Bacterial Diversity and Distribution from the Whole Mite Extracts in Acaricide Resistant and Susceptible Populations of Twospotted Spider Mite-Tetranychus urticae (Acari: Tetranychidae)

Investigations of the diversity of bacteria in acaricide resistant and susceptible populations from the whole mite extracts of twospotted spider mite-Tetranychus urticae were made using 8 different bacterial growth media and identified through 16S rRNA gene sequence analysis. The pyridaben resistant population was diversified with six genera including Chryseobacterium, Sphingomonas, Acidovorax, Herbaspirillum, Janthinobacterium, and Xenophilus, whereas the acequinocyl resistant population was associated with Bacillus, Pasteurella, Staphylococcus, Enterobacter, and Pseudomonas. The fenpropathrin resistant population harbored only two phylotypes (Pantoea and Pseudomonas). Citrobacter, Enterobacter, and Pantoea were recovered from the susceptible population. No correlation was observed between bacterial density and bacterial diversity. Of the 8 different growth media, R2A supported a greater number of cultivable bacterial phylotypes followed by Luria Bertani and brain heart infusion agar. This study suggests that knowledge of the diversity of bacterial phylotypes present in host insect pest species may be useful for developing biological approaches in insect-microbe interaction.