic hypothesis was constructed
based on genetic distances between the Hawaiian thomisids and
various outgroups using a 450 bp region of the mitochondrial cytochrome
oxidase I (COI) gene to test for close genetic relationships Despite
the extraordinary isolation of the Hawaiian islands, the numbers
of Misumenops and total thomisid species were found to
be significantly higher than predicted for an island system of
its size, Phylogenetic analysis of COI suggests the Hawaiian thomisids
are more closely related to each other than to representatives
of genera to which they have been previously assigned. These results
support the existence of a Hawaiian thomisid adaptive radiation,
and ment further investigation using comparative methods.
The Journal of
Arachnology 27:71-78
COMPARISON
OF RATES OF SPECIATION IN WEB-BUILDING AND NON-WEB-BUILDING GROUPS
WITHIN A HAWAIIAN SPIDER RADIATION
Rosemary G. Gillespie:
Department of Zoology & Center for Conservation Research and
Training. University of Hawaii, 3050 Maile Way, Honolulu, Hawaii
96822 USA
ABSTRACT. The
isolation of the Hawaiian archipelago has resulted in a fauna
that shows high levels of endemism I examined the role of lifestyle,
as inferred from web-building versus non-web-building behavior,
in dictating the rate of differentiation and species formation
within a lineage of spiders in the genus Tetragnatha from
the Hawaiian Islands. This genus compnses a group of morphologically,
ecologically and behaviorally diverse taxa. Included in the radiation
is a 'spiny-leg' clade which never builds webs and is relatively
loosely associated with a specific habitat, and a large group
of web-building species which are generally more tightly associated
with a given substrate and habitat. Sequences of mitochondrial
cytochrome oxidase DNA provided relative estimates of the age
of a clade. Both linear and logarithmic models were used to estimate
rates of speciation and the relative time required for speciation
for each clade. The results showed that several small clades of
web-building species have a greater rate of speciation as compared
to the 'spiny-leg' clade. One explanation is that the web-building
species may be capable of differentiation between more closely
contiguous habitats, which would be consistent with the hypothesis
that ecological differentiation promotes diversification and species
formation. Possible altemative explanations for the results include
differences in rates of molecular evolution, for example as a
consequence of differences in metabolic activity.
The Journal of
Arachnology 27:79-85
FOSSIL
EVIDENCE, TERRESTRIALIZATION AND ARACHNID PHYLOGENY
Jason A. Dunlop:
Institute fur Systematische Zoologie, Museum fur Naturkunde, D-10115
Berlin, Germany
Mark Webster: Department of Earth Sciences, University
of California, Riverside, California 92521 USA
ABSTRACT. Geological
and morphological evidence suggests that the earliest scorpions
were at least partially aquatic and that terrestnalization occurred
within the scorpion clade. Scorpions and one or more other arachnid
lineages are therefore likely to have come onto land independently.
The phylogenetic position of scorpions remains controversial and
we question Dromopoda, in which scorpions are placed denved within
Arachnida, as this is not supported by scorpions' lateral eye
rhabdomes, embryology and sperm morphology. We propose a synapomorphy
for scorpions + eurypterids, a postabdomen of five segments as
part of an opisthosoma of 13 segments. Scorpions and tetrapulmonates
must have evolved their book lungs convergently while fossil evidence
indicates that a stomotheca, synapomorphic for Dromopoda, is probably
convergent too. 'Arachnid' characters such as Malpighian tubules,
the absence of a carapace pleural margin, and an anteriorly directed
mouth may also be convergent, although their status as synapomorphies
can be defended using parsimony. Convergence is difficult to prove
unequivocally, but when there are strong grounds for suspecting
it, such characters are questionable evidence for arachnid monophyly.
The Joumal of
Arachnology 27:86 93
CEPHALOTHORACIC
SULCI IN LINYPHIINE SPIDERS (ARANEAE, LINYPHIIDAE, LINYPHIINAE)
Gustavo Hormiga:
Department of Biological Sciences,George Washington University,
Washington, D.C. 20052, USA
ABSTRACT.
Pore-bearing cephalothoracic sulci (pits) are described and illustrated
for the first time in several linyphiine spiders (Linyphiidae,
Linyphiinae). Sulci are reported in members of the genera Bathyphantes
Menge, Diplostyla Emerton, Kaestneria Wiehle, Pacifiphantes
Eskov & Marusik, Porrhomma Simon, and Vesicapalpus
Millidge. The phylogenetic implications of the presence of sulci
in linyphiines are discussed.
The Journal of
Arachnology 27:94-102
SPERMATOPHORES
AND THE EVOLUTION OF FEMALE GENITALIA IN WHIP SPIDERS (CHELICERATA,
AMBLYPYGI)
Peter Weygoldt:
Albert-Ludwigs-Universitat, Institut fur Biologie I (Zoologie),
Hauptstrasse 1, D-79104 Freiburg, Germany
ABSTRACT. Whip
spiders use stalked spermatophores for sperm transfer. These are
complex structures, and their morphology varies among genera and
farnilies. Usually, the paired sperm masses hidden within the
spermatophores are small, and there has been a co-evolution of
spermatophores and those parts of the female genitalia which are
used to pick up the spermatozoa and to store spermatozoa. These
are structures like specialized sclerotizations, glands or, in
a few species, seminal receptacles which are hidden inside the
genital atrium (or uterus externus). In most species there are
paired erectile bodies, homologous to genital appendages, which
are attached to the dorsal side of the genital operculum which
also is part of an appendage homologon. All these structures vary
among genera and families. The comparison of spermatophores and
genitalia of different species belonging to most genera and families
suggest that the female gonopods consist pumarily of paired cushion-like
structures, each equipped with a small finger-like appendage vestige.
