Three new species of Schistonchus (Aphelenchoididae) from the Ficus subgenus Sycomorus (Moraceae) in northern Australia

Abstract

Three new species of Schistonchus were recovered from sycones of Ficus racemosa, F. hispida and F. variegata (Moraceae Subgenus Sycomorus, Section Sycomorus) from the Cairns region in north-eastern Australia. Schistonchus baculum sp. n. is described from F. racemosa and F. hispida and is differentiated from other species of Schistonchus by a combination of morphological characters including having males with a walking-stick shape, excretory pore opening at the anterior end of the metacorpus, a long post-uterine sac, rose-thorn-shaped spicules, no gubernaculum, two pairs of subventral papillae on the tail, DNA sequence data, and apparent biogeographical range. Schistonchus fleckeri sp. n. is described from F. racemosa, F. hispida and F. variegata and is differentiated by a combination of morphological characters, including a C-shaped female and C-shaped to spiral males, the excretory pore opening near the lips, a short to medium length post-uterine sac, slender sickle-shaped spicules with a reduced rostrum, no gubernaculum, three pairs of subventral papillae on the tail, and apparent biogeographical range. Schistonchus cassowaryi sp. n. is described from F. variegata and is differentiated by a combination of morphological characters, including having C-shaped males and females, a posterior excretory pore situated posterior to the nerve ring, a short to medium length post-uterine sac, rose-thorn-shaped spicules, three pairs of subventral papillae on the tail (one adcloacal, one at mid-tail near lateral, and one near the tip), DNA sequence data, and apparent biogeographical range.