Studies on the function of the tritosternum in selected Gamasida (Acari)

This is the authors' abstract. We don't add key points for this paper.

Observations on the feeding behavior of Parasitus coleoptratorum (L.) and Glyptholaspis americana (Berl.) revealed that the tritosternum functions in concert with the capitular groove of the gnathosoma as a fluid transport and grooming mechanism. Excess prey fluids overflowing into the postcapitular channel are redirected to the prebuccal region between the tritosternal laciniae and the capitular groove, preventing loss of food material.Surgical removal of the tritosternum results in an overflow of fluids from the region behind the tritosternal remnant onto the sternal area. Feeding efficiency studies on normal and tritosternectomized P. coleoptratorum showed that mites which lack a tritosternum feed on significantly more prey than do normal individuals. It is postulated that this increase reflects impairment of feeding efficiency and resultant food loss during each feeding episode.Grooming of the capitular groove is accomplished through the combined raking action of the lacinial pili and the deutosternal denticles. Substantial accumulations of debris were observed only in the capitular grooves of tritosternectomized mites.