| THE
GENUS BRACHISTOSTERNUS IN ARGENTINA, DESCRIPTION OF A NEW
PATAGONIAN (SCORPIONES, BOTHRIURIDAE)by: Andrés
A. Ojanguren Affilastro: Museo Argentino de Ciencias
Naturales ‘‘Bernardino Rivadavia,’’ División
Aracnología, Av. Angel Gallardo 470, C1405 DJR Buenos Aires,
Argentina.
E-mail: ojanguren@ciudad.com.ar
& ojangur@yahoo.es
ABSTRACT.
The new species Brachistosternus paulae is described. This
is the southernmost species of the genus, occurring in southern
Patagonia in Santa Cruz Province. It can be distinguished from all
the other species of the genus by the presence of only 4 ventral
trichobothria on the pedipalpal chela, and by the shape of the hemispermatophore,
in which the cylindrical apophysis is shorter than the laminar apophysis;
all internal spines are absent, except for the row of spines, which
in some specimens is vestigial. This species can not be included
in any of the known subgenera due to its trichobothrial pattern;
nevertheless it is closer to the subgenus Leptosternus on
the basis of its remaining morphology. A key for the species of
the genus in the country is provided together with some data on
them. The hemispermatophores of the three subgenera are compared
and two maps detailing the distribution of the species in the country
are provided.
RESUMEN: El género
Brachistosternus en la Argentina, con la descripción
de una nueva especie de la Patagonia (Scorpiones, Bothriuridae).
En este trabajo se describe a Brachistosternus paulae n.
sp. Esta es la especie conocida más austral del género,
habitando en el sur de la Patagonia en la provincia de Santa Cruz.
Puede diferenciarse del resto de las especies del género
por la presencia de solo 4 tricobotrias ventrales en la pinza y
por el escaso desarrollo de su hemiespermatóforo,
en éste la apófisis
cilíndrica
se encuentra poco desarrollada y es más corta que la apófisis
laminar, además carece de todos los procesos espiniformes,
salvo las espinas en hilera que en algunos ejemplares pueden presentarse
en forma vestigial; la particular tricobotriotaxia de esta especie
no permite incluirla en ninguno de los subgéneros
descriptos hasta el momento, sin embargo su morfología
la aproxima más al subgénero Leptosternus. Se presenta además una clave para las
especies del género
en el país
y se aportan algunos datos sobre éstas.
Se comparan los hemiespermatóforos
de los distintos subgéneros
y se presentan dos mapas con la distribución
de las distintas especies presentes en el país.
Keywords: Scorpiones, Brachistosternus, key,
new species, Argentina
LIFE CYCLE, REPRODUCTIVE PATTERNS AND THEIR YEAR-TO-YEAR VARIATION
IN A FIELD POPULATION OF THE WOLF SPIDER PIRATA PIRATICUS
(ARANEAE, LYCOSIDAE)
by: Frederik Hendrickx:
Unit of Animal Ecology, Department Biology, Ghent University, K.L.
Ledeganckstraat 35, 9000 Ghent, Belgium. E-mail: frederick.hendrickx@rug.ac.be
and Jean-Pierre
Maelfait: Institute of Nature Conservation, Kliniekstraat
25, 1070 Brussels, Belgium and Unit of Animal Ecology, Department
Biology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent,
Belgium
ABSTRACT.
Patterns of growth, phenology and reproduction were studied in a
field population of the wolf spider Pirata piraticus from
November 1997 until October 1998 and in June 1999 to unravel the
intrapopulation variation and co-variation of these traits. Individuals
of P. piraticus overwinter as juveniles of different instars
while adults were found from the end of April until September. Strong
year to year variation in the age and size of overwintering juveniles
was present, resulting in a corresponding difference in adult size
in the subsequent breeding season. The main period of reproduction
occurred from May until August with larger individuals breeding
earlier in the season. The size at which adults breed was also significantly
different in the successive years. Clutch mass (cocoon mass), clutch
volume and fecundity are dependent on the size of the female according
to a weakly negative allometric relationship. The differences in
those reproductive traits between the succesive years are therefore
proportionate to the differences in female size. This was in clear
contrast to egg size, a life history trait that shows much less
variation and appears to be independent of female size. Therefore,
egg size was not significantly different between spring 1998 and
spring 1999. There is, however, some variation in fecundity due
to egg size and number independent of female size. When corrected
for female size, females with larger eggs produce relatively fewer
eggs indicating a trade-off between these two reproductive characters.Keywords: Life history, reproduction, egg size, fecundity, year-to-year variation, Pirata piraticus
DESCRIPTION OF THE FEMALES OF ANAPIS CASTILLA
AND ANAPISONA BORDEAUX (ARANEAE, ANAPIDAE)
by: Ricardo Ott: Museu de Ciências Naturais,
FZB / RS, 90690-000 Porto Alegre, RS, Brazil.
