North American Fireflies Host Low Bacterial Diversity

Area of Science:

• Microbiology
• Entomology
• Ecology

Background:

• Firefly biology is well-studied, focusing on mating signals, bioluminescence, and defense compounds.
• The microbiome of fireflies remains largely uncharacterized, representing a significant knowledge gap.
• Understanding insect-microbe interactions is crucial for ecological and evolutionary studies.

Purpose of the Study:

• To characterize the gut and body microbiomes of four North American firefly species.
• To investigate potential differences in microbiomes based on sex, body location, and life stage.
• To explore patterns of microbial community composition and identify dominant bacterial taxa.

Main Methods:

• Utilized 16S rRNA community amplicon sequencing for microbiome analysis.
• Sampled four firefly taxa: Ellychnia corrusca, Photuris versicolor complex, Pyractomena borealis, and Pyropyga decipiens.
• Compared gut and body microbiomes, as well as egg and adult microbiomes.

Main Results:

• All studied firefly microbiomes displayed very low species diversity, frequently dominated by a single bacterial species.
• Each firefly taxon possessed a distinct and characteristic microbiome.
• Photuris versicolor showed differences between gut and body microbiomes, with gut communities enriched in Pseudomonas and Acinetobacter; Mollicutes were prevalent across samples.

Conclusions:

• Firefly microbiomes are highly specific and simplified, suggesting co-evolutionary relationships.
• Evidence suggests potential vertical microbial transmission from mother to offspring in Ellychnia corrusca.
• The findings establish a foundation for future research into the function and transmission of firefly bacterial symbionts.