20th International Congress of Arachnology

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96 DENVER MUSEUM OF NATURE & SCIENCE REPORTS | No. 3, July 2, 2016
Cushing
Chemoreception in spiders is well known to play an
important sensitive role, mainly in the detection of prey
quality and conspecific recognition for potential mates.
The chemosensory setae are responsible for the contact
chemoreception and are distinguished from other setae
by having a curved morphology, a steeper insertion angle,
and an opening near the tip. They are usually found on
the tip of the legs, in the dorsal region of the cymbium,
and tarsus of female palp. Previous studies described a
concentration of chemosensory setae located in the ventral
region of Liphistius Schiödte, 1849 and Idiops Perty, 1833
males, a feature that brings out the inference of possible
female pheromone recognition for a potential mate choice.
In this study, we present an accurate examination of these
modified setae in males of eight Ariadna species, A. corti-
cola, A. maxima, A. araucana, A. boliviana, A. isthmica,
Ariadna sp. 1 (AUS), Ariadna sp. 2 (AFR-CONT), Ariadna
sp. 3 (AFR-MAD), describing its morphology, and bringing
up its possible importance to Ariadna biology. We detected
five morphologically different types of chemosensory setae
forming scopulae, type a–e, only in mature males. The
occurrence ranges from species to species: in A. corticola,
A. maxima, and A. araucana, it appears on the cymbium
and tarsi I–IV, whereas in A. boliviana, A. isthmica,
Ariadna sp. 1 (AUS), Ariadna sp. 2 (AFR-CONT), Ariadna
sp. 3 (AFR-MAD) it only appears on the tarsi (and some-
times metatarsi) I–IV. The results presented here are the
first record of chemosensory scopula on tarsi and metatarsi
of an Haplogynae spider. The occurrence of the chemosen-
sory scopula only on adult males of Ariadna can strongly
suggest a female sex pheromone reception function, as
described for Liphistius and Idiops, and maybe a possible
relation with the tube-dwelling behavior, shared by those
genera. Financial support: FAPESP.
Keywords: Haplogynae, sensory organs, pheromones
Student - poster presentation
Misbehaving on atrazine; an herbicide’s
impact on Pardosa milvina(Araneae,
Lycosidae)
Jake A. Godfrey1 , Ann L. Rypstra2
1Department of Biology, Miami University, Oxford,
Ohio, USA; 2Department of Biology, Miami University,
Hamilton, Ohio, USA
Chemical signals play an important role in evoking
appropriate behaviors in many arthropod species.
While many come from natural sources such as feces
and other excreta, anthropogenic chemicals could
potentially cause a response or disrupt other cues.
Atrazine is not overly toxic to arthropods in general,
but there is little information regarding its impact on
their behavior. Pardosa milvina (Araneae, Lycosidae)
is a predatory wolf spider commonly found in agro-
ecosystems where application of atrazine is prevalent.
This species is known to use both air- and substrate-
borne cues to locate mates and prey, minimize risk of
predation, and to differentiate sex and mating history.
The aim of this study was to investigate the effects a
commercial formulation of an atrazine based herbicide
has on the behavior and activity of Pardosa milvina.
Multiple metrics of spider activity were documented in
two types of arenas; they were lined with filter paper
treated with either herbicide or water. The activities
were combined using Principal Component Analysis.
The first two components were significantly impacted
by sex. Males traveled further, faster, and spent more
time mobile than females. The presence of atrazine
significantly influenced the activities that were captured
by the second principal component. The exposure to
herbicide decreased the distance that spiders traveled
and their velocity, while it increased the frequency with
which they changed their mobility state. These data
suggest that males are more active than females, and
that atrazine alters the behavior of these spiders and
therefore could have impacts on mating, foraging, and
survival.
Keywords: Pardosa, atrazine, info-disruption, agroecosystem
Student - oral presentation
Assessment of Ctenizidae monophyly
*Rebecca L. Godwin, Vera Opatova, Christopher A.
Hamilton, Jason E. Bond
101 Life Sciences Building, Auburn University, AL
36849, USA;