E-mail: rott@myway.com.br
and
Antonio
D. Brescovit: Laboratório Artrópodes Peçonhentos, Instituto
Butantan, Av.
Vital Brasil, 1500, Butantã, CEP 05503-900 São Paulo,
SP, Brazil.
ABSTRACT. The females of Anapis castilla Platnick & Shadab Anapisona bordeaux Platnick & Shadab from
the state of Rio Grande.
Keywords: Neotropical region, taxonomy, morphology
SPIDER WEBS AS HABITAT
PATCHES—THE DISTRIBUTION OF KLEPTOPARASITES (ARGYRODES,
THERIDIIDAE) AMONG HOST WEBS (NEPHILA, TETRAGNATHIDAE)by:
Ingi Agnarsson: Systematic Biology–Entomology, E-530,
Smithsonian Institution, NHB-105, PO Box 37012, Washington, D.C.
20013-7012 & Department of Biological Sciences, George Washington
University, Washington DC, 20052 USA
ABSTRACT.
Most adult golden orb weavers (Nephila clavipes) have kleptoparasites
of the genus Argyrodes in their webs. The kleptoparasitic
load correlates positively with web size. Clustered (interconnected)
webs have a more predictable number of kleptoparasites than do solitary
webs, but there is no difference in the mean number of kleptoparasites
between the two. From the view of the kleptoparasite, host webs
are habitat patches or islands. Isolated webs show characteristics
of small patches, where web size is a poor indicator of kleptoparasite
number and variation is high. The distribution of kleptoparasites
in clustered webs, on the other hand, seems to fit the ‘‘ideal
free distribution’’ where web size nearly entirely predicts
kleptoparasitic load. Thus clustered webs, as a habitat patch, are
more than merely the combination of their parts. The predictability
of kleptoparasite load in clustered webs may be a function of the
stability (longevity) of those habitat patches, and ease of colonization,
as neighboring webs act as sources. Keywords:
Habitat islands, habitat stability, ideal free distribution, orb
web, patch connectivity
SPIDER FAUNA OF SUGAR MAPLE AND WHITE ASH IN NORTHERN AND CENTRAL
NEW YORK STATEby: Bonnie
M. Brierton, Douglas C. Allen (corresponding author)
and Daniel T. Jennings
State University College of Environmental Science and Forestry,
1 Forestry Drive, Syracuse, New York 13210 USA
ABSTRACT. The purpose of this study was to identify
spiders associated with foliage of sugar maple, Acer saccharum Marsh. and white ash, Fraxinus americana L., and to investigate
their distribution and relative abundance within the crowns of these
two northern hardwoods. Spiders were collected during June through
August 1995 from the lower and mid-crowns of ten dominant/codominant
sugar maples, five white ash and understory sapling and herbaceous
foliage #2 m from the ground in a northern hardwood stand in Cortland
County New York. These samples were compared for differences in
species composition and density (number/25 leaf-clusters; number/100
g dry leaf weight). The spider fauna obtained from this intensive
sample was compared to that of an extensive, 20-year survey from
the midcrown of sugar maple in 15 northern hardwood stands in northern
New York (St. Lawrence and Lewis Counties). The intensive overstory
collection (1995) from maple provided 694 specimens (7 families,
11 genera, 13 species). The dominant families were Philodromidae
(43%) and Theridiidae (26%). The most abundant species were Philodromus
rufus Walckenaer 1826 and Enoplognatha ovata (Clerck
1757). Sugar maple averaged 2.6 6 0.6 spiders/25 leaf-clusters and
14.2 6 0.6/100 g of foliage. Density of dominant taxa and total
numbers did not differ significantly (a 5 0.05) between crown positions.
