Two new species of Ameroidea (Acari: Oribatida) from Madagascar

摘要

Two new oribatid mite species, Hymenobelba exclamationis and Pteramerus clypeatus spp. nov. (Ameridae), are described and illustrated based on specimens collected from mossy montane rainforest in the Malagasy Republic, Toamasina Province, Maromizaha forest. Both of them show a great variation of peculiar morphological features as having or not the costuliform prodorsal structure, the number and position of the notogastral setae and the abundance or position of aggenital and adanal neotrichy in genus Hymenobelba. A well observable variation can be observed in the form of pedotecta and in legs segments of the other species (Pteramerus clypeatus), which is only the second species belonging to this genus.