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LINYPHIA
TRIANGULARIS, A PALEARCTIC SPIDER (ARANEAE, LINYPHIIDAE) NEW TO NORTH AMERICA
by Daniel
T. Jennings: USDA, Forest
Service, Northeastern Research Station, 686 Government Road, Bradley,
Maine 04411 USA
Kefyn M. Catley: Rutgers, The State
University of New Jersey, 10 Seminary Place, New Brunswick, New
Jersey 08901-1183 USA
Frank Graham, Jr.: National Audubon Society, 700 Broadway,
New York, NewYork 10003 USA
ABSTRACT.
A Palearctic spider, Linyphia triangularis (Clerck 1757),
has been accidentally introduced to the U.S.A. and populations successfully
established in Maine. The date, origin, and focal point(s) of introduction
are unknown, but suspected to be recent, European, and maritime.
Extensive historical collections, records of maritime commerce,
and recent chronological collections support this hypothesis. Results
of cursory surveys in 1999 and 2000 indicate that L. triangularis
is now widely distributed in Maine with specimens taken in 15
of 16 counties. The potential impact(s) of L. triangularis on the native araneofauna are unknown, but possibly detrimental.
In Europe, this species exhibits aggressive behaviors (e.g.,
web "take-overs") toward conspecifics and congenerics.
INFLUENCE
OF FEEDING REGIME ON BODY SIZE, BODY CONDITION AND A MALE SECONDARY
SEXUAL CHARACTER IN SCHIZOCOSA OCREATA WOLF SPIDERS (ARANEAE,
LYCOSIDAE): CONDITION-DEPENDENCE IN A VISUAL SIGNALING TRAIT
by George
W. Uetz, Randi Papke, and Beril Kilinc: Department
of Biological Sciences, University of Cincinnati, Cincinnati, OH
45221-0006. e-mail: George.Uetz@uc.edu
ABSTRACT.
Male Schizocosa ocreata (Hentz) wolf spiders (Araneae,
Lycosidae) have tufts of elongated, dark bristles on the patella
and tibia of the forelegs, which are involved in visual signaling.
Previous research has suggested that these tufts are used by females
as a criterion in mate choice, raising the question of whether they
might serve as indicators of male condition. We tested the hypothesis
that tufts are condition-dependent indicator traits with a laboratory
rearing study subjecting spiders to lifelong feeding regimens representing
successful (high food) and unsuccessful (low food) foraging history,
after which males were measured upon reaching adulthood. Mortality
varied significantly with experimental treatment, and had a disproportionate
impact on some egg sacs assigned to the low food treatment. Age
at sexual maturity and several body size measures varied significantly
with feeding history. Well-fed spiders survived better, matured
earlier, were significantly larger, and were in relatively better
condition (measured as a residual body condition index) than deprived
spiders. Additionally, well-fed spiders had significantly larger
relative tuft size (scaled for body size). These data suggest that
male body size, condition and a conspicuous male signaling trait
vary with feeding history, and thus have the potential to serve
as "honest indicators" of male quality in mate choice.
THE
FIRST OLD WORLD SPECIES OF PHRYNIDAE (AMBLYPYGI): PHRYNUS EXSUL
FROM INDONESIA
by Mark
S. Harvey: Department of Terrestrial Invertebrates,
Western Australian Museum, Francis St, Perth, Western Australia
6000, Australia
ABSTRACT.
A new species of Phrynus, P. exsul, from the Indonesian
island of Flores, represents the first member of the family found
outside of the New World.
MALE
PEDIPALPAL STRIDULATORY DEVICES IN NEOTROPICAL WOLF SPIDERS AND THEIR
POSSIBLE ROLE IN SYSTEMATICS
by C.
Fernández-Montraveta: Dpto. Psicología
Biológica y de la Salud, Universidad Autónoma de Madrid,
Spain. Email: carmen.montraveta@uam.es
M. Simó: Sección de Entomología, Facultad de Ciencias,
Universidad de la República, Uruguay
ABSTRACT.