Significantly fewer hunters/100 g leaf weight occurred on the distal
half of mid-crown branches compared to the basal half. Hunters were
the dominant foraging guild in terms of both numbers (65%) and number/100
g leaf weight (56%). One hundred twenty four specimens were obtained
from white ash (7 families, 9 genera, 9 species). Density on ash
averaged 2.6 6 1.3/100 g leaf weight and P. rufus and
Araniella displicata (Hentz 1847) were the most abundant species.
Significantly fewer spiders occurred on white ash compared to sugar
maple (14.2 6 0.6/100 g of foliage. The extensive sample provided
712 specimens consisting of 12 families, 27 genera and 40 species.
The most abundant species recovered was Pelegrina proterva (Walckenaer 1837). The web spinner, E. ovata was the most
common species recovered from understory foliage (96% of 763 specimens).
Keywords: Spider diversity, community structure,
biodiversity
XYSTICUS BREVIDENTATUS (THOMISIDAE): FURTHER RECORDS AND
FIRST DESCRIPTION OF THE FEMALE
by: Elke Jantscher:
Institute of Zoology, Karl-Franzens-University, Universitätsplatz
2, A-8010 Graz, Austria.
E-mail: elke.jantscher@uni-graz.ac.at
ABSTRACT. The male of Xysticus brevidentatus
Wunderlich 1995 was originally described from Dubrovnik in Croatia,
but females have remained unknown. During a revision of museum material
in Vienna further specimens including both males and associated
females from Albania, Italy and Yugoslavia were discovered. The
morphology of the male pedipalp allows the placement of X. brevidentatus
in the cristatus group which contains, among others, X. cristatus
(Clerck 1757), X. audax (Schrank 1803), X. macedonicus
Silhavy 1944 and X. pseudocristatus Azarkina & Logunov
2001. Detailed analyses of the females showed that the shape of
the female epigyne and vulva is consistent with the general scheme
of the cristatus group and that the specimens can, due to a number
of distinctive characters, be regarded as the females of X. brevidentatus.
Keywords: Araneae, Thomisidae, Xysticus,
taxonomy, Balkans, cristatus group
THE FIRST FOSSIL CYPHOPHTHALMID (ARACHNIDA, OPILIONES)
FROM BITTERFELD AMBER, GERMANY
by: Jason A. Dunlop: Institut
für Systematische Zoologie, Museum für Naturkunde der
Humboldt-Universität zu Berlin, Invalidenstraße 43, D-10115
Berlin, Germany. E-mail:
jason.dunlop@museum.hu-berlin.de
and Gonzalo Giribet:
Department of Organismic and Evolutionary Biology, Harvard
University, 16 Divinity Avenue, Cambridge, Massachusetts 02138,
USA
ABSTRACT. The first fossil cyphophthalmid harvestman,
Siro platypedibus new species (Arachnida, Opiliones, Cyphophthalmi),
is described from Bitterfeld amber, Sachsen-Anhalt, Germany. The
age of this amber is in dispute. Geological studies support a Miocene
(20–22 Ma) date for the deposit, but the presence of insect
species identical to those in Baltic amber (dated at ca. 35–40
Ma) has led other authors to suggest that the Bitterfeld amber comprises
older, redeposited material, contemporary with Baltic inclusions.
Two features in this harvestman fossil are consistent with the Recent
genera Siro, Paramiopsalis and Tranteeva: (a)
smooth tarsi and metatarsi in legs 1 and 2 and (b) the apparent
absence of a dorsal crest on the basal article of the chelicera.
Unequivocal autapomorphies of any one of these genera are not clearly
preserved in this fossil, but Paramiopsalis is a monotypic
Iberian genus, and Tranteeva is a monotypic genus from Bulgaria,
while Siro is more diverse and widely distributed, including
living representatives in Central Europe relatively close to the
Bitterfeld type locality. For this reason we assign the fossil to
Siro.