These appendage vestiges are retained in many species, particular
in the Charinidae and Charontidae. They are erectile by increase
in blood pressure, and they are thereby probably bent in characteristic
ways and thus can pull off the sperm masses from the spermatophore.
In some Charinidae, and in some species of Damon and Phrynichus
(Phrynida, Phrynichidae) these appendage vestiges are totally
lost. In the Phrynidae, on the other hand, they have become sclerotized
and hard. They form the well-known claw-like sclerites, and an
invagination at the base of each sclerite has been shaped to form
a true seminal receptacle. Similar genitalia have evolved convergently
in the genus Trichodamon (Phrynida, Phrynichidae). Spermatophores
and the corresponding female genitalia and their mechanisms of
a number of genera from most farnilies are described and illustrated.
The Journal of
Arachnology 27:103-116
ONTOGENY
OF CHARACTERISTIC LEG MACROSETAE IN MIMETUS (ARANEAE, MIMETIDAE)
Bruce Cutler:
Electron Microscopy Laboratory and Department of Entomology, University
of Kansas, Lawrence, Kansas 66045-2106 USA
Hank Guarisco: RO. Box 3171, Lawrence, Kansas 66046 USA
Daniel J. Mott: Department of Biological and Physical Sciences,
Lincoln Land Community College, 5250 Shepherd Road, Springfield,
Illinois 62794-9256 USA
ABSTRACT.
The distinctive prolateral spination of the metatarsi and tibiae
of the first two legs in Mimetus is obscure in the first
post-eggsac eclosion instar. Only one of the small, acuminate
tipped macrosetae appears in the first instar, small macroseta
numbers increase in the second instar, and outnumber the large
macrosetae by the third instar. The high variability in adult
macroseta counts occurs in the third instar as well. The characteristic
macrosetae have a socketed base and longitudinally grooved shafts.
The large macrosetae are characterized by numbers of small pustules
on the base below the emergence of the shaft and the tips of the
macrosetae are round. The small macrosetae have fewer pustules
or none, and the tips of the macrosetae are falcate and acuminate.
Both the large and small macrosetae morphologically resemble presumptive
mechano-receptive setae on the legs, and may have a sensory function.
The Joumal of
Arachnology 27:117-122
VENTRAL
MESOSOMAL CHANGES IN EMBRYOS FROM THREE SCORPION FAMILIES: IURIDAE,
BUTHIDAE AND VAEJOVIDAE
Roger D. Farley:
Department of Biology, University of California, Riverside, California
92521 USA
ABSTRACT.
The scanning electron microscope was used to examine embryos at
a stage when booklungs and spiracles are forming. Earlier studies
with scorpion fossils suggest there was ventral mesosomal transition
from gills or booklungs above ventral plates to stemites, booklungs
and spiracles. In Hadrurus arizonensis (Iuridae), ventral
plates and then sternites are formed on the ventral surface of
mesosomal segments before spiracles appear. Bilateral invaginations
in body segments XII-XV apparently give rise to the booklungs,
with spiracles formed lateral to the site of invagination. Sternites
with bilateral depressions were also present before spiracles
in embryos of the buthid Centruroides exilicauda. In the
developmental stages herein examined, spiracles were formed in
embryos of Paruroctonus mesoensis (Vaejovidae); but there
was no indication of ventral plates or sternites on the ventral
mesosoma. Spiracles appear in the intersegmental area posterior
to body segments XIII-XV. Booklungs may form later from pumordia
associated with bilateral depressions observed in a later stage
in these segments.
The Journal of
Arachnology 27:123-128
THE
USE OF MORPHOMETRIC CHARACTERISTICS FOR THE RECOGNITION OF SPECIES
AMONG GONIOSOMATINE HARVESTMEN (ARACHNIDA, OPILIONES, GONYLEPTIDAE)
Pedro Gnaspini:
Departamento de Zoologia, Instituto de Biociencias, Universidade
de Sao Paulo, Caixa Postal 11461, 05422-970, Sao Paulo, SP, Brasil
ABSTRACT.
Morphometric data from males of six species of Goniosoma are
presented and their importance in characterization and recognition
of the species is discussed. Data presented show that it is important
to use intraspecific variation during descriptions of these harvestmen.
1999 The Journal
of Arachnology 27:129-134
SEXUAL
SELECTION IN PHOLCID SPIDERS (ARANEAE, PHOLCIDAE): ARTFUL CHELICERAE
AND FORCEFUL GENITALIA
Bernhard A. Huber:
Department of Entomology, American Museum of Natural History,
Central Park West at 79th Street, New York, New York 10024 USA
ABSTRACT.
Two aspects of pholcid reproductive biology are reviewed and appear
best explained by sexual selection by female choice: the rapid
and divergent evolution of male chelicerae (and clypei in some
groups) which contact the female epigynum during copulation and
probably act as copulatory courtship devices; and the often exceptionally
strong pedipalps in males, which possibly function in correlation
with the 'valve' in the internal female genitalia.
The Joumal of
Arachnology 27:135-141
A
COMPARISON OF THE RESPIRATORY SYSTEMS IN SOME CAVE AND SURFACE
SPECIES OF SPIDERS (ARANEAE, DYSDERIDAE)
Matjaz Kuntner
(1), Boris Sket (1), and Andrej Blejec (2)
(1) Department of Biology, Biotechnical Faculty, University of
Ljubljana, SI-1111 Ljubljana, Slovenia
(2)National Institute of Biology, POB 141, SI-1001 Ljubljana,
Slovenia
ABSTRACT.
