Morphological and biological characters of the entomophilic stage of Schistonchus pumilae (Aphelenchoididae) with an update of its molecular profiles

Abstract

Listen

Translate article

Summary Schistonchus pumilae was first reported from the syconi of a creeper fig, Ficus pumila, from Miyazaki, Japan, and the species was described based on propagative (plant-parasitic) females and males. Thus, the premature female (entomophilic form) of the species was not described. In the present study, male syconi of F. pumila were collected from the type locality of the nematode (Miyazaki, Japan), and the premature females of S. pumilae were collected from inside the syconi and also from the emerging pollinator fig wasps (Wiebesia pumilae). Although only 26 female wasps were recovered for dissections, seven of them harboured 1-7 nematodes each. Nematodes associated with the wasp were all premature females, and their typological and morphometric characters were similar with those isolated from inside the syconi. In addition, the premature females were slightly smaller than propagative females and had a less developed gonad, suggesting that the nematode is a phoretic associate, not a parasite. Regardless of its phylogenetic status, the carrier insect usage of S. pumilae is somewhat similar to two Ficophagus species, and clearly different from S. caprifici, which propagates in the host wasp haemocoel as a parasite. Additionally, the molecular profiles of S. pumilae (SSU and D1-D3 LSU of ribosomal RNA genes) were re-sequenced using a cloning technique, and the information was updated for phylogenetic analysis in the future.