Keywords: Cyphophthalmi, Sironidae, Siro,
taxonomy, paleontology, new species
THE MALE MATING SYSTEM IN A DESERT WIDOW SPIDER
by: Ori Segev (3),
Merav Ziv (2)
and Yael Lubin (1)
: Mitrani Department of Desert Ecology, Jacob Blaustein Institute
for Desert Research, Ben Gurion University of the Negev, Sede Boqer
84990, Israel
(1) Corresponding author.
(2) Published posthumously.
(3) Current address: Department of Biology, Faculty of Sciences
and Science Education, University of Haifa, Oranim, Tivon 36006,
Israel
ABSTRACT. Competition among males is a major force
shaping sexual selection. We investigated the male mating strategy
of the widow spider Latrodectus revivensis, a desert species
with an annual life cycle. Based on morphology of the sperm storage
organs reported for female Latrodectus, we predicted that
males should guard sub-adult or virgin adult females. In a natural
population, we found that males were generally monogamous, cohabiting
longer with sub-adult females approaching the final molt than with
adult females. Nevertheless, both the duration and timing of male
cohabitation were highly variable. Males were found with females
from a few days before or after female maturation to over two monthsafter
maturation. Maturation of males and females peaked in spring, with
a second, smaller peak in summer. Adult males that matured in spring
were larger than those maturing later in the summer, while for adult
females the pattern was reversed. We suggest that large males of
L. revivensis that mature in spring maximize reproductive
success by mating with virgins. Late males will gain greater reproductive
success from mating with large, late-maturing females, but the scarcity
of these females in the population at this season may make opportunistic
mating with non-virgin females a viable strategy.
Keywords: Mating strategy, Latrodectus, sexual cohabitation,
size dimorphism
THIRD SPECIES OF GUASINIIDAE (OPILIONES, LANIATORES)
WITH COMMENTS ON FAMILIAL RELATIONSHIPS
by: Ricardo Pinto-da-Rocha:
Depto. de Zoologia, Instituto de Biociências, Universidade
de São Paulo,
Rua do Matão,
Travessa 14, No. 321, 05508-900 São
Paulo/SP, Brazil. E-mail: ricrocha@usp.br
and Adriano B. Kury:
Museu Nacional, Quinta da Boa Vista s/n, São Cristóvão,
20.940-040, Rio de Janeiro, RJ, Brazil
ABSTRACT. Guasinia persephone, a new species
of the family Guasiniidae, is described from the soil of an inundation
forest in Brazilian Amazonia. This family was hitherto only known
from two species from Venezuela. Male genitalia of the new species
are described in detail. A close relationship of Guasiniidae with
Zalmoxidae and Fissiphalliidae is proposed on basis of genital morphology.
This is the third species of blind Laniatores from Brazil and the
first from leaf mold, one is from termite nests and the other is
from a cave.
Keywords: Guasiniidae, Neotropics, Opiliones, anophthalmy,
Brazil, Amazonia, Arachnida
LYSSOMANES (ARANEAE, SALTICIDAE) IN OLIGOCENE-MIOCENE
CHIAPAS AMBER
by: Miguel A. García-Villafuerte:
Museo de Zoología, Universidad de Ciencias y Artes de Chiapas,
Escuela de Biología, Calzada Samuel León Brindis 151.
C.P. 29000, Tuxtla Gutiérrez, Chiapas, México
and David Penney1: Earth Sciences, The University
of Manchester, Manchester, M13 9PL, UK
ABSTRACT. The genus Lyssomanes (Salticidae)
is recorded and described from a fossil in 20–30 Ma Oligocene–Miocene
amber from Chiapas, Mexico for the first time. This is the oldest
described Lyssomanes and extends the known geological range
of the genus by approximately 10 Ma from the previously oldest known
specimens in Dominican Republic amber. The geological age of the
family may be young compared to other extant spider families.