We tested the hypothesis that the respiratory system of hypogean
spiders is subject to regressive evolution by examining representatives
of the family Dysderidae. This comparison included the epigean
species Dysdera ninnii Canestrini 1868, and Harpactea
lepida (C.L. Koch 1838), and the hypogean species Stalita
toenaria Schiodte 1847, and Parastalita stygia (Joseph
1882). Both tube tracheae and book lungs of these species were
measured and compared using 10 indices. Both the tracheal system
and book lungs of the hypogean species were less developed than
those of the epigean ones. We suggest that the cause is reduction
of the respiratory system as a part of general structural reductions
in the troglobites. This is consistent with the lower respiratory
rates that characterize many troglobites.
The Journal of
Arachnology 27:142-148
A
NEW ALL-FEMALE SCORPION AND THE FIRST PROBABLE CASE OF ARRHENOTOKY
IN SCORPIONS
Wilson R. Lourengo:
Laboratoire de Zoologie (Arthropodes), Museum National d'Histoire
Naturelle, 61 rue de Buffon 75005 Paris, Erance
Orlando Cuellar: PO. Box 17074, Salt Lake City, Utah 84117-0074
USA
ABSTRACT.
A new parthenogenetic species of scorpion, Ananteris coineaui
Lourenco, is reported from French Guyana. Parthenogenesis
is based on the production of an all-female brood (thelytoky)
by a wild virgin female. Conversely, the first probable case of
male parthenogenesis (arrehnotoky) in scorpions is reported based
on the production of two successive all-male broods by a wild
caught virgin female of Tityus metuendus Pocock from Peru.
Both species were found in isolated palm trees within the rain
forest, conforming with the insular theory of parthenogenesis.
The Journal of
Arachnology 27:149-153
DISCOVERY
OF A SEXUAL POPULATION OF TITYUS SERRULATUS, ONE OF THE
MORPHS WITHIN THE COMPLEX TITYUS STIGMURUS (SCORPIONES,
BUTHIDAE)
Wilson R. Lourengo:
Laboratoire de Zoologie (Arthropodes), Museum National d'Histoire
Naturelle, 61 rue de Buffon 75005 Paris, France
John L. Cloudsley-Thompson: 10 Battshill Street, Islington,
London N1 1TE, United Kingdom
ABSTRACT.
Tityus serrulatus Lutz & Mello 1922 (in fact, the form
confluenciata within the Tityus stigmurus complex) is an
extremely toxic scorpion of considerable medical importance in
Brazil. Its rapid spread is partially due to parthenogenesis.
Speculation regarding the occurrence of sexual individuals has
been resolved by the discovery of a population, described here,
having a male-female sex ratio of 1/2.5. Four color morphs of
the T. stigmurus complex are described, and it is concluded
that T. serrulatus and Tityus lamottei Lourenco
1981 are junior synonyms of T. stigmurus (Thorell 1877).
The Journal of
Arachnology 27:154-158
ACTIVITY
RHYTHMS AND BEHAVIORAL CHARACTERIZATION OF TWO EPIGEAN AND ONE
CAVERNICOLOUS HARVESTMEN (ARACHNIDA, OPILIONES, GONYLEPTIDAE)
Sonia Hoenen
and Pedro Gnaspini: Departamento de Zoologia, Instituto
de Biociencias, Universidade de Sao Paulo, Caixa Postal 11461,05422-97O,
Sao Paulo, SP, Brasil
ABSTRACT.
The activity rhythms, feeding behavior, and reaction to light
of two epigean (surface inhabitant) species of harvestmen (Iporangaia
pustulosa and Iguapeia melanocephala) and of one cavernicolous
species (Pachylospeleus strinatii) have been recorded.
Both the epigean and the cavernicolous species showed a highly
pronounced circadian rhythmicity. The cave species showed a bimodal
pattern. Whereas the epigean species carried food away to feed,
the cave species fed where they found the food. The time of reaction
to light did not differ statistically between species. However,
when exposed to light, the cave species walked much longer distances
after it started walking. These differences are probably due to
cave adaptation. The cave species may have to wander further for
food (and maybe mates) because of the scarcity of resources and,
therefore, show greater activity and also a tendency to exploit
a resource wherever they find it.
The Journal of
Arachnology 27:159-164
COURTSHIP
AND MATING BEHAVIOR OF BRACHYPELMA KLAASI (ARANEAE, THERAPHOSIDAE)
Martha Yarlez
and Arturo Locht: Laboratorio de Acarologia, Facultad de
Ciencias, Universidad Nacional Autonoma de Mexico, Coyoacan 0451O,
D.E Mexico
Rogelio Macias-Ordoriez:
Departamento de Ecologia y Comportamiento Animal, Instituto de
Ecologia, A.C., Xalapa, Veracruz 9100O, Mexico
ABSTRACT.
Courtship and mating behavior of Brachypelma klausi, heretofore
unknown, is described on the basis of three courtship and mating
sequences, one in captivity and two in the field. Adult males
perform courtship movements (pedipalp drumming, leg drumming,
push-up and shaking) when they locate a female's burrow, probably
in order to avoid female aggression. After some physical contact,
the female raises the prosoma and extends her chelicerae. The
male then grasps her chelicerae with his tibial apophyses and
the female arches her body backwards leaving the epigyoum exposed.
The male starts boxing the female's sternum and presumably inserts
his pedipalps and inseminates the female. In two cases the female
vigorously attacked the male immediately after mating and probably
would have killed him had observers not intervened; the other
pair separated more slowly and peacefully. Males appear to use
chemical and/or tactile cues from the female's silk around the
burrow during short-range searching behavior. Males begin courtship
behavior by drumming on the silk to signal to the female that
he is present. One male of B. klausi observed in the field
laid silk over the female's silk around the burrow, possibly to
prevent subsequent matings by other males. A second male did not
detect the burrow after this act.
