Influence de l'environnement pre-imaginal et precoce dans le choix du site de nidification de Pachycondyla (=Neoponera) villosa (Fabr.) (formicidae, ponerinae).

In the Biosphera Reserve of Sian Ka'an, State of Quintana Roo in Mexico, it was observed that Pachycondyla villosa nest almost exclusively in Bromeliad epiphytes Aechmea bracteata. It is possible that winged females seek this plant to build their society. From this fact two hypothesis may be formulated. Two lots comprising workers and winged females were tested. In each case, the lot controlled comprised of individuals found in nature (societies settled on Aechmea). The tested lots were produced and bred in laboratory. The first lot was put in contact with a piece of Schomburgkia tibicinis, the second lot had no contact with a plant. At the time of the experiment, each lot was faced with a choice between two tubes. One contained a piece of Aechmea, the other was empty (1st series of tests), or contained a piece of Schomburgkia (2nd series of tests). The first series of tests permits to show that controls (individuals that have contact with Aechmea in nature) settle in tubes containing a piece of Aechmea whereas individuals from the other two lots settle indiscriminately in either of the tubes. The second series of tests permits to show that controls also settle in the tube containing Aechmea, that individuals raised in contact with Schomburgkia choose the tube containing this plant and that individuals raised in the absence of plant contact settle indiscriminately in either of the tubes. The influence of the original environmental influence on individuals in the choice between two types of tubes is thus demonstrated. This influence is due to an imprinting during larval life, and strenghened at the beginning of imago life.