20th International Congress of Arachnology

133 / 232

We conducted an ecological study in a resurgence of the
Po Plain (Northern Italy, Province of Vercelli) hosting a
relatively rich population of A. aquatica, aiming at iden-
tifying the ecological factors driving its presence/absence
at the micro-habitat level. By means of a specific sampling
methodology, we acquired distributional data of the spiders
in the study area and monitored physical-chemical and
habitat structure parameters at each plot. We analyzed the
data through Bernoulli Generalized Linear Models (GLM).
Results pointed out a significant positive effect of the
presence of aquatic vegetation in the plot. In addition, the
presence of the water spider was significantly associated
with areas of the resurgence characterized simultaneously
by high prey availability and low density of predators.
Keywords: water spider, Po Plain, wetlands, binomial
regressions
Oral presentation
Palaearctic and Nearctic versus Holarctic:
how do spiders fit into zoogeographic
regions?
Yuri M. Marusik
Institute for Biological Problems of the North, Porto-
vaya Street 18, Magadan 685000, Russia
There are two alternative opinions about the biogeo-
graphic subdivision of the Northern Hemisphere. Many
biogeographers recognize the Holarctic realm with
two main subdivisions: the Palaearctic and the Nearc-
tic, while some consider Palaearctic and Nearctic as
separate biogeographic realms. In this presentation, I
address the distribution of spider taxa in the northern
Eurasia, northern Africa and North America and show
how it corroborates different biogeographical schemes.
A special emphasis will be given to the spiders distrib-
uted in the Boreal and tundra zones. Spiders of these
zones are much better studied in both the Western and
Eastern hemispheres than the spiders of other ecologi-
cal zones.
Keywords: zoogeography, Holarctic, Palaearctic, Nearc-
tic, boreal zone, tundra zone
Poster presentation
Spiders of the Pardosa laura-group
(Araneae: Lycosidae) in the Far East Russia
Yuri M. Marusik1 , Mikhail M. Omelko2,3, Anatoly A.
Komisarenko2
1Institute for Biological Problems of the North, Portovaya
Street 18, Magadan 685000, Russia; 2Far Eastern
Federal University, Sukhanova 8, Vladivostok 690950,
Russia; 3Gornotaezhnaya Station FEB RAS, Gornotaezh-
noe Vil., Ussuriyski Dist., Primorski krai 692533, Russia
Pardosa laura-group is a group of small-sized lycosids
occurring in Far East Asia ( Japan, Korea, China and
Russia). It encompasses six species by now: P. baosha-
nensis Wang & Qiu, 1991, P. graminea Tanaka, 1985, P.
hokkaido Tanaka and Suwa, 1986, P. laevitarsis Tanaka
and Suwa, 1986; P. laura Karsch, 1879 and P. yamanoi
Tanaka and Suwa, 1986. Study of spiders from Primorskii
Province of Russia as well as from Japan reveals that
two species (P. agraria Tanaka, 1985 and P. diversa
Tanaka, 1985) are valid and should be removed from
synonymy with P. laura. The latter species most prob-
ably is an endemic of the Japanese islands and its records
from Korea, China and Russia actually refer to P. agraria .
One species (P. graminea) is found to be new for Russia.
Finding of P. hokkaido from Bolshekhekhtsirsky Nature
Reserve in Russia is doubtful and its status remains
unclear. Besides the structure of males and females copu-
latory organs, the following somatic characters were found
to be useful for distinguishing species: sternum coloration,
leg I coloration, leg I spination, male palp coloration, pres-
ence/absence of carapace lateral bands, presence/absence
of white hairs at eye area, and number of cymbial claws.
Keywords: wolf spiders, Asia, Pardosinae
Oral presentation
Phylogeography and diversification of
chthonid pseudoscorpions in the Pacific
Northwest, USA
Susan E. Masta, Brandi Welch, James Carroll
Department of Biology Portland State University
Portland, OR 97207, USA;
132 DENVER MUSEUM OF NATURE & SCIENCE REPORTS | No. 3, July 2, 2016
Cushing