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SPIDERS
OF THE GENUS TETRAGNATHA (ARANEAE, TETRAGNATHIDAE) IN THE
SOCIETY ISLANDS
by
R.G. Gillespie:
Division of Insect Biology, University of California Berkeley, 201Wellman
Hall, Berkeley, CA 94720-3112, USA.
ABSTRACT.
This study revises the status of knowledge of the spider fauna of
the Society Islands. Until recently, the literature on the spider
fauna in these islands has suggested that the genus Tetragnatha
in particular is noticeable for its poor representation in comparison
with the large radiation in the Hawaiian Islands. Expeditions were
conducted to determine whether this genus is indeed poorly represented
in the islands as the literature would suggest. The results indicate
that the islands actually have a number of endemic Tetragnatha,
although there is no noticeable adaptive radiation as is seen in
the Hawaiian Islands. Results of field expeditions in 1999–2000
and studies on historical collections have shown that: (1) Reports
of the cosmotropical species T. mandibulata in the Society
Islands are probably not valid; these were misidentifications for
either T. macilenta or T. nitens. (2) Tetragnatha
huahinensis is a synonym of T. macilenta. (3) There are
three new species of Tetragnatha, all of which are described
here and appear to be endemic to middle and high elevations of the
Society Islands (from Tahiti, Moorea and Raiatea). In total, there
are six species of Tetragnatha in the Society Islands: in
addition to the three endemic species there is one possibly indigenous
(T. macilenta), and two that may be of more recent introduction
(T. nitens and T. maxillosa).
Keywords: Tahiti,
Moorea, Pacific, descriptions, biogeography
PHYLOGENETIC
ANALYSIS OF SANTINEZIA WITH DESCRIPTION OF FIVE NEW SPECIES
(OPILIONES, LANIATORES, CRANAIDAE)
by
Ricardo Pinto-da-Rocha: Departamento de Zoologia,
Instituto de Biocièncias, Universidade de São Paulo,
Rua do Matão, Travessa 14, n. 321, 05508–900, São
Paulo, SP, Brazil. E-mail: ricrocha@usp.br
and Adriano B. Kury:
Departamento de Invertebrados, Museu Nacional, Quinta da Boa Vista,
São Cristóvão, 20.940-040, Rio de Janeiro,
RJ, Brazil
ABSTRACT.
The taxonomic status of all species of Santinezia Roewer
1923 is defined, and a catalogue is provided. Santinezia lucifer,
S. gracilis, S. onorei (all from Ecuador), S. furva (from
Colombia and Venezuela) and S. hermosa (from Peru) are newly
described. Santinezia biordi González-Sponga 1991
is newly considered as a junior subjective synonym of S. serratotibialis
Roewer 1932. Santinezia albilineata Roewer 1932, Goniosoma
pavani Muñoz-Cuevas 1972, S. benedictoi Soares
& Avram 1981, S. decui Avram 1987, S. orghidani
Avram 1987 and S. francourbani Avram 1987 are newly considered
as junior subjective synonyms of Inezia curvipes Roewer 1916.
Nieblia Roewer 1925, Chondrocranaus Roewer 1932, Macuchicola
Mello-Leitão 1943 and Carvalholeptes H. Soares 1970
are newly considered as junior subjective synonyms of Santinezia.
Nieblia camposi Mello-Leitão 1942 is transferred to
Spinicranaus Roewer 1913. Santinezia albimedialis
Goodnight & Goodnight 1943 is transferred to Phareicranaus
Roewer 1913. Nieblia magna Roewer 1932 is transferred to
Neocranaus Roewer 1913. Santinezia micheneri Goodnight
& Goodnight 1947 is newly considered as a junior subjective
synonym of Phareicranaus ornatus Roewer 1932. A character
survey is done including newly discovered characters of genital
morphology, patterns of colored marks of dorsal scutum and armature
of male leg IV. A phylogenetic analysis of the species of the genus
for which males are known is provided allowing the definition of
three new species groups. Comparative descriptions are given of
the penial morphology of one species of Ventrivomer, one
species of Phareicranaus and eight species of Santinezia.
Distribution maps for all species of Santinezia are given.
The type locality of S. serratotibialis Roewer 1932 is corrected
from Trinidad (Bolivia) to Trinidad (Trinidad & Tobago).