In males of several Uruguayan lycosid species of the genera Lycosa,
Schizocosa, Aglaoctenus and Allocosa, we used
scanning electron microscopy to investigate the existence and the
morphology of pedipalpal stridulatory-like structures. These kinds
of structures only appeared in species belonging to the subfamily
Lycosinae, and representatives of the Allocosinae and Sosippinae
subfamilies lacked them altogether. Unlike European Lycosa
species, all surveyed Uruguayan species of the genus Lycosa presented
the character to some extent, but interspecific differences occurred
in the relative size and development of the structure. Lycosa
thorelli, L. carbonelli and Lycosa sp. showed
a very well developed pedipalpal structure, which was smaller in
Lycosa poliostoma. Schizocosa malitiosa also exhibited
an only partially developed structure. A possible role of these
pedipalpal stridulatory-like structures in lycosid systematics is
discussed.
RESUMO. Mediante
Microscopía Electrónica de Barrido, hemos analizado
la existencia y la morfología de las estructuras pedipalpales
de tipo estridulador en los machos de varias especies uruguayas
de la familia Lycosidae (géneros Lycosa, Schizocosa,
Aglaoctenus y Allocosa). Este tipo de estructuras
sólo está presente en especies pertenecientes a la
subfamilia Lycosinae, mientras que las especies representativas
de las subfamilias Allocosinae y Sosippinae carecen por completo
de ellas. A diferencia de las especies europeas de Lycosa,
todas las especies uruguayas del género analizadas presentan
la estructura, aunque existen diferencias interespecíficas
en su tamaño y desarrollo relativos. Lycosa thorelli,
L. carbonelli y L. sp. presentan una estructura pedipalpal
muy bien desarrollada, mientras que su tamaño es menor en Lycosa poliostoma. Schizocosa malitiosa también
posee una estructura sólo parcialmente desarrollada. Discutimos
una posible aplicación de estas estructuras en la sistemática
de la familia Lycosidae.
EVIDENCE
THAT THE WOLF-SPIDER LYCOSA TARENTULA (ARANEAE, LYCOSIDAE)
NEEDS VISUAL INPUT FOR PATH INTEGRATION
by Joaquìn
Ortega-Escobar: Department of Biological Psychology,
Faculty of Psychology, University Autónoma of Madrid, 28049-Madrid,
Spain. Email: joaquin.ortega@uam.es
ABSTRACT.
The homing behavior of Lycosa tarentula (Linnaeus 1758)
(Araneae, Lycosidae) adult females was studied. They were tested
under two conditions, diffused light (200 lux) and darkness, after
having been placed in an open field. In both conditions the spiders
did not orient towards the burrow position; instead, under diffused
light, each spider turned at a constant angle with a value close
to135º; this is the turn that the spider should have made in
its terrarium to return to the burrow. In darkness, most of the
spiders (71.4%) turned at random. In both conditions, the trajectory
was roughly straight, finishing with a sudden directional change.
The speed was higher under diffused light than under darkness. These
results support the hypothesis that L. tarentula uses path
integration in laboratory conditions and that it needs visual input
to obtain a direction estimation in homing.
THE
OLDEST LINYPHIID SPIDER, IN LOWER CRETACEOUS LEBANESE AMBER (ARANEAE,
LINYPHIIDAE, LINYPHIINAE)
by David
Penney and Paul A. Selden:
Earth Sciences, University of Manchester, Manchester, M13 9PL, UK.
E-mail: david.penney@man.ac.uk
ABSTRACT. A
new fossil Linyphiidae: Linyphiinae is described from 125135
Ma old (Upper Neocomianbasal Lower Aptian) Cretaceous amber
from the Kdeirji/Hammana outcrop, Lebanon. This is the oldest known
linyphiid as well as the oldest described amber spider. The first
major radiation of the linyphiid subfamilies occurred in the early
Cretaceous, if not before, and the presence of Linyphiidae in this
period predicts the presence of Pimoidae then too. Current evidence,
which suggests the higher araneoids did not radiate and diversify
until after the end-Cretaceous mass extinction event may be an artefact
of sample size.
