Aggregation of Pteronarcella badia nymphs and effects of interaction with Claassenia sabulosa (Plecoptera)

In treatments with single individuals and groups of 4, P. badia, a shredder, distributed itself in proportion to the available surface area among fibrous, non-food substrates of different sizes. In treatments with 4 and 14 P. badia, the nymphs demonstrated aggregation, often with body contact. Its distribution became random and significantly different from substrate surface area in the presence of C. sabulosa, a predator, indicating an interspecific interaction. -from Authors