We investigated the impact of swarm-hunting army ants of the species Eciton burchelli on the ground spider assemblage in an Amazonian "terra firme" rain forest. Spiders were collected from 20 quadrat litter samples taken in front of 7 hunting swarms and 20 samples taken in the same areas after army ants had passed, and were identified to genus or species level. Observed significant effects on the abundance of several spider groups are discussed on the base of the prey-spider spectrum of the ants, known from a study in the same forest. We discuss several difficulties and chances of misinterpretation of the results, due to the high natural variability of arthropod abundance in the habitat and the restriction of the method under the conditions of the field study.
Army ants; Ecitonini; spiders; predation; litter fauna