ESTIMATING
THE STICKINESS OF INDIVIDUAL ADHESIVE
CAPTURE THREADS IN SPIDER ORB WEBS
by Brent
D. Opell: Department of Biology, Virginia Polytechnic
Institute and State University, Blacksburg, VA 24061 USA. E-mail:
bopell@vt.edu
ABSTRACT. Sticky
threads improve an orb web's ability to retain the insects that
strike it, allowing a spider more time to subdue these insects before
they can escape from the web. The adhesive capture threads found
in most orb webs feature small droplets of aqueous material. Inside
each droplet, glycoprotein granules coalesce to impart thread stickiness.
An independent contrast analysis of threads produced by the adults
of five species (Leucauge venusta, Argiope trifasciata,
Micrathena gracilis, Cyclosa conica, Araneus marmoreus)
and ontogenetic studies of the threads of two of these species show
that the volume of material in a thread's droplets is directly related
to its stickiness. Models based on these analyses predict thread
stickiness to within an average of 11% of the mean measured values
using measurements of droplet diameter and distribution that are
easily made with a compound microscope. This approach will facilitate
the inclusion of thread stickiness in studies that examine the properties
and performance of spider orb-webs.
A
COMPARATIVE STUDY OF PHENOLOGY AND DAILY ACTIVITY PATTERNS IN THE
WOLF SPIDERS PARDOSA MILVINA AND HOGNA HELLUO IN SOYBEAN AGROECOSYSTEMS
IN SOUTHWESTERN OHIO (ARANEAE, LYCOSIDAE)
by Samuel
D. Marshall, Daniel M. Pavuk and
Ann L. Rypstra: Miami University, 1601 Peck Boulevard,
Hamilton, OH 45011
ABSTRACT.
We studied the phenology and the daily activity patterns of Pardosa
milvina Hentz 1844 and Hogna helluo (Walckenaer 1837)
in replicated soybean fields in southwest Ohio over three years
(1994--1996) using pitfall traps. For the phenology study we established
an array of five pitfall traps in 12 replicate 0.42 ha fields. These
traps were either set for two days at two-week intervals (1994),
or for three days at three-week intervals (1995 & 1996), over
the field season from May--October on 20 trap dates each year. We
found that P. milvina was more common overall, and found
evidence for one population peak per year. Numbers of H. helluo
tended to be lowest in the earlier censuses, and we found evidence
for one peak of male activity per year. The immature male and female,
and adult female, H. helluo were larger (based on carapace
width) than the immature male and female, and adult female, P.
milvina on most trapping dates. For the circadian activity periodicity
study we used two different drift-fence trap designs, both with
dry-cup pitfall traps set for two or three days and checked at 12
h intervals. For three sampling periods in 1994 we found H. helluo
to be more frequently trapped at night, and for two sampling periods
P. milvina was more frequently trapped during the daylight
hours.
MATING
SUCCESS AND ALTERNATIVE REPRODUCTIVE STRATEGIES OF THE DIMORPHIC JUMPING
SPIDER, MAEVIA INCLEMENS (ARANEAE, SALTICIDAE)
by David
L. Clark (1) and Brandon Biesiadecki
(1,2):
1. Department of Biology,
Alma College, Alma, MI 48801, U.S.A. E-mail: clarkd@alma.edu
2. Department of Physiology and Biophysics, Case Western Reserve
University School of Medicine, Cleveland, OH 44106, US.A.
ABSTRACT.
The two male morphs of the dimorphic jumping spider, Maevia inclemens,
differ dramatically in morphology and courtship behavior.The purpose
of this study was to examine and compare the mating success of the
two male types. Mating success was measured by the number and duration
of copulation events, the latency of visual orientation by the female
to a courting male, signals of female receptivity, risk of predation
by the female, and the number of offspring produced by each morph.
The morphs did not differ significantly with respect to copulation
success, mating events, mating duration, signals of receptivity
or the number of offspring produced. However, males did differ with
respect to latency of visual orientation as a function of distance
from the female. Near to the female, the gray males attracted female
attention in significantly less time than tufted males. Conversely,
at far distances from the female, the tufted males attracted female
attention in less courtship time. This study suggests that males
attain equal levels of mating success and that the two male morphs
may have evolved alternative reproductive strategies for courtship
at different distances from the female.
