Checklist of the Collembola: Note on the predation of Collembola by Pseudoscorpiones

http://www.collembola.org/publicat/pseudo.htm - Last updated on 2008.12.01 by Frans Janssens

Checklist of the Collembola: Note on the predation of Collembola by Pseudoscorpiones

Frans Janssens, Department of Biology, University of Antwerp, Antwerp, B-2020, Belgium
Hans Henderickx Hemelrijkstraat 4, B-2400 Mol, Belgium
Ab H. Baas European Invertebrate Survey - Nederland, Postbus 9517, 2300 RA Leiden, Nederland

Abstract
To do...

Introduction

Pseudoscorpions are predators that feed on other arthropods. They grasp their prey with the palpal chelae and then pass it to the chelicerae. The pseudoscorpion uses the poison glands of its palpal chelae to anesthesise its prey, holding it until all movements cease. (after Weygoldt, 1969:8).

Materials and methods

On November 9, 2008, a humus sample was taken, by the junior author, from Vierhouten, the Netherlands, nearby the Hotel De Mallejan (UTM 31U 691945 m O 5801992 m N). The sample was placed in a plastic culture box with a floor made of a mix of plaster of Paris and charcoal. The plaster was moisted and the culture was fed dried aquarium fish food. The culture was kept at room temperature. The sample contained several specimens of Orchesella cincta and one specimen of Neobisium carcinoides.

Results

Fig.3. *Neobisium carcinoides*
finishing *Orchesella cincta*
Specimen from Vierhouten, the Netherlands
2008.11.12 © Baas, A.H.

Fig.2. *Neobisium carcinoides*
masticating the furca of *Orchesella cincta*
Specimen from Vierhouten, the Netherlands
2008.11.12 © Baas, A.H.

Fig.1. *Neobisium carcinoides*
piercing *Orchesella cincta*
Specimen from Vierhouten, the Netherlands
2008.11.12 © Baas, A.H.

On November 12, 2008, the pseudoscorpion Neobisium carcinoides, 2.5 mm long, grasped a juvenile specimen of Orchesella cincta, of 1.8 mm. First, the specimen was paralised by the palpal chelae, then it was pierced by the chelicerae lateroventrally in the genital area. In reaction, the paralised specimen released a drop of an excreted liquid through the apex of its collophore (fig.1). Subsequently, the furca was masticated (fig.2). Finally, the palpal chelae were cleaned by the chelicerae (fig.3).

Discussion

Neobisiidae masticate their prey with their chelicerae, which are alternatively opened and extended, pushed into the prey, closed, and then pulled back. At the same time the food is digested by a fluid poured over the prey from the mouth, and later the liquefied substances are ingested. The undigested material remains. (Weygoldt, 1969:8).

Conclusions