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84
DENVER MUSEUM OF NATURE & SCIENCE
REPORTS
|
No. 3, July 2, 2016
Cushing
status (well-fed or poorly fed); behavioural type (bold or
shy) and maturity level (juvenile or adult). In this para-
digm, we eliminated visual or tactile cues, and so isolate
the effect of volatiles. To characterize differences between
chemical cues from different stimulus females, we also col-
lected headspace samples (air surrounding the stimulus)
of each spider stimulus group (N=15) and compared them
with gas chromatography coupled with mass spectroscopy
(GCMS). We found that
L. hesperus
avoid subadult and
adult congeners, while
L. hasselti
reacted only to adult
ones. Both species also responded differentially to well-
fed compared to food-restricted females, but there was no
evidence the females react to the behavioral type of other
females. Future work will examine female web establish-
ment patterns and examine how these discrimination trials
relate to free-ranging behaviour.
Keywords: chemical communication, female-female-
interaction, behavioral biology
Student - poster presentation
Fact or myth: do natural substances repel
invasive spiders?
*Andreas Fischer
1
, Manfred Ayasse
1
, Maydianne Andrade
2
1
Institute of Evolutionary Ecology and Conservation
Genomics University of Ulm, Germany;
2
Integrative
Behaviour & Neuroscience Group, University of
Toronto Scarborough, Canada
andreas-1.fischer@uni-ulm.deArachnophobia is one of the most common irrational fears
of the general public and some people invest considerable
money and effort to avoid spiders. We searched the internet
and identified the three most popular natural substances
recommended as spider repellents (chestnuts, peppermint
oil and lemon zest oil). We tested whether these substances
were avoided by adult females of two invasive spider
species:
Araneus diadematus
(European, invasive in North
America) and
Latrodectus geometricus
(cosmopolitan
distribution). We used a dual-choice paradigm in which
free-walking females were released in one arm of a glass
y-tube apparatus connected to an air pump. We tested the
response of free-walking females to airborne chemicals
released from whole chestnut, peppermint oil or lemon
oil, with each stimulus compared to an empty control. We
found that neither species discriminated lemon oil from
controls, but both
A. diadematus
and
L. geometricus
avoid chestnut and peppermint oil. Thus, we have verified
two of the three most popular spider repellent myths. We
complement this with an analysis of the ‘headspace’ of each
substance using gas chromatographic detection coupled
with mass spectroscopy to identify the airborne chemicals
that might trigger this response and could be the basis of
a synthetic repellent. Although
A. diadematus
is little
more than a nuisance in locations where it is invasive,
L.
geometricus
is neurotoxic and anthropophilic, so an effec-
tive repellent would be beneficial. Future work will focus on
why the identified chemicals are repellent to female spiders,
and the phylogenetic distribution of this response.
Keywords: pest control, repellence, behavioral ecology
Poster presentation
Sicariidae family (Araneae) in Colombia,
new species and first records of
Sicarius
Eduardo D. Flórez
1
, Miguel E. Gutiérrez
2
, Franklyn Cala
1
,
Ingi Agnarsson
3
, Cecilia V. Cantor
4
1
Instituto de Ciencias Naturales, Universidad Nacional
de Colombia, Bogotá, Colombia;
2
Facultad de Ciencias
Básicas, Universidad de la Guajira, Colombia;
3
Department of Biology, University of Vermont, Bur-
lington VT, USA;
4
Grupo Colombiano de Aracnología,
Bogotá, Colombia;
aeflorezd@unal.edu.coThe genus
Loxosceles
Heineken & Lowe, 1832, commonly
known as “brown” or “violin” spiders, currently includes
107 species distributed in the subtropical areas and tropics
of Europe, Africa, Asia, Australia and America. Species of
this genus may live in both natural habitats (under rocks,
trunks, inside tree holes and caves) and inside houses.
Only two species of
Loxosceles
have been registered
for Colombia:
Loxosceles lutea
Keyserling, 1877 and
Loxosceles rufipes
(Lucas 1834). In addition, the genus
Sicarius
Walckenaer, 1847 (six-eyed sand spiders) cur-
rently includes 25 species found in the xeric environments
of southern Africa and South and Central America, mostly
in deserts and seasonally dry tropical forests. In the most
recent study of
Sicarius
in South America, Magalhães