RESUMEN.
Se describe el cortejo y apareamiento de Brachypelma klausi,
hasta ahora desconocidos con base en tres secuencias de cortejo
y apareamiento, una en cautiverio y dos en campo. Los machos adultos
realizan movimientos de cortejo (tambonleo con pedipalpos, tamborileo
con patas, lagartijas y temblado) cuando localizan nidos de hembras,
probablemente para evitar la agresion de las mismas. Despues de
un periodo de contacto fisico la hembra levanta el prosoma y evierte
los queliceros. El macho prende los queliceros de la hembra con
sus apofisis tibiales y la hembra se arquea hacia atras exponiendo
el epigineo. El macho boxea contra el esterndn de la hembra y
se asume que inserta sus pedipalpos y la insemina. En dos casos
la hembra ataco al macho inmediatamente despues del apareamiento
y probablemente lo hubiera matado de no haber intervenido el observador,
la tercera pareja se separ6 mas lenta y pacificamente. Aparentemente
los machos utilizan senales quimicas o tactiles de la seda de
la hembra alrededor del nido durante la bCsqueda de corto alcance.
Los machos inician el cortejo tamborileando en la seda, probablemente
para anunciar su presencia a la hembra. Un macho de B. klaosi
observado en el campo depbsito seda sobre la de la hembra
alrededor del nido, posiblemente para evitar copulas subsecuentes
de otros machos. Un segundo macho no parecio detectar el nido
despues de la conducta mencionada.
The Journal of
Arachnology 27:165-170
LOCATION
OF SUCCESSFUL STRIKES ON PREY BY JUVENILE CRAB SPIDERS MISUMENA
VATIA (ARANEAE, THOMISIDAE)
Douglass H. Morse:
Department of Ecology and Evolutionary Biology, Box G-W, Brown
University, Providence, Rhode Island 02912 USA
ABSTRACT.
Second-instar crab spiderlings Misumena vatia (ca. 0.6
mg) that had never previously fed made killing attacks on pomace
flies Drosophila melanogaster (ca. 1.0 mg) in direct proportion
to the surface areas of the flies' body patts: abdomen, 50%; thorax,
29%; head, 20%. They retained this pattern over their next six
encounters with these flies. They also attacked the different
surfaces of these body parts (front, side, above, below, behind)
with a frequency predicted by the respective areas of these surfaces.
All of the spiderlings tested more than once successfully attacked
prey on more than one body part. Fifth and sixth-instar Misumena
(ca. 7-15 mg) attacked small (4 mg) syrphid flies Toxamerus
marginatus more frequently on the head than the second instars
attacked Drosophila heads. This difference may result from
subsequent experience, greater activity of the syrphid flies than
the Drosophila, or maturation of the spiders.
The Journal of
Arachnology 27:171-175
SAMPLING
METHOD AND TIME DETERMINES COMPOSITION OF SPIDER COLLECTIONS
Jan Green: Department
of Zoology and Entomology, The University of Queensland, Brisbane,
Queensland, Australia 4072
ABSTRACT.
Sampling methods and times can misrepresent components of spider
assemblages found in tree crops. I collected 2561 spiders, including
20 families, 77 genera and 140 species, from inland and coastal
south-east Queensland citrus orchards maintained under Integrated
Pest Management programs. Spider assemblages, collected diurnally
and nocturnally using vacuum and pit-trap sampling methods over
four seasonal penods (spring, summer, autumn and winter), were
compared using Simpson and ShannonWiener diversity indices and
Morisita-Horn similarity index. Significantly different spider
assemblages were collected by the two sampling methods in all
orchards and seasons. Nocturnal and diurnal sample data differed
for spider abundance (similarity) and diversity for several orchards.
These results indicate the need to conduct nocturnal and diumal
sampling using a combination of sampling methods to reduce misinterpretation
of the composition of spider assemblages. Such misinterpretations
may underestimate the predatory importance of spiders in agricultural
ecosystems.
The Journal of
Arachnology 27:176-182
NOTES
ON THE BIOGEOGRAPHY AND NATURAL HISTORY OF THE ORBWEAVING SPIDER
CAREPALXIS (ARANEAE, ARANEIDAE), INCLUDING A GUMNUT MIMIC
FROM SOUTHWESTERN AUSTRALIA
Barbara York Main:
Department of Zoology, University of Western Australia, Nedlands,
Western Australia 6907 Australia
ABSTRACT.
The biogeography of the Gondwanan orbweaving spider Carepaixis
is reviewed. The genus occurs in Central and northern South America,
Australia and New Guinea. It is recorded for the first time from
Western Australia. Mimicry of a gumnut (eucalypt seed capsule)
is described and illustrated for a southwestern Australian species.
It is postulated that the mimicry protects the spiders from bird
predation.
The Journal of
Arachnology 27:183-188
EFFECTS
OF SHORT-TERM SAMPLING ON ECOLOGICAL CHARACTERIZATION AND EVALUATION
OF EPIGEIC SPIDER COMMUNITIES AND THEIR HABITATS FOR SITE ASSESSMENT
STUDIES
Uwe Riecken:
Federal Agency for Nature Conservation, Mallwitzstrasse 1-3, D-53177
Bonn, Germany
ABSTRACT.
Epigeic invertebrates such as spiders are of increasing importance
for habitat characterization and for assessments within environmental
plannings in Germany and other European countries. Due to high
costs for spider sampling (e g., with pitfall traps), proposals
for a limited sampling effort are required for the practical use
The results of a two-year study with continuous sampling are compared
to results of short-term sampling and to results of a reduced
number of traps The same data set is used for all evaluations
Decreasing sampling effort generally reduced the number of recorded
species and led to a biased ecological charactenzation of the
spider communities. Reducing the number of pitfall traps used
provided a more representative sample than did reducing the duration
of sampling. In general, errors based on reduced sampling were
lower for agricultural than for natural habitats. These results
offer practical use of spiders for bioindication in future environmental
planning.
