Soil Oribatei VII. Decomposition of Conifer Needles and Deciduous Leaf Petioles by Steganacarus diaphanum (Acarina: Phthiracaridae)2

The immatures of this oribatid fed specifically upon the decaying schlerenchyma and endoderm of conifer needles and the nonvascular portion of leaf petioles from deciduous species. The adults usually fed upon the same foodstuff but frequently wandered and fed upon decaying filter paper when not engaged in reproductive activity. Immatures were removed from the plant tissues during most of the months of the year in their laboratory environment. As many as five immatures were found in sections of conifer needles of 8–10 mm. length. At the completion of growth from egg to adult requiring approximately 5 months, a perforated cuticle and vascular bundles remained while most of the schlerenchyma and endoderm were reduced to particles of 1 µ to 20 µ size.