Poster – Microbial communities in Megamelus scutellaris: implications for water hyacinth biological control

Author 

Presenting author Alejandro J Sosa; alejsosa@fuedei.org

Coauthors 

Abstract

Biological control agents depend on complex interactions with their associated microbiota. Here, we characterize for the first time the fat body fungal and gut bacterial communities of Megamelus scutellaris, a biocontrol agent of water hyacinth (Pontederia crassipes), one of the world’s most invasive aquatic weeds. Native populations from Argentina (Buenos Aires, Misiones, Chaco) and introduced populations (USA and South Africa) were analyzed using 16S rRNA and ITS1 sequencing. In its native range, fat body fungal assemblages were dominated by Sordariomycetes, including Ophiocordycipitaceae—obligate symbionts in delphacids that contribute to host nutrition through amino acid production, sterol biosynthesis, and nitrogen recycling. Gut bacterial communities revealed reproductive parasites in both native and introduced populations. Buenos Aires and South Africa shared similar profiles dominated by Rickettsia, with Cardinium and Arsenophonus, suggesting microbiota conservation after introduction. Misiones exhibited high Rickettsia abundance with greater bacterial diversity, whereas Chaco was dominated by Wolbachia, showing a distinct microbial structure. These findings provide new insights into the microbial ecology of M. scutellaris, highlighting shared gut symbionts and microbiota stability in introduced populations as a potential factor influencing the success of biological control programs.

Keywords 

Bacterial Microbiota 

Fungal Microbiota 

Symbionts 

Rickettsia 

Cardinium 

Highlights 

First characterization of gut bacterial and fat body fungal communities in Megamelus scutellaris. 

The microbiota of the South African population remains similar to that of its native source 

Dominant microbial symbionts affect host nutrition, reproduction, and biocontrol success.