The Journal of
Arachnology 27:189-195
DISTRIBUTION
AND NATURAL HISTORY OF MEXICAN SPECIES OF BRACHYPELMA AND
BRACHYPELMIDES (THERAPHOSIDAE, THERAPHOSINAE) WITH MORPHOLOGICAL
EVIDENCE FOR THEIR SYNONYMY
A. Locht, M. Yanez
and I. Vazquez: Laboratorio de Acarologia "Anita Hoffmann,"
Facultad de Ciencias, Universidad Nacional Authnoma de Mexico,
Coyoacan 04510, D.F, Mexico
ABSTRACT.
This comparision of Brachypelmides and Brachypelma
species is based on newly collected spiders and more than 100
specimens from five museum collections. The results show that
there are six endemic species of Brachypelma in western
Mexico (B. auratum, B. baumgarteni, B. boehmei, B. emilia,
B. pallidum, B. smithi), presenting a gap in their distribution
only where Brachypelmides klaasi is found. Brachypelma
vagans is distributed along both coasts of Mexico and Brachypelmides
rahnaui is found in the central part of Mexico. Notes on natural
history, a morphological comparison of 27 characters of these
genera, and a discussion of the genenc affinities are included.
RESUMEN.
De junio de 1997 a Octubre de 1998 se hizo un estudio comparativo
de Brachypelmides y de las especies de Brachypelma.
Se revisaron especimenes de ambos generos obtenidos en el campo
recientemente y mas de 100 especimenes de cinco diferentes colecciones
para realizar este estudio. Los resultados muestran que hay seis
especies endemicas al Paclfico mexicano de Brachypelma
(B. auratum, B. baumgarteni, B boehmei, B. emillia, B. pallidum,
B. smithi), presentando una distribucidn continua a lo largo
de la costa del Pacifico, siendo interrumpida por la distribucion
de B. klausi. Brachypelma vagans se distribuye en
ambas costas y Brachypelmides ruhnaui en el centro del
pais. Se incluyen notas de historia natural, una comparacion morfologica
de 27 caractensticas de estos generos y una discusion de las afinidades
genencas.
The Journal of
Arachnology 27:196-200
COMMON
GROUND-LIVING SPIDERS IN OLD TAIGA FORESTS OF FINLAND
Seppo Koponen:
Zoological Museum, University of Turku, FIN-20014 Turku, Finland
ABSTRACT. Spiders
living on the forest floor in six old taiga forests were studied
using pitfall traps in 1994 (in Suomussalmi) and 1995 (in Puolanka),
central-eastem Finland, ca. 65° N. Seventy-seven species belonging
to eleven families were caught. Linyphiidae (s. lat.) dominated
both in species and individual numbers. The most common species
were Lepthyphantes alacris, Agyneta ramosa, Lepthyphantes
antroniensis, Centromerus arcanus and Agyneta subtilis.
The fauna found is, in general, typical of old Finnish boreal
forests.
The Joumal of
Arachnology 27:201-204
ABUNDANCE
AND PHENOLOGY OF SCHIZOMIDA (ARACHNIDA) FROM A PRIMARY UPLAND
FOREST IN CENTRAL AMAZONIA
J. Adis (1),
J. Reddell (2), J. Cokendolpher (3) and J.W.
de Morais (4)
(1) Max-Planck-lnstitute for Limnology, Tropical Ecology Working
Group, Postfach 165, D-24302 Plon, Germany
(2) Texas Memorial Museum, University of Texas, Austin, Texas
78705, USA
(3) 2007 29th St., Lubbock, Texas 79411 USA
(4)1nstituto Nacional de Pesquisas da Amazonia (INPA), C P. 478,
69.011-970 Manaus, AM, Brazil
ABSTRACT.
There were 193 schizomids (hubbardids) collected from the soil
(0-7 cm depth) during a 12 month study of a primary upland forest
(37.5 +/- 16.8 ind/m2/month) near Manaus. They were represented
by Surazomus brasiliensis (Kraus 1967) and an undescribed
species of a new genus (96% and 4% of the total catch, respectively).
About 68% of all specimens of S. brasiliensis inhabited
the organic soil layer (0-3.5 cm depth) where monthly catches
of juveniles were positively correlated with soil temperature.
Females were twice as abundant as males. The lack of a distinct
reproductive period and the presence of juveniles (in particular
the first nymphal instar) and adults (both sexes) throughout the
year indicate a plurivoltine mode of life. Few specimens were
caught on the soil surface, and none were on tree trunks or in
the canopy. Abundance of S. brasiliensis is compared to
that of the Palpigradi (microwhip scorpions) and Thelyphonida
(vinegaroons) from the same study site.
The Journal of
Arachnology 27:205-210
RELATIONSHIP
OF HABITAT AGE TO PHENOLOGY AMONG GROUND-DWELLING LINYPHIIDAE
(ARANEAE) IN THE SOUTHEASTERN UNITED STATES
Michael L. Draney:
Department of Biology, P.O. Box 30001, New Mexico State University,
Las Cruces, New Mexico 88003 USA
D.A. Crossley, Jr.:
Institute of Ecology, University of Georgia, Athens, Georgia 30602
USA
ABSTRACT.
