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ARS Home » Pacific West Area » Parlier, California » San Joaquin Valley Agricultural Sciences Center » Crop Diseases, Pests and Genetics Research » Research » Publications at this Location » Publication #412160
Research Project: Identifying Vulnerabilities in Vector-host-pathogen Interactions of Grapevine and Citrus Pathosystems to Advance Sustainable Management Strategies

Location: Crop Diseases, Pests and Genetics Research

Title: Genomic characterization of a novel bacterial strain BTU100, a potential biocontrol agent for two-spotted spider mite (Tetranychus urticae)

Author
item CHANG, SHU-CHEN - Agricultural Research Institute Of Taiwan
item LEE, CHUNG-CHIEH - Agricultural Research Institute Of Taiwan
item JIANG, MING-YAO - Agricultural Research Institute Of Taiwan
item SHEN-TU, HUSUAN - Agricultural Research Institute Of Taiwan
item Perez De Leon, Adalberto
item Chen, Jianchi

Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/19/2026
Publication Date: N/A
Citation: N/A

Interpretive Summary: The two-spotted spider mite is a pest of crops worldwide including citrus and grapes. This crop pest is known for its quick development of resistance to commonly used synthetic chemicals that kill mites known as acaricides. Microbial control methods offer a safer solution to manage mite populations. A bacterium discovered in Taiwan was described as BTU100 through this collaborative research. BTU100 killed almost all the two-spotted spider mites exposed to it in the laboratory. The impact of this research was augmented by sequencing the genome of BTU100. Genomic information was mined to try to classify BTU100. Genomic analyses revealed 2 possible acaricidal genes. Results from this study provide microbial and genomic information of BTU100 for further research to develop it as a biopesticide for two-spotted spider mite biocontrol.

Technical Abstract: The two-spotted spider mite (Tetranychus urticae), a globally significant pest, is known for its fast resistance development to synthetic acaricides. Microbial control methods offer multifaceted acaricidal mechanisms. Microbial acaricides are promising for delaying resistance onset and environmentally sustainable. In this study, a bacterial strain, BTU100, was isolated from naturally deceased T. urticae individuals in Taiwan. BTU100 showed potent lethality towards two-spotted spider mite, with a mortality rate of 28.3% in 24 hrs and 90.0% in 48 hrs. To better understand and characterize BTU100, the complete bacterial genome was sequenced. The BTU100 genome has a single circular chromosome of 5,066,903 bp encoding 5,026 genes and a plasmid of l64,574 bp encoding 166 genes. Analyses of 16S rRNA gene showed that BTU100 was 100% identical to Kosakonia sacchari DSM107661, a nitrogen-fixing bacterium from rice field in Sri Lanka, along with average nucleotide identity (ANI) of 98.67. Two possible acaricidal genes related to chitinolytic activities were identified, orf06548/BTU100_4753 (759 bp) encoding a chitin disaccharide deacetylase, and orf01525/BTU100_1127 (555 bp) encoding a chitin-binding protein. BLAST search against GenBank genome database showed that the chitin disaccharide deacetylase gene was common among members of Kosakonia and some Enterobacter, while the chitin-binding protein gene was specific only to K. sacchari DSM107661 and another bacterium, Enterobacter sp. R4-368. The results from this study provide baseline information of BTU100 for further research in acaricidal mechanisms and biological control of T. urticae.