Keywords: Laniatores,
Neotropics, harvestmen, phalangids, taxonomy
ON THE USE
OF AMPULLATE GLAND SILKS BY WOLF SPIDERS (ARANEAE, LYCOSIDAE) FOR
ATTACHING THE EGG SAC TO THE SPINNERETS AND A PROPOSAL FOR DEFINING
NUBBINS AND TARTIPORES
by Mark
A. Townley and Edward K. Tillinghast: Department of Zoology,
Rudman Hall, University of New Hampshire, Durham, New Hampshire
03824 USA. E-mail: mtownley@cisunix.unh.edu
ABSTRACT.
The means by which female wolf spiders attach an egg sac to their
spinnerets was investigated using scanning electron microscopy.
In four Pardosa species, we observed that silk fibers emerging
from ampullate gland spigots had been affixed to the surface of
the egg sac. More specifically, primary (1°) and secondary (2°)
major ampullate (MaA) glands and 1° and 2° minor ampullate
(MiA) glands all contributed fibers for this purpose. The diameters
of the 2° MaA and 2° MiA fibers were greater than those
of the 1° MaA and 1° MiA fibers and, correspondingly, the
widths of the 2° ampullate spigots were clearly greater than
those of the 1° ampullate spigots. Larger 2° ampullate spigots
were also observed in adult females of species from three other
lycosid genera. Thus, 2° ampullate glands, which in araneoids
function only in juveniles during proecdysis, are not only functional
in adult female lycosids (and adult females of several other families),
but they appear to play a greater role than the 1° ampullate
glands in egg sac attachment. Observations made on the 1° and
2° ampullate spigots of adult females from species belonging
to several other families are also presented. Cuticular structures
referred to as nubbins and tartipores are present in some spinning
fields on spinnerets. A proposal is made for defining these terms
by a criterion, namely their different origins, which differs from
that applied previously.
Keywords: Ampullate
silk gland, Pardosa, Hogna, Trochosa, Lycosoidea
WHEN TO QUIT?
ESTIMATING SPIDER SPECIES RICHNESS IN A NORTHERN EUROPEAN DECIDUOUS
FOREST
by Nikolaj Scharff (1), Jonathan A. Coddington (2), Charles E. Griswold
(3), Gustavo Hormiga (4) and Per de Place Bjørn (1)
(1) Dept. Entomology,
Zoological Museum, University of Copenhagen, Universitetsparken
15, DK-2100 Copenhagen, Denmark
(2) Dept. Systematic Biology, National Museum of Natural History
NHB 105, Smithsonian Institution, Washington DC, 20013-7012, USA
(3) Dept. Entomology,California Academy of Sciences, Golden Gate
Park, San Francisco, CA 94118, USA
(4) Dept. Biology, George Washington University, Washington DC,
20052, USA
Address correspondance
to: Nikolaj Scharff (145 35321107, fax 145 35321010; E-mail:
nscharff@zmuc.ku.dk
ABSTRACT.
Terrestrial arthropod surveys and inventories frequently suffer
from undersampling bias; common species are over-represented and
rare species may be missed entirely. This study compared a rapid
(3 days) and intense inventory of spiders from one hectare of a
mature beech forest (Fagus sylvaticus) in Hestehaven, Denmark,
comprising 8,710 adult spiders of 66 species to a previous, much
more thorough, bi-weekly survey of two years duration from the same
site that comprised 42,273 spiders (adult and juvenile) of 141 species.
Non-parametric species richness estimators were used to assess the
degree of undersampling bias in various data partitions. The current
study used five experienced, four novice collectors, and five semi-quantitative
collecting methods. Method and time of day strongly affected numbers
of species and adults per sample. Collector experience affected
numbers of species but not numbers of adults per sample. Despite
the intensive collecting, number of adults per sample did not decrease
over the course of the study. At the end of the sampling, 31 species
were still rare in the sample (singletons or doubletons). Non-parametric
richness estimators suggest that the actual richness of adult spiders
in the study plot at this time of year and susceptible to the methods
used was about 80 species. Species turnover between the two surveys
(ca 23 years) was remarkably small: the two lists were 92% identical.
The baseline study suggests that the rarity of 12 of the 31 rare
species was artifactual (10 due to phenology, one to method, another
to spatial edge effects). The rarity of the remainder is unexplained
and by default is interpreted as undersampling bias.
Keywords: Biodiversity,
Araneae, inventory, species richness estimation, singletons, beech
forest, Denmark
OBSERVATIONS
OF THEOTIMA MINUTISSIMUS (ARANEAE, OCHYROCERATIDAE), A PARTHENOGENETIC
SPIDER
by: Robert
L. Edwards: Box 505, Woods Hole, Massachusetts 02543,
USA,
Eric H. Edwards: 45 Canterbury Lane, East Falmouth, Massachusetts
02536, USA,
and Annabel D. Edwards: Massachusetts
General Hospital, Department of Anesthesia, Boston, Massachusetts
02114, USA.