Ground-dwelling Linyphiidae from eight South Carolina inner coastal
plain habitats were sampled for one year using pitfall traps Habitats
formed an age gradient, from a field disturbed yearly and pine
stands aged 5, 25 and 40 years, to xeric, mesic and hydric hardwoods
(50-75 years) and an oldgrowth forest (200 years) Sixteen of the
55 trapped species were represented in sufficient numbers (n adults
> = number of sampling periods, 26) to examine patterns of
correlation between phenology and habitat distribution Half of
the species are multivoltine, characterized by adults present
throughout the year, continuous reproduction, and overlapping
generations. Adult abundance of these species peaked during spring
through autumn. Other species were univoltine, with adults present
briefly, indicating synchronous reproduction and non-overlapping
generations. Adult abundance of these species always peaked dunng
winter months. This study examines relationships between observed
voltinism pattems and characteristic habitat (distribution among
the habitats) among the 16 most abundant species. Species from
older habitats tend to be univoltine, whereas species inhabiting
more recently disturbed habitats were more likely to be multivoltine.
Stenochronous winter reproduction (univoltines) probably increases
survivorship by limiting individuals' exposure to the harsh conditions
of the southeastern summer during vulnerable penods of immatunty
and reproduction. This phenological specialization appears optimal
in this region except in frequently disturbed habitats, where
rapid multivoltine reproduction is most advantageous.
The Journal of
Arachnology 27:211-216
HOUSE
SPIDERS OF KANSAS
Hank Guarisco:
Kansas Biological Survey, University of Kansas, Lawrence, Kansas
66047 USA
ABSTRACT:
Spiders found in and around buildings may be divided into three
categories: 1) true synanthropes, which can establish breeding
populations in houses, seldom occur locally in the natural environment,
and have broad ranges because they may be accidentally transported
to new locations, 2) spiders which are seasonally abundant in
natural habitats as well as in houses, but don't establish breeding
populations in houses, 3) spiders which are rarely found in houses
because they are locally rare or spiders that are locally common
but are rarely found indoors. Fifteen species, including the venomous
Loxosceles relusa and Cheiracanthium mildei are
true synanthropes in Kansas. Category 2 contains 26 species, including
the venomous species Latrodectus hesperus, L, mactans,
and L, variolus. There are 33 species which are rarely
found indoors in Kansas. Most species listed have been reported
from buildings across the United States.
The Journal of
Arachnology 27:217-221
SPIDER
AND HARVESTMAN COMMUNITIES ALONG A GLACIATION TRANSECT IN THE
ITALIAN DOLOMITES
Vito Zingerle:
Institute of Zoology and Limnology, University of Innsbruck, Technikerstrasse
25, 6020 Innsbruck, Austria
ABSTRACT.
Arachnid communities of alpine grassland, of screes and woodlands
near the timberline and of the nival zone have been compared along
a transect from the northern to the southern border of the Dolomites.
The region is zoogeographically interesting because of differences
of the ice cover during glaciation, which was less severe in the
southern area. Along the whole transect spider communities in
grasslands and at the timberline zone show approximately the same
composition. Endemic species, e.g, Harpactea grisea (Canestuni
1868), Amaurobius ruffoi Thaler 1990, Coelotes mediocris
Kulczynski 1887, Cybaeus intermedius Maurer 1992 and Eudasylobus
ligusticus Roewer 1923 occur mostly on the southernmost station,
which remained free of ice. Re-immigrants over short distance
are scarce, e.g., Coelotes mediocris at Passo Rolle and
Coelotes solitarius L. Koch 1868 in the Puez area. Endemic
species were not found in the alpine grassland of the northern
Dolomites, which suggests severe impact of glacial events on the
local fauna. Central alpine species, i.e., Erigonella subelevata
(L. Koch 1869), Metopobactrus nadigi Thaler 1976, Meioneta
orites (Thorell 1875), Pardosa blanda (C.L. Koch 1833)
and Pardosa mixta (Kulczynski 1887) are still present at
the southernmost boundary of the Alps. Nunataks in the northern
and central area of the Dolomites allowed speciation effects within
the nival fauna: Lepthyphantes brunneri Thaler 1984, Lepthyphantes
merretti Millidge 1974, Megabunus armatus (Kulczynski
1887). Further zoogeographically interesting records are Cryphoeca
nivalis Schenkel 1919 and Xysticus bonneti Denis 1938.
RIASSUNTO.
E stata studiata la composizione della fauna aracnologica della
zona subalpina, alpina e nivale lungo un transetto che parte dalle
Dolomti settentrionali (Parco Naturale Puez-Odle) e porta fino
al bordo meridionale delle Alpi (Monte Grappa). II versante meridionale
delle Alpi e di grande importanza ai fini di studi zoogeografici,
essendo queste regioni in parte rimaste libere dai ghiacciai durante
le epoche glaciali. Sul Monte Grappa sono state riscontrate piu
specie endemiche p.es. Harpactea grisea (Canestrini 1868),
Amaurobius ruffoi Thaler 1990, Coelotes mediocris
Kulczynski 1887, Cybaeus intermedius Maurer 1992 e Eudasylobus
ligusticus Roewer 1923. Alcune specie reimmigranti a breve
distanza hanno riconquistato parti delle Dolomiti raggiungendo
regioni piu a nord: Coelotes mediocris Kulczynski 1887
e stato catturato anche a Passo Rolle, Coelotes solitanus
L. Koch 1868 anche nel Parco Naturale Puez-Odle. Specie endemiche
sembrano essere assenti nella prateria alpina delle Dolomiti settentnonali,
dimostrando l'effetto distruttivo dei ghiacciai sulla fauna del
suolo. In questa zona si possono trovare specie endemiche sulle
cime piu alte nmaste libere dai ghiacciai: Lepthyphantes merretti
Millidge 1974, Lepthyphantes brunneri Thaler 1984 e Megabunus
armatus (Kulczynski 1887). Altre specie rare e di notevole
interesse zoogeografico catturate nell'ambito di questo studio
sono Cryphoeca nivalis Schenkel 1919 e Xysticus bonneu
Denis 1938. E particolarmente sorprendente la presenza sul Monte
Grappa di specie tipiche delle Alpi centrali che sembrano spingersi
fino al bordo piu meridionale delle Alpi, p.es. Erigonella
subelevata (L. Koch 1869), Metopobactrus nadigi Thaler
1976, Meioneta orites (Thorell 1875), Pardosa blanda
(C.L. Koch 1833) e Pardosa mixta (Kulczynski 1887).
