Analysis of the gut microbiota of walking sticks (Phasmatodea)
1 Department of Entomology, University of California, Davis, USA
2 Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
3 Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, National Chung Hsing University and Academia Sinica, Taipei, Taiwan
4 Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, Taiwan
5 Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
BMC Research Notes 2013, 6:368 doi:10.1186/1756-0500-6-368Published: 11 September 2013
Little is known about the Phasmatodea gut microbial community, including whether phasmids have symbiotic bacteria aiding in their digestion. While symbionts are near ubiquitous in herbivorous insects, the Phasmatodea’s distinctively thin body shape precludes the gut enlargements needed for microbial fermentation. High-throughput sequencing was used to characterize the entire microbiota of the fat bodies, salivary glands, and anterior and posterior midguts of two species of walking stick.
Most bacterial sequences belonged to a strain of Spiroplasma (Tenericutes) found primarily in the posterior midgut of the parthenogenetic species Ramulus artemis (Phasmatidae). Beyond this, no significant differences were found between the R. artemis midgut sections or between that species and Peruphasma schultei (Pseudophasmatidae). Histological analysis further indicated a lack of bacteriocytes.
Phasmids are unlikely to depend on bacteria for digestion, suggesting they produce enzymes endogenously that most other herbivorous insects obtain from symbionts. This conclusion matches predictions based on phasmid anatomy. The role of Spiroplasma in insects warrants further study.