20th International Congress of Arachnology

DENVER MUSEUM OF NATURE & SCIENCE

REPORTS

No. 3, July 2, 2016

International Congress of Arachnology

Keywords:

Anelosimus

, group size, metapopulation,

population persistence, sociality

Oral presentation

Developmental experience shapes life

history, behavior, and web structure of

black widows

Nicholas DiRienzo

, Pierre-Oliver Montiglio

University of Arizona, PO Box 210088, Tucson, AZ,

85721, USA;

McGill University, 1205 Dr Penfield

Avenue, Montreal, Quebec, H3A 1B1, Canada

ndirienzo@gmail.com

Developmental experience is known to affect life history

and behavior, yet rarely, these are studied in together. As a

result it is still unclear whether developmental experience

affects behavior through changes in life history, or inde-

pendently of it. Furthermore, the effect of developmental

experience on life history and behavior may be affected by

individual condition during adulthood. Thus, it is critical

to tease apart developmental from condition-dependent

effects. Here we manipulated food abundance during devel-

opment in the western black widow spider,

Latrodectus

hesperus

, by rearing spiders on either a restricted or ad lib

diet. We separated developmental from condition-depen-

dent effects by assaying adult foraging behavior (tendency

to attack a prey cue) and web structure multiple times

under different levels of satiation. Our results indicate that

spiders reared under food restriction matured slower and

at a smaller size than spiders reared in ad lib conditions.

We found that restricted spiders were more aggressive

towards prey and built webs structured for foraging, while

ad lib spiders were less aggressive and built safer webs. The

amount of individual variation in behavior and web struc-

ture varied with developmental treatment. Spiders reared

on a restricted diet exhibited consistent individual variation

in all aspects of foraging behavior and web structure, while

spiders reared on an ad lib diet exhibited consistent indi-

vidual variation in aggression and web weight only. Thus,

developmental experience affected the average life history,

behavior, and web structure of spiders, but also shaped the

amount of phenotypic variation observed among individu-

als. Finally, developmental treatment affected adult trait

plasticity: when condition increased, restricted spiders built

safer webs, but ad lib spiders reduced their aggression.

Keywords: developmental plasticity, web structure,

foraging behavior

Poster presentation

Iranian spiders (Araneae) in the National

Museum in Prague (Czech Republic)

Petr Dolejš

Department of Zoology, National Museum–Natural

History Museum, Cirkusová 1740, CZ–193 00, Praha

9–Horní Po

ernice, Czech Republic

petr_dolejs@nm.cz

Most of the Iranian arachnids in the collection of the

National Museum in Prague (NMP) were collected during

three Czechoslovak-Iranian entomological expeditions

organized by the NMP in 1970’s. The spider material was

collected by Bohumil Pražan at 18 Iranian localities during

the third expedition (26 March–12 August 1977) and

includes 217 specimens of spiders belonging to 50 species

from 21 families: Atypidae, Dipluridae, Nemesiidae, Sicari-

idae, Eresidae, Oecobiidae, Theridiidae, Tetragnathidae,

Araneidae, Lycosidae, Pisauridae, Oxyopidae, Agelenidae,

Dictynidae, Clubionidae, Zodariidae, Gnaphosidae, Sparas-

sidae, Philodromidae, Thomisidae, and Salticidae. Among

them, eight species are new to the spider fauna of Iran:

Atypus muralis

Bertkau, 1890,

Steatoda bipunctata

Lin-

naeus, 1758,

Arctosa similis

Schenkel, 1938,

Wadicosa

commoventa

Zyuzin, 1985, Zodariidae sp.,

Trachyzelotes

jaxartensis

(Kroneberg, 1875),

Thomisus albohirtus

Simon,

1884, and

Thomisus unidentatus

Dippenaar-Schoeman &

van Harten, 2007. Older material deposited in the NMP

is represented by a single

Lycosa singoriensis

(Laxmann,

1770) female collected by L. Král in 1944 in Karaj.

Recent material, unfortunately, comprises only two sub-

adult lycosid and sparassid females collected by P. Kabátek

in October 1998. All arachnologists are invited to cooperate

and study material deposited in the NMP. This work was

financially supported by Ministry of Culture of the Czech

Republic (DKRVO 2016/15, National Museum, 00023272).

Keywords: collection, expeditions, faunistics, Iran, new

records