The Journal of
Arachnology 27:222-228
SALTICIDAE
(ARACHNIDA, ARANEAE) OF ISLANDS OFF AUSTRALIA
Barbara Patoleta
and Marek Zabka: Zaklad Zoologii WSRP, 08-1 10 Siedlce,
Poland
ABSTRACT.
Thirty nine species of Salticidae from 33 Australian islands are
analyzed with respect to their total distribution, dispersal possibilities
and relations with the continental fauna. The possibility of the
Torres Strait islands as a dispersal route for salticids is discussed.
The Journal of
Arachnology 27:229-235
PSEUDOSCORPIONS
IN FIELD MARGINS: EFFECTS OF MARGIN AGE, MANAGEMENT AND BOUNDARY
HABITATS
James R. Bell, Simon
Gates, Alison J. Haughton, David W. Macdonald, and
Helen Smith: Wildlife Conservation Research Unit, Department
of Zoology, Oxford University, South Parks Road, Oxford OXI 3PS,
U.K.
C. Philip Wheater
and W. Rod Cullen: Department of Environmental and Geographical
Sciences, Manchester Metropolitan University, Manchester Ml SGD,
U.K.
ABSTRACT. Pseudoscorpions
(Chthonius ischnocheles (Hermann) and C. orthodactylus
(Leach) sensu strictus) were collected using a D-Vac over two-years
from 60 field margins at Oxford University farm at Wytham, U.K.
Old and new grassland margins were subjected to six different
treatments involving spraying, non-intervention and four different
cutting intensities. Significantly more pseudoscorpions were found
in old compared to new margins, suggesting they may be attracted
to litter build-up over time. Pseudoscorpion numbers were reduced
on treatments subjected to two cuts annually, particularly when
a summer cut was included, although this effect was ameliorated
when the cuttings were left. However, pseudoscorpions were most
numerous on treatments which involved no management because of
the increase in leaf litter which may replicate a woodland environment.
Adjacent hedges appear to buffer the effects of management: margins
with adjacent hedges (rather than ditches or tracks) having more
individuals In contrast to results for other invertebrate groups,
sowing wildflower seed did not significantly increase the abundance
of pseudoscorpions The effect of different treatments on pseudoscorpion
numbers demonstrates that they are useful indicators of the effects
of management practice
The Joumal of
Arachnology 27:236-240
COMPARATIVE
ANALYSES OF EPIGEIC SPIDER ASSEMBLAGES IN NORTHERN HUNGARIAN WINTER
WHEAT FIELDS AND THEIR ADJACENT MARGINS
Ferenc Toth
and Jozsef Kiss: Godollo University of Agricultural Sciences,
Department of Plant Protection, H-2103 Godollo, Hungary
ABSTRACT. Pitfall
trapping was carried out in northern Hungarian winter wheat fields
and their adjacent margins dunng the growing seasons of three
consecutive years, 1992-1994. The dominant species of both habitats
was the wolf spider Pardosa agrestis (Westring). A total
of 8403 adult individuals of 19 families of 149 spider species
was identified: 118 species from the winter wheat and 118 from
the margins with fewer traps. The efficiency of detecting species
by trapping was 90%, according to the BauleMitscherlich extrapolation
model. Provided that the sampling effort is the same in both habitats,
traps in the margin may catch higher number of individuals and
species, than traps located within the field. Calculations, however,
indicate that the field, with an area more than a hundred times
larger than that of the margins, has a higher total number of
species. Although the spider species spectrum of the field and
of the margin had a considerable overlap, the Renkonen similarity
index indicates that the spider fauna of the two types of habitats
were different. Spider assemblages of the margins were more diverse
(Renyi diversity), than those of the fields. The species richness
of epigeic spiders in our Hungarian winter wheat fields was high,
and it was increased by the presence of margins. Thus, for the
purposes of the protection of our fauna and promotion of integrated
pest management, establishment and maintenance of margins is strongly
desirable.
The Journal of
Arachnology 27:241-248
THE
EFFECTS OF DIFFERENT RATES OF THE HERBICIDE GLYPHOSATE ON SPIDERS
IN ARABLE FIELD MARGINS
Alison J. Haughton
(1), James R. Bell (2), Nigel D. Boatman (3) and
Andy Wilcox (1)
(1) Crop & Environment Research Centre, Harper Adams University
College, Newport Shropshire TF10 8NB UK
(2) Department of Environmental & Geographical Sciences, Manchester
Metropolitan University, Chester St., Manchester M1 5GD. UK
(3) Allerton Educational & Research Trust, Loddington House,
Loddington, Leicestershire LE7 9XE. UK
ABSTRACT. Field
margins are susceptible to agro-chemical spray dnfl, and the effects
of herbicide on spiders in semi-natural habitats have been little
studied In this experiment, an arable field margin was sprayed
with three rates of glyphosate (90 g active ingredient/hectare
(a.i/ha), 180 g a.i./ha & 360 g a.i./ ha) and control plots
leh unsprayed. Spiders were sampled monthly (June-October) using
a converted garden-vac and adult spiders were identified to species.
