Social integration of the myrmecophilic spider Gamasomorpha maschwitzi (Araneae : Oonopidae) in colonies of the South East Asian army ant, Leptogenysdistinguenda (Formicidae : Ponerinae)

The myrmecophilic spider Gamasomorpha maschwitzi (Oonopidae) lives in the n ests of the SE Asian ponerine ant Leptogenys distinguenda, a species with a rmy ant habits, Up to 13 spider specimens were found living within one ant colony. The spiders were never detected in raiding columns and left the nes t only during nest relocations. In emigration columns they were mostly foun d moving closely behind a worker, but they were also able to follow the tra il on their own over distances of up to 20cm. Experiments in the field and in the laboratory show that G. maschwitzi is a ble to detect freshly laid pheromone trails of L. distinguenda, While follo wing trails, tactile cues are important also. Under natural conditions, dir ect tactile contacts with workers in a "tandem running"-like fashion can be observed over longer distances, Behavioral observations suggest that the spider benefits directly from the prey captured by the ants. The permanent contact with the ants and their br ood within the bivouac nest and the ability to follow their host in the cen tral parts of the emigration columns demonstrate that the spiders are well integrated into the ant colony.