RESUMEN. El genero Lyssomanes (Salticidae)
es descrito y registrado por primera vez incluido en el ámbar
de Chiapas, México, tomando en cuenta una edad de 20 a 30
Ma (Oligoceno-Mioceno). Éste es el registro más antiguo
que se tienen de Lyssomanes y con esto se extiende el rango
geológico conocido para el género por aproximadamente
10 Ma de los especimenes previamente conocidos y ma´s antiguos
del ámbar de la Republica Dominicana. Geológicamente
la edad la familia puede ser joven comparado con otras familias
existentes de arañas.
Keywords: Fossil, jumping spider, Cenozoic, Mexico
WEB ORIENTATION OF THE BANDED GARDEN SPIDER ARGIOPE
TRIFASCIATA (ARANEAE, ARANEIDAE) IN A CALIFORNIA COASTAL POPULATION
by: Martin G. Ramirez, Estelle
A. Wall (1) and Monica
Medina (2): Department of Biology,
Loyola Marymount University, Los Angeles, California 90045
(1) Current address: Department of Cell and Neurobiology,
Keck School of Medicine, University of Southern California, Los
Angeles, California 90089.
(2) Current address: Venice Adult School, 13000 Venice Boulevard,
Los Angeles, California 90066.
ABSTRACT. Magnetic heading (direction the spider’s
ventrum faced) and web inclination (degree of slant from the vertical)
in Argiope trifasciata Forskål, a diurnal orb-weaving
spider, were studied at a coastal site in southern California for
nine weeks in fall 1999. Throughout the study, A. trifasciata largely occupied east-west oriented webs with their venters facing
south and southwest. Mean magnetic heading was unaffected by ambient
temperature extremes. Inclination levels varied from week to week
over an approximately 58 range. However, these changes followed
no discernible pattern and were independent both of the sun’s
decrease in maximum altitude during the course of the study and
of magnetic heading. Since the ventrum of A. trifasciata
is dark, the consistent southern orientation exhibited by spiders
at our study site suggests that they sought to maximize solar radiation
in an attempt to gain heat. In addition, the east-west, facing-the-sun
orientation of webs at this site places them parallel to the prevailing
western breezes, minimizing their exposure to wind disturbance.
As for inclination, it is unclear what factors may be influencing
the degree of slant in A. trifasciata webs and further study
will be needed to ascertain what they might be.
Keywords: Araneidae, Argiope trifasciata,
web orientation, web inclination, solar radiation
THE FIRST DNA PHYLOGENY OF FOUR SPECIES OF MESOBUTHUS (SCORPIONES,
BUTHIDAE) FROM EURASIA
by: Benjamin Gantenbein:
Institute of Cell, Animal and Population Biology, University of
Edinburgh, West Mains Road, Edinburgh EH9 3JT, United Kingdom
Victor Fet: Department of Biological
Sciences, Marshall University, Huntington, West Virginia 25755-2510
USA
Alexander V. Gromov: Institute of
Zoology, Akademgorodok, Almaty, 480060, Republic of Kazakhstan
ABSTRACT. The first molecular phylogeny is presented
for four species of the scorpion genus Mesobuthus, based
on DNA sequences of three gene fragments (two mitochondrial and
one nuclear protein coding gene, ~1 kb). The inferred phylogeny
based on a pooled maximum likelihood analysis revealed a clear deep
splitting between the ‘‘western clade’’ consisting
of M. gibbosus and M. cyprius (Greece/Anatolia, Cyprus)
and the ‘‘eastern clade’’ consisting of M.
eupeus and M. caucasicus (Anatolia/Central Asia). The
species M. caucasicus (recently placed in the genus Olivierus
Farzanpay 1987) groups monophyletically within Mesobuthus;
thus, the genus Olivierus is synonymized here with Mesobuthus.
Sequences of M. eupeus and M. caucasicus sampled mainly
from Kazakhstan and Uzbekistan are highly structured, indicating
the possible existence of multiple species.
Keywords: Scorpions, Buthidae, Mesobuthus, phylogeny,
DNA, 16S, coxI, protein kinase, biogeography
SHORT COMMUNICATION: CREEP
AND LOW STRENGTH OF SPIDER DRAGLINE SUBJECTED TO CONSTANT LOADS
by: Christopher
Smith, Joanne Ritchie, Fraser I. Bell, Iain J. McEwen
and Christopher Viney (1,
2): Department of Chemistry, Heriot-Watt University, Edinburgh
EH14 4AS, Scotland.