A total of 23,393 spiders was sampled with the web-spinners representing
more than 90% of the individuals. The effects of glyphosate application
on the abundance of wandering and web-spinning prey-capture guilds,
and the two most abundant species (Gonatium rubens and
Lepthyphantes tenuis) were analyzed using ANOVA F tests.
The highest rate of glyphosate consistently reduced the total
number of spiders, the numbers of web-spinners, G. rubens
and L. tenuis but not numbers of wandering spiders. Changes
in vegetation structure and microclimate caused by the glyphosate
are implicated in the reduction of numbers of spiders in plots
receiving the highest rate of glyphosate. We conclude that glyphosate
drift at rates of more than 360 g a.i./ha (active ingredients
per hectare) into arable field margins could result in significant
losses of important arthropod predators in farmland and a reduction
in spider biodiversity in agroecosystems.
The Joumal of
Arachnology 27:249-254
A
FAUNISTIC AND ZOOGEOGRAPHICAL REVIEW OF THE SPIDERS (ARANEAE)
OF THE BALKAN PENINSULA
Christo Deltshev:
Institute of Zoology, Bulgarian Academy of Sciences, Blvd. Tsar
Osvoboditel 1, 1000-Sofia, Bulgaria
ABSTRACT.
The Balkan Peninsula is home to 1409 species, included in 337
genera and 47 famulies. This number was established after a critical
review of the existing literature and taxonomic revlsion of some
available collections containing spider material from this region.
The highest number of specles is recorded for the territories
of Bulgaria (775), Greece (642), Croatia (615) and Serbia (508).
This biodiversity depends not only on the size of the regions,
but also on the degree of exploration by researchers. The territories
of Albania, Turkey, Montenegro and Bosnia are less well investlgated.
Accordmg to thelr current distribution, the established 1409 species
can be classified into 24 zoogeograpical categories, grouped into
four complexes (widely distributed, European, Balkan endemics,
and Mediterranean). The largest number of species belongs to the
widely distributed complex, but the most characterlstlc are the
Balkan endemics. Their established number (379 species) is high
and reflects the local character of the fauna. This phenomenon
can be attributed to the relative isolation of the mountains compared
with the lowlands, in the context of paleo-environmental changes
since Pliocene. Thelr high percentage (26.9%) suggests an important
process of autochtonous speciation. Thus, the Balkan Peninsula
can be considered as a main center of speciation for the European
araneofauna.
The Journal of
Arachnology 27:255-261
GUILD
STRUCTURE OF SPIDERS IN MAJOR CROPS
George W. Uetz:
Department of Biological Sciences, University of Cincinnati, Cincinnati,
Ohio 45221-0006, USA
Juraj Halaj and Alan B. Cady: Department of Zoology,
Miami University, Oxford, Ohio 45056 USA
ABSTRACT. The
ecological guild concept has been of great interest to arachnologists,
and the different manner in which spiders forage for a common
resource-prey arthropods-has led to numerous attempts to classify
them into guilds. However, questions have been raised about the
validity of guilds and the taxon-centered basis of their definition.
Here, we propose an altemative approach to guild classification,
using quantitative analysis of ecological characteristics of spider
families. While generalizations may not apply to all species within
a taxon, results from this approach suggest eight major spider
guilds similar to earlier guild assignments by some authors and
provide a reasonable framework for future studies. We used this
classification in a comparison of spider guild composition across
several major crops (from published studies). While total species
richness varied widely among crops, the proportion of the total
species within each guild was remarkably even across crops. The
relative abundance of guilds (based on numbers of individuals)
varied greatly, which may reflect availability of resources within
a crop type. Pattems of similarity in guild composition suggest
the possibility of plant habitat structure as an influence on
the spider community. Further detailed analyses of spider guilds
in various crops have been constrained by both a lack of comparable
quantitative data and the paucity of behavioral and natural history
information available for many taxa. As recent studies have shown
that assemblages of spiders can impact pest populations and reduce
crop damage, a better understanding of spider guild composition
and variation in spider community structure among crops is essential
in future studies of the arthropod fauna in agroecosystems.
The Journal of
Arachnology 27:270-280
AN
AERIAL LOTTERY: THE PHYSICS OF BALLOONING IN A CHAOTIC ATMOSPHERE
Robert B. Suter:
Department of Biology, Vassar College, Poughkeepsie, New York
12604 USA
ABSTRACT.
The annual recolonization of many agroecosystems by spiders is
accomplished more by aerial deposition of ballooning spiders than
by cursonal invasion from refugia such as forests and fence lines.
The resulting spider communities can have major direct impacts
on prey populations and can therefore strongly influence crop
productivity. In this paper I first review what we know about
ballooning in the broad sense, and then explore the influence
of localized atmospheric structure on the physics and dynamics
of ballooning. I used relatively high frequency measurements of
air movement (speed and inclination) to develop a statistical
characterization of the aerial microclimate at the top of the
canopy in a field dominated by goldenrod (Solidago sp.),
and analyzed the known physics of ballooning in the context of
that statistical characterization The major findings are (1) that
the spider's perception of the current state of its microclimate
at least with respect to air direction and speed, has almost no
predictive value and can only contribute to the spider's decision-making
in a statistical sense, and (2) that the size distribution of
the population of aeronauts is well explained by constraints imposed
by aerodynamics and the probabilistic structure of the turbulent
atmosphere.
The Joumal of
Arachnology 27:281-293
DIFFERENTIAL
AERIAL DISPERSAL OF LINYPHIID SPIDERS FROM A GRASS AND A CEREAL
FIELD
C.F.G. Thomas
and P.C. Jepson: Department of Biology, University of Southampton,
Bassett Crescent East, Southampton SO9 3TU, U.K.
ABSTRACT.
Ground and aerial populations of linyphiid spiders were sampled
|