NEST CONSTRUCTION AND RECOGNITION IN A GRYLLACRIDID - THE DISCOVERY OF PHEROMONALLY MEDIATED AUTORECOGNITION IN AN INSECT

The mechanisms of nest building and relocation were examined in Hyalog ryllacris sp. 14 (Orthoptera: Gryllacrididae). This nocturnal, thigmot actic species readily constructed silken nests in artificial shelters or 'tents'. The architecture and silk density of nests did not differ significantly between individuals, although nests of males contained s ignificantly more silk that those of females. Disturbing the insects d uring photophase elicited defensive displays. Gryllacridids reoccupied their original nest significantly more often than an empty tent or th e nest of a conspecific, after a night of foraging in a laboratory are na. When offered heat-treated (80 degrees C for 2 h) nests, gryllacrid ids showed a significant preference for those with greater amounts of silk. The heating (chemical cue elimination), tearing (tactile cue eli mination), and heating-tearing of an insect's nest significantly reduc ed the tendency of the subject to occupy its own nest. Gryllacridids w ere significantly more likely to occupy nests of conspecifics that had been heat-treated than those that were untreated. They were also sign ificantly more likely to occupy heat-treated nests to which acetone ex tracts from their own nests had been applied than similar nests treate d only with solvent. Thus, individuals of Hyalogryllacris sp. 14 are a ble to relocate their own nests and avoid those of conspecifics based on a chemical cue. This study provides the first evidence of the capac ity for individual or self recognition in insects or other invertebrat es through a pheromone or any other sensory modality.