Broad infectivity of Leidynema appendiculatum (Nematoda: Oxyurida: Thelastomatidae) parasite of the smokybrown cockroach Periplaneta fuliginosa (Blattodea: Blattidae).

Sota Ozawa,Koichi Hasegawa

doi:10.1002/ece3.3948

Abstract

Host specificity of parasites is important for the understanding of evolutionary strategies of parasitism that would be a basis of predictions of the disease expansion when parasitized hosts invade new environments. The nematode order Oxyurida is an interesting parasite group for studying the evolution of parasitism as it includes parasites of both invertebrates and vertebrates. In our survey, we found that the smokybrown cockroach Periplaneta fuliginosa was primarily infected with only one nematode species Leidynema appendiculatum. In two cases, L. appendiculatum was isolated from two additional cockroach species Pycnoscelus surinamensis, sold in Japan as a reptile food, and Blatta lateralis, captured in the field and cultured in the laboratory. Inoculation of L. appendiculatum into three additional cockroach species P. japonica, Blattella nipponica, and P. surinamensis also resulted in parasitism. Infection prevalence was high, and timing of postembryonic development from hatched nematode larva to mature adult in these hosts was identical with that in P. fuliginosa. While ecological interactions strongly determine the host range, such broad infectivity is still possible in this parasitic nematode.

Highlights

The host specificity of parasites is important as it reflects the evolutionary strategy of parasitism
Because we found that four cockroach strains (P. fuliginosa EE, P. fuliginosa UF, P. surinamensis Pet, and B. lateralis KX) were originally infected with L. appendiculatum, we analyzed the infrapopulation of nematode male, female, and juvenile by the software Quantitative Parasitology 3.0 (Rózsa, Reiczigel, & Majoros, 2000)
We have not finished identification and description of all parasitic nematodes yet, host specificity of the nematodes belonging to the family Thelastomatidae was seemingly high

Summary

| INTRODUCTION

The family Thelastomatidae have been reported for more than forty Blattodea species (Adamson & van Waerebeke, 1992; Ozawa et al, 2014, 2016; Sriwati, Ozawa, Morffe, & Hasegawa, 2016). We reported earlier for the first time that the smokybrown cockroach Periplaneta fuliginosa in Japan was infected with only one nematode species Leidynema appendiculatum with high prevalence (Ozawa et al, 2014). We show the broad infectivity of L. appendiculatum through natural and artificial infection of five cockroach species within three families and two suborders. Intensity, and infrapopulation of L. appendiculatum in five host cockroach species were similar. While ecological interactions with P. fuliginosa seemingly strongly determine the host range of L. appendiculatum, such broad infectivity is still possible in this parasitic nematode

| MATERIALS AND METHODS

Findings

| DISCUSSION