Ontogenetic Development of Interindividual Relations in Cockroach Periplaneta-Americana
Ontogénèse des relations interindividuelles chez Periplaneta americana
Résumé
A description and a classification of the behavior patterns and interaction sequences of P. americana were presented. Only males were discussed. They were kept from hatching until different stages of growth, under tactile and visual isolation (isolated animals), or in groups of 5 individuals (grouped animals). The observations were made during the dark phase (12 h-12 h photoperiod) under red light, at 27 .+-. 1.degree. C, on groups of 5 individuals of the same stage, whether composed of Grouped or Isolated males. Some aspects were similar in the development of the grouped and isolated behavior, such as increasing in frequency of aggression from hatching to the adult stage, with 2 main discontinuities (at 2nd-3rd stage and 8th-9th stage) where this frequency shows a sudden increase. The social contacts provoke a delay, and a lesser frequency, in the expression of some aggressive patterns by the grouped males. The social conditions of development induce variations of physiology (rate and length of growth, etc.) and in individual experience of the social situations. The social development conditions may have some influence on the social organization of the group.