THE
FIRST MYGALOMORPH SPIDER WITHOUT SPERMATHECAE: SICKIUS LONGIBULBI,
WITH A REVALIDATION OF SICKIUS (ARANEAE, THERAPHOSIDAE, ISCHNOCOLINAE)
by Rogerio
Bertani and Pedro Ismael da Silva Junior:
Laboratório de Artrópodes, Instituto Butantan, Av.
Vital Brazil 1500, São Paulo, São Paulo, 05503-900,
Brazil. Email: rbert@usp.br.
ABSTRACT.
The monotypic Brazilian genus Sickius Soares & Camargo
1948 is revalidated, rediagnosed, and tentatively transferred to
the Ischnocolinae. The formerly unknown female of S. longibulbi Soares & Camargo 1948 is found to lack spermathecae. This unusual
genital feature, not found in any other mygalomorph spider species,
is described and discussed.
KEYS
TO THE GENERA OF ARANEID ORBWEAVERS (ARANEAE, ARANEIDAE) OF THE AMERICAS
by Herbert
W. Levi: Museum of Comparative Zoology, Harvard University,
Cambridge, MA 02138-2902, USA E-mail: herblevi@mac.com
ABSTRACT.
This paper contains keys to the 65 genara of araneid spiders known
from the Americas. These genera hold approximately fifteen hundred
species found in the Americas. The key to females uses mostly artificial
character; the key to males uses diagnostic characters. There are
four new synonyms and two new placements.
FOUR
NEW SPECIES OF THE GENUS LEPTONETA (ARANEAE, LEPTONETIDAE)
FROM TAIWAN
by Ming-Sheng
Zhu: College of Life Sciences, Hebei University, Baoding
071002, China
I-Mn
Tso: Department of Biology, Tunghai University, Taichung
407, Taiwan Division of Zoology, National Museum of Natural Science,
Taichung 404, Taiwan
ABSTRACT.
The new species Leptoneta changlini, L. huisunica, L. nigrabdomina
and L. taiwanensis are described and illustrated from Taiwan,
and the natural history of L. changlini and L. huisunuca
is described. These species are only known from male specimens.
REPRODUCTIVE
BIOLOGY OF URUGUAYAN THERAPHOSIDS (ARANEAE, MYGALOMORPHAE)
by Fernando
G. Costa: Laboratorio de Etología, Ecología
y Evolución, IIBCE, Av. Italia 3318, Montevideo, Uruguay.
E-mail:fgc@iibce.edu.uy
Fernando
Pérez-Miles: Sección Entomología,
Facultad de Ciencias, Iguá 4225, 11400 Montevideo, Uruguay
ABSTRACT.
We describe the reproductive biology of seven theraphosid species
from Uruguay. Species under study include the Ischnocolinae Oligoxystre
argentinense and the Theraphosinae Acanthoscurria suina,
Eupalaestrus weijenberghi, Grammostola iheringi, G. mollicoma, Homoeomma
uruguayense and Plesiopelma longisternale. Sexual activity
periods were estimated from the occurrence of walking adult males.
Sperm induction was described from laboratory studies. Courtship
and mating were also described from both field and laboratory observations.
Oviposition and egg sac care were studied in the field and laboratory.
Two complete cycles including female molting and copulation, egg
sac construction and emergence of juveniles were reported for the
first time in E. weijenberghi and O. argentinense.
The life span of adults was studied and the whole life span was
estimated up to 30 years in female G. mollicoma, which seems
to be a record for spiders. A comprehensive review of literature
on theraphosid reproductive biology was undertaken. In the discussion,
we consider the lengthy and costly sperm induction, the widespread
display by body vibrations of courting males, multiple mating strategies
of both sexes and the absence of sexual cannibalism.
