26th European Congress of Arachnology in Midreshet Ben-Gurion

Early in September, 130 arachnologists and 11 accompanying persons from 27 countries from all over the world headed to Israel to attend the 26th European Congress of Arachnology hosted by the Jacob Blaustein Institutes for Desert Research

On the enigmatic scent glands of dyspnoan harvestmen (Arachnida, Opiliones): first evidence for the production of volatile secretions

La utilización en encuestas de preguntas con tarjetas de respuesta está totalmente aceptada por la comunidad investigadora. Esto supone una carga de trabajo “extra” en la tarea del entrevistador, lo que explica que en ocasiones no se utilicen correctamente. Pese a esta situación, hay muy poca literatura sobre la influencia de las tarjetas en las respuestas del entrevistado. El objetivo de este trabajo es profundizar en los efectos que la utilización de tarjetas tiene en la calidad de las respuestas del cuestionario, partiendo de la hipótesis que considera que las tarjetas —pese a complicar la tarea del encuestador— suponen importantes mejoras en la administración del cuestionario. Utilizaremos para ello un estudio del Centro de Investigaciones Sociológicas con 23 preguntas de tarjeta, comparando las respuestas de los entrevistados que utilizaron las tarjetas con aquellos que no las emplearon.Using “response cards” in question surveys is unanimously approved by the research community. The fact that this represents an extra workload for the interviewer’s task explains why they sometimes are not used correctly. Despite this situation there is a paucity of literature on the influence of the response card on the respondent’s answers. The aim of this study is to deepen the analysis of how using these cards affect the quality of the survey’s responses. To do so, we start from the assumption that the cards —while complicating the interviewer’s task, result in significant improvements in the survey’s administration. For this purpose we will use a study with 23 card questions (question cards) by the Centro de Investigaciones Sociológicas, (the Spanish Centre for Sociological Research), and we will compare the answers of respondents that used cards with those who did not

A Novel Class of Defensive Compounds in Harvestmen: Hydroxy-γ-Lactones from the Phalangiid Egaenus convexus

When threatened, the harvestman Egaenus convexus (Opiliones: Phalangiidae) ejects a secretion against offenders. The secretion originates from large prosomal scent glands and is mainly composed of two isomers of 4-hydroxy-5-octyl-4,5-dihydro-3H-furan-2-one (1), a β-hydroxy-γ-lactone. The compounds were characterized by GC-MS of their microreaction derivatives, HRMS, and NMR. After the synthesis of all four possible stereoisomers of 1, followed by their separation by chiral-phase GC, the absolute configurations of the lactones in the Egaenus secretion was found to be (4S,5R)-1 (90%) and (4S,5S)-1 (10%). Hydroxy-γ-lactones represent a new class of exocrine defense compounds in harvestmen

Naphthoquinones and Anthraquinones from Scent Glands of a Dyspnoid Harvestman, Paranemastoma quadripunctatum

Extracts of Paranemastoma quadripunctatum (Opiliones, Dyspnoi, Nemastomatidae) contained seven components, all of which likely originated from the secretion of well-developed prosomal scent glands. The two main components (together accounting for more than 90% of the secretion) were identified as 1,4-naphthoquinone and 6-methyl-1,4-naphthoquinone. The minor components were 1,4-naphthalenediol, two methoxy-naphthoquinones (2-methoxy-1,4-naphthoquinone, and 2-methoxy-6-methyl-1,4-naphthoquinone) and two anthraquinones (2-methyl-9,10-anthraquinone and a dimethyl-9,10-anthraquinone). While some chemical data on scent gland secretions of the other suborders of Opiliones (Cyphophthalmi, palpatorean Eupnoi, and Laniatores) already exist, this is the first report on the scent gland chemistry in the Dyspnoi. Naphthoquinones are known scent gland exudates of Cyphophthalmi and certain Eupnoi, methoxy-naphthoquinones and anthraquinones are new for opilionid scent gland secretions

26th European Congress of Arachnology in Midreshet Ben-Gurion

Volume: 42Start Page: 60End Page: 6

Unusual organization of scent glands in Trogulus tricarinatus (Opiliones, Trogulidae): evidence for a non-defensive role

Volume: 37Start Page: 78End Page: 8

A Model for Phylogenetic Chemosystematics: Evolutionary History of Quinones in the Scent Gland Secretions of Harvestmen

By the possession of unique exocrine scent glands, Opiliones (harvestmen) arise as a perfect model for studies on the evolutionary history of secretion chemistry. Among gland compounds of harvestmen, it is the quinones that represent recurring elements across the secretions of all suborders. Reliable data on quinone-distribution, however, is only known for Laniatores (benzoquinones) and Cyphophthalmi (naphthoquinones). We here unraveled the quinone-distribution across scent gland secretions of the third large harvestman suborder, the Palpatores (= Eu- and Dyspnoi): Naphthoquinones were found in phalangiid Eupnoi across all subfamilies as well as in nemastomatid (and at least one ischyropsalid) Dyspnoi. Benzoquinones (1,4-benzoquinone) were restricted to a small entity within Eupnoi, namely platybunine Phalangiidae, probably misplaced Gyantinae (currently Sclerosomatidae) and Amilenus (incertae sedis). Our findings, combined with data from Laniatores and Cyphophthalmi, allow evaluation of a comprehensive chemosystematic model for Opiliones for the first time. Evolutionary scenarios imply naphthoquinones as scent gland compounds of common ancestry, having evolved in an early harvestman ancestor and present in cyphophthalmids and palpatoreans, but lost in laniatoreans. Benzoquinones evolved later and independently at least twice: once in the secretions of gonyleptoid Laniatores (alkylated benzoquinones), and a second time in a lineage of phalangiid Eupnoi (1,4-benzoquinone)