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ARS Home » Northeast Area » Ithaca, New York » Robert W. Holley Center for Agriculture & Health » Emerging Pests and Pathogens Research » Research » Publications at this Location » Publication #392786

Research Project: Management and Biology of Arthropod Pests and Arthropod-borne Plant Pathogens

Location: Emerging Pests and Pathogens Research

Title: Sources of fungal symbionts in the microbiome of a mobile insect host, spodoptera frugiperda

item WATSON, MONICA - University Of Minnesota
item MAY, GEORGIANA - University Of Minnesota
item Bushley, Kathryn

Submitted to: Microbial Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/2/2022
Publication Date: 12/8/2022
Citation: Watson, M., May, G., Bushley, K.E. 2022. Sources of fungal symbionts in the microbiome of a mobile insect host, spodoptera frugiperda. Microbial Ecology. 86:900-913.

Interpretive Summary: Fall Armyworm (Spodoptera frugiperda) is a significant pest of sorghum, rice, and corn in the U.S. and now an invasive pest in many regions of the globe. In examining possible sources (soil, host plant, or other insects) of fungal symbionts of this insect, we report that the Fall Armyworm obtains a larger proportion of symbionts from other insects of the same species than from environmental sources. We found little evidence of exchange of fungi between the insect and its plant host, sorghum. We conclude there is a low risk of this insect transmitting fungal pathogens to its plant host and the knowledge gained of where this insect obtains fungal symbionts will inform how best to apply fungi for biological control of this pest.

Technical Abstract: The sources of fungal symbionts of insects are not well understood, yet the acquisition and assembly of fungal communities in mobile insect hosts have important implications for the ecology of migratory insects and of their plant hosts. To determine potential sources of fungal symbionts in the fall armyworm (Spodoptera frugiperda), we characterized the fungal communities in four different ecological compartments (insects, infested leaves, uninfested leaves, and soil) and estimated the contributions of each of these potential sources to the insect microbiome. Results show that insect fungal community composition was distinct from and more varied than was the composition of fungal communities in the environment of those insects (plants and soil). Despite observed variation in community composition across individual insects, we found that fungal communities from other insects were more commonly attributed as sources of the microbiome of individual insect hosts than were soil or plant communities. Yet, a large proportion of the insect microbiome was attributed to unknown sources. We find that mobile insects such as S. frugiperda obtain their fungal symbionts from a variety of sources, including other conspecific insects, and that transmission among insects may play a role in fungal symbiont acquisition. Alternatively, insects may filter fungal symbionts acquired from multiple environmental sources in similar ways. This research furthers our understanding of the role of host species and environment in structuring fungal symbiont communities.