COURTSHIP
AND SPERM TRANSFER IN THE WHIP SPIDER PHRYNUS GERVAISII (AMBLYPYGI,
PHRYNIDAE): A COMPLEMENT TO WEYGOLDT´S 1977 PAPER
by Alfredo
V. Peretti: CONICET- Cátedra de Diversidad Animal
I, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad
Nacional de Córdoba. Avda. Vélez Sarsfield 299 (5000),
Córdoba, Argentina. E-mail: aperetti@com.uncor.edu
ABSTRACT. The
aim of this study was to provide descriptive and quantitative data
regarding behaviors involved in courtship and in sperm transfer
of the whip spider Phrynus gervaisii (Pocock 1894) in order
to complete the previous description for this same species given
by P. Weygoldt. The specimens were captured in anthills of Paraponera
clavata, on Barro Colorado Island, Panama. Ten courtship and
five sperm transfer sequences were recorded. Four out of five mating
sequences with sperm transfer ocurred between adults with similar
body size and in the other case the female was smaller than the
male. Sexual interactions did not occur between very small adults.
Two male behavior patterns that have not been reported were observed
during the initial stage of courtship: "pedipalp rubbing"
and "female operculum rubbing". Contrary to Weygoldt´s
description, in this study the female never performed "shaking"
movements with her antenniform legs. It was observed that the two
distal horn-like extensions of the spermatophore facilitate the
female´s movements during the sperm transfer. The distal part
of the spermatophore stalk provides a suspension area when the female
rests on those horns. It was verified that the female can move the
claw-like sclerites of the gonopods in all directions. The male
executed copulatory courtship and successfully transferred sperm
in five analyzed sequences. The female did not pick up the sperm
packages when copulatory courtship was not performed. Males that
lacked one antenniform leg were able to mate, however they had to
perform vibrations more intensely with their non-injured leg for
a longer duration. The data are compared with those previously obtained
in other whip spiders. Some functional characteristics of the spermatophore
and female genitalia of P. gervaisii are also discussed.
RESUMEN. El
objetivo de este trabajo es aportar datos descriptivos y cuantitativos
sobre patrones de comportamiento que ocurren durante el cortejo
y transferencia espermática del amblipígido Phrynus
gervaisii (Pocock 1894) con la finalidad de completar la descripción
previa de P. Weygoldt para esta misma especie. Los especímenes
fueron capturados en hormigeros de Paraponera clavata, en
la Isla de Barro Colorado, Panamá. Se registraron 10 secuencias
de cortejo y cinco de transferencia espermática. Cuatro de
las cinco secuencias de apareamiento con transferencia espermática
completa ocurrieron entre adultos de tamaño corporal similar
mientras que en el otro caso la hembra fue más pequeña
que el macho. No se produjeron interacciones sexuales entre adultos
muy pequeños. Durante la etapa inicial del cortejo fueron
observados dos patrones de comportamiento masculinos que no habían
sido citados con anterioridad: "roces de pedipalpos" y
"roces al opérculo genital femenino". Al contrario
de la descripción de Weygoldt, en el presente estudio la
hembra nunca realizó movimientos de "latigueo"
con sus patas anteniformes. Se observó que las dos expansiones
distales con forma de cuerno del espermatóforo facilitan
los movimientos de la hembra durante la transferencia espermática.
La parte distal del tallo del espermatóforo ofrece un área
de suspensión cuando la hembra se apoya sobre estos cuernos.
Se verificó que la hembra puede mover los escleritos en form
de uña de sus gonópodos hacia todas las direcciones.
El macho efectuó cortejo copulatorio en cinco secuencias
analizadas, en ellas la transferencia espermática fue existosa.
Por el contrario, la hembra no recogió los paquetes espermáticos
cuando no existió cortejo copulatorio. Los machos que carecían
de una pata anteniforme también fueron capaces de aparear.
Sin embargo, ellos tuvieron que realizar más intensamente
las vibraciones con sus patas no dañadas, y sobre todo durante
un tiempo más prolongado para evitar que la hembra se alejara.
