Bacteria-based artificial diets modulate larval development, survival and gut microbiota of two insect pests

Authors: Adesemoye, Anthony; ANTONY-BABU, SANJAY - Texas A&M University; NAGY, E - Texas A&M University; KAFLE, BASU - Texas A&M University; GREGORY, T - Texas A&M University; XIONG, CAIXING - Texas A&M University; FADAMIRO, HENRY - Texas A&M University

Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/10/2025
Publication Date: 4/26/2025
Citation: Adesemoye, A.O., Antony-Babu, S., Nagy, E.M., Kafle, B., Gregory, T.A., Xiong, C., Fadamiro, H.Y. 2025. Bacteria-based artificial diets modulate larval development, survival and gut microbiota of two insect pests. Biological Control. 205:105769. https://doi.org/10.1016/j.biocontrol.2025.105769.
DOI: https://doi.org/10.1016/j.biocontrol.2025.105769

Interpretive Summary: Insect pest damage to crops leads to huge economic losses, while the most widely used control methods, chemical pesticides, are losing efficacy and have negative environmental and health impacts. This study was conducted to evaluate groups of plant growth-promoting rhizobacteria (PGPR) for the management of insect pests through the impact on the insect-gut microorganisms. Bacteria were recovered from corn roots and identified through 16S rRNA gene sequencing. A total of eight strains of bacteria were combined in three groups, blended into an artificial diets, and fed to 4th instar larvae of corn earworm (Helicoverpa zeae) and tobacco budworm (Chloridea [=Heliothis] virescens). The artificial diets inoculated with the bacterial blends resulted in less larval weight compared to the control and caused changes in the microbial composition of insect gut. The understanding of how to utilize bacterial strains to manipulate insect’s gut microbial population and health is important for developing sustainable and environmentally friendly pest management strategies.

Technical Abstract: Insect pest damage to crops leads to huge economic losses, while the most widely used control methods, chemical pesticides, are losing efficacy and have deleterious environmental and health impacts. The goal of this study was to evaluate consortia of plant growth-promoting rhizobacteria (PGPR) strains for the management of insect pests through the impact on insect-gut microbiota. The PGPR isolates were recovered from corn rhizosphere in Texas and characterized through 16S rRNA gene sequences. Eight strains were combined in three different consortia, blended into an insect artificial diet, and fed to larvae of corn earworm (Helicoverpa zea [Boddie, 1850]) and tobacco budworm (Chloridae virescens [Fabricius, 1777]). Insect growth and development was monitored, and gut microbiota was assessed through culture-dependent and -independent approaches. The inoculated diet resulted in significant reduction in the larval weight for both insect species compared to the control and caused changes in the taxonomic diversity and evenness of H. zea gut microbiota. The results of the culture-dependent and -independent approaches were generally in agreement and showed a dominance of bacilli. While the mechanism of the changes in gut microbiota is currently unknown, understanding how to utilize bacterial strains to manipulate insect’s gut microbiota and health is important for developing sustainable and environmentally friendly pest management strategies. Further studies should focus on elucidating the mechanisms and how to effectively deploy these findings for field applications.