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These cases seem to indicate occurrence of a chain process
that generates rapid increase of the chromosome number.
Keywords: Opiliones, chromosomal evolution, geo-
graphic variation, speciation, hybrid zones
Poster presentation
Mass findings of an uncommon spider
Pro-
didomus rufus
from Komon-jo: Time capsule
of indoor spider fauna from Edo Period
Nobuo Tsurusaki
1
, Hiromi Fukagawa
2,3
1
Laboratory of Biology, Faculty of Regional Sciences,
Tottori University, Tottori, 680-8551, Japan;
2
Tottori
Prefectural Museum, Tottori, 680-0011, Japan;
3
Shima-
nouchi 1-20-11, Chuo-ku, Osaka City, 542-0082, Japan
ntsuru@rs.tottori-u.ac.jpA conspicuous amount of antique documents (= Komon-
jo) that had been housed in a warehouse in Nakajima’s
residence in Iwami-cho, in Tottori Prefecture, Japan, were
transferred to Tottori Prefectural Museum in 2008. The
Nakajima family had served as a village headman of
Tottori han (clan) in the Edo Period (1603–1868). During
the process of the transfer, all the dried dead bodies and
exuviae of insects and spiders that had attached to the
documents were collected for the purpose of pest control.
Identification of a total of 151 examples of spiders (33
bodies, 118 exuvieae) revealed 18 spider species. Of these,
most abundantly found was
Prodidomus rufus
Hentz
1847 (Prodidomidae) that comprises 2 males, 3 females,
and 45 exuviae. This was followed by
Loxosceles rufescens
(Dufour 1820) (Sicariidae: 5 juveniles + 40 exuviae)
and Gnaphosidae gen. & sp. (probably
Trachyzelotes
jaxartensis
(Kroneberg 1875 or
Urozelotes rusticus
(L.
Koch 1872 (1 juvenile + 16 exuviae).
Prodidomus rufus
is a very rare species, though distribution of the species is
worldwide. Only 5 collecting records (latest is in 1991 are
available in Japan after the first finding in Japan from
inside house in Ozu City, Shikoku in 1913. The specimens
also included
Dictis striatipes
L. Koch 1872 (Scytodidae)
which lacks recent records in Japan and
Oecobius navus
Blackwall 1859 (Oecobiidae) which has never been
recorded from the Sea of Japan side of Japan. The results
suggests that indoor spider fauna in the Edo Period is quite
different from the one today. Beetles that feed dry provi-
sions or wooden building materials such as deathwatch
beetles (Anobiidae) were the most abundant in the samples
collected. Prevalence of inexpensive bug repellents such as
camphor balls might cause the change in the communities
of house insect pests and house spiders as their predators.
Keywords: indoor spider fauna, historical faunal
change, antique documents,
Prodidomus rufus
, rare
species
Student - poster presentation
Spatio-temporal dynamics of generalist
predators (
Tetragnatha
spider) and dipteras
in environmentally friendly paddy fields
*Masaru H. Tsutsui
1
, Yuki G. Baba
2
, Koichi Tanaka
2
,
Tadashi Miyashita
1
1
Laboratory of Biodiversity Science, School of Agricul-
ture and Life Sciences, University of Tokyo, 1-1-1 Yayoi,
Tokyo 113-8656, Japan;
2
Biodiversity Division, Institute
for Agro-Environmental Sciences, NARO. 3-1-3 Kan-
nondai Tsukuba-shi, Ibaraki Pref, 305-8604, Japan
masaru-t@es.a.u-tokyo.ac.jpSpiders have long been known as biological control
agents in agricultural landscapes. This function is
thought to be of particular importance for environ-
mentally friendly farming (EFF) where agrochemical
application is limited. For reducing pest damage in EFF,
it is crucial to identify environmental conditions that
increase spider abundance. In this study, we focused on
spatio-temporal dynamics of
Tetragnatha
spiders that
heavily rely on wetland habitats including paddy fields. As
paddy fields are probably unsuitable habitats for spiders
in non-crop (non-flooding) season, nearby ditches are
likely to be alternative habitats for these spiders. More-
over, dipterans that emerge in large numbers from paddy
fields are expected to be important bottom-up agents
maintaining spider populations. Field surveys were con-
ducted in 15 paddy fields under conventional fields and
18 paddy fields under EFF during three seasons in Tochigi
Prefecture, central Japan. The results showed that
Tetrag-
natha
spiders were more abundant in paddy fields than
in ditches during the growing season, but this tendency
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DENVER MUSEUM OF NATURE & SCIENCE
REPORTS
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No. 3, July 2, 2016
Cushing