Se comparan los datos aquí registrados con aquellos previamente
obtenidos en otros amblipígidos. Se discuten algunas características
funcionales del espermatóforo y genitalia femenina de P.
gervaisii.
ORIENTATION
AND MOVEMENT OF WOLF SPIDERS PARDOSA LAPIDICINA (ARANEAE, LYCOSIDAE)
IN THE INTERTIDAL ZONE
by Douglass
H. Morse: Department of Ecology
and Evolutionary Biology, Box G-W, Brown University, Providence,
RI 02912 USA. Email: d_morse@brown.edu
ABSTRACT.
Wolf spiders, Pardosa lapidicina Emerton 1885, occupy cobble
beaches along the tide line about Narragansett Bay, Rhode Island,
USA, and move back and forth on the beaches with the tides. I compared
the orientation and movement in the low intertidal of three groups
with normal access to the entire intertidal zone and a group from
the high intertidal prevented from using the low intertidal by a
barrier of dense salt-marsh cordgrass Spartina alterniflora.
They included a group captured in the high intertidal (High), one
captured in the low intertidal (Low), one from the low intertidal
but not captured (Observed), and one captured behind cordgrass (Cordgrass)
. The High group moved farther and more unidirectionally than the
others, and the Cordgrass group exhibited the most variable orientation
of the manipulated spiders. All groups exhibited a roughly southwesterly
orientation from the release site. The Low and Observed groups moved
shorter distances than the others, and High individuals appeared
more strongly inclined to leave the low intertidal than individuals
initially positioned there (Low, Observed). Thus, experience likely
played a role in the orientation and movement of the spiders.
SHORT
COMMUNICATION:
A NEW
OGRE-FACED SPIDER (DEINOPIS) FROM THE GAOLIGONG MOUNTAINS,
YUNNAN, CHINA (ARANEAE, DEINOPIDAE)
by Chang-Min
Yin: College of Life Science, Hunan Normal University,
Changsha, Hunan Province 410081, P. R. China
Charles E. Griswold: California
Academy of Sciences, San Francisco, California 94118, USA
Heng-Mei Yan: College of Life
Science, Hunan Normal University, Changsha, Hunan Province 410081,
P. R. China
ABSTRACT.
The present paper describes Deinopis liukuensis new species,
from the Gaoligong Mountains, Yunnan Province, China. This is the
first mature deinopid described from China.
SHORT
COMMUNICATION:
FEEDING
IN MAXCHERNES IPORANGAE (PSEUDOSCORPIONES, CHERNETIDAE) IN
CAPTIVITY
by Renata
de Andrade and Pedro Gnaspini:
Departamento de Zoologia, Instituto de Biociências, Universidade
de São Paulo, Caixa Postal 11461, 05422-970 São Paulo,
SP, Brazil. E-mail: gnaspini@ib.usp.br
ABSTRACT.
The feeding behavior of the cave pseudoscorpion Maxchernes iporangae Mahnert & Andrade 1998 was studied in the laboratory. We also
investigated aspects such as preference and frequency. Nymphs are
more active in prey capture. Cannibalism is uncommon. The frequency
of feeding of adults was about once a month, with an increased rate
for females during the reproductive period.
SHORT
COMMUNICATION:
NOTES
ON THE NATURAL HISTORY AND HUNTING BEHAVIOR OF AN ANT EATING ZODARIID
SPIDER (ARACHNIDA, ARANEAE) IN COLORADO
by Paula
E. Cushing: Department of Zoology, Denver Museum of Nature & Science, 2001 Colorado Blvd., Denver, CO 80205-5798 USA
Richard G. Santangelo: 3803 Holly
Lane, Raleigh, North Carolina 27612 USA
ABSTRACT.
The ant hunting behavior of Zodarion rubidum (Araneae, Zodariidae)
is described from specimens collected in Colorado, USA. Like other
members of this genus, Z. rubidum constructs igloo-shaped
stone retreats under rocks and feeds on ants. Details of the prey
capture behavior are provided including initial and subsequent reactions
of ants to the bites of Z. rubidum and data on the time it
takes for ants to become completely paralyzed as a result of the
bites.
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