ABSTRACT.
It has been suggested by several authorities that at least one species
of spider of the genus Theotima, family Ochyroceratidae,
occurring in tropical regions in South Africa, the Caribbean and
Asia may be parthenogenetic. Theotima minutissimus is particularly
abundant in the tropical rainforest leaf litter on El Yunque, Puerto
Rico. While many hundreds of specimens have been collected over
many years, none has been a male. To examine the possibility that
this small species, 6 0.9 mm body length, is parthenogenetic, live
specimens were collected and maintained in the laboratory. A second
generation spiderling, raised separately, produced viable progeny.
Keywords: Parthenogenesis,
spider, tropical rainforest, leaf litter, Wolbachia
THE
EFFECTS OF SIZE, SEX, AND REPRODUCTIVE CONDITION ON THERMAL AND
DESICCATION STRESS IN A RIPARIAN SPIDER (PIRATA SEDENTARIUS,
ARANEAE, LYCOSIDAE)
by: Jill
DeVito and Daniel R. Formanowicz, Jr.: Biology Department,
Box 19498 University of Texas at Arlington, Arlington, TX 76019.
E-mail: devitoj@muohio.edu
ABSTRACT.
Within a species, physiological tolerances and thermoregulatory
behaviors may vary among ontogenetic stages or between sexes. Such
different tolerances can strongly affect the ecology and life history
of a species. In a laboratory study, we tested the hypothesis that
Pirata sedentarius Montgomery 1904 is differentially susceptible
to thermal/desiccation stress by size and sex. As predicted, male
adults were more susceptible to thermal/desiccation stress than
females. Unexpectedly, however, juvenile spiders survived longer
under thermal/desiccation stress than adults. Furthermore, female
adults without egg sacs displayed a trend toward higher thermal/desiccation
tolerance than females carrying egg sacs. These results suggest
that for P. sedentarius, microhabitat preferences and/or
thermoregulatory behaviors may change over the course of development,
and may vary between sexes and between females with and without
egg sacs.
Keywords: Microhabitat
partitioning, ontogenetic changes in physiological tolerances
CLUTCH SIZE
AND OFFSPRING SIZE IN THE WOLF SPIDER PIRATA SEDENTARIUS
(ARANEAE, LYCOSIDAE)
by: Christopher
A. Brown, Bridget M. Sanford and Rebekah R. Swerdon:
Dept. of Biology, State University of New York College at Fredonia,
Fredonia, New York 14063 USA
ABSTRACT.
Wolf spiders in the genus Pirata are common, often locally
abundant, inhabitants of many moist or mesic habitats. However,
relatively little is known about the ecology or life history of
these spiders. Here we present data collected during 2000–2001
on female size, offspring size and clutch size for two populations
(Ball Gulf, Hardscrabble Creek) of Pirata sedentarius from
western New York. In both populations, mean offspring size was less
variable than was female size, clutch size or total clutch mass.
At Ball Gulf, 67% of females produced two egg sacs and 48% produced
three sacs. Clutch size declined across the egg sac sequence for
all females. Female size, measured as cephalothorax length, was
uncorrelated with mean offspring size in all cases. However, larger
females produced larger and heavier clutches during 2001 for both
populations; female size was uncorrelated with these variables during
2000 at Hardscrabble Creek. Larger clutches from both populations
contained more offspring, and larger clutches contained smaller
offspring at Hardscrabble Creek in 2001. We found a significant
offspring size-number trade-off at Ball Gulf, while at Hardscrabble
Creek this trade-off was marginally significant in 2001 and non-significant
in 2000.
Keywords: Lycosidae,
Pirata, life history, clutch size, offspring size
NATURAL HISTORY
OF MISUMENOPS ARGENTEUS (THOMISIDAE): SEASONALITY AND DIET
ON TRICHOGONIOPSIS ADENANTHA (ASTERACEAE)
by: Gustavo
Quevedo Romero and João Vasconcellos-Neto: Departamento
de Zoologia, Universidade Estadual de Campinas (UNICAMP), C.P. 6109,
Campinas, SP, 13083-970, Brazil, E-mail: gqromero@unicamp.br
ABSTRACT.