E-mail: cviney@umerced.edu
(1) Corresponding author.
(2) Current address: University of California Merced, School of
Engineering, PO Box 2039, Merced, CA 95344, USA. ABSTRACT.
Major ampullate (dragline) silk is attracting significant attention
as a potentially useful engineering fiber. This interest is motivated
by reports that the silk exhibits high mean strength, stiffness
and toughness as measured in tensile tests. However, the typical
testing conditions (constant strain rate; experiment completed within
less than an hour) imposed during such assessments do not reflect
typical demands (e.g. ability to support constant load for long
times) made on real high-tensile materials. We demonstrate here
that Nephila clavipes major ampullate silk subjected to constant
loads performs poorly: its breaking strength is significantly lower
than that measured in conventional constant strain rate tests, and
even very small constant loads can cause elongation to increase
appreciably over long timescales.
Keywords:
Creep, dragline, Nephila clavipes, silk, strength
SHORT
COMMUNICATION: HUNGRY SPIDERS AREN’T AFRAID OF THE BIG
BAD WOLF SPIDER
by: Sean
E. Walker (1): Department of Zoology,
Miami University, Oxford, OH 45056 USA
and Ann L. Rypstra:
Department of Zoology, Miami University, 1601 Peck Boulevard, Hamilton,
OH 45011, USA
(1) Present Address: Sean E. Walker, Department
of Biological Sciences, University of Lethbridge, Lethbridge, Alberta,
T1K 3M4, Canada
ABSTRACT. Foraging behavior in spiders can be influenced
by a variety of factors. Here we investigate the effects of hunger
and predation risk on feeding behavior in the wolf spider Pardosa
milvina (Hentz 1877) (Araneae, Lycosidae). Pardosa milvina
is preyed upon by the larger wolf spider, Hogna helluo (Walckenaer
1837), and responds with appropriate antipredator behavior to the
silk and feces of this species. We predicted that hungry Pardosa
milvina would be more likely to forage and consume prey under
predation risk than satiated individuals. We found that hungry Pardosa
under predation risk consumed as many prey as spiders not under
predation risk. However, satiated Pardosa consumed significantly
fewer prey when under predation risk. Our data suggest that the
animal’s energetic needs are weighed against the risks of foraging
when predators may be present.
Keywords: Wolf spider, predation risk, hunger, foraging
SHORT
COMMUNICATION: WATER SURFACE LOCOMOTION BY SPIDERS: DISTINCT
GAITS IN DIVERSE FAMILIES
by: Robert
B. Suter: Department of Biology, Vassar College, 124
Raymond Avenue, Poughkeepsie, New York 12604 USA. E-mail: suter@vassar.edu
Gail Stratton: Department of Biology,
University of Mississippi, University, Mississippi 38677 USA
Patricia R. Miller: Department of
Biology, Northwest Mississippi Community College, Senatobia, Mississippi
38668 USA
ABSTRACT. Pisaurids such as Dolomedes triton
(Walckenaer 1837) are well known as inhabitants of ponds and streams
and are adept at locomotion on the water surface. In a broad survey
of water surface locomotion in spiders, we have found that most
taxa do not use specialized gaits under these circumstances. However,
some tetragnathids, araneids, and salticids (three families that
are outside of the superfamily Lycosoidea to which the pisaurids
belong) resemble D. triton to the extent that they do use
specialized gaits when on the water surface. Of these, the tetragnathids
are particularly accomplished at water surface locomotion, achieving
velocities that exceed those of D. triton when it rows, but
not when it gallops.
Keywords: Aquatic locomotion, gaits, Pisauridae,
Tetragnathidae, Philodromidae, Salticidae, Araneidae, Lycosidae,
Gnaphosidae
SHORT
COMMUNICATION: BURROW USE IN A NORTHERN CALIFORNIA POPULATION
OF THE WOLF SPIDER SCHIZOCOSA MCCOOKI (ARANEAE, LYCOSIDAE)
by: K.
