20th International Congress of Arachnology

152 / 232

151
DENVER MUSEUM OF NATURE & SCIENCE REPORTS | No. 3, July 2, 2016
Buparellus insolitus Suzuki, 1985, from Thailand.
Keywords: systematic, taxonomy, Opiliones, molecular
phylogenetic analysis, genital morphology, Indo-
Malayan Region
Oral presentation
Scopula, pseudoscopula and claw tufts in
Mygalomorphae: morphology, evolution
and experimental approach
Fernando Pérez-Miles, Laura Santamaría, Rodrigo
Becco, Carlos Perafán
Sección Entomología, Facultad de Ciencias, Universidad
de la República, Iguá 4225, 11400 Montevideo, Uruguay
We studied the morphology of scopula, claw tufts and a
scopula-like feature (pseudoscopula) of tarsi on repre-
sentatives of all Mygalomorphae families. The taxonomic
distribution of these features was mapped on a recent
phylogeny of Mygalomorphae and the association of them
with the lifestyles of the spiders was analyzed. Setae present
in the adhesive features were described and some setal
types characterized. The adhesive face of setae varied in
the orientation in different parts of the tarsi, this variation
is more conspicuous in the spiders which only have claw
tufts or scopula. We confirmed the association of adhesive
scopulae and claw tufts with burrower/cursorial or thin
wafer lid trapdoor Mygalomorphs as suggested for cursorial
spiders, but we found that the pseudoscopula is associated
with some cork trap-door and some weavers Mygalomor-
phae. With the exception of some Diplurids (Diplurinae)
most Mygalomorph weavers lack adhesive setae. The setal
morphology of pseudoscopula suggest at first their senso-
rial function but the anterior-posterior gradation and
sexual differences additionally suggest their contribution in
copulation. The mechanism proposed to explain adhesion
in tarantulas is anisotropic friction, where friction is higher
when the leg pushes than when it pulls. However, previous
studies of adhesion in theraphosids were performed using
dead specimens. To test their ability to climb, we studied
static friction of live theraphosid spiders on different
surfaces and at different inclines. We also compared bur-
rower with arboreal species. We found a complementary
participation of claw tufts and scopula of anterior and
posterior legs when the tarantula climbs. The mechanics of
climbing in association with the biological characteristics
of the species are discussed. Supported by CSIC-UDELAR.
Keywords: scopula, claw-tufts, adhesion, locomotion
Oral presentation
Behavioral effects of octopamine across
contexts in the wolf spider Pardosa milvina
Matthew Persons, Chelsea McCormick, Jose Ikeda Neto,
Da’Mique Sellers
514 University Avenue, Susquehanna University,
Selinsgrove, PA 17870
The biogenic amine, octopamine (OA) serves as an inverte-
brate homolog of norepinephrine. We compared the effect
of ingested octopamine on boldness in the wolf spider,
Pardosa milvina across multiple contexts. Using a within-
between subjects experimental design, we quantified
startle responses to a puff of air and a poke from a plastic
pipette tip. We also measured male activity in the presence
of predator cues, willingness to attack large prey, and
court in the presence of silk cues from an unmated adult
female. Spider behavioral responses across these contexts
were measured before and after octopamine consump-
tion. Males that ingested octopamine showed significantly
shorter courtship latency and higher courtship intensity.
They also showed shorter latency to attack prey, more prey
attacks, and longer latency to flee from a disturbance.
Octopamine generally increased boldness among spiders
however we found no difference in antipredator responses
among treatments suggesting some defensive behaviors are
not strongly mediated by this neurohormone.
Keywords: ingested octopamine, personality, boldness,
prey capture, courtship, predator avoidance
Oral presentation
The phylogeny of wolf spiders (Araneae:
Lycosidae)
Luis Norberto Piacentini, Martín Javier Ramírez
Museo Argentino de Ciencias Naturales “Bernardino
Rivadavia”– CONICET, Av. Angel Gallardo 470, 1405
20th International Congress of Arachnology