Seasonal fluctuations, phenology and diet of Misumenops argenteus
(Araneae, Thomisidae) on Trichogoniopsis adenantha (Asteraceae)
were investigated in the Serra do Japi, southeastern Brazil, over
a 2 year period. This spider population increased at the beginning
of the rainy season, reaching a peak in March, and decreased in
May, reaching its lowest density in the cold/dry season. In the
rainy season (December–May), most of the individuals were in
the young or juvenile phase (3rd–6th instars). The spiders
reached adulthood between the end of the cold/dry season and the
beginning of the hot/rainy season. Analysis of temporal displacement
(with up to a 3 month delay) detected a one month delay between
the blooming period of T. adenantha and the beginning of
the rainy season. The number of arthropods (potential prey of
M. argenteus) on the plants increased concomitantly with the
increase in the number of reproductive branches. The M. argenteus
population also increased numerically 2 months after the rise in
arthropod density. These results indicate that the spiders require
time to respond to changes in environmental conditions. Of the 595
spiders examined, 76 (12.8%) had prey. Prey items included arthropods
belonging to several guilds, but spiders showed a preference for
wingless prey or prey that remained on the branches for longer periods
of time.
Keywords: Prey,
seasonal distribution, plant-animal interactions
SHORT
COMMUNICATION
EFFECTS
OF MATERNAL BODY SIZE ON CLUTCH SIZE AND EGG WEIGHT IN A PHOLCID
SPIDER (HOLOCNEMUS PLUCHEI)
by: Christa
D. Skow: Neuroscience and Behavior Program, Tobin Hall,
University of Massachusetts, Amherst, Massachusetts 01002 USA
and Elizabeth
M. Jakob: Department of Psychology, Tobin Hall, University
of Massachusetts, Amherst, Massachusetts 01002 USA
ABSTRACT.
The pholcid spider Holocnemus pluchei (Scopoli 1763) competes
for food with conspecifics, and spiders reared on high food levels
are generally larger. In this study, we examined whether larger
female body size (as estimated by tibia-patella length) translated
into increased reproductive success in the form of increased clutch
size, clutch weight, and average egg weight. Larger spiders had
more eggs and thus heavier clutches, but there was no relationship
between maternal size and average egg weight. We also looked for
a tradeoff between average egg weight and egg number, and we found
a weak relationship in which average egg weight was highest for
intermediate-sized clutches. Larger female body size thus translates
into increased reproductive success in terms of egg number and clutch
weight, but not weight of individual eggs.
Keywords: Pholcidae,
fecundity, egg size, clutch size, fitness
SHORT
COMMUNICATION
IS
THE HAIRY GROOVE IN THE GIBBOSUS MALE MORPH OF OEDOTHORAX GIBBOSUS
(BLACKWALL 1841) A NUPTIAL FEEDING DEVICE?
by: Danny
Vanacker, Liesbeth Maes, Sylvia Pardo, Frederik Hendrickx:
Laboratory of Animal Ecology, Zoogeography and Nature Conservation,
Ghent University, Ledeganckstraat 35, 9000 Ghent, Belgium, E-mail:
Danny.Vanacker@rug.ac.be
and: Jean-Pierre Maelfait:
Laboratory of Animal Ecology, Zoogeography and Nature Conservation,
Ledeganckstraat 35, 9000 Ghent, Belgium; Institute of Nature Conservation,
Kliniekstraat 25, 1070 Brussels, Belgium
ABSTRACT.
Oedothorax
gibbosus (Blackwall 1841) (Erigoninae, Linyphiidae, Araneae)
is a dwarf spider characterized by dimorphic males. There is a ‘‘gibbosus’’
male morph characterized by a hunch on the posterior third of the
carapace, anterior to which is a hairy groove, and a ‘‘tuberosus’’ morph without these features. We observed several gustatorial courtship
interactions by a gibbosus male morph and a conspecific female as
well as a by a gibbosus male and a male of the closely related species,
Oedothorax fuscus (Blackwall 1834). These interactions suggest
that the hairy groove in the gibbosus male morph is a nuptial feeding
device possibly under the influence of sexual selection. The interspecific
interactions can possibly be interpreted as ‘robbings’
of the nuptial feeding. The interspecific interactions indicate
that the cephalic structure of gibbosus probably does not function
as a ‘‘lock and key’’ mechanism.
Keywords: Oedothorax
gibbosus, Oedothorax fuscus, interspecific courtship,
nuptial feeding, gustatorial courtship
ERRATUM:
ERRATUM In Brookhart & Cushing (2002, Journal of Arachnology 39:84–97),
the type locality for the male holotype of Eremobates gerbae was erroneously stated as: Rincon Mountains, Cochise County, Arizona,
collected August–8 October 1995. The Rincon Mountains are in
Pima county not Cochise County and the holotype was collected 30
August 1994. The female allotype of E. gerbae was also collected
in the Rincon Mountains in Pima County and was collected on 8 October
1995.
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