An Adhesive Collophore May Help Direct the Springtail Jump

The collophore of Entomobrya multifasciata (Tullberg) (Collembola: Entomobryidae) is composed of four segments. The third segment telescopes in and out of the second and the fourth is an eversible vesicle that is entirely enclosed in the third when not deployed. Low temperature scanning electron micrographs document that the collophore may remain adhered to the substrate even as the springtail initiates its jump. This adherence appears to force the posterior abdomen into the air, causing the jump itself to be initiated in a forward direction and accompanied by a forward flip. Among the several other documented functions of the collophore, we suggest that it may serve to affect the direction and trajectory of the springtail during its jump.