Blake Suttle: Department of Integrative Biology, University
of California, Berkeley, CA 94720-3140 USA. E-mail: kbsuttle@socrates.berkeley.edu
ABSTRACT. Observations on the wolf spider Schizocosa
mccooki in northern California grasslands reveal previously
unreported burrowing behavior, known to occur in only one other
member of the genus. Adult and penultimate female S. mccooki
may occupy burrows that vary widely in depth and the occurrence
of silk linings. Mark-resight techniques revealed burrow fidelity
spanning several weeks for individual spiders. Behaviors such as
courtship and prey consumption can occur at, but are not restricted
to, the entrances to these burrows. Burrows appear to offer daytime
shelter for S. mccooki, though it remains unclear whether
protection from predators or amelioration of abiotic conditions
is the primary basis for burrow use.
Keywords: Burrow use, northern California, lycosids
SHORT
COMMUNICATION: TREES USED FOR TUBE SUPPORT BY SPHODROS RUFIPES
(LATREILLE 1829) (ARANEAE, ATYPIDAE) IN NORTHWESTERN LOUISIANA
by: Laurence
M. Hardy: Museum of Life Sciences, Louisiana State University
in Shreveport, One University Place, Shreveport, LA 71115-2399
ABSTRACT. Little information is available concerning
the tree species preferred by the American redlegged purseweb spider,
Sphodros rufipes (Latreille 1829), for supporting their webs.
During a study of the spiders of northwestern Louisiana, 26 pursewebs
of S. rufipes were found. All were on deciduous trees, with
58% found on sweetgum or oak. None of the webs were on conifers
or herbaceous plants even though conifers made up 7–92% of
the trees in the sampled areas. All pursewebs were within 20 m of
a stream and were on trees with a trunk less than 70 cm dbh.
Keywords: Purseweb, habitat, hardwoods, habitat preference,
web placement
SHORT
COMMUNICATION: MALE EGG GUARDING BEHAVIOR IN THE NEOTROPICAL
HARVESTMAN AMPHERES LEUCOPHEUS (MELLO-LEITÃO 1922)
(OPILIONES, GONYLEPTIDAE)
by: Marcos
Ryotaro Hara and Pedro Gnaspini:
Departamento de Zoologia, Instituto de Biociências, Universidade
de São Paulo,
Caixa Postal 11461, 05422-970 São
Paulo, SP, Brazil. E-mail: marcosrh@usp.br
and Glauco Machado:
Museu de História Natural, Instituto de Biologia, Universidade
Estadual de Campinas, Caixa Postal 6109, 13083-970 Campinas, SP,
Brazil
ABSTRACT. Males of the Neotropical harvestman Ampheres
leucopheus (Mello-Leitão 1922) were observed guarding
egg-batches attached to the undersurface of leaves. As recorded
for other paternal harvestmen, males of A. leucopheus guard
egg-batches containing eggs in different developmental stages as
well as newly hatched nymphs. This is the second case of paternal
care recorded among gonyleptids and the fifth in the order Opiliones.
Keywords: Harvestmen, Caelopyginae, parental care,
postzygotic investment
SHORT
COMMUNICATION: MATING WITHOUT SEXUAL CANNIBALISM IN TIDARREN
SISYPHOIDES (ARANEAE, THERIDIIDAE)
by: Barbara
Knoflach: Institute of Zoology and Limnology, University
of Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria. E-mail:
konrad.thaler@uibk.ac.at
and Suresh P. Benjamin:
Department of Conservation Biology, University of Basel, St. Johannes
Vorstadt 10, CH-4056 Basel, Switzerland. E-mail: suresh.benjamin@unibas.ch
ABSTRACT. Copulatory behavior of Tidarren sisyphoides
is described for the first time. Courtship proceeds without construction
of a mating thread. The male dies during insertion and remains coupled
to the female epigynum for 2.4 hours on average (n = 15). In contrast
to other species hitherto studied, females of T. sisyphoides
do not consume their mates after copulation. Instead, the dead males
are removed from the webs by the females.
Keywords: One-palped spiders, copulatory behavior,
male sexual suicide, mating plug
This page was posted
12 / 19 / 2003 and modified 11 / 27 / 2009 |