Release of marketed individuals increases the risk of genetic disturbance in the pet insect Trypoxylus dichotomus

By

Hamano, Tomo
Suyama, Yoshihisa
Matsuo, Ayumi
Ban, Teruaki
Watanabe, Kohei
Yamasaki, Takeshi
Yamada, Kazutaka
Ishida, Hiroaki
Nakahama, Naoyuki

Type

Article

Date of Publication

2025-10-3

Original Publication

Zoosystematics and evolution

Volume

101

Pages

303--320

Subjects

Coleoptera , Genetic distance , MIG-seq , pet insects , release , Scarabaeidae

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia Pensoft

Identifiers

DOI: https://doi.org/10.3897/neobiota.101.159665

 

Abstract

Genetic disturbance can be caused by the release or escape of individuals with different genetic characteristics into wild habitats, risking impacts on native biodiversity. The risk of genetic disturbance in pet insects due to release and escape is particularly common because a wide variety of affordable pets are available on the market. Trypoxylus dichotomus (Coleoptera, Scarabaeidae), the Japanese rhinoceros beetle, is a renowned pet insect in Japan and thus is a suitable target species for studying genetic disturbances in pet insects. However, the detailed spatial genetic structure and genetic disturbances of this species in Japan remain unclear. Here, we estimated the genetic diversity and spatial genetic structure of wild and marketed individuals using mitochondrial DNA sequences and genome-wide single-nucleotide polymorphisms (SNPs) obtained via MIG-seq. Using MIG-seq, 570 SNPs were obtained, revealing a weak yet significant spatial genetic structure in the Japanese archipelago. Although significant isolation by distance (IBD) was observed in wild individuals, no significant IBD was observed in marketed individuals. Comparisons between wild and marketed individuals revealed clear differences in spatial genetic structure. These findings highlight the risks of releasing marketed individuals into the wild owing to their artificial long-distance migration. Our results provide valuable insights into the genetic disturbance of human-mediated distribution and underscore the need for informed management practices to protect native biodiversity.